|Other names||Zika virus disease, Zika, Zika virus infection|
|Rash during Zika fever infection|
|Symptoms||Fever, red eyes, joint pain, headache, maculopapular rash, Sometimes none|
|Complications||Guillain–Barré syndrome, during pregnancy can cause microcephaly in the baby|
|Causes||Zika virus mainly spread by mosquitoes, can also be sexually transmitted|
|Diagnostic method||Testing blood, urine, or saliva for viral RNA or blood for antibodies|
|Differential diagnosis||Chikungunya, malaria, dengue, leptospirosis, measles|
|Prevention||Decreasing mosquito bites, condoms|
|Treatment||Supportive care, Generally not needed in mild cases|
|Deaths||None during initial infection|
Zika fever, also known as Zika virus disease or simply Zika, is an infectious disease caused by the Zika virus. Most cases have no symptoms, but when present they are usually mild and can resemble dengue fever. Symptoms may include fever, red eyes, joint pain, headache, and a maculopapular rash. Symptoms generally last less than seven days. It has not caused any reported deaths during the initial infection. Mother-to-child transmission during pregnancy can cause microcephaly and other brain malformations in some babies. Infections in adults have been linked to Guillain–Barré syndrome (GBS).
Zika fever is mainly spread via the bite of mosquitoes of the Aedes type. It can also be sexually transmitted and potentially spread by blood transfusions. Infections in pregnant women can spread to the baby. Diagnosis is by testing the blood, urine, or saliva for the presence of the virus's RNA when the person is sick, or the blood for antibodies after symptoms are present more than a week.
Prevention involves decreasing mosquito bites in areas where the disease occurs and proper use of condoms. Efforts to prevent bites include the use of insect repellent, covering much of the body with clothing, mosquito nets, and getting rid of standing water where mosquitoes reproduce. There is no effective vaccine. Health officials recommended that women in areas affected by the 2015–16 Zika outbreak consider putting off pregnancy and that pregnant women not travel to these areas. While there is no specific treatment, paracetamol (acetaminophen) may help with the symptoms. Admission to hospital is rarely necessary.
The virus that causes the disease was first isolated in Africa in 1947. The first documented outbreak among people occurred in 2007 in the Federated States of Micronesia. An outbreak started in Brazil in 2015, and spread to the Americas, Pacific, Asia, and Africa. This led to the World Health Organization declared it a Public Health Emergency of International Concern in February 2016. The emergency was lifted in November 2016, but 84 countries still reported cases as of March 2017. The last proven case of Zika spread in the Continental United States was in 2017.
Signs and symptoms
Most people who are infected have no or few symptoms. Otherwise the most common signs and symptoms of Zika fever are fever, rash, conjunctivitis (red eyes), muscle and joint pain, and headache, which are similar to signs and symptoms of dengue and chikungunya fever. The time from a mosquito bite to developing symptoms is not yet known, but is probably a few days to a week. The disease lasts for several days to a week and is usually mild enough that people do not have to go to a hospital.
Due to being in the same family as dengue, there has been concern that it could cause similar bleeding disorders. However that has only been documented in one case, with blood seen in semen, also known as hematospermia.
Zika virus infections have been strongly associated with Guillain–Barré syndrome (GBS), which is a rapid onset of muscle weakness caused by the immune system damaging the peripheral nervous system, and which can progress to paralysis. While both GBS and Zika infection can simultaneously occur in the same individual, it is difficult to definitively identify Zika virus as the cause of GBS. Though Zika virus has been shown to infect human Schwann cells. Several countries affected by Zika outbreaks have reported increases in the rate of new cases of GBS. During the 2013–2014 outbreak in French Polynesia there were 42 reported cases of GBS over a 3-month period, compared to between 3 and 10 annually prior to the outbreak.
The disease spreads from mother to child in the womb and can cause multiple problems, most notably microcephaly, in the baby. The full range of birth defects caused by infection during pregnancy is not known, but they appear to be common, with large scale abnormalities seen in up to 42% of live births. The most common observed associations have been abnormalities with brain and eye development such as microcephaly and chorioretinal scarring. Less commonly there have been systemic abnormalities such as hydrops fetalis, where there is abnormal accumulation of fluid in the fetus. These abnormalities can lead to intellectual problems, seizures, vision problems, hearing problems, problems feeding and slow development.
Whether the stage of pregnancy at which the mother becomes infected affects the risk to the fetus is not well understood, nor is whether other risk factors affect outcomes. One group has estimated the risk of a baby developing microcephaly at about 1% when the mother is infected during the first trimester, with the risk of developing microcephaly becoming uncertain beyond the first trimester. Affected babies might appear normal but actually have brain abnormalities; infection in newborns could also lead to brain damage.
Zika virus is a mosquito-borne flavivirus closely related to the dengue and yellow fever viruses. While mosquitoes are the vector, the main reservoir species remains unknown, though serological evidence has been found in both West African monkeys and rodents.
Transmission is via the bite of mosquitoes from the genus Aedes, primarily Aedes aegypti in tropical regions. It has also been isolated from Ae. africanus, Ae. apicoargenteus, Ae. luteocephalus, Ae. Albopictus, Ae. vittatus and Ae. furcifer. During the 2007 outbreak on Yap Island in the South Pacific, Aedes hensilli was the vector, while Aedes polynesiensis spread the virus in French Polynesia in 2013.
Zika virus can also spread by sexual transmission from infected men to their partners. Zika virus has been isolated from semen samples, with one person having 100,000 times more virus in semen than blood or urine, two weeks after being infected. It is unclear why levels in semen can be higher than other body fluids, and it is also unclear how long infectious virus can remain in semen. There have also been cases of men with no symptoms of Zika virus infection transmitting the disease. The CDC has recommended that all men who have travelled to affected areas should wait at least 6 months before trying to attempt conception, regardless of if they were ill. To date there have been no reported sexual transmissions from women to their sexual partners. Oral, anal or vaginal sex can spread the disease.
Cases of vertical perinatal transmission have been reported. The CDC recommends that women with Zika fever should wait at least 8 weeks after they start having symptoms of disease before attempting to conceive. There have been no reported cases of transmission from breastfeeding, but infectious virus has been found in breast milk.
Like other flaviviruses it could potentially be transmitted by blood transfusion and several affected countries have developed strategies to screen blood donors. The U.S. FDA has recommended universal screening of blood products for Zika. The virus is detected in 3% of asymptomatic blood donors in French Polynesia.
It is difficult to diagnose Zika virus infection based on clinical signs and symptoms alone due to overlaps with other arboviruses that are endemic to similar areas. The US Centers for Disease Control and Prevention (CDC) advises that "based on the typical clinical features, the differential diagnosis for Zika virus infection is broad. In addition to dengue, other considerations include leptospirosis, malaria, rickettsia, group A streptococcus, rubella, measles, and parvovirus, enterovirus, adenovirus, and alphavirus infections (e.g., chikungunya, Mayaro, Ross River, Barmah Forest, O'nyong'nyong, and Sindbis viruses)."
In small case series, routine chemistry and complete blood counts have been normal in most patients. A few have been reported to have mild leukopenia, thrombocytopenia, and elevated liver transaminases.
Zika virus can be identified by reverse transcriptase PCR (RT-PCR) in acutely ill patients. However, the period of viremia can be short and the World Health Organization (WHO) recommends RT-PCR testing be done on serum collected within 1 to 3 days of symptom onset or on saliva samples collected during the first 3 to 5 days. When evaluating paired samples, Zika virus was detected more frequently in saliva than serum. Urine samples can be collected and tested up to 14 days after the onset of symptoms, as the virus has been seen to survive longer in the urine than either saliva or serum. The longest period of detectable virus has been 11 days and Zika virus does not appear to establish latency.
Later on, serology for the detection of specific IgM and IgG antibodies to Zika virus can be used. IgM antibodies can be detectable within 3 days of the onset of illness. Serological cross-reactions with closely related flaviviruses such as dengue and West Nile virus as well as vaccines to flaviviruses are possible. As of 2019, the FDA has authorized two tests to detect Zika virus antibodies.
Screening in pregnancy
The CDC recommends screening some pregnant women even if they do not have symptoms of infection. Pregnant women who have traveled to affected areas should be tested between two and twelve weeks after their return from travel. Due to the difficulties with ordering and interpreting tests for Zika virus, the CDC also recommends that healthcare providers contact their local health department for assistance. For women living in affected areas, the CDC has recommended testing at the first prenatal visit with a doctor as well as in the mid-second trimester, though this may be adjusted based on local resources and the local burden of Zika virus. Additional testing should be done if there are any signs of Zika virus disease. Women with positive test results for Zika virus infection should have their fetus monitored by ultrasound every three to four weeks to monitor fetal anatomy and growth.
