Type: Viral

Geography: Africa, Asia, the Americas, the Pacific

Cases Per Year: 100 to 30,000

Fatality Rate: under 10%

First Discovered: 1947 by Alexander John Haddow in Uganda

Zika is caused by Aedes mosquitos, which bite during the day and live in tropical and subtropical regions. The virus is transmitted between people from mother to fetus during pregnancy, through sexual contact, transfusion of blood, and organ transplantation.

The incubation period is between 3 and 14 days. The majority of people infected with Zika virus do not develop symptoms. Symptoms usually last for 2 to 7 days and include fever, rash, conjunctivitis, muscle and joint pain, malaise, and headache. Zika infection during pregnancy is a cause of microcephaly and other congenital abnormalities in the developing fetus. It can result in pregnancy complications such as fetal loss, stillbirth, and preterm birth. Infection can also trigger Guillain-Barre syndrome, neuropathy, and myelitis in adults and older children.

There is no treatment available for Zika virus. To date, a total of 86 countries and territories have reported evidence of mosquito transmitted Zika infection.

Photo: Mosquito cells infected by Zika virus, stained green – Electron micrograph.