Grunt: The Curious Science of Humans at War Read online

  § The dose makes the poison. In small amounts, a mimic of the cholera/ETEC toxin is an effective treatment for constipation (in particular, the constipation that afflicts a third of irritable bowel syndrome sufferers). In 2012, Ironwood Pharmaceuticals released a synthetic version that was promptly forecast by one pharmaceutical market researcher to achieve “blockbuster status,” and what could be more fitting for a constipation drug?

  ¶ I tried, but I cannot tell you who decided how much toilet paper to include in MREs, or how. But I can tell you a lot of other things about the TP, because I found the federal specifications, ASTM D-3905. I can tell you the required tensile strength, wet and dry. I can tell you the colors it’s allowed to come in (white, dull beige, yellow, green), the minimum grammage and basis weight, the percentage of postconsumer fiber, the required speed of water absorption. And maybe that’s our answer right there. Because if your anus is as securely clamped as the anus of whoever is in charge of “toilet tissue used as a component of operations rations,” ASTM D-3905, you probably don’t need much.

  # Other bases require this at 4:30 or 5:00 p.m., when the flag is taken in. When the music begins playing, you stop what you’re doing and face the flag. I was at Natick Labs when this happened. Without explanation, my hosts stopped talking, turned, and solemnly faced a display model of a new containerized latrine standing in the sight lines of the flag. Having heard about the horrors of open-bay toileting, it seemed wholly appropriate for us to direct some respect, however unintended, to the Expeditionary Tricon Latrine System.

  ** Tips for hole-living: Double-bag your peanut butter sandwiches in gallon Ziplocs, as the bags serve double-duty as the toilet. Bring cat litter to put in the bags in case diarrhea strikes, which it does reliably enough that the man who told me this, an air strike controller just back from Niger, was confronted by his commander wanting to know why Special Operations Command was requisitioning kitty litter.

  †† The clean-shaving rule began with the gas attacks of World War I. Whiskers compromise the airtight seal of a gas mask. (Special Operators are exempt because they may need to blend in with bearded Muslim locals, and because they’re Special.) There were also some hygiene concerns. In 1967, the Department of the Army undertook an investigation entitled “Microbiological Laboratory Hazard of Bearded Men.” To see whether bearded sixties bio-warfare lab workers might be putting their family members at risk via “intimate contact,” the researchers fashioned some human hair beards, contaminated them with deadly pathogens, and attached them to manikin heads. The heads then became intimate with some chicks. “Each of three 6-week-old chickens was held with its head alternately nestled in the beard and stroked across one-third of the beard (one chicken on each side and one on the chin).” When the beards were washed according to lab safety protocol, none of the nine chicks exposed to the highest concentration of the virus became infected. The heads with unwashed beards, however, transmitted deadly disease to the chicks with whom they’d been intimate. The chicks died, and the heads were never really the same after that.

  ‡‡ Dale Smith, a historian of military medicine at the Uniformed Services University of the Health Sciences, is dubious. Bollet, he says, drew the conclusion from one man’s story. Certainly no such etiquette prevails among military historians, who take any opportunity to shoot each other down.

  §§ How did Mexico become the poster child for travelers’ diarrhea? One hypothesis, mine, points a finger at the godfather of diarrhea research, Herbert DuPont. For almost thirty years, DuPont ran studies out of Guadalajara, Mexico. If you plug “Guadalajara” and “diarrhea” into the PubMed database, you get forty-five journal articles and a persuasive argument for changing your holiday destination to Switzerland. (“Enteric pathogens in Mexican sauces in popular restaurants in Guadalajara . . .”; “Coliform contamination of vegetables obtained from popular restaurants in Guadalajara . . .”; “Coliform and E. coli contamination of desserts served in public restaurants in Guadalajara . . .”)

