Zika virus

Zika virus zē´kə [key], single-stranded RNA virus of the genus flavivirus that infects human and primates and causes a disease known as Zika fever or zika. It is transmitted by the bite of a female Aedes mosquito. The virus was first isolated from a rhesus monkey from Uganda's Zika Forest in 1947, and was first found in humans in Nigeria in 1954. The symptoms of Zika fever typically include a low-grade fever accompanied by a rash, joint pain, or conjunctivitis there also may be muscle pain, swelling of the joints in the hands or feet, headache, pain behind the eyes, and vomiting. In most cases there are no severe complications and the infected individual recovers fully. Roughly three fourths of the people infected with the virus show no symptoms, and Zika fever is often misdiagnosed dengue fever in areas where dengue fever is common because of similar symptoms. There is no vaccine or treatment for the virus, other than alleviating the symptoms of infection. Like other mosquito-borne infections, prevention focuses on controlling the mosquitoes that spread the virus and avoiding being bitten.

Outbreaks of the disease initially occurred in tropical Africa and SE Asia, but in 2007 there was an outbreak in the Pacific, on Yap island in the Federated States of Micronesia. In 2013 an outbreak occurred in French Polynesia and the disease then spread to other parts of the Pacific. The virus has also been identified since 2015 in a number of South and Central American countries, Mexico, and parts of the Caribbean. An outbreak of Zika fever that occurred in Brazil beginning in 2015 is suspected of being linked to a sharp increase in the occurrence of microcephaly, a birth defect characterized by an unusually small head and brain damage.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

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