For infants with suspected congenital Zika virus disease, the CDC recommends testing with both serologic and molecular assays such as RT-PCR, IgM ELISA and plaque reduction neutralization test (PRNT). RT-PCR of the infants serum and urine should be performed in the first two days of life. Newborns with a mother who was potentially exposed and who have positive blood tests, microcephaly or intracranial calcifications should have further testing including a thorough physical investigation for neurologic abnormalities, dysmorphic features, splenomegaly, hepatomegaly, and rash or other skin lesions. Other recommended tests are cranial ultrasound, hearing evaluation, and eye examination. Testing should be done for any abnormalities encountered as well as for other congenital infections such as syphilis, toxoplasmosis, rubella, cytomegalovirus infection, lymphocytic choriomeningitis virus infection, and herpes simplex virus. Some tests should be repeated up to 6 months later as there can be delayed effects, particularly with hearing.
The virus is spread by mosquitoes, making mosquito avoidance an important element to disease control. The CDC recommends that individuals:
- Cover exposed skin by wearing long-sleeved shirts and long pants treated with permethrin.
- Use an insect repellent containing DEET, picaridin, oil of lemon eucalyptus (OLE), or ethyl butylacetylaminopropionate (IR3535)
- Always follow product directions and reapply as directed
- If you are also using sunscreen, apply sunscreen first, let it dry, then apply insect repellent
- Follow package directions when applying repellent on children. Avoid applying repellent to their hands, eyes, or mouth
- Stay and sleep in screened-in or air-conditioned rooms
- Use a bed net if the area where you are sleeping is exposed to the outdoors
- Cover cribs, strollers and carriers with mosquito netting for babies under 2 months old.
The CDC also recommends strategies for controlling mosquitoes such as eliminating standing water, repairing septic tanks and using screens on doors and windows. Spraying insecticide is used to kill flying mosquitoes and larvicide can be used in water containers.
Because Zika virus can be sexually transmitted, men who have gone to an area where Zika fever is occurring should be counseled to either abstain from sex or use condoms for 6 months after travel if their partner is pregnant or could potentially become pregnant. Breastfeeding is still recommended by the WHO, even by women who have had Zika fever. There have been no recorded cases of Zika transmission to infants through breastfeeding, though the replicative virus has been detected in breast milk.
When returning from travel, with or without symptoms, it is suggested that prevention of mosquito bites continue for 3 weeks in order reduce the risk of virus transmission to uninfected mosquitos.
CDC travel alert
This section needs to be updated.May 2020)(
Because of the "growing evidence of a link between Zika and microcephaly", in January 2016, the CDC issued a travel alert advising pregnant women to consider postponing travel to countries and territories with ongoing local transmission of Zika virus. Later, the advice was updated to caution pregnant women to avoid these areas entirely if possible and, if travel is unavoidable, to protect themselves from mosquito bites. Male partners of pregnant women and couples contemplating pregnancy who must travel to areas where Zika is active are advised to use condoms or abstain from sex entirely. The agency also suggested that women thinking about becoming pregnant should consult with their physicians before traveling.
As of September 2016, the CDC travel advisories include:
- Cape Verde
- Many parts of the Caribbean: Anguilla, Antigua and Barbuda, Aruba, The Bahamas, Barbados, Bonaire, British Virgin Islands, Cayman Islands, Cuba, Curaçao, Dominica, Dominican Republic, Grenada, Guadeloupe, Haiti, Jamaica, Martinique, Puerto Rico, Saba, Saint Saint Barthélemy, Saint Lucia, Saint Martin, Saint Vincent and the Grenadines, Sint Eustatius, Sint Maarten, Trinidad and Tobago, and the U.S. Virgin Islands
- Central America: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama
- Most of South America: Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, and Venezuela
- Several Pacific Islands: American Samoa, Fiji, Marshall Islands, Micronesia, New Caledonia, Papua New Guinea, Samoa, and Tonga
- In Asia: Singapore, Malaysia, Brunei
Both the regional Pan American Health Organization (PAHO) as well as the WHO have issued statements of concern about the widespread public health impact of the Zika virus and its links to GBS and microcephaly. The WHO Director-General, Margaret Chan, issued a statement in February 2016 "declaring that the recent cluster of microcephaly cases and other neurological disorders reported in Brazil, following a similar cluster in French Polynesia in 2014, constitutes a Public Health Emergency of International Concern." The declaration allowed the WHO to coordinate international response to the virus as well as gave its guidance the force of international law under the International Health Regulations. The declaration was ended in November 2016.
As of 2016 there was no available vaccine. Development was a priority of the US National Institutes of Health (NIH), but officials stated that development of a vaccine could take years. To speed new drug development regulatory strategies were proposed by the WHO and NIH. Animal and early human studies were underway as of September 2016. As of December 2019, there were several vaccine candidates in various stages of development.
Disease control in the affected countries currently centres around mosquito control. Several approaches are available for the management of Aedes aegypti mosquito populations, including the destruction of larval breeding sites (the aquatic pools in which eggs are laid and larvae hatch prior to mosquito development into flying adults); and, insecticides targeting either the larval stages, adult mosquitoes or both. Additionally, a whole host of novel technologies are under current development for mosquito control and the World Health Organization has recently lent its support for the accelerated development of modern methods for mosquito control such as the use of Wolbachia bacteria to render mosquitoes resistant to the virus, and, the release of sterilized male mosquitoes that breed with wild female mosquitoes to give rise to non-viable offspring (offspring that do not survive to the biting, adult stage).
Oxitec’s genetically modified OX513A mosquito was approved by Brazil's National Biosecurity Technical Commission (CTNBio) in April 2014 and it was being used to try to combat mosquitoes carrying the Zika virus in the town of Piracicaba, São Paulo in 2016.
In the 1940s and 1950s, the Aedes aegypti mosquito was eradicated on some Caribbean islands and in at least eighteen Latin American countries. Decreasing political will and presumably available money, mosquito resistance to insecticide, and a pace of urbanization which exceeded eradication efforts led to this mosquito's comeback.
There is currently no specific treatment for Zika virus infection. Care is supportive with treatment of pain, fever, and itching. Some authorities have recommended against using aspirin and other NSAIDs as these have been associated with hemorrhagic syndrome when used for other flaviviruses. Additionally, aspirin use is generally avoided in children when possible due to the risk of Reye syndrome.
Zika virus had been relatively little studied until the major outbreak in 2015, and no specific antiviral treatments are available as yet. Advice to pregnant women is to avoid any risk of infection so far as possible, as once infected there is little that can be done beyond supportive treatment.
Most of the time, Zika fever resolves on its own in 2 to 7 days, but rarely, some people develop Guillain–Barré syndrome. The fetus of a pregnant woman who has Zika fever may die or be born with congenital central nervous system malformations, like microcephaly.
In April 1947, as part of studies sponsored by the Rockefeller Foundation into yellow fever, 6 caged rhesus monkeys were placed in the canopy of the Zika Forest of Uganda. On April 18 one of the monkeys (no. 776) developed a fever and blood samples revealed the first known case of Zika fever. Population surveys at the time in Uganda found 6.1% of individuals to be seropositive for Zika. The first human cases were reported in Nigeria in 1954. A few outbreaks have been reported in tropical Africa and in some areas in Southeast Asia. There have been no documented cases of Zika virus in the Indian subcontinent. Surveys have found antibodies to Zika in healthy people in India which could indicate past exposure, though it could also be due to cross-reaction with other flaviviruses.
By using phylogenetic analysis of Asian strains, it was estimated that Zika virus had moved to Southeast Asia by 1945. In 1977–1978, Zika virus infection was described as a cause of fever in Indonesia. Before 2007, there were only 13 reported natural infections with Zika virus, all with a mild, self-limited febrile illness.
The first major outbreak, with 185 confirmed cases, was reported in 2007 in the Yap Islands of the Federated States of Micronesia. A total of 108 cases were confirmed by PCR or serology and 72 additional cases were suspected. The most common symptoms were rash, fever, arthralgia, and conjunctivitis, and no deaths were reported. The mosquito Aedes hensilli, which was the predominant species identified in Yap during the outbreak, was probably the main vector of transmission. While the way of introduction of the virus on Yap Island remains uncertain, it is likely to have happened through introduction of infected mosquitoes or a human infected with a strain related to those in Southeast Asia. This was also the first time Zika fever had been reported outside Africa and Asia. Before the Yap Island outbreak, only 14 human cases had ever been reported.
In 2013–2014, several outbreaks of Zika were reported in French Polynesia, New Caledonia, Easter Island and the Cook Islands. The source of the virus was thought to be an independent introduction of the virus from Southeast Asia, unrelated to the Yap Islands outbreak.
Genetic analyses of Zika virus strains suggest that Zika first entered the Americas between May and December 2013. It was first detected in the Western Hemisphere in February 2014, and rapidly spread throughout South and Central America, reaching Mexico in November 2015. In 2016 it established local transmission in Florida and Texas. The first death in the United States due to Zika occurred in February 2016.
In May 2015, Brazil officially reported its first 16 cases of the illness. Although, a case of illness was reported in March 2015 in a returning traveller. According to the Brazilian Health Ministry, as of November 2015 there was no official count of the number of people infected with the virus in Brazil, since the disease is not subject to compulsory notification. Even so, cases were reported in 14 states of the country. Mosquito-borne Zika virus is suspected to be the cause of 2,400 possible cases of microcephaly and 29 infant deaths in Brazil in 2015 (of the 2400 or so notified cases in 2015, 2165 were under investigation in December 2015, 134 were confirmed and 102 were ruled out for microcephaly).