  There has been at least one well-intentioned effort to clear Mexico’s name. The author of a paper in California Medicine had read that Mexicans often get travelers’ diarrhea when they visit California. She wondered if perhaps the stress of travel, rather than poor sanitation, was to blame. She interviewed 215 foreign UCLA freshmen and 238 American freshmen about “changes in frequency and consistency of stools.” None of the foreign students appeared to have had travelers’ diarrhea, though it was difficult to tell because many “did not understand the interviewer’s terms.” You can see where “watery stool” or “explosive diarrhea” might be confusing, frightening even, for the non-native speaker.

  The Maggot Paradox

  Flies on the battlefield, for better and worse

  IN A MEMORABLE CARTOON from my formative years, a well-dressed man with a goatee is seated at a restaurant table across from a fly. It’s a giant fly, a fly large enough to fill a dining room chair much the way a person would. The man addresses a waiter. I’m paraphrasing here. “I’ll have the gazpacho, and some shit for my fly.” It was a commentary on flies, or perhaps an observation on the odd human habit of elevating nutrient intake to social ritual. Or maybe just this: No matter how fond you are of a fly, dining out together is going to be awkward.

  And the cartoonist only drew the half of it. Because flies have no teeth, they must first liquefy what they plan to eat. (Or order the gazpacho.) This they do by applying their digestive enzymes outside their body. The process was captured on film and included in the 1940s British Army hygiene filmstrip The Housefly. “Their vomit is puddled about your food to make a kind of porridge,” says an incongruously posh-sounding narrator, “which the fly then sucks up.” Technical Guide No. 30 (Filth Flies) of the US Armed Forces Pest Management Board would also have you know that “flies further contaminate food by defecating on it while they feed.”

  No flies of any size are eating at Mi Rancho Mexican restaurant in downtown Silver Spring this evening, but some fly biologists are here, and that can be equally disquieting. We’re talking now about those out-of-body digestive enzymes. A researcher I had spoken to the previous week referred to the salivary glands, not the stomach, as the source. For clarification, I have turned to one of my dinner companions, George Peck, resident filth fly expert at the Entomology Branch of the Walter Reed Army Institute of Research (WRAIR), just down the road.

  “I think it’s both,” Peck is saying. “They vomit up enzymes from the crop along with the saliva and let it—”

  “Are you all done here?”

  Peck looks up to acknowledge our waitress. “I am, thanks . . . and let it fall onto the food.”

  With George Peck, the topic of flies and their unusual physiology doesn’t elicit disgust. Awe, mostly. I have heard him marvel at the sensitivity of the fly’s body hairs, how they enable it to detect the bow wave of an approaching hand and lift off in the split second before contact is made. He talks about the halteres, tiny gyroscopes that enable the fly to hover or change direction “faster than the fastest flight computer on any jet.”

  Less awesome: Researchers in Japan established that the strain of E. coli known as 0157:H7—deadly outbreaks of which periodically make headlines in the United States—thrives in housefly mouthparts and frass.* Bacteria on or in filth flies have been shown to transmit typhoid fever, cholera, dysentery, and a whole wet bar of lesser diarrheal infections. (Both houseflies and blowflies fall under the grouping “filth flies.”) British researchers documented a close association between filth fly populations and cases of food poisoning from the campylobacter bacterium, both of which peak during the warmest months. (The English used to speak of “summer diarrhea”—loose stools and cramping having joined warm nights and fireflies as hallmarks of the season.) In a 1991 study, an Israeli military field unit that undertook an intensive filth fly control program saw 85 percent fewer cases of food poisoning than a similar one that did not.

  The Armed Forces Pest Management Board’s filth fly tech
nical guide includes a figure for the number of times in twenty-four hours that a single fly vomits and defecates on its food after a controlled feeding of milk. The figure, a range from 16 to 31, was arrived at not by staying up all night watching but by counting “fecal spots” and “vomit spots” (the latter distinguishable from the former by their lighter color). The reader is invited to speculate about the number of “spots” on food in a military chow line in the era before sealed dining facilities. Fly infestation in the mess halls of the Vietnam War, the guide relates, was so intense that “it was difficult to eat without ingesting one or two . . .”

