Grunt: The Curious Science of Humans at War

“Depends on the mission. You’re watching for something to happen that might not happen.”

“Right, and most likely you’re out in some village, and you’ve had to be eating stuff that’s not prepared as hygienically as—”

“Goat,” he says. I had heard a story earlier about a goat meal in rural Afghanistan. It contained the phrases “singed hair” and “otherwise uncooked.” Unsanitary conditions, Carey confirms, are a given. “Unfortunately, we don’t fight in first-world countries.”

Carey says he does not, as Mark Riddle had heard some men did, take antibiotics or Imodium prophylactically before the mission or after the goat. He takes one precaution. It is a strict rule among Special Operators. “You go to the bathroom before going into a danger situation.” There has been no shift from the gravely quiet tone with which Carey has been speaking. Nonetheless, Seamus blurts, “Kind of like a road trip with the family, and Dad’s like, ‘I don’t care that you don’t need to go.’”

On a family road trip, no one has you in the sights of a semiautomatic rifle while you squat in the dirt. Historian of military medicine A. J. Bollet quotes a letter written by a Civil War soldier who explained that an unwritten code of honor forbade the shooting of a man “attending to the imperative calls of nature.”?? In the war on terror, there’s no such etiquette.

I’m still trying to get Carey to tell the story of a specific high-stakes operation. “Have you have been in a situation where you’ve been—”

“Inabilitated?” I like this: a combination of inability and disabled. “Yes. I have been inabilitated because of food sickness.” Carey leans back, one arm along the back of the adjacent chair. “I’m not sure what you guys want from me.”

Seamus tries to help. “Can you walk us through the story. You know, like: There I was . . .”

Carey isn’t going to supply the There-I-Was. “I have many stories where I’ve soiled my pants on missions. In Iraq, I’ve soiled my pants. In Afghanistan, I’ve soiled my pants.” No one stays back or leaves to find a toilet once an operation is under way. Diarrhea cannot be a “kill stopper.”

“And then what happens?” Seamus leaning forward like a kid at story hour. “You go on to . . . do the job?”

“There’s no other option. I mean, it’s kind of a life or death thing. So.” He shrugs one shoulder. “You go. Worry about it later. As long as you walk out and the mission is accomplished. And that’s about as specific as I can get.”

I tell him about Mark Riddle’s TrEAT TD study. “You should bring along a single sixteen-hundred-milligram dose of rifaximin and a bottle of Imodium.”

Carey holds my gaze for a moment. “What is the objective here?”

I restate my mission. I show him my notebook, open to the page where Mark Riddle is describing what, for the purposes of his study, constitutes diarrhea (“has to be pourable or take the shape of the container”).

“Well, you’re in the wrong place, Mary.” Carey tells me to go down to Somalia. Yes, let’s picture it—middle-aged American with her cork-bed comfort sandals and wheelie bag, wandering the desert redoubts of the local al-Qaeda affiliate. Yoo-hoo! I’m looking for the Navy SEAL safe house?

“You could get yourself down there if you wanted to. It’s not dangerous.” He pushes two fingertips through the curl of his beard. “Well, it’s a little dangerous.”

Carey apologizes for the frosty reception earlier. “I thought you guys were NCIS.” Naval Criminal Investigative Service. “You scared me.”



CAREY IS right. People don’t get diarrhea by eating at Camp Lemonnier. They get it by “eating on the economy”: the Special Operators get it in remote villages, and everyone else gets it by going in to Djibouti City for a change of pace from spaghetti and Taco Tuesdays. Like you on your Mexican§§ holiday, they ingest contaminated tap water or food that’s been sitting out unrefrigerated. Before a downtown suicide bombing caused the base to be put on restricted liberty, a month before I arrived, Riddle was seeing two dozen food poisoning cases a week. During the past month, since everyone’s been confined to base, only one person—the guy who found a restaurant that delivers—has stepped through the door. Riddle catches up on paperwork. The lonely diarrhea researcher.

The Camp Lemonnier galley goes to lengths to keep bacteria away from the food. The entry hall is flanked by rows of knee-operated hand-washing stations, with pole-mounted Purell dispensers at the end of these. All well and good, but here’s what really matters. First, the cooks and prep crew wash their hands after they go number two. So if any of them has diarrhea, that person isn’t spreading the bacteria to food that then sits out at room temperature, allowing said bacteria to multiply to levels at which they cause illness. And second: There are no flies in the Dorie Miller Galley. Since the dawn of air-conditioning, military chow halls have been sealed. No one needs to open a window, and no one can.

It was as a result of this connection—fewer flies in the mess equals fewer gastrointestinal infections—that the filth fly was originally busted as a vector of disease. In 1898, during the Spanish-American War, a trio of army physicians, including the illustrious and eponymous Walter Reed, were called to Cuba to investigate an outbreak of typhoid fever that was killing one in five US troops. (It was Reed’s medical sleuthing that proved it was mosquitoes, not bad air or unclean bedding, that transmitted yellow fever.) Straightaway, the team noticed that the infection rate was lower among the officers whose mess tents had screens to keep bugs out. It also varied by the different camps’ methods of “disposing of the excretions.” Open pit latrines were associated with higher rates, possibly because, as Reed’s team wrote, “flies swarm over the infected fecal matter.”

Reed had his two suspects—flies and the bacteria-laden feces they feed on—but no smoking gun. Flies don’t bite. How were they transmitting the pathogen? One fine day Reed’s gaze fell upon a fly walking around on the soldiers’ food. Looking more closely, he noticed white powder on its little hairy legs. Where had he just seen a white powder? The pit latrines! Soldiers had been sprinkling lime in an attempt at camp sanitation. The flies’ feet were delivering bacteria from shit to stew. They’re what’s called a mechanical vector. Ten Salmonella enterica serovar Typhimurium isolates multiplying in a pot of beans in the warmth of a Cuban noon will be a million by dinnertime.

Reed’s legacy lives on in the Entomology Branch of the Walter Reed Army Institute of Research, my next destination. Military entomology runs the gamut you’d likely expect: killing disease-carrying insects, keeping them away from soldiers, and creating vaccines and treatments for the times when neither of those can be managed. In the case of filth flies, something less usual has been going on. Unlike in most military entomology war stories, the insect this time is the hero.