One epidemic, two problems

Last week, the New York Times reported on the current epidemic of Dengue fever in Key West, FL, so let’s back up a bit and get a larger view of this.

Dengue fever is caused by a virus transmitted by mosquitoes. It’s the most common arthropod-borne illness in the world, but, like malaria, has been of only limited concern in the U.S. over the last half-century. The illness is characterized by high fevers, rash, and terrible pain that gives it its nickname: Breakbone Fever. As unpleasant as it can be, a case of Dengue usually passes and leaves the victim with nothing worse than bad memories. For a typical American traveler, this can lead to an unpleasant vacation.

But for people who are repeatedly exposed to the virus, it can have much more devastating effects. Exposure to a different strain of the virus can lead to Dengue hemorrhagic fever (DHF), an frightening illness that is rarely fatal when patients have access to good medical care. But many areas where Dengue is endemic do not have access to good medical care. People with DHF have high fevers, but also develop bleeding and vascular leak, causing fluid to accumulate in places it shouldn’t, such as the lungs, and can lead to shock and death.

While Dengue fever is a painful inconvenience to travelers, it can be deadly if it becomes a endemic in an area because of the risk of DHF when re-infected. This is the primary reason surveillance and prevention are so important. Which leads to problem number one (asie from the outbreak itself): according to the Times, the CDC is going to be cutting back the Division of Vector Borne Infectious Diseases, which is responsible for important emerging diseases such as Dengue, West Nile Fever, and Lyme disease.

The second problem is also economic, but in more human and less bureaucratic way. The Times is reporting that residents of Key West, who are dependent on tourism, are reluctant to acknowledge and deal with the epidemic. About five percent of the Key West population is believed to have been exposed to Dengue, a huge number considering that this part of the U.S. rarely sees the disease. It is also a popular tourist destination, meaning that travelers can acquire it, and bring it home to their local mosquitoes, potentially leading to its establishment elsewhere.

The worst possible reaction to an epidemic is denial, but reactions in Key West from residents and officials has been disappointing. One local health official called the CDCs report “alarmist”. There are active mosquito eradication efforts ongoing, but as we saw with West Nile Fever in other parts of the country, it is possible to inform the public without panicking them.

Prevention of mosquito-borne diseases like West Nile and Dengue requires not only local control of populations, but personal protection. Minimizing exposed skin, and applying a repellent containing DEET (usually at a concentration 20-30%) can provide protection from bites thereby minimizing the risk of acquiring mosquito-borne diseases.
uiring mosquito-borne diseases.