The Brazilian Health Ministry has reported at least 2,400 suspected cases of microcephaly in the country in 2015 as of 12 December, and 29 fatalities. Before the Zika outbreak, only an average of 150 to 200 cases per year were reported in Brazil. In the state of Pernambuco the reported rates of microcephaly in 2015 are 77 times higher than in the previous 5 years. A model using data from a Zika outbreak in French Polynesia estimated the risk of microcephaly in children born to mothers who acquired Zika virus in the first trimester to be 1%.
On 24 January 2016, the WHO warned that the virus is likely to spread to nearly all countries of the Americas, since its vector, the mosquito Aedes aegypti, is found in all countries in the region, except for Canada and continental Chile. The mosquito and dengue fever have been detected in Chile's Easter Island, some 3,500 km (2,200 mi) away from its closest point in mainland Chile, since 2002.
In February 2016, WHO declared the outbreak a Public Health Emergency of International Concern as evidence grew that Zika is a cause of birth defects and neurological problems. In April 2016, WHO stated there is a scientific consensus, based on preliminary evidence, that Zika is a cause of microcephaly in infants and Guillain–Barré syndrome in adults. Studies of this and prior outbreaks have found Zika infection during pregnancy to be associated with early pregnancy loss and other pregnancy problems.
In 2016 imported or locally transmitted Zika was reported in all the countries of Asia except Brunei, Hong Kong, Myanmar and Nepal. Serological surveys have indicated that Zika virus is endemic in most areas of Asia, though at a low level. While there was a sharp rise in the number of cases of Zika detected in Singapore after the 2016 Summer Olympics in Brazil, genetic analysis revealed that the strains were more closely related to strains from Thailand than from those causing the epidemic in the Americas.
Origin of the name
Microcephaly and other infant disorders
Zika virus was first identified in the late 1940s in Kampala, Uganda, Africa but was first confirmed in Brazil. Since it was first identified, Zika has been found in more than 27 countries and territories. Following the initial Zika outbreak in Northeastern Brazil in May 2015, physicians observed a very large surge of reports of infants born with microcephaly, with 20 times the number of expected cases. Many of these cases have since been confirmed, leading WHO officials to project that approximately 2,500 infants will be found to have born in Brazil with Zika-related microcephaly.
Proving that Zika causes these effects was difficult and complex for several reasons. For example, the effects on an infant might not be seen until months after the mother's initial infection, long after the time when Zika is easily detected in the body. In addition, research was needed to determine the mechanism by which Zika produced these effects.
Since the initial outbreak, studies that use several different methods found evidence of a link, leading public health officials to conclude that it appears increasingly likely the virus is linked to microcephaly and miscarriage. On 1 February 2016, the World Health Organization declared recently reported clusters of microcephaly and other neurological disorders a Public Health Emergency of International Concern (PHEIC). On 8 March 2016, the WHO Committee reconfirmed that the association between Zika and neurological disorders is of global concern.
The Zika virus was first linked with newborn microcephaly during the Brazil Zika virus outbreak. In 2015, there were 2,782 suspected cases of microcephaly compared with 147 in 2014 and 167 in 2013. Confirmation of many of the recent cases is pending, and it is difficult to estimate how many cases went unreported before the recent awareness of the risk of virus infections.
In November 2015, the Zika virus was isolated in a newborn baby from the northeastern state of Ceará, Brazil, with microcephaly and other congenital disorders. The Lancet medical journal reported in January 2016 that the Brazilian Ministry of Health had confirmed 134 cases of microcephaly "believed to be associated with Zika virus infection" with an additional 2,165 cases in 549 counties in 20 states remaining under investigation. An analysis of 574 cases of microcephaly in Brazil during 2015 and the first week of 2016, reported in March 2016, found an association with maternal illness involving rash and fever during the first trimester of pregnancy. During this period, 12 Brazilian states reported increases of at least 3 standard deviations (SDs) in cases of microcephaly compared with 2000–14, with the northeastern states of Bahia, Paraíba and Pernambuco reporting increases of more than 20 SDs.
In January 2016, a baby in Oahu, Hawaii, was born with microcephaly, the first case in the United States of brain damage linked to the virus. The baby and mother tested positive for a past Zika virus infection. The mother, who had probably acquired the virus while traveling in Brazil in May 2015 during the early stages of her pregnancy, had reported her bout of Zika. She recovered before relocating to Hawaii. Her pregnancy had progressed normally, and the baby's condition was not known until birth.
In February 2016, ocular disorders in newborns have been linked to Zika virus infection. In one study in Pernambuco state in Brazil, about 40 percent of babies with Zika-related microcephaly also had scarring of the retina with spots, or pigment alteration. On 20 February 2016, Brazilian scientists announced that they had successfully sequenced the Zika virus genome and expressed hope that this would help in both developing a vaccine and in determining the nature of any link to birth defects.
Also in February 2016, rumors that microcephaly is caused by the use of the larvicide pyriproxyfen in drinking water were refuted by scientists. "It's important to state that some localities that do not use pyriproxyfen also had reported cases of microcephaly", read a Brazilian government statement. The Brazilian government also refuted conspiracy theories that chickenpox and rubella vaccinations or genetically modified mosquitoes were causing increases in microcephaly.
Researchers also suspected that Zika virus could be transmitted by a pregnant woman to her babies ("vertical transmission"). This remained unproven until February 2016, when a paper by Calvet et al. was published, showing not only was the Zika virus genome found in the amniotic fluid but also IgM antibodies against the virus. This means that not only can the virus cross the placental barrier, but also the antibodies produced by the mother can reach the fetus, which suggests that vertical transmission is plausible in these cases. One other study published in March 2016 by Mlakar and colleagues analyzed autopsy tissues from a fetus with microcephaly that was probably related to Zika virus; researchers found ZIKV in the brain tissue and suggested that the brain injuries were probably associated with the virus, which also shed a light on the vertical transmission theory. Also in March 2016, first solid evidence was reported on how the virus affects the development of the brain, indicating that it appears to preferentially kill developing brain cells.
The first cases of birth defects linked to Zika in Colombia and in Panama were reported in March 2016. In the same month, researchers published a prospective cohort study that found profound impacts in 29 percent of infants of mothers infected with Zika, some of whom were infected late in pregnancy. This study did not suffer from some of the difficulties of studying Zika: the study followed women who presented to a Rio de Janeiro clinic with fever and rash within the last five days. The women were then tested for Zika using PCR, then the progress of the pregnancies were followed using ultrasound.
A high rate of the autoimmune disease Guillain–Barré syndrome (GBS), noted in the French Polynesia outbreak, has also been found in the outbreak that began in Brazil. Laboratory analysis found Zika infections in some patients with GBS in Brazil, El Salvador, Suriname and Venezuela, and the WHO declared on 22 March 2016 that Zika appeared to be "implicated" in GBS infection and that if the pattern was confirmed it would represent a global public health crisis.
Research has been ongoing to better understand how Zika virus causes microcephaly and other neurological disorders.
It may involve infection of the primary neural stem cells of the fetal brain, known as neural progenitor cells. The main roles of brain stem cells are to proliferate until the correct number is achieved, and then to produce neurons through the process of neurogenesis. Zika proteins NS4A and NS4B have also been shown to directly suppress neurogenesis. Infection of brain stem cells can cause cell death, which reduces the production of future neurons and leads to a smaller brain. Zika also appears to have an equal tropism for cells of the developing eye, leading to high rates of eye abnormalities as well.
In addition to inducing cell death, infection of neural progenitor cells may alter the process of cell proliferation, causing a depletion in the pool of progenitor cells. A large number of cases of microcephaly have been associated with inherited gene mutations, and specifically with mutations that lead to dysfunction of the mitotic spindle. There is some evidence that Zika virus may directly or indirectly interfere with mitotic function, this may play a role in altering cell proliferation.
Another line of research considers that Zika, unlike other flaviviruses, may target developing brain cells after it crosses the placenta, and considers the resulting damage likely to be the result of inflammation as a byproduct of the immune response to the infection of those cells.
Some experimental methods of prevention include breeding and releasing mosquitoes that have been genetically modified to prevent them from transmitting pathogens, or have been infected with the Wolbachia bacterium, believed to inhibit the spread of viruses. A strain of Wolbachia helped to reduce the vector competence of the Zika virus in infected Aedes aegypti released in Medellin, Colombia. Gene drive is a technique for changing wild populations, for instance to combat insects so they cannot transmit diseases (in particular mosquitoes in the cases of malaria and Zika). Another method which been researched aims to render male mosquitoes infertile by nuclear radiation in the hope to reduce populations; this is done with a cobalt-60 gamma cell irradiator. In 2016 the World Health Organization encouraged field trials of transgenic male Aedes aegypti mosquitoes developed by Oxitec to try to halt the spread of the Zika virus.
- "Zika virus". World Health Organization. January 2016. Archived from the original on 3 February 2016. Retrieved 3 February 2016.
