Wednesday, December 30, 2015

Zika virus and microcephaly

A surge in the number of infants born with tiny brains has led Brazil’s health ministry to warn pregnant women to take extreme measures to avoid mosquito bites, which may infect them with a recently arrived virus. Some prominent obstetricians in Brazil now advise women against becoming pregnant at all.
The increase in microcephaly — an incurable form of brain damage — has been blamed on an epidemic of the Zika virus, which was unknown in Latin America before this year.
A few Zika infections have been detected in the United States in returning travelers. Those imported cases “will likely increase and may result in local spread of the virus in some areas of the United States,” the Centers for Disease Control and Prevention warned recently.
The mosquito species that transmits Zika virus are common in Florida and along the Mexican border, but the pathogen has not yet been found in them.
More than 2,700 microcephalic babies have been born in Brazil this year, up from fewer than 150 in 2014, according to news media reports in Brazil. Though the increase is tentatively blamed on spreading Zika virus, some say the link is not clear.
“We don’t know if it’s only Zika or if it’s a combination of Zika, dengue and chikungunya,” said Dr. Marco Collovati, the founder of OrangeLife, a Brazilian diagnostics company that is working on a rapid test for the virus. “Maybe a woman was infected by dengue a year before, and now is pregnant and gets Zika.”
Microcephaly is often not detectable by ultrasound during pregnancy before the third trimester. Abortion is illegal in Brazil.
Zika fever emerged in Africa decades ago — it is named after the Ugandan forest where it was discovered in monkeys in 1947 — and has long circulated in Asia. The virus began appearing on South Pacific islands in 2007 and emerged in Brazil early this year, said Scott C. Weaver, the director of the Institute for Human Infections and Immunity at the University of Texas Medical Branch in Galveston.
Zika is from the same family of mosquito-borne viruses as dengue, chikungunya, West Nile and yellow fever, and the symptoms of infection — fever, rash and joint pain — are similar. Only a few top Brazilian laboratories can test for Zika, so a diagnosis is often made only by first eliminating other possibilities like dengue. There is no treatment.
The suspected connection between Zika and microcephaly emerged in the past few weeks. After an outbreak in French Polynesia in 2013, researchers have suspected that Zika also leads to Guillain-Barré syndrome in adults, in which muscle weakness may evolve into paralysis.
Because of El Niño this year, Brazil’s weather has been unusually hot and rainy, and it will probably grow hotter, with more mosquitoes before the Olympics begin this summer. “So as you can see, it’s a big, big mess,” Dr. Collovati said.
Courtesy of a colleague


  1. Gatherer D, Kohl A. Zika virus: a previously slow pandemic spreads rapidly through the Americas. J Gen Virol. 2015 Dec 18. doi: 10.1099/jgv.0.000381. [Epub ahead of print]


    Zika virus (Flaviviridae) is an emerging arbovirus. Spread by Aedes mosquitoes, it was first discovered in Uganda in 1947, and later in humans elsewhere in sub-Saharan Africa, arriving in south-east Asia at latest by mid-20th-century. In the 21st century, it spread across the Pacific Islands reaching South America around 2014. Since then it has spread rapidly northwards reaching Mexico in November 2015. Its clinical profile is that of a dengue-like febrile illness, but recently associations with Guillain-Barré syndrome and microcephaly have appeared. The final geographical range and ultimate clinical impact of Zika virus are still a matter for speculation.

  2. Authorities in Brazil have recently issued an unusual and unprecedented announcement to women: don’t get pregnant, at least not just yet. Amidst an intractable outbreak of the mosquito-borne Zika virus, public health authorities in Brazil are highly suspicious of an unusual surge of cases of microcephaly among newborn children.

    Much like the emerging Chikungunya virus, Zika virus was first identified in east Africa in the mid-twentieth century and has rapidly swept through Central and South America in the past year. For children and adults, the infection is relatively benign, causing a mild fever with rash, conjunctivitis or pink eye, and muscle and joint pain.

    For an unborn child, however, health authorities suspect that the virus may be responsible for causing premature death or serious congenital abnormalities, the most profound being microcephaly, a neurodevelopmental disorder that manifests itself in the form of a notably small cranium and incomplete brain development. Children with this rare condition face a reduced life expectancy and often have profound cognitive and developmental problems. Due to the severity of impairment in these children, they require long-term, specialized care for the entirety of their lives.

    Since it was first identified in May of this year, the Zika virus, first isolated in a rhesus monkey in Uganda’s Zika Forest, has infiltrated the mosquito population in Brazil. The total number of infections in Brazil is sketchy, but estimates range from half a million to over 1.3 million cases.

    As of December 22nd, there have been 2782 cases of microcephaly this year in children born to Brazilian women that report having symptoms of a Zika-like infection early in the first trimester. There have also been 80 cases of stillborns and premature neonatal deaths among pregnant women testing positive for Zika virus. These numbers represent an astonishing departure from the statistics for last year, in which only 150 cases of microcephalic babies were recorded in the country.

    The connection between the virus and whether it affects fetal development is still largely conjectural, however, and the mechanism of its pathology has yet to be worked out. No causative relationship between the two phenomena has yet to be established. In light of these findings, however, Brazilian physicians are recommending that women avoid becoming pregnant at least until the end of the rainy season, which encourages mosquito breeding and will begin in January and may last as long as May...

    Pregnant women must also take increased care to protect themselves from illness, as certain infectious diseases during the perinatal period can cross the placenta and infect the nascent central nervous system of the fetus, resulting in birth defects. These infections include toxoplasmosis, syphilis, rubella, cytomegalovirus and herpes. Such perinatal infections are very rare, responsible for only 2 to 3% of all congenital defects, but can be devastating to the healthy development of a fetus (2). Pending further research into the exact effects of the disease, Zika virus may soon join the ranks of this ignoble group of microbial pathogens.

    The CDC reports that they are unaware of any research that evinces an association between microcephaly and other viral infections spread by mosquitoes (3). This outbreak is frankly unexpected and unprecedented, if there is indeed a connection. The association between the two is under investigation and whether there is an ongoing public health emergency in Brazil remains to be determined.

  3. New ECDC risk assessment evaluates the possible link between the observed increase of congenital microcephaly in Brazil and Zika virus (ZIKV) infection and assesses the potential risks associated with ZIKV infection for travellers, the EU, and the EU Overseas Countries and Territories and Outermost Regions.

