The Defense Department is exploring a replacement for permethrin, the bug repellent and insecticide that is soaked into most military combat uniforms.
Officials declined to provide details on the new product, which is still being tested and evaluated, but said it may be used "at a lower toxicity level" and last a uniform's lifetime. Permethrin lasts through about 50 launderings.
"We are looking at new chemistries," said Lt. Cmdr. James Dunford, a medical entomologist at the Uniformed Services University of the Health Sciences in Bethesda, Maryland, speaking with reporters on a call Wednesday to promote the Defense Health Agency's "Bug Week."
"We are working on a new chemical ... that would also include environmental factors like sweat, ultraviolet light and abrasion, so we are trying to make it last longer," added Dr. James English, a global health specialist with the Uniformed Services University, addressing several of the shortcomings of permethrin that cause it to lose its bug-fighting powers.
"DoD is always actively engaged in testing new products, methodologies and technologies to enhance the efficacy of the vector-borne disease protection we can provide for our service members. Any time we find a better tool ... we are going to add it to our tool box," English said.
The Pentagon's marked its second annual "Bug Week" July 27 to Aug. 3 to raise awareness of the slew of disgusting diseases carried by bugs and provide information to service members and their families on preventing illness.
According to the Defense Department, Lyme disease continues to be the top domestic threat to U.S. troops when it comes to bug-borne diseases, with illnesses carried by mosquitoes being the major challenge overseas.
"Outdoor activities like farming, camping and military training exercises in grasslands or edges of the forest increase chances of these pathogens' transmission," Army Maj. Elizabeth Wanja of the Uniformed Services University for Health Sciences said in a news release.
The most ubiquitous vector-borne disease in the United States by far is Lyme, with more than 30,000 diagnosed cases of Lyme reported to the Centers for Disease Control and Prevention each year and estimates of infections as high as 300,000 annually.
From 2010 to 2016, the U.S. armed forces saw 721 confirmed cases and 3,266 suspected cases of Lyme, as well as 64 cases of Rocky Mountain spotted fever and 14 cases of ehrlichiosis -- all carried by ticks.
Also from 2010 to 2016, the services saw 346 confirmed and 475 suspected cases of malaria, 86 cases of dengue, 78 cases of chikungunya and 52 cases of Zika.
Other diseases on the rise in the U.S. include the rare Powassan virus, with 33 cases across the U.S. in 2017. This illness, carried by the deer tick, affects the human nervous system, causing respiratory complications and brain swelling. And alpha-gal syndrome, which can be caused by a bite from the lone star tick, can cause a red meat allergy in humans.
To prevent infections, the Defense Department takes a "three-pronged approach," English said.
This includes proper wearing of uniforms -- "tucking your pants into your boots, long sleeves" -- caring for uniforms so they maintain their insecticide impregnation and taking preventive medications for diseases such as malaria before and during deployment to endemic countries.
Officials say the key to preventing infection off-duty is to maintain similar practices. They recommend using an effective repellent containing DEET, IR3535 or oil of lemon eucalyptus, all of which the CDC classifies as providing "reasonably long-lasting protection," wearing proper clothing (again, long pants and long sleeves) and conducting tick checks after being in grassy areas and woods.
"The more time you spend outside, the more likely you are to pick up ticks. The best way to prevent it is to not get them in the first place," English said.
According to English, ticks need roughly 24 hours to transmit a disease, so if one is found on the body, remove it carefully, using tweezers to grasp it and pull away gently and "straight out in slow motion."
Do not, he said, use a hot match to make it release or smother it with Vaseline or baby oil.
"None of that works and, in fact, all that does is make them regurgitate if they get trauma like that, and it can either [lead to] an infection or the pathogen can be vomited when it otherwise it wouldn't," he said.
To prevent mosquito-borne illnesses, deprive them of their breeding grounds, Dunford added. This means eliminating all standing water in yards and using environmentally friendly mosquito dunks in bird baths or fountains. Being aware of the potential for standing water has been especially important in a year that has seen extensive flooding at military bases, he said.
"As far as mosquitoes go, aedes aegypti [mosquitoes that carry dengue, Zika and other tropical diseases] don't fly more than a block in their entire life, so if you are getting bit at your home in the daytime, they probably are breeding within a block of your home ... even in something as small as a bottle cap full of water," English said.
Again, wear protective clothing and use repellents, he added.
While several of these diseases are curable, many are not, and they not only pose a threat to readiness, given the symptoms and related down-time, they can carry long-term consequences.
In July, military researchers wrote a case study in the journal Military Medicine about a 24-year-old Army officer and U.S. Military Academy graduate who was discharged after exposure to Lyme disease resulted in chronic inflammation of his knees, rendering him unfit for duty.
In 2016, the Military Health System confirmed 156 cases of Zika, including five cases in pregnant beneficiaries. The Zika virus can cause severe birth defects in children, including microcephaly, a condition where a baby's head is much smaller than normal that is linked to developmental and intellectual delays, seizures and other disabilities.
The Defense Department's relationship with ticks made headlines earlier this month, thanks to an amendment to the proposed House national defense authorization act that seeks to determine whether the Pentagon has experimented with ticks and insects to spread disease.
Sponsored by Rep. Christopher Smith, R-New Jersey, the legislation would require the Pentagon inspector general to investigate the "possible involvement of DoD biowarfare labs in the weaponization of Lyme disease in ticks and other insects" from 1950 to 1975.
Smith said he was inspired to write the amendment based on several books, including "Bitten: The Secret History of Lyme Disease and Biological Weapons" by Kris Newby, that claim DoD research may have played a role in spreading Lyme.
"My amendment tasks the DoD Inspector General to ask the hard questions and report back," Smith said in a news release.
Defense officials said Wednesday that the goal in studying Lyme and other tick-borne diseases is to prevent them.
Department spokeswoman Heather Babb said that the Pentagon cannot comment on Smith's proposed legislation. But, she added, "DoD takes extreme care in all of our research programs to ensure the protection of our personnel and the community."
-- Patricia Kime can be reached at Patricia.Kime@Military.com. Follow her on Twitter @patriciakime.
