The explosive nature of recent Zika virus epidemics and links to Guillain-Barre syndrome and microcephaly, have scientists concerned, according to an article published in Annals of Internal Medicine. Poor understanding of the transmission and pathogenesis of Zika virus presents an enormous challenge in responding to the rapidly emerging threat to human health.
Zika was identified in 1947 and for decades caused only sporadic cases of mild human disease. However, the recent Zika epidemic that began in Brazil in 2015 has spread rapidly to more than 30 countries in the Americans and the Caribbean and shows no signs of slowing. Answers are needed to inform vaccine development and also to properly advise those living in or traveling to Zika-endemic areas.
While the contribution of Zika infection to the total increase in microcephaly cases being observed relative to other unidentified causes remains unknown, blood evidence suggests that Zika infection at any stage of pregnancy could increase risk for microcephaly, intrauterine growth restriction, and fetal death. As such, pregnant women in unaffected areas are currently advised to postpone travel to Zika-endemic regions, if possible.
Pregnant women are also advised to avoid sex with males who have traveled to Zika-endemic regions. Zika virus is detectable in semen for at least two months following infection and multiple cases of suspected sexual transmission of Zika are currently under investigation in the United States. The relative importance of sexual transmission with regard to the overall burden of Zika transmission and risk for microcephaly is unknown.
At present, there is no specific antiviral and no vaccine for Zika, though vaccines are in development. Providers should maintain a high level of suspicion for Zika infection in any patient presenting with rash and either a personal history of recent travel to an area with active Zika transmission or a history of travel in a sexual partner.