    There is currently only ecological evidence of an association between the two events, while a possible causative association cannot be ruled out; further investigations and studies are needed to understand the association and the possible role of other factors, states the ECDC risk assessment.

    In November the Brazilian Ministry of Health declared a public health emergency in relation to an unusual increase in the number of children born with microcephaly in 2015.

    The north-Brazilian state of Pernambuco has reported 141 cases of microcephaly in newborns in 2015, in comparison to an average of 10 cases per year from 2010–2014. A ten-fold increase in the incidence of microcephaly among newborns was observed in other north-eastern Brazilian states.

    As the increase is within nine months of the Zika emergence, the Ministry of Health of Brazil has suggested a possible relationship between the increase in microcephaly and the ongoing Zika outbreak. While investigations are still ongoing, the authorities issued specific recommendations for pregnant women relating to protection from mosquito bites: such as keeping doors and windows closed or screened, wearing trousers and long-sleeved shirts and using repellents.

    In comparison, in French Polynesia there was an increase of central nervous system malformations in foetuses and newborns following an epidemic of ZIKV infection: at least 17 such cases were reported during 2014–2015, coinciding with the Zika outbreaks on the French Polynesian islands, four tested women were found positive for flavivirus.

    Congenital microcephaly is a descriptive diagnosis for a neurodevelopmental disorder causing small head of the newborn. It can be caused by a variety of factors, such as genetic disorder, brain injury, consumption of teratogenic drugs, exposure to chemicals as well as transplacental infections.

    The involvement of ZIKV in microcephaly is not documented in the scientific literature, however, other Flavivirus infections are known to have the potential to cause premature birth, congenital defects and microcephaly.

  4. The case of Zika in a traveler recently returned from El Salvador was confirmed through investigations by Harris County, Texas, health officials and the Centers for Disease Control and Prevention (CDC). The case is expected to result in major new surveillance and vector-control initiatives.

    Peter Hotez, MD, dean of the National School of Tropical Medicine at Baylor College of Medicine, president of the Sabin Vaccine Institute, and Texas Children's Hospital Endowed Chair of Tropical Pediatrics, Houston, told Medscape Medical News, "There is a perfect storm brewing for Zika virus in the US. I was never worried that Ebola would take off here, but I am worried about Zika. We have 2 species of Aedes mosquitoes that can transmit Zika in our area. We also have high levels of poverty, resulting in people living without window screens and near discarded tires and other water-catching containers where the mosquitoes can breed."

    Dr Hotez said that Zika infection usually produces nonspecific, influenza-like symptoms in pregnant women, with the associated birth defects becoming apparent only 9 months later.

    "By that time, it is too late," Dr Hotez said. "This first case of Zika infection in Harris County is a wake-up call, a warning that we should immediately start implementing programs of active surveillance. As we move into the spring and summer months, if we start seeing cases among people who have never traveled outside of the country, we need to implement aggressive mosquito control measures as well as health advisories for people to implement personal protection measures."
    "My advice for travelers is to Prevent and Present: Prevent getting bitten by mosquitoes, and if you do develop symptoms, present yourself promptly for medical care. If you have symptoms, don't ignore them," Dr Shah said.

    Finally, Dr Hotez stressed that the confirmed case of Zika in Texas highlights the need to immediately deploy research support and resources to develop a vaccine against the virus.

    Heightened international concern about Zika was driven not by its relatively mild effect on infected adults, who typically recover in about a week, but by its devastating effect on babies in utero. In Brazil, cases of microcephaly, in which the brain does not develop fully before birth, surged from an average 150 per year to almost 4000 cases in 2015. Dr Regina Coeli, a pediatric infectologist at Oswaldo Cruz Hospital in Recife, the region worst affected in Brazil, told BBC World Service that a link between Zika and microcephaly was established when Zika was found in the amniotic fluid of two women and in the brain and heart of an affected infant.

    The fast-moving epidemic of Zika in Brazil led Brazilian health authorities to advise women to delay conception to reduce the risk of bearing children with devastating birth defects.

  5. The first case of brain damage linked to the Zika virus within the United States was reported on Friday in Hawaii.

    The Hawaii State Department of Health said that a baby born in an Oahu hospital with microcephaly — an unusually small head and brain — had been infected with the Zika virus, which is believed to have caused the same damage in thousands of babies in Brazil in recent months. The presence of the virus was confirmed by the Centers for Disease Control and Prevention.

    The child’s mother had lived in Brazil in May last year and probably was infected by a mosquito then, early in her pregnancy, the health department said. The virus presumably reached the embryo and damaged its developing brain.

    “We are saddened by the events that have affected this mother and her newborn,” Dr. Sarah Park, Hawaii’s state epidemiologist, said in a statement. “This case further emphasizes the importance of the C.D.C. travel recommendations released today.”

    Also on Friday, the C.D.C. recommended that pregnant women consider postponing travel to any countries or regions with active Zika virus transmission.

    As of Saturday, those included 17 Latin American and Caribbean countries and territories: Brazil, Colombia, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Saint Martin, Suriname, Venezuela and the Commonwealth of Puerto Rico. The list of countries with transmission has been steadily growing; on Saturday, Barbados reported its first cases.

    Women considering becoming pregnant were advised to consult doctors before going to Zika-infested areas, and all travelers headed to such areas were urged to take vigorous measures to avoid mosquito bites...

    The connection to microcephaly was not made until late last year in Brazil. The virus first appeared in the country in May, and epidemiologists estimate that more than 1.5 million Brazilians have been infected.

    In October, doctors in Pernambuco State noticed a surge in cases of microcephaly. Normally, about 150 cases of the birth defect are reported in Brazil each year. Since October, more than 3,500 have been reported there.

    It is also not known whether the virus alone causes microcephaly or if it happens only if the mother has a previous infection, such as with dengue virus.

    Dengue is unusual in that a first infection is rarely life-threatening, but a subsequent infection with a different strain can trigger dengue hemorrhagic fever, which can be fatal.

  6. The U.S. Centers for Disease Control and Prevention on Tuesday issued guidelines for doctors caring for pregnant women during the Zika outbreak, a mosquito-borne illness linked with microcephaly marked by unusually small head size and brain damage.