- Chen, Lin H.; Hamer, Davidson H. (2016). "Ideas and Opinions. Zika Virus: Rapid Spread in the Western Hemisphere". Annals of Internal Medicine. 164 (9): 613–5. doi:10.7326/M16-0150. ISSN 0003-4819. PMID 26832396.
- Musso, D.; Nilles, E.J.; Cao-Lormeau, V.-M. (2014). "Rapid spread of emerging Zika virus in the Pacific area". Clinical Microbiology and Infection. 20 (10): O595–6. doi:10.1111/1469-0691.12707. PMID 24909208.
- "Factsheet for health professionals". Zika virus infection. European Centre for Disease Prevention and Control. Archived from the original on 23 December 2015. Retrieved 22 December 2015.
- Rasmussen, Sonja A.; Jamieson, Denise J.; Honein, Margaret A.; Petersen, Lyle R. (2016). "Zika Virus and Birth Defects — Reviewing the Evidence for Causality". New England Journal of Medicine. 374 (20): 1981–1987. doi:10.1056/NEJMsr1604338. ISSN 0028-4793. PMID 27074377.
- "CDC Concludes Zika Causes Microcephaly and Other Birth Defects". CDC. 13 April 2016. Archived from the original on 14 April 2016. Retrieved 14 April 2016.
- Bope, Edward T.; Kellerman, Rick D. (2016). Conn's Current Therapy 2017 E-Book. Elsevier Health Sciences. p. 635. ISBN 9780323443357. Archived from the original on 10 September 2017.
- Oster, Alexandra M.; Russell, Kate; Stryker, Jo Ellen; Friedman, Allison; Kachur, Rachel E.; Petersen, Emily E.; Jamieson, Denise J.; Cohn, Amanda C.; Brooks, John T. (1 April 2016). "Update: Interim Guidance for Prevention of Sexual Transmission of Zika Virus — United States, 2016". MMWR. Morbidity and Mortality Weekly Report. 65 (12): 323–325. doi:10.15585/mmwr.mm6512e3. PMID 27032078.
- "Zika Virus Microcephaly And Guillain–Barré Syndrome Situation Report" (PDF). World Health Organization. 7 April 2016. Archived (PDF) from the original on 16 April 2016. Retrieved 8 April 2016.
- "Brazil warns against pregnancy due to spreading virus". CNN. 24 December 2015. Archived from the original on 24 December 2015. Retrieved 24 December 2015.
- Olson, Ken E.; Haddow, Andrew D.; Schuh, Amy J.; et al. (2012). "Genetic Characterization of Zika Virus Strains: Geographic Expansion of the Asian Lineage". PLOS Neglected Tropical Diseases. 6 (2): e1477. doi:10.1371/journal.pntd.0001477. ISSN 1935-2735. PMC 3289602. PMID 22389730.
- "WHO Director-General summarizes the outcome of the Emergency Committee regarding clusters of microcephaly and Guillain–Barré syndrome". Media Centre. World Health Organization. 1 February 2016. Archived from the original on 3 February 2016. Retrieved 3 February 2016.
- "Zika situation report". World Health Organization. Archived from the original on 25 May 2017. Retrieved 26 May 2017.
- "Zika Virus". CDC. 5 November 2014. Retrieved 20 June 2019.
- "Symptoms, Diagnosis, & Treatment of Zika Virus". Zika Virus Home. Centers for Disease Control and Prevention. 5 November 2014. Archived from the original on 30 April 2016. Retrieved 29 April 2016.
- Heang, Vireak; Yasuda, Chadwick Y.; Sovann, Ly; et al. (2012). "Zika Virus Infection, Cambodia, 2010". Emerging Infectious Diseases. 18 (2): 349–351. doi:10.3201/eid1802.111224. ISSN 1080-6040. PMC 3310457. PMID 22305269.
- "Signs and Symptoms". Zika virus home. Centers for Disease Control and Prevention. 5 November 2014. Archived from the original on 29 January 2016. Retrieved 30 January 2016.
- Sikka, Veronica; Chattu, Vijay Kumar; Popli, Raaj K.; et al. (11 February 2016). "The emergence of zika virus as a global health security threat: A review and a consensus statement of the INDUSEM Joint working Group (JWG)". Journal of Global Infectious Diseases. 8 (1): 3–15. doi:10.4103/0974-777X.176140. ISSN 0974-8245. PMC 4785754. PMID 27013839.
- Foy, Brian D.; Kobylinski, K.C.; Foy, J.L.C.; et al. (2011). "Probable Non–Vector-borne Transmission of Zika Virus, Colorado, USA". Emerging Infectious Diseases. 17 (5): 880–882. doi:10.3201/eid1705.101939. ISSN 1080-6040. PMC 3321795. PMID 21529401.
- Frontera, Jennifer A.; Silva, Ivan R.F. da (5 October 2016). "Zika Getting on Your Nerves? The Association with the Guillain–Barré Syndrome". New England Journal of Medicine. 375 (16): 1581–1582. doi:10.1056/nejme1611840. PMID 27705077. S2CID 42198417.
- "Guillain–Barré syndrome Q & A". Centers for Disease Control and Prevention. 8 February 2016. Archived from the original on 11 March 2016. Retrieved 10 March 2016.
- Dhiman, Gaurav.; Abraham, R.; Griffin, D. (2019). "Human Schwann cells are susceptible to infection with Zika and yellow fever viruses, but not dengue virus". Scientific Reports. 9 (1): 9951. Bibcode:2019NatSR...9.9951D. doi:10.1038/s41598-019-46389-0. PMC 6616448. PMID 31289325.
- Cao-Lormeau, Van-Mai; Blake, Alexandre; Mons, Sandrine; et al. (2016). "Guillain–Barré Syndrome outbreak associated with Zika virus infection in French Polynesia: a case-control study". The Lancet. 387 (10027): 1531–1539. doi:10.1016/S0140-6736(16)00562-6. ISSN 0140-6736. PMC 5444521. PMID 26948433.
- Brasil, Patrícia; Pereira, Jr., Jose P.; Raja Gabaglia, Claudia; et al. (4 March 2016). "Zika Virus Infection in Pregnant Women in Rio de Janeiro – Preliminary Report". New England Journal of Medicine. 375 (24): 2321–2334. doi:10.1056/NEJMoa1602412. ISSN 0028-4793. PMC 5323261. PMID 26943629.
- Brasil, Patrícia; Pereira, José P.; Moreira, M. Elisabeth; Nogueira, Rita M. Ribeiro; Damasceno, Luana; Wakimoto, Mayumi; Rabello, Renata S.; Valderramos, Stephanie G.; Halai, Umme-Aiman (4 March 2016). "Zika Virus Infection in Pregnant Women in Rio de Janeiro". New England Journal of Medicine. 375 (24): 2321–2334. doi:10.1056/nejmoa1602412. PMC 5323261. PMID 26943629.
- de Paula Freitas B; de Oliveira Dias J; Prazeres J; et al. (9 February 2016). "Ocular findings in infants with microcephaly associated with presumed zika virus congenital infection in salvador, brazil". JAMA Ophthalmology. 134 (5): 529–535. doi:10.1001/jamaophthalmol.2016.0267. ISSN 2168-6165. PMC 5444996. PMID 26865554.
- Sarno, Manoel; Sacramento, Gielson A.; Khouri, Ricardo; Rosário, Mateus S. do; Costa, Federico; Archanjo, Gracinda; Santos, Luciane A.; Jr, Nivison Nery; Vasilakis, Nikos (25 February 2016). "Zika Virus Infection and Stillbirths: A Case of Hydrops Fetalis, Hydranencephaly and Fetal Demise". PLOS Negl Trop Dis. 10 (2): e0004517. doi:10.1371/journal.pntd.0004517. ISSN 1935-2735. PMC 4767410. PMID 26914330.
- Li, Hongda; Saucedo-Cuevas, Laura; Shresta, Sujan; Gleeson, Joseph G. (2016). "The Neurobiology of Zika Virus". Neuron. 92 (5): 949–958. doi:10.1016/j.neuron.2016.11.031. PMID 27930910.
- Boeuf, Phillipe; Drummer, Heidi E.; Richards, Jack S.; Scoullar, Michelle J. L.; Beeson, James G. (1 January 2016). "The global threat of Zika virus to pregnancy: epidemiology, clinical perspectives, mechanisms, and impact". BMC Medicine. 14 (1): 112. doi:10.1186/s12916-016-0660-0. ISSN 1741-7015. PMC 4973112. PMID 27487767.
- "Risk estimates for microcephaly related to Zika virus infection - from French Polynesia to Bahia, Brazil". 2 May 2016. bioRxiv 10.1101/051060.
- França, Giovanny V A; Schuler-Faccini, Lavinia; Oliveira, Wanderson K; Henriques, Claudio M P; Carmo, Eduardo H; Pedi, Vaneide D; Nunes, Marília L; Castro, Marcia C; Serruya, Suzanne; Silveira, Mariângela F; Barros, Fernando C; Victora, Cesar G (2016). "Congenital Zika virus syndrome in Brazil: A case series of the first 1501 livebirths with complete investigation". The Lancet. 388 (10047): 891–7. doi:10.1016/S0140-6736(16)30902-3. PMID 27372398.
