In the June 11, 2009 issue of the New England Journal of Medicine appears an article by Mark Duffy and colleagues entitled “Zika Virus Outbreak on Yap Island, Federated States of Micronesia.” This outbreak occurred in 2007, and was described as a cluster of 108 persons with confirmed or suspected infection, characterized with main symptoms of skin rash, fever, conjunctivitis, and painful joints. Other less common symptoms were muscle aches, pain behind the eyes, tissue swelling and vomiting.
As reported by the authors, there were no hospitalizations, bleeding problems in victims, or deaths. The predominant mosquito culprit was Aedes hensilli. The disease was determined to be mild in this outbreak. Zika virus is in the family of flaviviruses, which include West Nile, dengue, and yellow fever viruses. It has been diagnosed in Asia and Africa, and is transmitted by infected mosquitoes. Before this particular outbreak, there had only been 14 cases of human Zika virus disease previously documented.
The diagnosis was made in this outbreak by sending serum samples from patients to the Centers for Disease Control and Prevention (CDC) Arbovirus Diagnostic and Reference Laboratory in Fort Collins, Colorado.
How did this virus turn up in Yap? The most likely introducer was an infected mosquito or human. So, given the abundance of mosquitoes and propensity of people to travel, we may soon see this disease in other regions around the globe.
image courtesy of www.cdc.gov