 There are many uncertainties about the number of subjects that meet this case definition. There are limits to the ability to enroll based on staffing and other resources. If there are many cases, an emphasis will be placed on enrolling pregnant subjects and adults with neurologic complications that meet the case definition, as this is the area of highest clinical need. If there are few pregnant women or subjects with neurologic problems that can be enrolled, then any adults or children meeting the criteria can be enrolled. Not all cohorts will be active at all sites, based on the type of facility and type of patients typically seen. If sufficient numbers of certain populations are enrolled i.e. children born to women infected with Zika, the protocol may be amended to study those populations in more detail. 