- Hayes, Edward B. (2009). "Zika Virus Outside Africa". Emerging Infectious Diseases. 15 (9): 1347–50. doi:10.3201/eid1509.090442. PMC 2819875. PMID 19788800.
- Brack, Manfred (6 December 2012). Agents Transmissible from Simians to Man. Springer Science & Business Media. ISBN 978-3-642-71911-0. Archived from the original on 17 June 2016.
- "Aedes luteocephala". Medically Important Mosquitoes. Walter Reed Biosystematics Unit. Archived from the original on 28 January 2016. Retrieved 1 February 2016.
- Grard, G; Caron, M; Mombo, I M; Nkoghe, D; Ondo, S M; Jiolle, D; Fontenille, D; Paupy, C; Leroy, E M (2014). "Zika Virus in Gabon (Central Africa) – 2007: A New Threat from Aedes albopictus ?". PLOS Negl Trop Dis. 8 (2): e2681. doi:10.1371/journal.pntd.0002681. ISSN 1935-2735. PMC 3916288. PMID 24516683.
- Wong, PJ; Li, M I; Chong, C; Ng, L; Tan, C (2013). "Aedes ( Stegomyia ) albopictus (Skuse): A Potential Vector of Zika Virus in Singapore". PLOS Negl Trop Dis. 7 (8): e2348. doi:10.1371/journal.pntd.0002348. ISSN 1935-2735. PMC 3731215. PMID 23936579.
- "Zika virus". Archived from the original on 25 December 2015. Retrieved 24 December 2015.
- Oster, Alexandra M.; Brooks, John T.; Stryker, Jo Ellen; et al. (2016). "Interim Guidelines for Prevention of Sexual Transmission of Zika Virus — United States, 2016". MMWR. Morbidity and Mortality Weekly Report. 65 (5): 120–121. doi:10.15585/mmwr.mm6505e1. ISSN 0149-2195. PMID 26866485.
- "CDC encourages following guidance to prevent sexual transmission of Zika virus". CDC Newsroom Releases. Centers for Disease Control and Prevention. 23 February 2016. Archived from the original on 27 February 2016.
- Hills, Susan L.; Russell, Kate; Hennessey, Morgan; et al. (2016). "Transmission of Zika Virus Through Sexual Contact with Travelers to Areas of Ongoing Transmission — Continental United States, 2016". MMWR. Morbidity and Mortality Weekly Report. 65 (8). doi:10.15585/mmwr.mm6508e2er. ISSN 0149-2195. Archived from the original on 15 March 2016.
- Mansuy, Jean Michel; Dutertre, Marine; Mengelle, Catherine; et al. (2016). "Zika virus: high infectious viral load in semen, a new sexually transmitted pathogen?". The Lancet Infectious Diseases. 16 (4): 405. doi:10.1016/S1473-3099(16)00138-9. ISSN 1473-3099. PMID 26949027.
- Brooks, Richard B.; Carlos, Maria Paz; Myers, Robert A.; White, Mary Grace; Bobo-Lenoci, Tanya; Aplan, Debra; Blythe, David; Feldman, Katherine A. (1 January 2016). "Likely Sexual Transmission of Zika Virus from a Man with No Symptoms of Infection — Maryland, 2016". MMWR. Morbidity and Mortality Weekly Report. 65 (34): 915–916. doi:10.15585/mmwr.mm6534e2. ISSN 0149-2195. PMID 27585037.
- Petersen, Emily E.; Meaney-Delman, Dana; Neblett-Fanfair, Robyn; Havers, Fiona; Oduyebo, Titilope; Hills, Susan L.; Rabe, Ingrid B.; Lambert, Amy; Abercrombie, Julia (1 January 2016). "Update: Interim Guidance for Preconception Counseling and Prevention of Sexual Transmission of Zika Virus for Persons with Possible Zika Virus Exposure — United States, September 2016". MMWR. Morbidity and Mortality Weekly Report. 65 (39): 1077–1081. doi:10.15585/mmwr.mm6539e1. ISSN 0149-2195. PMID 27711033.
- Jr, Donald G. Mcneil (14 April 2016). "Zika Virus Can be Transmitted Through Anal Sex, C.D.C. Says". The New York Times. Archived from the original on 21 December 2016. Retrieved 3 March 2017. Zika Virus Can Be Transmitted Through Anal Sex, C.D.C. Says
- D’Ortenzio, Eric; Matheron, Sophie; de Lamballerie, Xavier; Hubert, Bruno; Piorkowski, Géraldine; Maquart, Marianne; Descamps, Diane; Damond, Florence; Yazdanpanah, Yazdan (2 June 2016). "Evidence of Sexual Transmission of Zika Virus". New England Journal of Medicine. 374 (22): 2195–2198. doi:10.1056/NEJMc1604449. ISSN 0028-4793. PMID 27074370.
- Gatherer, Derek; Kohl, Alain (18 December 2015). "Zika virus: a previously slow pandemic spreads rapidly through the Americas" (PDF). Journal of General Virology. 97 (2): 269–273. doi:10.1099/jgv.0.000381. PMID 26684466.
- Petersen, Emily E.; Polen, Kara N.D.; Meaney-Delman, Dana; et al. (2016). "Update: Interim Guidance for Health Care Providers Caring for Women of Reproductive Age with Possible Zika Virus Exposure — United States, 2016". MMWR. Morbidity and Mortality Weekly Report. 65 (12): 315–322. doi:10.15585/mmwr.mm6512e2. ISSN 0149-2195. PMID 27031943. Archived from the original on 28 March 2016.
- Dupont-Rouzeyrol, Myrielle; Biron, Antoine; O'Connor, Olivia; et al. (2016). "Infectious Zika viral particles in breastmilk". The Lancet. 387 (10023): 1051. doi:10.1016/s0140-6736(16)00624-3. PMID 26944028.
- Franchini, M.; Velati, C. (2016). "Blood safety and zoonotic emerging pathogens: now it's the turn of Zika virus!". Blood Transfusion. 14 (2): 93–94. doi:10.2450/2015.0187-15. PMC 4781775. PMID 26674809.
- "FDA advises testing for Zika virus in all donated blood and blood components in the US". 26 August 2016. Archived from the original on 2 September 2016.
- Guillaume, Theiry (27 April 2016). "Zika virus-associated Guillain–Barré syndrome: a warning for critical care physicians". Intensive Care Medicine. 42 (9): 1485–1486. doi:10.1007/s00134-016-4364-x. PMID 27118575.
- Molly Chiu (14 November 2019). "How maternal Zika virus infection results in newborn microcephaly". Cite journal requires
- Fauci, Anthony S.; Morens, David M. (18 February 2016). "Zika Virus in the Americas – Yet Another Arbovirus Threat". New England Journal of Medicine. 374 (7): 601–604. doi:10.1056/NEJMp1600297. PMID 26761185. S2CID 4377569.
- "Clinical Evaluation & Disease". For Health Care Providers. Centers for Disease Control and Prevention. Archived from the original on 25 December 2015. Retrieved 24 December 2015.
- Waggoner, Jesse J.; Pinsky, Benjamin A. (17 February 2016). "Zika Virus: Diagnostics for an Emerging Pandemic Threat". Journal of Clinical Microbiology. 54 (4): JCM.00279–16. doi:10.1128/JCM.00279-16. ISSN 0095-1137. PMC 4809954. PMID 26888897.
- "Interim Guidance for Zika Virus Testing of Urine - United States, 2016". MMWR. Morbidity and Mortality Weekly Report. 65 (18): 474. 13 May 2016. doi:10.15585/mmwr.mm6518e1. PMID 27171368.
- Faye, Oumar; Faye, Ousmane; Dupressoir, Anne; et al. (2008). "One-step RT-PCR for detection of Zika virus". Journal of Clinical Virology. 43 (1): 96–101. doi:10.1016/j.jcv.2008.05.005. ISSN 1386-6532. PMID 18674965.
- Lanciotti, Robert S.; Kosoy, Olga L.; Laven, Janeen J.; et al. (2008). "Genetic and Serologic Properties of Zika Virus Associated with an Epidemic, Yap State, Micronesia, 2007". Emerging Infectious Diseases. 14 (8): 1232–1239. doi:10.3201/eid1408.080287. ISSN 1080-6040. PMC 2600394. PMID 18680646.
- Commissioner, Office of the (18 July 2019). "Zika Virus Response Updates from FDA". FDA. Retrieved 18 July 2019.
- Oduyebo, Titilope; Petersen, Emily E.; Rasmussen, Sonja A.; et al. (2016). "Update: Interim Guidelines for Health Care Providers Caring for Pregnant Women and Women of Reproductive Age with Possible Zika Virus Exposure — United States, 2016". MMWR. Morbidity and Mortality Weekly Report. 65 (5): 1–6. doi:10.15585/mmwr.mm6505e2er. ISSN 0149-2195. PMID 26866840.
