MedicalResearch.com Interview with: Mary E. Wilson, MD Visiting Professor of Epidemiology and Biostatistics School of Medicine, University of California San Francisco Adjunct Professor of Global Health and Population Harvard T.H. Chan School of Public Health Boston, Massachusetts  Medical Research: What is the background for this study? Response: Zika virus infections are spreading explosively in the Americas. This flavivirus infection, spread by Aedes mosquitoes, is new to the Americas, so the majority clinicians have little knowledge of the infection and its potential complications. The country most affected so far is Brazil, where more than a million infections have been reported in less than a year. Infection has also spread to at least 20 other countries in the Americas (the Caribbean, Mexico, Central and South America). Prior to 2007 Zika virus was known to cause infections only in Africa and Asia. Since then, it has spread and caused epidemics in Micronesia, French Polynesia, Easter Island, and since 2015 in Brazil. Most of the movement of the virus from one region to another is via travelers who are infected and then are bitten by mosquitoes in a new region. In Brazil an increase in cases of infants born with microcephaly (small head) has been noted coincident with the Zika epidemic, and the virus has been recovered from amniotic fluid and from fetal tissue, suggesting that Zika infection during pregnancy may cause microcephaly in the developing fetus. An increase in cases of Guillain-Barre syndrome has also been observed during this and previous outbreaks. Studies are underway to determine if Zika virus is the cause of microcephaly and Guillain-Barre syndrome. Most countries in the Americas, including the United States, are infested with types of mosquitoes that are competent to transmit the virus, but weather conditions also have to be warm enough to permit the virus to disseminate in the mosquito so that it can be transmitted to another person. The symptoms of Zika virus infection are typically mild and self-limited  – fever, aches, rash, and conjunctivitis. In fact, the majority of those infected have no symptoms. Because the virus can enter the bloodstream even in asymptomatic infected persons, there is concern that the virus could be spread by blood transfusion, if a person donates blood during the short period (probably a few days at most) when virus is in the blood. Other reasons for the paper are to highlight what is known about some of the insect repellents and to point out important gaps in our knowledge of their use and urgent research needs. (more…)