  Infestations still happen, mostly in the rough and not entirely ready first few days or weeks of a war. Early on, weapons and ammo take priority over latrines and refrigeration units in terms of what supplies get shipped. During the first Gulf war, Marines arrived in the region via the port of Jubail, where the Saudis housed them in a warehouse. “We had ten thousand Marines and two squat toilets,” recalls Joe Conlon, a retired Navy entomologist. The toilets soon clogged and sewage ran in the streets. Meanwhile, with no refrigerated storage, pallets of produce began piling up on the dock in the 100-degree heat. Thousands of flies converged. Conlon estimates 60 percent of the Marines got sick.

  Historically, battlefields were even worse. Combat is a filth fly cornucopia—a bounty of rotting organic matter to eat, to lay eggs in, to nourish the offspring. On Pacific islands during World War II, says the Armed Forces Pest Management Board guide, “flies developed in corpses on battlefields and excrement in latrines to levels beyond modern comprehension.” A similar scenario developed in the aftermath of battle in El Alamein, Egypt, prompting officers of the British Eighth Army to mandate fly death quotas—each soldier responsible for killing at least fifty flies a day. During the Vietnam War, corpses became so heavily infested with maggots that pesticides had to be used inside body bags.† In Conlon’s camp on the Kuwait border, accumulating garbage exacerbated the problem. The Marines weren’t allowed to burn it—the normal disposal strategy—because the fires would give away the camp’s position. (The garbage eventually became part of military strategy. It was hauled away under cover of darkness and burned at a distant site, to trick the Iraqis.)

  Nowhere was the filth fly situation more dire—or perhaps just more memorably documented—than in the American Civil War. “Few recruits bothered to use the slit trench latrines . . . ,” wrote Stewart Marshall Brooks, in Civil War Medicine. “Garbage was everywhere . . . [alongside] the emanations of slaughtered cattle and kitchen offal.” Entomologists Gary Miller and Peter Adler, in a paper on insects and the Civil War, quote a letter by an Indiana infantryman describing the scene: “The deluge of rain which had fallen . . . soaked the ground until the whole face of the earth was a reeking sea of carrion. . . . Countless thousands of green flies . . . were constantly depositing their eggs . . . which the broiling sun soon hatched into millions of maggots, which wiggled until the leaves and grass on the ground moved and wiggled too.”

  You can imagine what might happen to the open wounds of a soldier lying on a battlefield for any length of time. Most likely you would be wrong.

  THE SOLDIERS, two of them, are not named, nor is the battlefield on which they were hit. We know that it happened in France during World War I, sometime in 1917. We know that it wasn’t winter, because the men arrived at an army hospital having lain “in the brush” for seven days. And because it was fly season.

  On removing the clothing from the wounded part, much was my surprise to see the wound filled with thousands and thousands of maggots. . . . The sight was very disgusting and measures were taken hurriedly to wash out these abominable looking creatures. Then the wounds were irrigated with normal salt solution and the most remarkable picture was presented. . . . these wounds were filled with the most beautiful pink granulation tissue that one could imagine.

  That’s US Expeditionary Forces surgeon William Baer relating the story of how he came upon the unseemly idea of intentionally infesting wounds with maggots to help them heal. Filth fly larvae—blowfly maggots, most notably—prefer their meat dead or decaying. When the meat is part of an open wound, the act of eating performs upon the meal a kind of natural debridement. Debridement—the removal of dead or dying tissue—fights infection and facilitates healing. Because dead tissue has no blood supply and thus no immune defenses, it’s easily colonized by bacteria. This encourages infection of the healthy tissue and inflammation, which slows healing.