- Russell, Kate; Oliver, Sara E.; Lewis, Lillianne; Barfield, Wanda D.; Cragan, Janet; Meaney-Delman, Dana; Staples, J. Erin; Fischer, Marc; Peacock, Georgina (1 January 2016). "Update: Interim Guidance for the Evaluation and Management of Infants with Possible Congenital Zika Virus Infection — United States, August 2016". MMWR. Morbidity and Mortality Weekly Report. 65 (33): 870–878. doi:10.15585/mmwr.mm6533e2. ISSN 0149-2195. PMID 27559830.
- Leal, Mariana C; Muniz, Lilian F; Ferreira, Tamires S.A; Santos, Cristiane M; Almeida, Luciana C; Van Der Linden, Vanessa; Ramos, Regina C.F; Rodrigues, Laura C; Neto, Silvio S. Caldas (2016). "Hearing Loss in Infants with Microcephaly and Evidence of Congenital Zika Virus Infection — Brazil, November 2015–May 2016". Morbidity and Mortality Weekly Report. 65 (34): 917–9. doi:10.15585/mmwr.mm6534e3. PMID 27585248.
- "Avoid bug bites". Travelers' Health. Centers for Disease Control and Prevention. Archived from the original on 13 March 2016. Retrieved 15 March 2016.
- "Zika Virus - Protect Yourself from Mosquito Bites". 5 November 2014. Archived from the original on 1 October 2016. Retrieved 1 October 2016. Permethrin-treated clothing will protect you after multiple washings
- Louis, Catherine Saint (4 April 2016). "DEET Seen as Safe for Pregnant Women to Avoid Zika Despite Few Studies". The New York Times. Archived from the original on 17 September 2016. Retrieved 3 March 2017. DEET Seen as Safe for Pregnant Women to Avoid Zika Despite Few Studies
- "Surveillance and Control of Aedes aegypti and Aedes albopictus in the United States". Chikungunya Virus Home: Resources. Centers for Disease Control and Prevention. 10 March 2016. Archived from the original on 6 February 2016.
- "Help Control Mosquitoes that Spread Dengue, Chikungunya, and Zika Viruses" (PDF). Chikungunya Virus Home: Fact Sheets and Posters. Centers for Disease Control and Prevention. August 2015. Archived (PDF) from the original on 1 February 2016.
- "Breastfeeding in the context of Zika virus" (PDF). Institutional Repository for Information Sharing. World Health Organization. 25 February 2016. Archived (PDF) from the original on 5 March 2016. Retrieved 28 February 2016.
- Lowes, R. (15 January 2016). "CDC Issues Zika Travel Alert". Medscape Medical News. Archived from the original on 26 January 2016. Retrieved 16 January 2016.
- "How to Protect Yourself". Centers for Disease Control and Prevention. 4 March 2016. Archived from the original on 12 March 2016. Retrieved 16 March 2016.
- "CDC issues interim travel guidance related to Zika virus for 14 Countries and Territories in Central and South America and the Caribbean". CDC Newsroom Releases. Centers for Disease Control and Prevention. 15 January 2016. Archived from the original on 18 January 2016.
- "Zika Travel Information | Travelers' Health | CDC". wwwnc.cdc.gov. Archived from the original on 7 September 2016. Retrieved 2 September 2016.
- "Neurological syndrome, congenital malformations, and Zika virus infection – Epidemiological Update". Epidemiological Alerts and Updates CHA.01.04b Epidemic Alert and Response. Pan American Health Organization. 17 January 2016. Archived from the original on 26 January 2016.
- "WHO Declares Zika a Public Health Emergency". NBC News. Archived from the original on 7 February 2016. Retrieved 8 February 2016.
- Tavernise, Sabrina; McNeil, Jr., Donald G. (1 February 2016). "Zika Virus a Global Health Emergency, W.H.O. Says". The New York Times. ISSN 0362-4331. Archived from the original on 8 February 2016. Retrieved 8 February 2016.
- "IHR Procedures concerning public health emergencies of international concern (PHEIC)". World Health Organization. Archived from the original on 3 February 2016. Retrieved 8 February 2016.
- Debra Goldschmidt. "WHO ends Zika public health emergency". CNN. Archived from the original on 23 December 2016. Retrieved 24 December 2016.
- Sifferlin, Alexandra (21 January 2016). "U.S. Launches 'Full-court Press' for a Zika Vaccine". Time. Archived from the original on 22 January 2016. Retrieved 23 January 2016.
- J., Thomas, Stephen; Maïna, L’Azou; D.T., Barrett, Alan; A.C., Jackson, Nicholas (28 September 2016). "Fast-Track Zika Vaccine Development — Is It Possible?". New England Journal of Medicine. 375 (13): 1212–1216. doi:10.1056/nejmp1609300. PMID 27682032.
- D., Marston, Hilary; Nicole, Lurie; L., Borio, Luciana; S., Fauci, Anthony (28 September 2016). "Considerations for Developing a Zika Virus Vaccine". New England Journal of Medicine. 375 (13): 1209–1212. doi:10.1056/nejmp1607762. PMID 27682031.
- Barzon, Luisa; Trevisan, Marta; Sinigaglia, Alessandro; Lavezzo, Enrico; Palù, Giorgio (1 September 2016). "Zika virus: from pathogenesis to disease control". FEMS Microbiology Letters. 363 (18): fnw202. doi:10.1093/femsle/fnw202. ISSN 1574-6968. PMID 27549304.
- Morrison, Chris (1 August 2016). "DNA vaccines against Zika virus speed into clinical trials". Nature Reviews Drug Discovery. 15 (8): 521–522. doi:10.1038/nrd.2016.159. ISSN 1474-1776. PMID 27469223.
- Poland, Gregory A.; Ovsyannikova, Inna G.; Kennedy, Richard B. (2019). "Zika Vaccine Development: Current Status". Mayo Clinic Proceedings. 94 (12): 2572–2586. doi:10.1016/j.mayocp.2019.05.016. ISSN 0025-6196. PMC 7094556. PMID 31806107.
- Yakob, Laith; Walker, Thomas (March 2016). "Zika virus outbreak in the Americas: the need for novel mosquito control methods". The Lancet Global Health. 4 (3): e148–e149. doi:10.1016/S2214-109X(16)00048-6. PMID 26848089.
- Tracy Thompson: Oxitec’s solution for controlling the dengue mosquito is approved by CTNBio. Archived 1 March 2016 at the Wayback Machine Oxitech, 11 April 2014
- Pollack, Andrew (30 January 2016). "New Weapon to Fight Zika: The Mosquito". New York Times. Archived from the original on 3 February 2016. Retrieved 16 March 2016.
- Dennis, Brady (19 February 2016). "How a tiny mosquito became one of the world's 'most efficient killers'". Washington Post. Retrieved 20 January 2018.
- Fulginiti, Vincent A.; Brunell, Philip A.; Cherry, James D.; et al. (June 1982). "Aspirin and Reye Syndrome". Pediatrics. 69 (6): 810–812. ISSN 1098-4275. PMID 7079050. Retrieved 11 March 2016.
- Petersen, Emily E.; Staples, J. Erin; Meaney-Delman, Dana; et al. (2016). "Interim Guidelines for Pregnant Women During a Zika Virus Outbreak — United States, 2016". Morbidity and Mortality Weekly Report. 65 (2): 30–33. doi:10.15585/mmwr.mm6502e1. ISSN 0149-2195. PMID 26796813.
- CDC Zika Virus: Health Effects & Risks Archived 20 August 2016 at the Wayback Machine Page last reviewed: August 9, 2016; Page last updated: August 9, 2016
- Musso, Didier; Gubler, Duane J. (1 July 2016). "Zika Virus". Clinical Microbiology Reviews. 29 (3): 487–524. doi:10.1128/CMR.00072-15. ISSN 0893-8512. PMC 4861986. PMID 27029595.
- MacNamara, F.N. (1954). "Zika virus : A report on three cases of human infection during an epidemic of jaundice in Nigeria". Transactions of the Royal Society of Tropical Medicine and Hygiene. 48 (2): 139–145. doi:10.1016/0035-9203(54)90006-1. ISSN 0035-9203. PMID 13157159. Archived from the original on 1 April 2016.
- Simpson, D.I.H. (1964). "Zika virus infection in man". Transactions of the Royal Society of Tropical Medicine and Hygiene. 58 (4): 339–348. doi:10.1016/0035-9203(64)90201-9. ISSN 0035-9203. PMID 14175744. Archived from the original on 6 February 2016.
- Smithburn, K. C.; Kerr, J. A.; Gatne, P. B. (1 April 1954). "Neutralizing antibodies against certain viruses in the sera of residents of India". Journal of Immunology. 72 (4): 248–257. PMID 13163397.
- Olson, J. G.; Ksiazek, T. G. (1 January 1981). "Zika virus, a cause of fever in Central Java, Indonesia". Transactions of the Royal Society of Tropical Medicine and Hygiene. 75 (3): 389–393. doi:10.1016/0035-9203(81)90100-0. PMID 6275577. Archived from the original on 6 February 2016.
