While the U.S. Navy is better known for its role in protecting Americans from enemies abroad, its scientists also works in labs throughout the world, combatting an unseen enemy: infectious disease.

And now, U.S. Naval Medical Research Unit 6 (NAMRU-6), based in Lima, Peru, has set its sights on the Zika virus — declared by the World Health Organization to be a public health emergency.

 Zika, which is spread by mosquitos, was once thought to be a minor health threat because its symptoms were typically mild and lasted for about a week. However, scientists increasingly believe there is a link between Zika infections in pregnant women and microcephaly in newborns, where the child’s head is unusually small due to abnormal brain development.

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Zika, a virus transmitted through mosquito bites, is affecting multiple countries in Latin America, and is expected to spread to the U.S.

The Lima-based unit, known in Navy lingo as NAMRU-6, was NAMRU-6, the research unit officially established in 2011, but has roots going back to 1978, when a . An official with the Peruvian Navy official asked the United States to set up a lab to assist Peru in studying tropical medicine and diseases. B and by 1983, a research unit had been established began to study diseases and search for cures, benefitting that would benefit both countries. The unit also has labs in Puerto Maldonado and Iquitos, along the Amazon River.

Now lLed by Capt. Adam Armstrong, the commanding officer and an infectious disease physician, and by Cmdr. Commander Guillermo Pimentel, a clinical microbiologist, the research unit NAMRU-6 has focused on health surveillance and the development of treatments for a range of infectious diseases. In particular, researchers have focused on mosquito-borne illnesses like dengue fever, chikungunya and, most recently, Zika.

Military research into infectious diseases has had programs have a long history, said Audrey Jackson, a health researcher at the Center for Strategic and International Studies. Most malaria-control efforts have had U.S. military involvement; recently the military led promising vaccine research on HIV in Thailand, she said during a telephone interview.

Notably, in 2014 the Defense Department developed the first diagnostic test for Ebola approved for emergency use in the U.S., Jackson said.

While there are many infectious diseases being studied across the globe, military research looks to tackle diseases that could pose health risks for deployed troops and their families.

"The military is focused on things that could impact service members wherever they deploy," said George Weightman, an executive advisor at the government consulting firm Booz Allen Hamilton, Inc. "It’s a pretty big sandbox to play in."

Lead researchers at the unit base in Peru — Dr. Max Grogl, Dr. Christopher Mores and Lt. Cmdr. Lieutenant Commander Craig Stoops — said in a joint email that NAMRU-6 has been tracking the current Zika outbreak as well as providing diagnostic tools to help identify infected U.S. personnel. Additionally, the researchers have sought new funding to study Zika in light of the threat the virus may pose to pregnant women.

Before the new outbreak of Zika, the research unit NAMRU-6 was heavily invested in controlling disease-spreading insects like the mosquito. However, the researchers said tThe new threat from Zika may allow them to better understand how effectively similar diseases can be transmitted, the researchers said.

One focus in particular is whether Zika can infect wild animals in South America, as has been the case in Africa, they said. Zika has been found in Africa and parts of Asia in the past, but the recent outbreak has rapidly covered large parts of South and Central America.

Research on diseases in regions like South America not only benefits deployed troops and allied countries, but also serves a significant U.S. national security interest, Audrey Jackson said. By helping other countries improve their ability to respond to disease outbreaks, the threat to the U.S. is also limited, she said. By the time a nation closes its borders, it is usually too late.

"The first line of defense is to be able to detect what's going on. In an increasingly interconnected world, the best way for the U.S. to prepare is to help other countries improve their own capacities," Jackson said.

U.S. military scientists at the NAMRU-6 lab in Lima people work alongside Peruvian researchers and in collaboration with academic organizations like the University of California-Davis, which coordinated with the research unit NAMRU-6 to study dengue fever. In the email, the researchers said their work on dengue has been is invaluable in guiding their work on Zika control and prevention.

Lt. Kimberly Edge and Christian Baldeviano examine a positive malaria blood smear at U.S. Naval Medical Research Unit 6. The unit, based in Lima, Peru, is now heavily involved in Zika virus research.

Photo Credit: Navy

NAMRU-6 also works with other Navy units like the Infectious Diseases Research Directorate, as well as with other governmental groups like the Centers for Disease Control and Prevention and the National Institutes of Health.

However, while agencies organizations groups like the NIH and CDC National Institutes of Health and the Centers for Disease Control and Prevention focus more intently on bench research, or lab-centered work, the Defense Department and military branches focus on translational research, Tthat is, testing ideas that are meant to serve a need, said Booz Allen’s Weightman said.

"I think they're comfortable having that role," Weightman said. "When (bench research) progresses, then DoD cherry-picks and directs what they can toward their needs."

Weightman, who served as an Army Mmajor Ggeneral in charge of medical research and development before retiring in 2009, estimates research costs about $2 billion a year within the Defense Department. But he said that most research is outsourced by the military to other groups. (Weightman was relieved of his command at Walter Reed Army Medical Center in 2007 following a series of articles by the Washington Post on conditions at the center)

And while labs like NAMRU-6 are equipped to respond to serious disease outbreaks, they also provide early warnings on emerging illnesses around the globe.

"One of the keys is surveillance. If you can improve your surveillance, it gives you more time to respond when you see an outbreak emerging," Jackson said. "It just needs to be noted that continuous funding is important, because you don't know where the next threat is going to come from."