    The new guidelines urge doctors to ask their pregnant patients about their travel history to areas with Zika virus transmission.

    Women who had traveled to regions in which Zika virus is active and who report symptoms during or within two weeks of travel should be offered a test for Zika virus infection. Pregnant women who had no clinical symptoms associated with the infection such be offered an ultrasound to check the fetus' head size or check for calcium, two signs of microcephaly.

  7. Now a third virus, the Zika virus, has been a cause for concern. This virus, first described in Africa and Southeast Asia, appears to now be epidemic in Brazil. The Zika virus has also been reported in Mexico and no doubt is probably elsewhere in the same distribution in both the Northern and Southern Hemispheres, or certainly will be in short order. It's a flavivirus, much like dengue or yellow fever. It can cause fever, rash, joint pain, and conjunctivitis, but generally has not resulted in death or severe illness.

    However, it can be confusing because Zika represents a third virus that must be considered and which can be hard to distinguish on a clinical basis from the other two viruses. There has also been concern about an increased rate of birth defects in Brazil, specifically microcephaly, which might be caused by the Zika virus. The link isn't clear, but the possibility has created a lot of concern among pregnant women in that country.

    For US travelers, unfortunately, the dengue vaccine is not yet available. Therefore, mosquito avoidance is the only practical measure to prevent dengue. This nice handout from the Centers for Disease Control and Prevention (CDC)describes recommended mosquito avoidance maneuvers that should be followed as carefully as possible by anyone who is planning to travel to areas where they could acquire a mosquito-borne illness.

    The Zika virus is new diagnostically, with no easy tests. You have to contact your local health authorities to ship a sample to the CDC for polymerase chain reaction or antibody testing. But keep in mind that if you are evaluating a patient who has recently returned from Central or South America with a febrile illness, rash, and joint pains, maintain a suspicion for Zika virus, along with chikungunya and dengue.

  8. Two pregnant women from Illinois contracted the mosquito-borne Zika virus while traveling in Honduras and Haiti, the Illinois health department announced Tuesday.

    Zika has been linked to potentially fatal birth defects in Brazil, where authorities are investigating a spike in newborns with microcephaly, or underdeveloped brains. The virus is circulating via mosquitoes in the Caribbean, Central America and South America.

    The women are being monitored by doctors. The virus is not spread from person to person.

    “There is virtually no risk to Illinois residents since you cannot contract Zika virus from another person, but only through the bite of an infected mosquito,” said Dr. Nirav Shah, the health department’s director, in a statement. “But since this is a time of year when people travel to warmer climates and countries where Zika virus is found, we are urging residents, especially pregnant women, to take preventive measures when traveling in affected countries and check health travel advisories.”

    The Centers for Disease Control and Prevention has issued a health warning for travel to countries where the Zika virus is circulating including Brazil, Colombia, El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Suriname and Venezuela. The warning also includes Puerto Rico. Pregnant women are advised not to travel to those locations.

    Health officials in Jamaica have advised women to delay pregnancy for six to 12 months.

    The Zika virus usually only causes mild symptoms including fever, rash, joint pain and eye redness. Since October, Brazil has reported more than 3,500 cases of microcephaly in infants compared to less than 150 in all of 2014. Many of the mothers are believed to have contracted the virus while pregnant. The Zika virus was found in the placentas from two women who miscarried and the brains of two newborns who died. The newborns had microcephaly.

    Researchers in Brazil are working on a vaccine to prevent Zika but there is no treatment available.

    Hawaii health officials say a baby recently born with microcephaly at an Oahu hospital was infected with the Zika virus in utero, according to The Associated Press. In reporting the laboratory confirmation from the CDC, the Hawaii health department said the child’s mother probably had a Zika infection while living in Brazil during the spring.

  9. Pregnant women in any trimester should consider postponing travel to 14 countries and territories in South and Central America and the Caribbean where mosquitos are spreading the Zika virus, the Centers for Disease Control and Prevention (CDC) announced tonight. Viral infection in pregnant women has been associated with microcephaly in infants.

    In what it calls a level 2 travel alert, the CDC also advises women who are thinking about becoming pregnant to consult with their physician before traveling to these areas, and if they do, follow strict precautions to avoid mosquito bites. Safeguards include wearing long-sleeve shirts and long pants and using insect repellent.

    The 14 countries and territories covered by the travel alert are Brazil, Colombia, El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Suriname, Venezuela, and the Commonwealth of Puerto Rico.

    Lyle Petersen, MD, director of the CDC's Division of Vector-Borne Diseases, told reporters at a 7 PM ET briefing that the travel alert couldn't wait until Monday.

    "We believe this is a fairly serious problem," said Dr Petersen. "Because there's growing evidence of a link between Zika and microcephaly, we thought it was important to warn people as soon as possible."

    Babies with microcephaly have a smaller-than-expected head. They often have smaller brains as well that may not have developed properly. Problems associated with microcephaly, which include seizures, developmental delays, intellectual and motor disabilities, and hearing loss can range from mild to life-threatening.

    Microcephaly aside, the Zika virus normally does not cause illness that requires hospitalization or leads to fatalities. Roughly one in five people infected with the virus will develop symptoms such as fever, rash, joint pain, and conjunctivitis. The symptoms usually are mild and last a few days to a week. There is no vaccine to prevent Zika, or medicine to treat it.

    Of the 14 countries and territories cited in the travel alert, Brazil troubles the CDC the most. The agency said Brazilian public health authorities have identified 3500 cases of microcephaly, some severe and fatal, between October 2015 and January 2016.

    Cynthia Moore, MD, PhD, director of the agency’s Division of Birth Defects and Developmental Disabilities, told reporters tonight that this number represented a definite but unquantified increase over the normal incidence of microcephaly in Brazil. The baseline for the condition there, Dr Moore said, is hard to determine. However, even half of the reported cases "would be quite a large increase."

    Brazilian health authorities provided the CDC with samples from two pregnancies that ended in miscarriages, and from two infants with microcephaly who died soon after birth. All four mothers said they had experienced Zika symptoms. CDC tests showed that the Zika virus was in the brain of the two full-term infants, and a genetic sequence analysis showed that the virus in all four cases matched that of the Zika virus circulating in Brazil.

