Chikungunya Still A Problem, Cases Rise On St. Croix

Although chikungunya is not being talked about as much compared to when it first struck the Virgin Islands in the spring, the disease remains a problem in the territory, new data released by the Virgin Islands Department of Health shows.

The disease first appeared on St. Thomas, and while most confirmed and suspected cases can still be found there, the numbers are growing on St. Croix with 12 confirmed cases as of Nov. 1, compared to 5 confirmed cases on Oct. 4. The number of suspected cases on St. Croix also rose substantially, with the island now seeing 338 of those cases as of Nov. 1, compared to 91 on Oct. 4.

Although St. Thomas saw a slight increase in the number of cases overall, the disease has lost momentum there, with the number of confirmed cases now at 102 compared to 63 on Oct. 4, while suspected cases saw an increase of 29 cases from 828 to 857. St. John confirmed cases decreased to 4 from 5; however, suspected cases grew to 41, an increase of 6 additional suspected cases as of Nov. 1.

The latest report shows that the Dept. of Health’s awareness efforts have been moderately working, as the speed in which the disease grew in the territory has waned.

There had been discussions about the possibility of  utilizing fogging to control the disease, however officials said fogging, in this case, would not be effective in the territory.

“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. Extensive trials carried out by the CDC others have repeatedly shown disappointing results, and there is no well-documented example of using fogging to interrupt an epidemic,” Brett Ellis, Health Department entomologist said recently.

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 Plaskett 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, recently said the territory was 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 has held steady 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. DOH has also been preparing for possible Ebola cases in the territory.