Army Public Health Command-Pacific evaluates in-field concept for vector-borne disease tests
US Army | 2021-11-18
CAMP ZAMA, Japan — After completing a 14-day deployment to Okinawa, the Public Health Command-Pacific’s Entomology and Environmental Molecular Biology Laboratory is one step closer to achieving its goal of providing on-the-spot and rapid results for vector-borne diseases pre-exercise and during the entirety of a deployment.
The team’s target was to study mosquitos and ticks on the island, which are both known to be carriers of diseases.
Broken down into two surveillance/collection sub-teams and one molecular team — which processed the collected specimens for analysis — the team as a whole set out to not only make history, but ensure the Army warfighter would be better prepared while conducting operations in remote areas.
The end result is to have teams such as these deploy in advance of or with the units.
“Places such as motor pools [that have old tires that collect water] and jungle-type environments are great places to collect mosquito specimens”, said Staff Sgt. Matthew Pascual, Entomology noncommissioned officer in charge, who not only set traps for mosquitoes, but dragged areas for tick collection with team mate, entomologist Kei Jimbo.
Once the traps were set and specimens collected, they were then handed-off to the molecular team for nucleic acid sequencing. The specimens collected during the Okinawa study, were taken from Camps Hansen, Schwab, Courtney and Gonsalves and labeled accordingly so each area in which the specimen was collected can be identified after sequencing is complete.
The laboratory was set up on Camp Shields, a small U.S. Navy Seabee installation near Kadena Air Base in Okinawa.
“This is a proof of concept to show that we can actually sequence in the field, real time,” said Director of Laboratory Services, Maj. Karen E. Thomas. “The premise behind Capt. Eads’ GEIS (Global Emerging Infectious Surveillance) protocol is pre-exercise field detection.”
Established in 1997 by the Department of Defense, the Global Emerging Infections Surveillance program, follows a Presidential Decision Directive to improve the Department’s infectious disease surveillance, prevention, and response capability to better protect the health of the military force. A branch of the Armed Forces Health Surveillance Division, GEIS joined the Defense Health Agency's Public Health Directorate in 2015. This organizational move positions the GEIS program to help fulfill the DHA’s Combat Support mission.
“Before units move out [locations such as Thailand], we can give the combatant commanders the real-time information of the pathogens in the area and then they can have the force health protection measures in place,” continued Thomas. “Whether it’s making control recommendations or locating mosquito breeding sites or something along those lines or even making sure that the surgeons or doctors that go with them, have the necessary antibiotics on hand. Especially in those areas where we don’t have any historical information. So that’s what we’re looking for."
“Also, by performing the genetic sequencing, were able to conduct pathogen discovery. With climate change and our global nature there might be new diseases in that area that we’re not aware of,” said Thomas. “Instead of only targeting specific diseases that we already know about, we’re able to discover ones that we don’t yet know.”
The COVID-19 pandemic has halted or slowed many temporary duty assignments of the PHC. However, because this surveillance mission was of the utmost importance, it was realized the teams didn’t have to travel outside of Japan to operate in an environment that would be conducive to collecting insects helpful to the study of vector-borne diseases in a tropical climate.
“We’re going to take these specimens and extract nucleic acids from them, then we’re going to convert them to complimentary DNA (cDNA), which is more stable, especially at room temperature conditions,” said Gary P. Crispell, a microbiologist at the PHC-P EMBL at Camp Zama.
“Once we have our cDNA, we’ll load that into our MinION [a paradigm shifting device allowing rapid, real-time long-read sequencing of nucleic acids] Next-generation sequencing platform where we can then search through the genomic data for pathogens of interest and pathogens of human disease,” he said.
“When we take this back home, we have other tests to perform, so the cDNA will assist with preventing our nucleic acids from degrading. We will use a comprehensive pan-viral research panel that tests for most all viruses known to cause disease in humans, over 3,100 viral genomes,” said Crispell.
“Not only is this a proof of concept for our team, but also for our new pieces of instrumentation,” Thomas added, as she pointed out a piece of equipment.