  10. The Centers for Disease Control and Prevention (CDC) issued interim guidance today for obstetricians and other healthcare providers caring for pregnant women returning to the United States from areas affected by the Zika virus.

    The new guidance, published online today in Morbidity and Mortality Weekly Report, follows a travel alert issued by the agency late on Friday. In that advisory, the CDC advised women who are or might become pregnant not to travel to 14 countries and territories in Central and South America and the Caribbean where the Zika virus is spreading.

    Working in consultation with the American Congress of Obstetricians and Gynecologists and the Society for Maternal Fetal-Medicine, CDC advised clinicians to ask all pregnant women about recent travel to areas where Zika virus transmission is ongoing. Those who report such travel and develop fever, rash, muscle aches, or conjunctivitis during or within 2 weeks of travel should be tested for Zika virus infection, and positive tests for Zika should be reported to the appropriate local or state health department.

    Maternal serum from symptomatic women can be tested using reverse-transcription-polymerase chain reaction (RT-PCR) within 1 week of symptom onset. Antibody testing is not recommended 4 or more days after symptom onset, as there can be cross-reactivity to other flaviviruses (eg, dengue or yellow fever). Amniotic fluid can also be tested using RT-PCR, but the sensitivity and specificity are unknown at this time.

    The agency notes that no test is currently commercially available, but testing can be done at the CDC and several state departments of health. Detailed instructions on Zika clinical evaluation and on Zika diagnostic testing, including detailed instructions for preparing and sending specimens, are provided in the website.

    The CDC guidance recommends that clinicians who care for Zika-positive pregnant women should consider scheduling regular ultrasounds to monitor the growth of the fetus, as Zika has been linked to microcephaly.

    There is as yet no effective antiviral treatment for Zika. CDC recommends symptomatic treatment, including acetaminophen for pregnant women who have fever.

    The first confirmed case of Zika-related microcephaly in the US was reported this week and involved a mother who had lived in Brazil in May 2015 before moving to Hawaii.

    In addition, public health officials have recently confirmed several cases of Zika in adults in the continental United States, including a woman in Harris County, Texas, who had travelled to El Salvador. There were also three cases confirmed in Florida, two in Miami-Dade County, in residents who had traveled to Colombia in December, and one in a Hillsborough County resident who had traveled to Venezuela in December.

  11. Health officials in Arkansas and Virginia confirmed Tuesday that residents of those states had tested positive for the mosquito-borne Zika virus.

    The Virginia Department of Health said an adult resident of the state had recently traveled to a country where the Zika virus transmission was ongoing. The department didn’t specify where the person traveled, nor did it clarify his or her gender or age. Health officials confirmed in a statement that other residents were not at risk of catching the virus from the infected person...

    Earlier Tuesday, the Arkansas Department of Health confirmed that an individual who recently traveled outside of the United States had also tested positive for the virus, which is carried by the Aedes aegypti mosquito. The department said the resident has a mild case of Zika, but it would not confirm the individual’s age or gender. The individual traveled to the Central America-Caribbean region, but officials did not specify which country...

    The move comes as Puerto Rico also reported a jump in the number of confirmed cases from one to 19. None of the cases include pregnant women, but the country is testing more than 200 other potential cases that have tested negative for dengue and chikungunya, two other viruses the Aedes aegypti mosquito carries. Puerto Rico epidemiologist Brenda Rivera said the majority of cases are in the island’s southeast region, and many of the victims are elderly...

    In Colombia, officials said 16,490 people are infected with the disease, including 1,090 pregnant women. The increase in cases comes as Colombian President Juan Manuel Santa said officials expect to see 600,000 cases of Zika this year. The rise has prompted the country’s authorities, as well as those in El Salvador, to advise women against getting pregnant for anywhere up to two years...

    In Mexico, where there are 18 confirmed cases of Zika, officials said there is currently “no justification” for asking women to delay pregnancy.

  12. A Centers for Disease Control and Prevention (CDC) official said today that "limited outbreaks" of Zika infections are expected in the US, but certain factors may limit the spread of the disease in the states.

    Such is not the case in the Americas, though. In a separate briefing earlier today, Margaret Chan, MD, director-general of the World Health Organization (WHO), said, "last year the virus was detected in the Americas, where it is now spreading explosively. As of today, cases have been reported in 23 countries and territories in the region. The level of alarm is extremely high."

    Over the next 12 months, she said, as many as 4 million people in the Americas could be infected by the virus.

    The Aedes aegypti mosquito — which is responsible for transmitting the virus — is common in some parts of the US, particularly the South. Thus it is possible that the US will have limited outbreaks of Zika virus infection, most likely in the southern states, Anne Schuchat, MD, principal deputy director of the CDC, said in a press briefing.

    Urban areas in the US are not as densely populated as some of those in Central and South America, and air conditioning is more widely used in the US. In addition, the US has more widespread mosquito control measures in place. These factors may help limit the disease's spread here, she explained.

    "All of the continental US cases to date have been in people who have travelled to a country where mosquitos carrying Zika virus are circulating. We have not yet seen local transmission of Zika in the continental US," Dr Schuchat said...

    The CDC is also working with public health officials in Brazil to determine whether there is a connection between Zika infection and Guillain-Barré, she said.

    In the US, Dr Schuchat said, 31 people in 11 states and Washington, DC, have been infected with the virus (she did not say how many of them were pregnant women).

    Zika infections have been confirmed in more than 20 countries in South America and Central America, and a limited number of cases have been reported in Puerto Rico and the US Virgin Islands, she said. "The virus is spreading throughout the Americas and we expect more countries to be affected."

    In the Americas, the WHO's Dr Chan said, "the possible links [microcephaly]…have rapidly changed the risk profile of Zika from a mild threat to one of alarming proportions. The increased incidence of microcephaly is particularly alarming as it places a heartbreaking burden on families and communities."

    Four factors are particularly concerning to the WHO, she explained: the potential for birth malformations and neurological sequelae, the potential for international spread because of the mosquito, the lack of immunity in newly infected communities, and the lack of a vaccine or treatments for the disease.

  13. Texas health officials reported the first case of sexual transmission of the Zika virus in the USA on Tuesday.

    The patient contracted the virus from a sexual partner who was ill with Zika. The sexual partner became infected while traveling to Venezuela, which has a Zika outbreak, the Dallas County Health and Human Services said.

