MONROVIA, Liberia (Dec. 4, 2014) -- During the American Revolution, George Washington used part of the Continental Army's scarce budget to purchase quinine for the treatment of malaria in his troops.

According to Professor Dale Smith, a military medical historian at the Uniformed Services University of the Health Sciences, the U.S. military counted more than a half-million cases of malaria, during World War II.

"This will be a long war, if for every division I have facing the enemy, I must count on a second division in the hospital with malaria, and a third division convalescing from this debilitating disease," said Gen. Douglas MacArthur, commander of Allied Forces in the Pacific Theater, during World War II.

The U.S. armed forces have had a bitter, long-standing battle with malaria. Despite continuous research and advances in antimalarial medicine, this parasitic disease, spread by infected Anopheles mosquitoes, continues to threaten the health of the U.S. military.

In 2003, about 300 Marines deployed to Liberia for a military peacekeeping operation; however, the mission failed due to 80 cases of malaria within the first three weeks.

In October 2014, Service members returned to Liberia for Operation United Assistance, an operation supporting the U.S. Agency for International Development-led efforts to contain the Ebola virus outbreak in western Africa. The fight against Ebola, however, poses a significantly smaller threat than malaria.

"Right now, based on current statistics, someone who is unprotected from malaria has a 50 percent chance per month of getting malaria in Liberia," said Capt. Neel Shah, physician and Barclay Training Center aid station officer in charge, Joint Forces Command-United Assistance. "Mathematically, statistically, in every way you look at it, malaria is the biggest killer."

According to U.S. Africa Command, the vast majority of DOD personnel in Liberia will have no contact with patients with Ebola.

"We pretty much have zero exposure risk to Ebola right now, and 100 percent exposure risk to malaria," said Maj. Benjamin Platt, physician, Army Medical Support Company, Joint Forces Command - United Assistance.

With 90 percent of the world's malaria-related deaths reported in Africa, and the devastation it caused to military operations, the Department of Defense budgets approximately $8 million per year in malaria vaccine research, according to PATH, an international, nonprofit, health organization who heads the Malaria Vaccine Initiative.

Troops deployed in support of Operation United Assistance received antimalarial medication, special equipment and clothing to prevent mosquito bites and infection. Extra precautionary measures are also in place to prevent mosquito breeding grounds such as eliminating standing pools of water and vector spraying.

Soldiers have been issued mosquito nets and tents to cover their cots, insect repellent for their skin, uniforms treated in insect repellent and prescription drugs, said Platt, a Wyoming native.

The U.S. Army predominantly distributes the antimalarial medications Doxycycline or Malarone, said Shah. Doxycycline is generally used in places like Afghanistan, where the threat of malaria is significantly less than in West Africa. Although Malarone is about 60 times more expensive per pill compared to Doxycycline, the efficacy of Doxycycline drops to zero if you miss a dosage. Malarone will stay in the system for a day or two in the event a Service member misses a dose, he said.

Despite the increased price, the DOD has decided to spend whatever it takes to protect Service members and DOD personnel, said Platt.

"Each individual Soldier has been given all the tools to protect himself from malaria," said Platt. "It's now up to the individual Soldier to use those tools to protect himself. If he doesn't do it, it's on his shoulders."

Leaders are expected to engage Soldiers often and ensure they're taking their medications; however, complacency can also pose a threat to troop health.

Shah said he encourages Service members to not get too comfortable, and not forget the life-threatening risk of malaria.