Mosquito-borne viruses hit summer peak, WNV discovered on Fort McNair
August 7, 2014
By Damien Salas
JOINT BASE MYER-HENDERSON HALL, Va. - The Army Public Health Command on July 31 released a report showing positive West Nile Virus (WNV) detections located in two military mosquito-trapping sites on the Fort McNair portion of Joint Base Myer-Henderson Hall, which constitutes the first discovery of the virus on the installation in 2014.
As 2014 moves into the seasonal doldrums of August, warm weather and increased moisture support higher mosquito populations, and along with them comes a higher risk of mosquito-borne pathogens.
The Army Public Health Command on July 31 released a report showing positive West Nile Virus (WNV) detections located in two military mosquito-trapping sites on the Fort McNair portion of Joint Base Myer-Henderson Hall, which constitutes the first discovery of the virus on the installation in 2014.
"The infected areas were found behind the O-club and Bldg. 59 (Eisenhower Hall) on Fort McNair," said Richard LaFreniere, chief of Environmental Management on JBM-HH. "Pest Management on the installation is currently working with the Directorate of Public Works to eliminate the problem areas."
Mosquitos breeding in the pools of water located in various parts of the National Capital Region monitored by the Army, Navy and Air Force serve as a canary in a coal mine when high levels of WNV and other viruses are present in the area.
Standing water in tarps, storm drains and open trash cans with decaying leaf and debris held the mosquitos that tested positive for WNV, according to LaFreniere.
"This is what is called a level three response, which indicates hits of WNV in multiple pools around the area, but no cases of human-infection coming from the pools," he said. "Next, DPW will drain the pools they can, and use what are called 'dunks,' or environmentally-friendly larvicide tablets, to eliminate the rest."
The mosquito traps around the National Capital Region remain active and are checked bi-weekly. Mosquito samples gathered from the sites are ground up and sent to Fort Meade for analysis, according to LaFreniere.
In order to prevent mosquito-borne illnesses, residents of Joint Base Myer-Henderson Hall should take similar precautions the Pest Management team on Fort McNair use to eliminate breeding grounds for mosquitos around their own homes.
Recommended precautions to deter mosquito bites include:
- Use of insect repellents containing DEET, picaridin, IR3535 and some oil of lemon eucalyptus and para-menthane-diol products to provide longer-lasting prevention;
- Wear long sleeve shirts and pants from dusk through dawn, which is when mosquitos are most active;
- Ensure screens on windows and doors are not torn or otherwise provide openings for mosquitos to enter residences;
Use of air conditioning;
- Empty standing water from outside containers, such as flowerpots, gutters, buckets, pool covers, pet water dishes, discarded tires and bird baths.
Not all mosquito-related illnesses are contracted in the United States, but instead come from popular tourist destinations and military installations overseas, according to the Centers for Disease Control and Prevention.
Another mosquito-borne disease, the Chikungunya Virus, found only in the western hemisphere before 2013, has been reported in both local and imported cases in the Caribbean and imported cases in the U.S., according to the CDC.
Contraction of the disease happens typically overseas, where the virus originates. Symptoms appear three to seven days after the bite occurs and include fever and severe joint pain, as well as headache, muscle pain and joint swelling or rash, according to the CDC.
CHIKV transmits through the yellow fever mosquito and Asian tiger mosquito through a person-to-mosquito-to-person cycle, unlike WNV, which spreads at a faster rate due to the high viral rate amongst birds.
Eleven imported incidents of CHIKV, or three percent of cases reported in the U.S., appeared in Virginia as of July 29, according to the CDC.
Although no locally-acquired cases have been reported among Virginia residents at time of press, there is a risk of infected travelers transmitting CHIKV to local Asian tiger mosquitoes, a very common mosquito in the region, according to a report by the Virginia Department of Public Health.
The CDC does not consider the virus a nationally-notifiable disease; however, the risk of importing the disease from areas where outbreaks occur is high.
For more information on high-risk areas overseas, visit http://goo.gl/pEVlXC and for travel safety tips visit http://goo.gl/6Z6yXF.