Putting Zika Virus into Context

Now that a case of Zika virus was recently confirmed in one of the 50 states (Texas), I expect a lot of domestic media attention to be focused on this virus that heretofore was not considered a major public health threat. Indeed only 1 in 5 people infected with this mosquito-borne virus actually experience symptoms.

What changed the perception? The correlation of its appearance in Brazil and the increase in fetal microcephaly cases, which number in the thousands. Fetal microcephaly refers to an abnormally small-sized head on a developing fetus. This condition has myriad causes and Zika virus has not been definitively proven to be an etiologic agent in any of the cases -- though the data is very suggestive. Microcephaly is a devastating diagnosis that can lead to abnormal brain functioning and a shortened lifespan. Thus far just 3 deaths of been reported, including one microcephalic newborn who died within 5 minutes of life. There are 2 deaths in El Salvador from the autoimmune neurologic disorder Guillan-Barre-- a rare complication of Zika and many other infections -- being investigated for possible linkages to Zika (something also being investigated in Brazil).

What is most significant, to me, about Zika virus is that it is spread by Aedes mosquito which also serve as the vector for the much more dangerous dengue and chikunguna viruses that are relatively neglected and haven't claimed international headlines as forcefully as the benign-in almost-cases Zika has (the subject of a blog post by another infectious disease physician). Societal has little tolerance for infections that target developing fetuses (witness the rubella elimination campaigns) even if they do not incur much damage to adult hosts. (Inappropriate aside that I can't resist -- Beetlejuice didn't like his own microcephaly either). 

With the attention on Zika however, there should be a renewed push to optimize Aedes mosquito vector control -- which should include the use of GMO Aedes mosquitoes to decrease population sizes -- as well as draw attention to the GSK Dengue vaccine (approved in Brazil, Mexico, and the Philippines -- but not yet the US). 

One last thing, though this Texas Zika case may capture headlines, Zika has been here before (confirmed cases and likely undiagnosed mild cases that escaped notice). What remains to be seen is if this virus will be successful like its forebears dengue and chikungunya in setting up foci of autochthonous transmission within the United States.