Malaria: Military Enemy No. 1
By Douglas J. Gillert
American Forces Press Service
WASHINGTON, July 30, 1996 In the 15 years since the epidemic began, health organizations estimate between 2.5 million and 5 million people have died from AIDS. During this same time frame, malaria killed nearly 50 million.
There's more malaria in the world than ever, according to Navy Dr. (Capt.) Stephen L. Hoffman, director of the malaria program at the Naval Medical Research Institute, Rockville, Md. And due to global climate changes, Hoffman said, experts predict the existence of malaria could double in the next 50 years.
For the military, Hoffman said, this spells trouble.
"In every [U.S.] military campaign this century," Hoffman said, "we lost more casualties to malaria than bullets. " During World War II and the Vietnam War, entire divisions ceased to be effective combat units due to malaria, he added.
Six of the last seven U.S. troop deployments were to malarial regions (Bosnia is the exception). "In Somalia and Operation Restore Hope, malaria was the No. 1 cause of casualties," Hoffman said. Under the most heavily enforced discipline for taking medications, one Marine unit suffered a 10 percent attack rate in a single month.
In sub-Saharan Africa -- Kenya, for example -- the malarial attack rate would be much worse, Hoffman said. "If 50,000 troops [deployed to] Kenya sustained a 25 percent attack rate, the direct costs of malaria [treatment] would be $11 million to $30 million, and that force would cease to be operationally effective."
Currently, service members deployed to malarial regions take drugs to avoid infection. "All [malaria] drugs licensed and used in the United States and much of the world were developed by DoD," Hoffman said. Service members take either Mefloquine weekly or Doxycycline daily. The Navy is testing a third drug, Primaquine, that also would be taken daily.
Drugs, however, aren't always effective, Hoffman said, and researchers are discovering more and more strains of drug-resistant malaria.
The malaria parasite enters the body through mosquito bites. Uncomplicated malaria causes high fevers, chills, headaches and muscle pain, Hoffman said. Treated properly, victims are laid up anywhere from a few days to several weeks. If malaria isn't treated properly -- or the medication doesn't work -- victims may develop kidney, liver and lung problems.
The most serious complication affects the brain, and victims at this advanced stage become disoriented, delirious and often comatose. Hoffman said it's not unusual, however, for malaria victims to hallucinate within a week of becoming ill, but then fully recover.
Because of the enormous costs in dollars and human misery, Hoffman said, medical researchers rank malaria as the top priority for new and better drugs and, ultimately, vaccination. And because malaria severely impacts military readiness, DoD leads the development effort, Hoffman said.
"We continue to develop and license new drugs, but they have to be taken every day and for four weeks after you leave the malarial region," he said. "We know people don't always do that. The most efficient, cost-effective and easiest way to prevent any infectious disease is with a vaccine."
The problem is, nobody's ever made a vaccine against a complex parasite like malaria. A micro-organism with multiple stages of life, malaria lives near a blood stream in the liver as well as inside and outside cells in the blood stream. It exists at a different stage in mosquitoes.
To be effective, a vaccination must attack the parasite at all stages of its life cycle, Hoffman said. "Developing this vaccine requires whole new types of technology, which we're at the forefront of, but it takes time. We've made enormous progress and should field a vaccine in five to 10 years."
Other agencies, including the National Institutes of Health, Centers for Disease Control and World Health Organization, seek a malaria vaccination as well, but their objective is different from DoD's. "They're interested in preventing death from malaria, and their first objective is sub-Saharan Africa," Hoffman said. DoD, on the other hand, wants a vaccination that would protect people from ever getting sick with malaria.
Hoffman foresees a vaccine that will last about a year. "Eventually, we would like a vaccine that would be lifelong," he said. "However, it has to offer lifelong protection against infection, which is far different from lifelong protection against disease.
"If we can make children in Africa not die from malaria, that will be an amazing contribution, because it will wipe out millions of deaths a year. But that's not good enough for DoD," Hoffman said, "because [to sustain operational capability] military people can't get malaria at all."