“It looks like a Tuff Box, but it’s actually a cryo-cube, and we’re holding the temperature at minus nine degrees Celsius. We just want to keep it as cold as possible. The box has been in the hotel, but we’re not guaranteed to be in a hotel in Thailand or another austere place.”
“Part of the problem of why most molecular biology can’t be done in the field is the controlling of temperatures,” said Crispell. “We have enzymes that are very sensitive to rises in temperature. The longer it’s exposed to temperatures above freezing, the quicker it will degrade.”
“The history of casualties in warfare cannot be understood without an understanding of the impact on infectious diseases throughout military history,” said U.S. Marine Corps Lt. Col. Peter J. Hersey, Director, Jungle Warfare Training Center, located on Okinawa, as he explained the importance of studies such as this.
“This is especially true in tropical and sub-tropical environments, where the risk associated with vector-borne diseases is great. During the Spanish American War, 14 times as many personnel died from tropical diseases than enemy action. More recently, in 2014, 47 Marines were hospitalized, due to a leptospirosis outbreak here at the Jungle Warfare Training Center in Okinawa, highlighting the continuing environmental hazards of operating in this type of environment.”
Hersey continued, “As we prepare for future combat operations in tropical environments, we can’t do so without having an understanding of the unseen hazards that exist in our environment. In tropical environments the risk from infection of vector-borne diseases is particularly high due to the large numbers of mosquitoes and ticks. Our relationship with the entomologists at the Pacific Public Health Command at Camp Zama has been critical as we prepare the warfighter for the next fight,” he concluded.
Both Thomas and Crispell agree that this study may not be the first of its kind, their approach is designed to be the standard and can be done with just an advance team.
“It may have been attempted before,” said Crispell, “there are a couple of groups that are trying to do this, However, we’re not only trying to do this and succeed, but to standardize this so others can do it. We want this to become the future of in-field medicine of pathogen detection.”
According Capt. John J. Eads, chief of entomology at Camp Zama and team lead for the GEIS study, the Okinawa field study has been a success.
“This [mission] was successful for our intent of testing the protocols, testing equipment and learning. It was spot on,” he said.
“There are versions of field laboratories, but a lot are clinical,” said Eads, “and there has been rapid tests in the past where Soldiers could process the mosquitoes and then put them on a little test cartridge — sort of like an at-home pregnancy test but the accuracy rate wasn’t very good. This is the first time we’ve tested in the field.”
Since its inception, the GEIS program has focused on the rapid and accurate detection of infectious disease threats to DOD interests around the globe. The GEIS program operates through a global network of U.S. military service laboratories positioned in strategic locations worldwide. These DOD Service laboratories are engaged on the front lines of global infectious disease surveillance and have developed strong and long-standing relationships with U.S. interagency partners and international public health authorities. Laboratory confirmed pathogen identification, epidemiological data, and other related information are shared through these collaborations and provide critical details about emerging or expanding infectious disease threats around the world that may impact the health of the force.
While COVID-19 hampered the ability to travel to remote locations, according to Eads, it helped with some of the technology and the push for sequencing.
“The technology has been there, we’re just finally investing in it to get this field laboratory going” he said. “For example, the MinION has been around for a few years now, but I don’t think anyone has successfully used it for this method of environmental field sampling that we’re doing.
“The accuracy of genetic sequencing just can’t be matched by the other routes that we’ve had in the field previously. So by bringing this technology into the field, we’re getting that accurate information in near real time,” Eads explained.
As stated by Eads as well as the other team members, this mission was not just to prove this in-field laboratory concept is functional and logical, but to also demonstrate to those commanders of units its practicality for deployments.
“This was the first proof of concept to see what we need to refine and is the equipment capable of doing what we want it to do,” he explained. “In this protocol, we’re trying to streamline all of the procedures and once we get this wrapped up, then we can push out this information to the other Public Health Commands and units to see what we can do with it. Can we develop other teams based out of the Public Health Commands? Or do we create teams based out of the Preventative Medicine detachments? How far can we go with this?"
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