Chikungunya Out Of Control: 832 Suspected Cases In The Virgin Islands

As the chikungunya epidemic continues to rock the U.S. Virgin Islands, the Department of Health (DOH) released an updated report this week revealing the disease’s reach — with St. Thomas continuing to be the hardest hit in the territory, but also showing a growing number of cases on St. Croix.

According to the latest numbers, there have been 832 suspected chikungunya cases in the territory as a whole, with 757 of those on St. Thomas, 50 on St. Croix and 25 on St. John. Confirmed cases see St. Thomas leading the way with 59 cases, St. Croix with 5 and St. John with only 3.

The latest report represents a rise by more than half since the last numbers were revealed, making known the difficulty the DOH has had in subduing the viral disease. In early September, the Department reported 415 suspected cases. Of that number, 389 cases were suspected on St. Thomas and St. John, while only 22 cases were suspected on St. Croix.

St. Thomas residents have been advocating for a fogging campaign, but health officials have ruled out the move, insisting that its effect will be limited because of the nature of the virus and how it’s bred.

“The impact of fogging to control Aedes aegypti, the mosquito responsible for transmitting dengue and chikungunya, has been controversial but most vector control programs acknowledge its extremely limited effect,” Brett Ellis, health department entomologist, said last month. “Extensive trials carried out by the CDC and others have repeatedly shown disappointing results, and there is no well-documented example of using fogging to interrupt an epidemic.”

He added: “The primary reason for this is not because the chemicals are ineffective, but that it has been difficult to get the chemical in direct contact with the mosquito. This type of mosquito spends a lot of its time indoors near us, in dark places like our closets or under our beds, and do not come into contact with the chemicals when sprayed. Unlike many mosquito species, Aedes aegypti mosquitoes are aggressive daytime bitters, and fogging is typically performed in the evening. Fogging can also kill other beneficial insects such as bees.”

Ellis went on to say there were “unique concerns” with implementing fogging in the territory, particularly as it relates to safeguarding cisterns and potable water sources.

“Control programs should focus their efforts on an integrated approach that includes effective surveillance, clinical case management, community education, personal protection, and the destruction of mosquito breeding sites in and around our homes and public places,” he said.

Health Commissioner Darice Plaskett, speaking last month, backed up Ellis’ claim, adding that, according to CDC’s arboviral experts and vector control specialists, “the most effective method of abatement for Aedes aegypti mosquito in the territory is source reduction/elimination (draining and dumping stagnant water from containers like buckets, pet dishes, flower pots and tires),” and eradicating mosquito larva from large bodies of stagnant water that cannot be drained or dumped, by using the bacterial insecticide known as Bti briquettes or mosquito dunks.”

The Department of Health’s territorial epidemiologist, Dr. Esther Ellis, has said the territory was now experiencing a chikungunya epidemic and gave residents, as well as visitors pertinent advice to protect themselves from contracting the disease.

They include:

• Use insect repellents — Repellents containing DEET or oil of lemon eucalyptus. Apply repellent only to exposed skin or clothing, follow product instructions carefully. Do not use repellents on babies less than two months of age.
• Use air conditioning or window/door screens to keep mosquitoes outside. If you are not able to protect yourself from mosquitoes inside your home or hotel, sleep under a mosquito bed net.
• Wear clothing that protects you from mosquito bites (long-sleeved shirts and long pants).
• Protect infants: cover cribs, strollers and baby carriers with cotton mosquito netting at all times, day and night, both inside and outside of your home. Dress babies in loose cotton clothing that covers arms and leg.
• Treat clothing with permethrin or purchase permethrin-treated clothing.

Even as chikungunya cases continue to rise in the territory, the DOH has been keeping an eye on, and warning residents of, Enterovirus D68 (EVD68), a fast-spreading, extremely contagious virus that has ravaged many states on the mainland and in Canada. Details here.