News | Dec. 26, 2016

Tiny Enemy

By Kimberly K. Fritz, Craig M. Rader, Chris Erbe and Michael Tuttle

With Zika virus established in South Florida and public-health officials warning it could easily spread to other warm parts of the country, Defense Logistics Agency personnel are taking action to fight mosquitos, detect any new cases of Zika and make sure troops have what they need to avoid infection.

DLA installations began trapping and testing mosquitos in March 2016, on instruction from the Department of Defense. Since then, DLA installations have worked with other federal, state and local governments to share information and strategy.

DLA Aviation in Richmond, Virginia, is one of four federal installations in Central Virginia that collect mosquitoes to test for Zika during the months when mosquitos are present. DLA Installation Support at Richmond’s Environmental Division is working with Kenner Army Health Clinic’s Preventive Medicine Clinic to monitor the spread of Zika in the area.

“State-of-the-art mosquito traps [are] placed in areas specifically identified as potential breeding grounds for the Zika-bearing mosquitos,” said Jimmy Parrish, chief of the Environmental Division. Trapping and testing last about two months, during which his staff checks the traps daily and collects any captured mosquitoes. Last year his team collected 51 mosquitos and sent them for testing at Fort Lee, Virginia, and the Army Public Health Center at Aberdeen Proving Ground, Maryland. None tested positive for Zika, Parrish said.

“We also took a very proactive approach regarding the identification and treatment of any potential mosquito breeding areas,” Parrish said. “The mosquitos that have the potential to carry the Zika virus prefer to breed in smaller bodies of water, such as what might be collected in buckets, tarps and even flower pots.”

In the warmer months, his staff routinely canvass the entire installation to look for those items, he said.

“Our goal [is] to not only capture and identify the types of mosquitos found on the installation but to minimize, if not eliminate, the concerns our fellow employees might have for their health and well-being,” he said.

Meanwhile, health officials at DLA Land and Maritime in Columbus, Ohio, are preparing to once again work with Army entomologists this summer to collect mosquitos for testing. Brad Sparks, a pest controller at DLA Land and Maritime, spent last summer on mosquito patrol, placing and collecting traps at the installation, to collect eggs and adult specimens.

None of the mosquitoes were positive for Zika, dengue or chikungunya virus, said Benedict Pagac, chief of the Entomological Sciences Branch, Public Health Command – Atlantic reported the installation leaders at the testing sites of Columbus, Ohio, and Richmond and Fort Belvoir, Virginia.

For installations outside or on the edge of the known ranges of the species known to carry Zika, the news gives some measure of assurance that the likelihood of Zika, dengue, or chikungunya virus transmission by mosquitoes at those locations is low, according to Pagac.

DLA Troop Support’s Clothing and Textiles supply chain provides combat fatigues treated with insecticide to protect Marines and soldiers from disease-carrying insects. Since February 2014, C&T has delivered than 10 million uniforms treated with permethrin to warfighters in the United States and overseas, said Steve Merch, director of supplier operations for the supply chain.

“Permethrin repels many species of crawling and flying insects, including mosquitoes, ticks, chiggers and flies,” Merch said. “The factory-treatment process binds permethrin so tightly to the fabric of the uniform that soldiers wearing the [treated uniform] will have protection from arthropod bites through 50 launderings, the expected lifetime of the uniform.”

According to the U.S. Army Public Health Center, the permethrin treatment means soldiers will never need to treat their uniforms. Factory treatment guarantees a safe and effective amount of permethrin is precisely applied to each uniform. This improvement over field application means better protection from insect bites and the diseases they may cause.

Determining how the spread of the Zika virus will slow or stop with the onset of cooler temperatures isn’t a simple answer, Pagac said.

“In some areas of the region with military presence [e.g., the Caribbean, Florida, Louisiana, Mississippi and Texas] there aren’t killing freezes, so mosquitoes can potentially be active and infective year-round,” Pagac said. “In areas where there are killing freezes, newly emerged mosquitoes in the spring will need to bite an infected human host to pick up the virus.”

And even in colder regions, some mosquitoes can hide underground and in basements and remain alive. Under normal field conditions, the virus is not known to be able to be passed from female adult to egg, to larvae, to pupae, and then to the next generation of adults. There is some evidence this may be possible under certain circumstances, but it has not been proven, Pagac said.

According to the Centers for Disease Control and Prevention, many areas of the nation have either type of mosquito (either the yellow fever mosquito, or the Asian tiger mosquito) can spread Zika virus. However, only areas of Miami-Dade County, Florida, have reported local mosquito-borne transmission. October 13, Florida announced a new area of mosquito-borne spread of Zika in an additional one-square-mile area in Miami-Dade.

In addition to contracting Zika by a mosquito bite, the virus can be passed from mother to child during pregnancy or around the time of birth, if she is already infected. The CDC reports no known cases of infants getting Zika virus through breast milk. Because of the benefits of breastfeeding, mothers are encouraged to breastfeed even in areas where Zika virus is found.

CDC warnings note that Zika can be passed through sex with a person who has the virus to his or her partners, even if the infected person does not show symptoms. Zika can be passed before symptoms appear and after symptoms end — or by a person who carries the virus but never develops symptoms. The virus has the potential to spread through blood transfusions, but the CDC reports there have been no confirmed cases transmitted this way in the United States.

Anyone who lives in or travels to an area where Zika virus is found and has not already been infected with Zika virus can get it from mosquito bites, the CDC advises. Once infected, a person is likely to be protected from future infections. Many people infected with Zika virus won’t have symptoms or will only have mild symptoms. The most common symptoms of Zika are fever, rash, joint pain and conjunctivitis (red eyes). Other symptoms include: muscle pain and headache. Zika is usually mild, with symptoms lasting several days to a week. People usually don’t get sick enough to go to the hospital, and they rarely die of Zika. For this reason, many people might not realize they have been infected.

Symptoms are similar to those of other viruses spread through mosquito bites, like dengue and chikungunya. Zika virus usually stays in the blood for about a week. A doctor may order blood tests to look for Zika or other similar viruses. Once a person has been infected, he or she is likely to be protected from future infections. Pregnant women or women who may become pregnant should not travel to Zika-infected areas, the CDC has warned. The agency advises those who must travel to talk with their doctor first.

Everyone can protect themselves from mosquito bites by wearing long-sleeved shirts and long pants, staying in places with air conditioning and window and door screens, treating clothing and gear with permethrin, and using insect repellents containing DEET, picaridin, IR3535, oil of lemon eucalyptus, para-menthane-diol, or 2-undecanone.

Notably, in May of last year, DoD provided $1.76 million of additional funding to military labs to expand their surveillance of the virus and to determine how the virus is affecting service members’ health and readiness, the department reported. And more recently, the National Institute of Allergy and Infectious Diseases has begun testing a Zika vaccine and is in the first of five early clinical trials.

Although winter in much of the United States sees mosquitos vanish from sight or at least markedly diminish, DLA is preparing to start collecting and testing mosquitos again this summer.

“No matter what the future may bring in regard to Zika, DLA is ready to respond,” Parrish said. “We’re all taking this fight very seriously.”

 
The authors are public affairs specialists at DLA Aviation, Land and Maritime, Headquarters, and Troop Support, respectively.