    Although scientists have known for some time that Zika can be transmitted through sex, the vast majority of cases are spread through the bite of infected mosquitoes, much like malaria or West Nile virus.

    “Now that we know Zika virus can be transmitted through sex, this increases our awareness campaign in educating the public about protecting themselves and others,” said Zachary Thompson, director of the Dallas County health department. "Next to abstinence, condoms are the best prevention method against any sexually transmitted infections.”...

    Although more than 30 Americans have been diagnosed with Zika, these have largely been travel-related cases, which pose a relatively low risk for spreading. The continental USA is not considered to have a Zika outbreak because the virus has not become entrenched in the mosquitoes that cause the illness.

    Zika is spreading among mosquitoes and residents of Puerto Rico and the U.S. Virgin Islands, as well as American Samoa.

  14. The effects of the Zika virus outbreak are already being felt in the U.S. as the American Red Cross announced new guidelines to blood donation policy due to the virus' rapid spread.

    The American Red Cross, the largest blood collection organization in the nation, announced today that it is asking people to defer donating blood for 28 days if they have been in any country with Zika infection.

    The virus is primarily spread through mosquito infection, though isolated cases have been reported where it spread through blood transfusion or sexual contact. The news comes as the U.S. Food and Drug Administration considers changing its guidelines around blood donation due to the Zika virus.

    “The American Red Cross is dedicated to providing the safest, most reliable blood products possible to patients in need," said Dr. Susan Stramer, vice president of scientific affairs at the American Red Cross. "We are closely monitoring the spread of Zika virus."

    Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said during a news conference last week that the FDA is looking into changing its policy, which would affect all blood donations in the U.S.

    "The FDA is looking at the issue of blood supply, blood donors and travelers," Fauci said. "We know it’s in the blood stream very briefly, most people have cleared the bloodstream of the virus after about a week."

    An FDA spokeswoman confirmed to ABC News today that the agency is working with the U.S. Centers for Disease Control and Prevention as the agency considers changing the guidelines for blood donation.

    The United Kingdom and Canada have already implemented changes to their blood donation policies in the face of the Zika virus outbreak. U.K. officials are asking prospective blood donors to wait 28 days after returning from a country with Zika virus transmission, while Canadian officials are asking potential donors to wait one month.

  15. Congenital Zika Infection and Microcephaly

    What is the link between Zika virus in Brazil and the high numbers of infants born there with microcephaly?

    Zika virus infections have been confirmed in several infants with microcephaly from Brazil. The time frame and geographic location of reports of infants with microcephaly coincides with the outbreak of Zika virus infections in Brazil. The baseline prevalence of congenital microcephaly is difficult to determine because of underreporting, and the inconsistency of clinical criteria used to define microcephaly. Although population-based estimates of congenital microcephaly in Brazil vary, the number of infants with microcephaly currently being reported in Brazil is greater than would be expected.

    What birth defects have been reported in in infants with confirmed Zika virus infection?

    Brain abnormalities reported in infants with microcephaly and laboratory-confirmed congenital Zika infection include microcephaly and disrupted brain growth. Some infants with possible Zika virus infection have been found to have intracranial calcifications and abnormal eye findings. It is not known if Zika virus infection caused any of these abnormalities.

    What birth defects have been reported in infants with suspected Zika virus infection?

    A report of 35 infants with microcephaly who were born during an outbreak of Zika virus infection in Brazil in 2015 described the following brain abnormalities: intracranial calcifications, ventriculomegaly, and neuronal migration disorders (lissencephaly and pachygyria). Other anomalies included congenital contractures and clubfoot. An important distinction is that neither these infants nor their mothers had laboratory-confirmed Zika virus; however, most of the mothers (~75%) reported symptoms consistent with Zika virus. (continued)

  16. (continued) Which newborns should be tested for Zika virus infection?

    Testing for Zika virus infection is recommended for infants born to women who traveled to or resided in an area with ongoing Zika virus transmission during pregnancy who were 1) diagnosed with microcephaly or intracranial calcifications detected prenatally or at birth, or 2) who have mothers with positive or inconclusive test results for Zika virus infection.

    How are infants diagnosed with Zika virus infection?

    Zika virus infection can be diagnosed by performing reverse transcriptase-polymerase chain reaction (RT-PCR) on infant serum. Serology assays can also be used to detect Zika virus-specific IgM and neutralizing antibodies. However, since it has not been established which test is most reliable for a diagnosis in infants, RT-PCR and IgM tests should both be performed. Plaque-reduction neutralization testing (PRNT) can also be performed to measure virus-specific neutralizing antibodies and differentiate from other flaviviruses.

    If Zika virus testing of a newborn is indicated, how is the test ordered?

    There are no commercially available tests for Zika virus. Zika virus testing is performed at the CDC Arbovirus Diagnostic Laboratory and at some state and territorial health departments. Healthcare providers should contact their state and local health department to facilitate testing. See the Diagnostic Testing webpage for information on how to obtain Zika testing.

    If Zika virus testing of a newborn is indicated, what specimens are recommended?

    Zika virus RT-PCR and serology assays can be performed on infant serum or serum or plasma collected from the umbilical cord. If cerebrospinal fluid (CSF) specimens are available, Zika virus RT-PCR should be performed; however, CSF specimens should not be collected for the sole purpose of Zika virus testing. Other specimens that can be tested include the placenta and the umbilical cord. Histopathologic examination and immunohistochemical staining can be performed. Zika virus RT-PCR on fixed and frozen tissue should also be considered.

    Should healthcare providers report infants with positive or inconclusive Zika virus test results?

    Healthcare providers should report positive or inconclusive results to their state or territorial health department. As an arboviral disease, Zika virus disease is a nationally notifiable condition.

    What should healthcare providers do to evaluate infants with positive or inconclusive Zika virus test results?

    A thorough physical examination should be performed, including careful measurement of the head circumference, length, weight, and assessment of gestational age. Cranial ultrasound is recommended unless it was performed as part of prenatal screening in the third trimester and clearly showed no abnormalities of the brain. Ophthalmologic evaluation is recommended as well as repeat hearing screen at six months of age. Continued evaluation of developmental characteristics and milestones, including head circumference, is recommended through the first year of life.