- Baden, Lindsey R.; Petersen, Lyle R.; Jamieson, Denise J.; Powers, Ann M.; Honein, Margaret A. (30 March 2016). "Zika Virus". New England Journal of Medicine. 374 (16): 1552–1563. doi:10.1056/nejmra1602113. PMID 27028561.
- Duffy, M.R.; Chen, T.H.; Hancock, W.T.; et al. (2009). "Zika Virus Outbreak on Yap Island, Federated States of Micronesia". New England Journal of Medicine. 360 (24): 2536–43. doi:10.1056/NEJMoa0805715. PMID 19516034.
- Faye, Oumar; Freire, Caio C. M.; Iamarino, Atila; et al. (9 January 2014). "Molecular Evolution of Zika Virus during Its Emergence in the 20th Century". PLOS Neglected Tropical Diseases. 8 (1): e2636. doi:10.1371/journal.pntd.0002636. PMC 3888466. PMID 24421913.
- Faria, Nuno Rodrigues; Azevedo, Raimunda do Socorro da Silva; Kraemer, Moritz U.G.; Souza, Renato; Cunha, Mariana Sequetin; Hill, Sarah C.; Thézé, Julien; Bonsall, Michael B.; Bowden, Thomas A. (15 April 2016). "Zika virus in the Americas: Early epidemiological and genetic findings". Science. 352 (6283): 345–349. Bibcode:2016Sci...352..345F. doi:10.1126/science.aaf5036. ISSN 0036-8075. PMC 4918795. PMID 27013429.
- Dyer, Owen (23 December 2015). "Zika virus spreads across Americas as concerns mount over birth defects". BMJ. 351: h6983. doi:10.1136/bmj.h6983. PMID 26698165. Archived from the original on 30 December 2015.
- Jr, Donald G. Mcneil; Fernandez, Manny (28 November 2016). "Local Transmission of Zika Virus Is Reported in Texas". The New York Times. ISSN 0362-4331. Archived from the original on 11 December 2016. Retrieved 9 December 2016.
- Likos, Anna; Griffin, Isabel; Bingham, Andrea M.; Stanek, Danielle; Fischer, Marc; White, Stephen; Hamilton, Janet; Eisenstein, Leah; Atrubin, David (1 January 2016). "Local Mosquito-Borne Transmission of Zika Virus — Miami-Dade and Broward Counties, Florida, June–August 2016". MMWR. Morbidity and Mortality Weekly Report. 65 (38): 1032–1038. doi:10.15585/mmwr.mm6538e1. ISSN 0149-2195. PMID 27684886.
- "First Zika virus-related death reported in U.S. in Puerto Rico". Washington Post. Archived from the original on 1 June 2016. Retrieved 29 April 2016.
- "Ministério da Saúde confirma 8 casos de zika vírus no RN e 8 na BA" [Ministry of Health confirms 8 cases of zika virus in infants and 8 in BA]. Ben Estar (in Portuguese). 14 May 2015. Archived from the original on 18 May 2015.
- Zammarchi, L; Tappe, D; Fortuna, C; Remoli, M; Günther, S; Venturi, G; Bartoloni, A; Schmidt-Chanasit, J (11 June 2015). "Zika virus infection in a traveller returning to Europe from Brazil, March 2015" (PDF). Eurosurveillance. 20 (23): 21153. doi:10.2807/1560-7917.ES2015.20.23.21153. PMID 26084316.
- "Monitoramento dos casos de microcefalias no Brasil" [Monitoring cases of microcephaly in Brazil] (PDF) (in Portuguese). Centro de Operações de Emergências em Saúde Pública sobre Microcefalias. 12 December 2015. Retrieved 24 December 2015.
- "Governo confirma relação entre zika vírus e epidemia de microcefalia" [Government confirms relationship between zika virus and epidemic microcephaly]. BBC Brasil (in Portuguese). 28 November 2015. Archived from the original on 31 January 2016. Retrieved 10 March 2016.
- Blount, Jeb (28 November 2015). "Brazil confirms zica virus link to fetal brain-damage outbreak". Reuters. Archived from the original on 5 March 2016. Retrieved 4 February 2016.
- "País registra 1.248 casos de microcefalia e sete mortes; maioria em PE" [The country has recorded 1,248 cases of microcephaly and seven deaths; most are in PE]. UOL Notícias (in Portuguese). 30 November 2015. Archived from the original on 4 February 2016. Retrieved 4 February 2016.
- "Rapid risk assessment: Zika virus epidemic in the Americas: potential association with microcephaly and Guillain–Barré syndrome" (PDF). European Centre for Disease Prevention and Control. 10 December 2015. Archived from the original (PDF) on 12 February 2016. Retrieved 11 February 2016.
- Cauchemez, Simon; Besnard, Marianne; Bompard, Priscillia; Dub, Timothée; Guillemette-Artur, Prisca; Eyrolle-Guignot, Dominique; Salje, Henrik; Kerkhove, Maria D Van; Abadie, Véronique (2016). "Association between Zika virus and microcephaly in French Polynesia, 2013–15: a retrospective study". The Lancet. 387 (10033): 2125–2132. doi:10.1016/s0140-6736(16)00651-6. PMC 4909533. PMID 26993883.
- "Zika Virus likely to spread throughout the Americas, says WHO". The Guardian. 25 January 2016. Archived from the original on 24 August 2016.
- "PAHO Statement on Zika Virus Transmission and Prevention". Pan American Health Organization. Archived from the original on 26 January 2016.
- Collao, X.; Prado, L.; González, C.; et al. (February 2015). "Detection of flavivirus in mosquitoes (Diptera: Culicidae) from Easter Island-Chile". Revista Chilena de Infectología (in Spanish). 32 (1): 113–6. doi:10.4067/S0716-10182015000200021. PMID 25860055.
- "WHO Director-General summarizes the outcome of the Emergency Committee regarding clusters of microcephaly and Guillain–Barré syndrome". World Health Organization. 1 February 2016. Archived from the original on 2 February 2016. Retrieved 2 February 2016.
- Roberts, Michelle (1 February 2016). "Zika-linked condition: WHO declares global emergency". BBC News Online. Archived from the original on 1 February 2016. Retrieved 1 February 2016.
- Pearson, Michael (2 February 2016). "Zika virus sparks 'public health emergency'". CNN. Archived from the original on 2 February 2016. Retrieved 2 February 2016.
- "Zika Fever". Centers for Disease Control and Prevention. 1 February 2016. Archived from the original on 31 January 2016. Retrieved 1 February 2016.
- Rosen, Meghan (22 January 2016). "Rapid spread of Zika virus in the Americas raises alarm". Science News. 189 (4): 16. Archived from the original on 23 February 2016. Retrieved 16 February 2016.
- Duong, Veasna; Dussart, Philippe; Buchy, Philippe (2017). "Zika virus in Asia". International Journal of Infectious Diseases. 54: 121–128. doi:10.1016/j.ijid.2016.11.420. PMID 27939768.
- de Bernardi Schneider, Adriano; Malone, Robert W.; Guo, Jun-Tao; Homan, Jane; Linchangco, Gregorio; Witter, Zachary L.; Vinesett, Dylan; Damodaran, Lambodhar; Janies, Daniel A. (1 December 2016). "Molecular evolution of Zika virus as it crossed the Pacific to the Americas". Cladistics. 33: 1–20. doi:10.1111/cla.12178. ISSN 1096-0031.
- Maurer-Stroh, Sebastian; Mak, Tze-Minn; Ng, Yi-Kai; Phuah, Shiau-Pheng; Huber, Roland G; Marzinek, Jan K; Holdbrook, Daniel A; Lee, Raphael TC; Cui, Lin (2016). "South-east Asian Zika virus strain linked to cluster of cases in Singapore, August 2016". Eurosurveillance. 21 (38). doi:10.2807/1560-7917.es.2016.21.38.30347. PMC 5073200. PMID 27684526.
- Fisher, Dale; Cutter, Jeffery (1 January 2016). "The inevitable colonisation of Singapore by Zika virus". BMC Medicine. 14 (1): 188. doi:10.1186/s12916-016-0737-9. ISSN 1741-7015. PMC 5116805. PMID 27866470.
- Sikka, Veronica; Chattu, Vijay Kumar; Popli, Raaj K.; Galwankar, Sagar C.; Kelkar, Dhanashree; Sawicki, Stanley G.; Stawicki, Stanislaw P.; Papadimos, Thomas J. (11 February 2016). "The emergence of zika virus as a global health security threat: A review and a consensus statement of the INDUSEM Joint working Group (JWG)". Journal of Global Infectious Diseases. 8 (1): 3–15. doi:10.4103/0974-777X.176140. ISSN 0974-8245. PMC 4785754. PMID 27013839.
- Basarab, Marina; Bowman, Conor; Aarons, Emma J; Cropley, Ian (26 February 2016). "Zika virus". BMJ. 352: i1049. doi:10.1136/bmj.i1049. PMID 26921241.
- Romero, Simon (30 December 2015). "Alarm Spreads in Brazil Over a Virus and a Surge in Malformed Infants". The New York Times. Archived from the original on 3 January 2016. Retrieved 24 January 2016.
