Zika is a disease caused by the Zika virus, which is spread to people primarily through the bite of an infected mosquito. However, Zika can also be spread sexually and from a pregnant mother to the fetus. The illness is usually mild, but it can have serious consequences in pregnant women. Zika infections during pregnancy have been linked to birth defects, including microcephaly (small brain and skull) in newborns.
Zika was first identified in 1947 in the Zika forest in Uganda, and traditionally has been found in Africa and Southeast Asia. Human cases of Zika were first detected in 1952. Since then, outbreaks of Zika have been reported in tropical Africa, Southeast Asia, and the Pacific Islands.
In February 2016, the World Health Organization (WHO) declared a Public Health Emergency of International Concern because the virus had emerged in Mexico and countries in the Caribbean and Central/South America. Local mosquito-borne Zika virus transmission has not been found in Philadelphia, but Zika is still present in tropical locations. The Philadelphia Department of Public Health is working hard to identify travelers with this infection, prevent emergence and spread of the disease in Philadelphia, and keep residents informed about Zika.