    If a mother had Zika virus infection during pregnancy but the newborn tests negative for Zika virus, what is recommended for additional follow-up?

    If the newborn does not have abnormal findings on examination, the infant should receive routine pediatric care including measurement of growth and development, and appropriate evaluation and follow-up for any clinical findings that arise. If the newborn has abnormal findings on examination, diagnostic testing for other causes of the newborn's conditions should be performed including testing for other congenital viral infections if indicated.

  17. Rapidly mounting public health concerns about the spread of Zika virus have physicians debating whether the 2016 Summer Olympics in Rio de Janeiro, Brazil should be canceled.

    “If we are looking at it just as a public health question, probably cancelling would be the best thing,” said Marcus Sandling, MD, an infectious disease fellow at the Drexel University College of Medicine in Philadelphia, PA.

    But in the real world, he added, that is not likely, since Brazil has spent a great deal of time and money getting ready for the event. “There’s been so much planning,” said Sandling.

    At New York University Langone Medical Center, bioethicists have argued that it would be irresponsible not to move the games, but agree that will not be a popular decision.

    Athletes have trained for years to be there, and as with any Olympic Games, this one could be an individual athlete’s best or only chance to compete and do well.

    Also, Sandling said, "It's not like having the Olympics in West Africa at the height of the ebola epidemic."...

    Sandling noted that the initial illness is usually mild. But the big problem is the threat it apparently poses to pregnant women, and to women and their male partners who could contract the virus, not know it, and spread it to a fetus.

    Sandling said his advice for potential parents would be to use condoms for at least six weeks after one partner has been to a country where Zika warning are in effect.

    A larger problem is that as the virus migrates, it could become endemic anywhere that mosquitos live year-round, including Florida.

    That would make it much harder to prevent transmission, since any woman who might become pregnant would be at risk all year.

    That is already a problem in countries where the virus is endemic, particularly in many Latin American countries where birth control is hard to obtain, Sandling noted.

    “The question of what to do about that is beyond my pay grade,” he said.

    Vaccines are in the works, but will take years. Genetically altering mosquitoes so they can’t reproduce is also a possibility.

    - See more at:

  18. Among a cohort of 35 infants with microcephaly born during August–October 2015 in eight of Brazil’s 26 states and reported to the registry, the mothers of all 35 had lived in or visited Zika virus-affected areas during pregnancy, 25 (71%) infants had severe microcephaly (head circumference >3 SD below the mean for sex and gestational age), 17 (49%) had at least one neurologic abnormality, and among 27 infants who had neuroimaging studies, all had abnormalities. Tests for other congenital infections were negative. All infants had a lumbar puncture as part of the evaluation and cerebrospinal fluid (CSF) samples were sent to a reference laboratory in Brazil for Zika virus testing; results are not yet available. Further studies are needed to confirm the association of microcephaly with Zika virus infection during pregnancy and to understand any other adverse pregnancy outcomes associated with Zika virus infection. Pregnant women in Zika virus-affected areas should protect themselves from mosquito bites by using air conditioning, screens, or nets when indoors, wearing long sleeves and pants, using permethrin-treated clothing and gear, and using insect repellents when outdoors. Pregnant and lactating women can use all U.S. Environmental Protection Agency (EPA)-registered insect repellents according to the product label...

    The MoH[Ministry of Health]rapidly established a microcephaly registry in Brazil. On November 17, 2015, the MoH reported the increase in microcephaly cases, and possible association of microcephaly with Zika virus infection during pregnancy on its website; and the Pan American Health Organization (PAHO) published an alert regarding the increase in occurrence of microcephaly in Brazil. In December, PAHO reported the identification of Zika virus RNA by reverse transcription-polymerase chain reaction (RT-PCR) in amniotic fluid samples from two pregnant women whose fetuses were found to have microcephaly by prenatal ultrasound, and the identification of Zika virus RNA from multiple body tissues, including the brain, of an infant with microcephaly who died in the immediate neonatal period.(continued)

  19. (continued)Although 37 infants with microcephaly were evaluated, only 35 cases are included in this report. Two infants with microcephaly were excluded from the original cohort of 37 babies: one had autosomal recessive microcephaly with sibship recurrence, and one had cytomegalovirus infection. Overall, 26 (74%) mothers of infants with microcephaly reported a rash during the first (n = 21) or second (5) trimester. Residence in or travel during pregnancy to areas where Zika virus is circulating was confirmed for all mothers, including women without a history of rash. Twenty-five (74%) infants had severe microcephaly (head circumference >3 SD below the mean for gestational age). Computed tomography scans and transfontanellar cranial ultrasounds showed a consistent pattern of widespread brain calcifications, mainly in the periventricular, parenchymal, and thalamic areas, and in the basal ganglia, and was associated in approximately one third of cases with evidence of cell migration abnormalities (e.g., lissencephaly, pachygyria). Ventricular enlargement secondary to cortical/subcortical atrophy was also frequently reported. Excessive and redundant scalp skin, reported in 11 (31%) cases, also suggests acute intrauterine brain injury, indicating and arrest in cerebral growth, but not in growth of scalp skin. Four (11%) infants had arthrogryposis (congenital contractures), indicative of central or peripheral nervous system involvement. All 35 infants in the cohort tested negative for syphilis, toxoplasmosis, rubella, cytomegalovirus, and herpes simplex virus infections. CSF samples from all infants enrolled in the cohort were sent to a reference laboratory in Brazil for Zika virus testing; the results are not yet available...

    CDC recently tested samples from two pregnancies that ended in miscarriage and from two infants with microcephaly who died shortly after birth. All four cases were from Brazil and were positive for Zika virus infection, indicating that the infants had become infected during pregnancy. Zika virus was present in the brain of the full term infants, and genetic sequence analyses show that the virus in all four cases was the same as the Zika virus strain currently circulating in Brazil. All four mothers reported having experienced a febrile rash illness during their pregnancies.

    This findings in this report are subject to at least four limitations. First, historical birth prevalence of microcephaly in Brazil, approximately 0.5 cases per 10,000 live births, calculated from birth certificates, was lower than expected estimates of 1–2 cases per 10,000 live births, which might indicate general underascertainment of microcephaly in Brazil. However, during the second half of 2015 alone, >3,000 suspected cases of microcephaly (approximately 20 cases per 10,000 live births) were reported to the MoH through the special notification protocol, suggesting a sharp increase in birth prevalence, although the special notification protocol might have also increased case reporting.