- Romero, Simon; McNeil, Donald G., Jr. (21 January 2016). "Zika Virus May be Linked to Surge in Rare Syndrome in Brazil". The New York Times. Archived from the original on 21 February 2016. Retrieved 13 March 2016.
- Sun, Lena H. (22 March 2016). "Zika: More than 2,500 babies born with microcephaly in Brazil, WHO predicts". Washington Post. Archived from the original on 22 March 2016. Retrieved 23 March 2016.
- Tavernise, Sabrina (22 March 2016). "Birth Defects Tied to Zika in Panama". New York Times. Archived from the original on 23 March 2016. Retrieved 23 March 2016.
- Fine Maron, Dina (28 January 2016). "Zika–Microcephaly Link: Public health officials are not yet ready to say the connection is causal". Scientific American. Archived from the original on 20 March 2016. Retrieved 13 March 2016.
- McNeil Jr., Donald G. (19 February 2016). "Proof of Zika's Role in Birth Defects Still Months Away, W.H.O. Says". New York Times. Archived from the original on 12 March 2016. Retrieved 13 March 2016.
- "WHO statement on the 2nd meeting of IHR Emergency Committee on Zika virus and observed increase in neurological disorders and neonatal malformations". World Health Organization. 8 March 2016. Archived from the original on 12 March 2016. Retrieved 13 March 2016.
- McNeil, Donald G., Jr.; Saint Louis, Catherine (4 March 2016). "Two Studies Strengthen Links Between the Zika Virus and Serious Birth Defects". New York Times. Archived from the original on 12 March 2016. Retrieved 13 March 2016.
- Heymann, David L; Hodgson, Abraham; Sall, Amadou Alpha; et al. (20 February 2016). "Zika virus and microcephaly: why is this situation a PHEIC?". The Lancet. 387 (10020): 719–721. doi:10.1016/S0140-6736(16)00320-2. PMC 7134564. PMID 26876373.
- "Brazil may have fewer Zika-related microcephaly cases than previously reported". Archived from the original on 16 March 2016.
- "Brazil's Pre-Zika Microcephaly Cases". Archived from the original on 14 March 2016.
- Triunfol, Marcia (2016). "A new mosquito-borne threat to pregnant women in Brazil". The Lancet Infectious Diseases. 16 (2): 156–157. doi:10.1016/S1473-3099(15)00548-4. ISSN 1473-3099. PMID 26723756.
- Kleber de Oliveira, Wanderson; Cortez-Escalante, Juan; De Oliveira, Wanessa Tenório Gonçalves Holanda; et al. (2016). "Increase in Reported Prevalence of Microcephaly in Infants Born to Women Living in Areas with Confirmed Zika Virus Transmission During the First Trimester of Pregnancy – Brazil, 2015". MMWR. Morbidity and Mortality Weekly Report. 65 (9): 242–247. doi:10.15585/mmwr.mm6509e2. ISSN 0149-2195. PMID 26963593.
- McNeil Jr., Donald G. (16 January 2016). "Hawaii Baby With Brain Damage Is First U.S. Case Tied to Zika Virus". The New York Times. Archived from the original on 23 February 2017.
- Ventura, Camila V; et al. (January 2016). "Zika virus in Brazil and macular atrophy in a child with microcephaly". The Lancet. 387 (10015): 228. doi:10.1016/S0140-6736(16)00006-4. PMID 26775125.
- "Zika virus: Americas, Asia". ProMED-mail. International Society for Infectious Diseases. 28 January 2016. Archived from the original on 2 February 2016. Retrieved 8 February 2016.
- Martinez, Michael (20 February 2016). "Zika virus: Brazilian scientists decipher its genome, agency says". CNN. Archived from the original on 21 February 2016.
- Jacobs, Andrew (16 February 2016). "Conspiracy Theories About Zika Spread Along With the Virus". The New York Times. Archived from the original on 17 February 2016. Retrieved 16 February 2016.
- Bowater, Donna (15 February 2016). "Zika virus: Brazil dismisses link between larvicide and microcephaly". Daily Telegraph. Archived from the original on 17 February 2016.
- Calvet, Guilherme; Aguiar, Renato S; Melo, Adriana S O; et al. (February 2016). "Detection and sequencing of Zika virus from amniotic fluid of fetuses with microcephaly in Brazil: a case study". The Lancet Infectious Diseases. 16 (6): 653–660. doi:10.1016/S1473-3099(16)00095-5. ISSN 1473-3099. PMID 26897108.
- Mlakar, Jernej; Korva, Misa; Tul, Nataša; et al. (10 March 2016). "Zika Virus Associated with Microcephaly". New England Journal of Medicine. 374 (10): 951–958. doi:10.1056/NEJMoa1600651. ISSN 0028-4793. PMID 26862926.
- Vogel, Gretchen (4 March 2016). "Zika virus kills developing brain cells". Science. Archived from the original on 6 March 2016.
- Butler, Declan (4 March 2016). "First Zika-linked birth defects detected in Colombia". Nature. 531 (7593): 153. Bibcode:2016Natur.531..153B. doi:10.1038/nature.2016.19502. ISSN 0028-0836. PMID 26961637. S2CID 4470808.
- "Zika: Panama has 'first microcephaly case outside Brazil'". BBC News Latin America. BBC. 19 March 2016. Archived from the original on 20 March 2016. Retrieved 20 March 2016.
- McNeil, Donald G. Jr.; Saint Louis, Catherine (4 March 2016). "Two Studies Strengthen Links Between the Zika Virus and Serious Birth Defects". New York Times. Archived from the original on 22 March 2016. Retrieved 23 March 2016.
- "Zika situation report" (PDF). World Health Organization. 17 March 2016. Archived (PDF) from the original on 20 March 2016. Retrieved 23 March 2016.
- Bosley, Sarah (22 March 2016). "WHO: Zika virus 'implicated' in large numbers of brain-damaged babies". The Guardian. Archived from the original on 22 March 2016. Retrieved 23 March 2016.
- Faizan, MI; Abdullah, M; Ali, S; Naqvi, IH; Ahmed, A; Parveen, S (2016). "Zika Virus-Induced Microcephaly and Its Possible Molecular Mechanism". Intervirology. 59 (3): 152–158. doi:10.1159/000452950. PMID 28081529.
- Nayak, Shriddha; Lei, Jun; Pekosz, Andrew; Klein, Sabra; Burd, Irina (9 September 2016). "Pathogenesis and Molecular Mechanisms of Zika Virus". Seminars in Reproductive Medicine. 34 (5): 266–272. doi:10.1055/s-0036-1592071. ISSN 1526-8004. PMID 27612156.
- Rakic, P (October 2009). "Evolution of the neocortex: a perspective from developmental biology". Nature Reviews. Neuroscience. 10 (10): 724–35. doi:10.1038/nrn2719. PMC 2913577. PMID 19763105.
- Merfeld, Emily; Ben-Avi, Lily; Kennon, Mason; Cerveny, Kara L. (1 July 2017). "Potential mechanisms of Zika-linked microcephaly". Wiley Interdisciplinary Reviews: Developmental Biology. 6 (4): n/a. doi:10.1002/wdev.273. ISSN 1759-7692. PMC 5516183. PMID 28383800.
- Bullerdiek, J; Dotzauer, A; Bauer, I (2016). "The mitotic spindle: linking teratogenic effects of Zika virus with human genetics?". Molecular Cytogenetics. 9: 32. doi:10.1186/s13039-016-0240-1. PMC 4837584. PMID 27099632.
- Wang, A; Thurmond, S; Islas, L; Hui, K; Hai, R (22 March 2017). "Zika virus genome biology and molecular pathogenesis". Emerging Microbes & Infections. 6 (3): e13. doi:10.1038/emi.2016.141. PMC 5378920. PMID 28325921. Archived from the original on 4 April 2017.
- Gale, Jason (4 February 2016). "The Best Weapon for Fighting Zika? More Mosquitoes". Bloomberg. Archived from the original on 6 April 2017.
- Aliota, Matthew T.; Peinado, Stephen A.; Velez, Ivan Dario; Osorio, Jorge E. (2016). "The w Mel strain of Wolbachia Reduces Transmission of Zika virus by Aedes aegypti". Scientific Reports. 6: 28792. Bibcode:2016NatSR...628792A. doi:10.1038/srep28792. PMC 4929456. PMID 27364935. The wMel strain of Wolbachia Reduces Transmission of Zika virus by Aedes aegypti
- Flam, Faye (4 February 2016). "Fighting Zika Virus With Genetic Engineering". Bloomberg. Archived from the original on 6 June 2016.
- Viegas, Luciana (23 February 2016). "IAEA Helps Brazil Step up the Fight Against 'Zika' Mosquitoes". International Atomic Energy Agency. Archived from the original on 29 June 2016.
- Kelland, Kate (18 March 2016). "WHO backs trials of genetically modified mosquitoes to fight Zika". The Globe and Mail. Archived from the original on 18 March 2016. Retrieved 19 March 2016.
- Managing Zika in babies (CDC)