Americans usually catch dengue fever, the excruciatingly painful tropical disease nicknamed “breakbone fever,” when they travel to one of over 100 foreign countries that harbor the disease. However, the virus that infected over 90 people in Key West, Florida in 2009-2010 is a strain of dengue local to that area, according to a new DNA study by the US Centers for Disease Control and Prevention (CDC). The CDC team will publish their genetic analysis in the April issue of Emerging Infectious Diseases.
The original outbreak caught health authorities offguard. The first victim, a visitor to Key West from New York, suffered from agonizing pain for days before doctors identified her disease as dengue with help from the CDC office in Puerto Rico.
Although she displayed the first known case of dengue caught in Florida since 1934, more would follow. The CDC ultimately estimated that roughly 1,000 people, around 5% of the local population of Key West, were infected by the virus in 2009.
And it came back in 2010, although it hasn’t occurred since.
While up to 100 million dengue fever infections are reported worldwide each year, there are zero known cases of the virus being caught in the United States between 1946 and 1980. After that time, only a few scattered cases had been found in Texas near the border with Mexico.
Dengue fever isn’t spread person to person. Instead, it’s carried by one species of mosquito, Aedes aegypti. In addition to implementing normal public health methods of mosquito control like spraying and draining mosquito-infected standing waters, some scientists including a group from the University of California in Irvine are developing genetically modified versions of the species that produce offspring that can’t survive into adulthood.
Some observers like Mother Jones’ Kiera Butler have questioned the push for the GMO mosquitoes, which are being produced in association with British company Oxitec.
However, public health authorities may take another look at such projects in light of the CDC’s new evidence for a local strain of dengue fever.