  20. Spread of the pandemic Zika virus lineage is associated with NS1 codon usage adaptation in humans

    Caio Cesar de Melo Freire, Atila Iamarino, Daniel Ferreira de Lima Neto, Amadou Alpha Sall, Paolo Marinho de Andrade Zanotto



    Zika virus (ZIKV) infections were more common in the zoonotic cycle until the end of the 20th century with few human cases in Africa and Southeastern Asia. Recently, the Asian lineage of ZIKV is spreading along human-to-human chains of transmission in the Pacific Islands and in South America. To better understand its recent urban expansion, we compared genetic differences among the lineages. Herein we show that the recent Asian lineage spread is associated with significant NS1 codon usage adaptation to human housekeeping genes, which could facilitate viral replication and increase viral titers. These findings were supported by a significant correlation with growth in Malthusian fitness. Furthermore, we predicted several epitopes in the NS1 protein that are shared between ZIKV and Dengue. Our results imply in a significant dependence of the recent human ZIKV spread on NS1 translational selection. (PDF of article is accessible)
    Courtesy of:

  21. Complications and long-term impacts of the Zika virus are unknown, but three deaths have just been tied to the disease.

    The first Zika cases in Venezuela were reported in November 2015. The state-run newspaper, Correo Del Orinoco, reported that there have been 319 confirmed Zika virus cases in the nation as of February 11.

    President Nicolas Maduro said that three people died in Venezuela from complications associated with the Zika Virus, CNN reported on February 12. In addition, 68 patients have been hospitalized due to problems caused by the mosquito-borne illness...

    It was on February 1 that the World Health Organization (WHO) declared an international public health emergency for Zika. The next day, Dallas officials confirmed the first sexually transmitted case, which was also the first locally transmitted case in the United States. Shortly after that, Florida governor declared a public health emergency for multiple diagnoses in the Sunshine State. In the wake of all of this, President Obama announced a proposal to Congress for $1.8 billion to combat the disease.

    Thirty countries and regions currently have active Zika transmission, according to the Centers for Disease Control and Prevention (CDC):
    •The Americas: Barbados, Bolivia, Brazil, Colombia, Costa Rica, Curacao, Dominican Republic, Ecuador, El Salvador, French Guiana, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Jamaica, Martinique, Mexico, Nicaragua, Panama, Paraguay, Puerto Rico, Saint Martin, Suriname, US Virgin Islands, and Venezuela
    •Oceania/Pacific Islands: American Samoa, Samoa, and Tonga
    •Africa: Cape Verde

    Zika is especially dangerous to pregnant women. The virus is strongly believed to cause microcephaly – a condition where infants are born with smaller-than-normal brain and heads, which is then linked with vision-threatening problems. Officials have advised women in certain countries to avoid pregnancy for up to two years.

    In more bad news about Zika, the CDC reported that two miscarriages and two newborn deaths occurred as a result of the virus. All four of the mothers had clinical signs of the disease during the first trimester, but not at the time of miscarriage or delivery. Also, a 68-year-old man who was infected with Zika in 2014 had traces of the virus in his semen both 27 and 62 days after the initial signs of symptoms.

    - See more at:

  22. Mlakar J, Korva M, Tul N, Popović M, Poljšak-Prijatelj M, Mraz J, Kolenc M, Resman Rus K, Vesnaver Vipotnik T, Fabjan Vodušek V, Vizjak A, Pižem J, Petrovec M, Avšič Županc T. Zika Virus Associated with Microcephaly. N Engl J Med. 2016 Feb 10. [Epub ahead of print]


    A widespread epidemic of Zika virus (ZIKV) infection was reported in 2015 in South and Central America and the Caribbean. A major concern associated with this infection is the apparent increased incidence of microcephaly in fetuses born to mothers infected with ZIKV. In this report, we describe the case of an expectant mother who had a febrile illness with rash at the end of the first trimester of pregnancy while she was living in Brazil. Ultrasonography performed at 29 weeks of gestation revealed microcephaly with calcifications in the fetal brain and placenta. After the mother requested termination of the pregnancy, a fetal autopsy was performed. Micrencephaly (an abnormally small brain) was observed, with almost complete agyria, hydrocephalus, and multifocal dystrophic calcifications in the cortex and subcortical white matter, with associated cortical displacement and mild focal inflammation. ZIKV was found in the fetal brain tissue on reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay, with consistent findings on electron microscopy. The complete genome of ZIKV was recovered from the fetal brain.

    Courtesy of:

  23. de Paula Freitas B, de Oliveira Dias JR, Prazeres J, Sacramento GA, Ko AI, Maia M, Belfort R Jr. Ocular Findings in Infants With Microcephaly Associated With Presumed Zika Virus Congenital Infection in Salvador, Brazil. JAMA Ophthalmol. 2016 Feb 9. doi:10.1001/jamaophthalmol.2016.0267. [Epub ahead of print]



    The Zika virus (ZIKV) has rapidly reached epidemic proportions, especially in northeastern Brazil, and has rapidly spread to other parts of the Americas. A recent increase in the prevalence of microcephaly in newborn infants and vision-threatening findings in these infants is likely associated with the rapid spread of ZIKV.


    To evaluate the ocular findings in infants with microcephaly associated with presumed intrauterine ZIKV infection in Salvador, Bahia, Brazil.

    Design, Setting, and Participants:

    Case series at a tertiary hospital. Twenty-nine infants with microcephaly (defined by a cephalic circumference of ≤32 cm) with a presumed diagnosis of congenital ZIKV were recruited through an active search and referrals from other hospitals and health unities. The study was conducted between December 1 and December 21, 2015.


    All infants and mothers underwent systemic and ophthalmic examinations from December 1 through December 21, 2015, in the Roberto Santos General Hospital, Salvador, Brazil. Anterior segment and retinal, choroidal, and optic nerve abnormalities were documented using a wide-field digital imaging system. The differential diagnosis included toxoplasmosis, rubella, cytomegalovirus, herpes simplex virus, syphilis, and human immunodeficiency virus, which were ruled out through serologic and clinical examinations.

    Main Outcomes and Measures:

    Ocular abnormalities associated with ZIKV.


    Twenty-three of 29 mothers (79.3%) reported suspected ZIKV infection signs and symptoms during pregnancy, 18 in the first trimester, 4 in the second trimester, and 1 in the third trimester. Of the 29 infants (58 eyes) examined (18 [62.1%] female), ocular abnormalities were present in 17 eyes (29.3%) of 10 children (34.5%). Bilateral findings were found in 7 of 10 patients presenting with ocular lesions, the most common of which were focal pigment mottling of the retina and chorioretinal atrophy in 11 of the 17 eyes with abnormalities (64.7%), followed by optic nerve abnormalities in 8 eyes (47.1%), bilateral iris coloboma in 1 patient (2 eyes [11.8%]), and lens subluxation in 1 eye (5.9%).

    Conclusions and Relevance:

    Congenital infection due to presumed ZIKV exposure is associated with vision-threatening findings, which include bilateral macular and perimacular lesions as well as optic nerve abnormalities in most cases.

  24. Ventura CV, Maia M, Ventura BV, Linden VV, Araújo EB, Ramos RC, Rocha MA, Carvalho MD, Belfort R Jr, Ventura LO. Ophthalmological findings in infants with microcephaly and presumable intra-uterus Zika virus infection. Arq Bras Oftalmol.2016 Feb;79(1):1-3.



    In 2015, a twenty-fold increase in the prevalence of microcephaly in Brazil was reported, and the Ministry of Health associated this abnormal prevalence with the maternal-fetal Zika virus (ZIKV) transmission.


    We assessed the ophthalmological findings of ten mothers and their infants that had been clinically diagnosed with ZIKV-related microcephaly and presented ocular abnormalities, born from May to December 2015.


    Seven mothers (70.0%) referred symptoms during pregnancy (malaise, rash and arthralgia), of which six (85.7%) were in the first trimester. At the time of exam, no ophthalmological abnormalities were identified in the mothers and they did not report ocular symptoms during pregnancy. Serology was negative in all infants for Toxoplasmosis, Rubella, Cytomegalovirus, Syphilis and Human Immunodeficiency Viruses. Ocular findings included macular alterations (gross pigment mottling and/or chorioretinal atrophy) in fifteen eyes (75.0%), and optic nerve abnormalities (hypoplasia with double-ring sign, pallor, and/or increased cup-to-disk ratio) in nine eyes (45.0%).


    Patients presented normal anterior segment and important macular and optic nerve abnormalities. Further studies will assess the visual significance of these alterations.

  25. Rolling Stones guitarist Ronnie Wood said Monday that his pregnant wife is not on the band's tour of Latin America in order to avoid exposure to the Zika virus.

    The musician tweeted that Sally Wood was not accompanying him on the band's tour of Latin America because the Zika virus and excessive flying are "too dangerous" for their unborn twin daughters.

    In a tweet right before that one, Wood made clear that his wife had not "been sent home" from the tour.

  26. Federal and state health officials are investigating 14 new reports of potential sexual transmission of the Zika virus, including several cases involving pregnant women, the Centers for Disease Control and Prevention disclosed Tuesday.

    In at least two of these U.S. cases, infection was confirmed in women whose only known risk factor was sexual contact with an ill male partner who recently had returned from one of the approximately three dozen countries where the virus has now spread. Four other women have tested positive for Zika in preliminary lab tests but are awaiting final confirmation. The CDC said the eight other cases remain under investigation.

    "We were surprised, given the numbers actively being investigated," said CDC Deputy Director Anne Schuchat. "We were concerned enough that we thought it was important to share that information. ... We are seeing more than we expected to see."

    Even if all the cases are not ultimately confirmed, Schuchat said, the growing number of reports suggests that sexual transmission of the virus is more possible than researchers previously had realized. That development could further complicate efforts to stop the spread of Zika, as well as force couples to contemplate abstaining from sex or using condoms to prevent transmission, particularly when a woman is pregnant.

    Officials said the same scenario played out in most, if not all, of the suspected cases: A man who had traveled to a Zika-affected area returned home to the United States and had sex with a female partner, who soon began to display symptoms consistent with the virus. The agency did not identify the states where these cases are being pursued.

    "Like previously reported cases of sexual transmission, these cases involve possible transmission of the virus from men to their sex partners," the CDC wrote in announcing the new cases. "At this time, there is no evidence that women can transmit Zika virus to their sex partners; however, more research is needed to understand this issue."

    Schuchat said that in each of the current cases under investigation, the man had displayed symptoms of Zika, such as fever, rash or joint pain -- a notable detail given that as many as 80 percent of people infected never experience symptoms. She said researchers still aren't sure whether only men who have symptoms can transmit the virus to their partners, but it's a possibility scientists are exploring.

    Years earlier, in 2008, a Colorado researcher named Brian Foy came to the conclusion that he had acquired Zika while traveling in Senegal and had later sexually transmitted the disease to his wife, who had not left Colorado. He wrote about the experience in an academic article in 2011.

    "It was clear that she got Zika and I had Zika, and so we made the connection that I certainly did transfer it to her," Foy told The Washington Post recently.

  27. Florida health officials said Wednesday that three pregnant women in the state had tested positive for the Zika virus.

    Secretary of Health Dr. John Armstrong announced the cases Wednesday in his daily Zika update. A news release says all three cases are believed to be travel-related. Officials weren't identifying the counties where the pregnant women were diagnosed.

    In response to the news, Florida Gov. Rick Scott said he had requested 250 more Zika antibody tests from the Centers for Disease Control and Prevention.

    Zika is rapidly spreading through Latin America, and scientists are studying the virus' possible connection to babies born with unusually small heads. The birth defect called microcephaly can signal underlying brain damage.

    A total of 32 cases have now been reported in Florida. Miami-Dade County leads the state with 11 reported cases. All the cases so far have been travel-related, but the virus can be spread by bites from mosquitoes that are common in Florida.

    Florida health officials told the Miami Herald that only three of the 32 confirmed cases are still showing symptoms of the virus. Those symptoms include a fever, rash, joint pain and red eyes and can last between a few days and one week.

    There is no vaccine agaisnt the virus, which remains in a person's bloodstream for between 10 days and two weeks.