  Baer was impressed that the soldiers had no fever or signs of gangrene. The mortality rate from the type of injuries the men had—compound fractures and large, open wounds—was about 75 percent with “the best of medical and surgical care that the Army and Navy could provide.” In 1928, a decade after the war had ended, Baer summoned his courage and experimented on civilians. His inaugural patients were children, four of them, all with recurrent bone infections from blood-borne tuberculosis, a condition that antiseptics and surgery sometimes failed to quell. Raymond Lenhard, the author of a biographical monograph on Baer, recalled hearing the great surgeon tell the story. Lenhard had been a student of Baer’s at Children’s Hospital School in Baltimore and, reluctantly, a dining companion. (“Often during lunch he would make us lose our appetites.”) Using the offspring of blowflies trapped near the hospital, Baer “loaded up” a wound and proceeded to watch the results. After six weeks, the wound had healed. As did the wounds of the other three children.

  What sort of person experimentally infests a child with maggots? A confident sort, certainly. A maverick. Someone comfortable with the unpretty facts of biology. Someone who is perhaps himself an unpretty fact of biology. “The Chief was overweight, breathed audibly, and snorted in the fashion of a tic,” wrote Lenhard. Baer would sometimes go from operating room to lecture hall without changing, delivering his talks in baggy, bloodstained surgical trousers. He bred Chow Chows at his home, bringing yet more snorting and audible breathing to the Baer household.

  Beneath the earthy exterior, Baer was an exacting and dedicated practitioner. He considered his “maggot treatment” far less abhorrent than the alternative: amputation. To Baer, the removal of a limb was “the ultimate in destruction,” wrote Lenhard, showing a flair for video game marketing eighty years premature.

  So impressed was Baer by the work of his larval “friends” that he designed and built a thermostat-controlled wood and glass fly incubator at the hospital. Only thrice in an ensuing eighty-nine cases did the maggots fail and the patient succumb to infection. Fearing that the larvae may have introduced the offending bacteria, Baer devised a protocol for raising sterile specimens. Remnants of his technique live on today at Monarch Labs, in Irvine, California. Their Medical Maggots are also sterile, as required by the Food and Drug Administration (FDA), which in 2007 approved live blowfly larvae as a medical device.

  While the majority of modern “maggot therapists” treat the hard-to-heal foot ulcers of diabetics, WRAIR’s George Peck has been seeking to take medicinal maggots back to their roots in the military. In 2010, he was funded for a study looking into the efficacy of blowfly larvae in treating chronically infected IED wounds. More recently, Peck received a grant to genetically modify blowfly maggots such that they produce antibiotics. Though maggots already prevent infection, these “supermaggots” could be tailored for specific bacterial infections.

  Peck offered to hatch a “clutch” of maggots for me, taking care to time things such that when I arrive at his and his wife’s home for dinner, the larvae will be the size of Medical Maggots at the time they’re released in a wound (about two millimeters long). I don’t have any wounds. Just questions.

  GEORGE PECK and his future wife, Vanessa, worked together in the basement insectary at WRAIR. An insectary is a facility for rearing insects—insects used, in this case, for testing vaccines and repellents against whatever has been lately plaguing troops. Vanessa cared for a colony of sand flies,‡ while George was down the hall with his filth flies. It’s a
setting that might dampen the ardor of another pair, but Peck remains besotted. You hear it behind his words when he talks about her. Peck is a man easily taken by emotion. At Mi Rancho a few nights earlier, as we were getting ready to leave, the topic turned briefly away from flies. As I rose from my chair I heard Peck say, to no one specific, “I just love bees.” The word love breathy with feeling.

  Peck abandoned a career in solar physics, because he felt it was taking him too far away from the natural world. He and Vanessa share their home with more of that world than most. They keep as pets a tarantula (Henrietta) and a small community of Madagascar hissing cockroaches. Like William Baer, Peck is a man some might find eccentric, but those who know him even slightly can see that it all comes down to a generous and open heart.

  Vanessa clears the dinner plates while I finish my wine. The children are doing homework in the living room. George sets a glass dessert dish in front of me. Chocolate pudding, my brain offers optimistically, but it’s not that. It’s raw liver.

  “These are about one day old.” Peck points out a cluster of maggots, maybe twenty or thirty, feeding side by side, packed in close. They’re easy to miss, because all that can be seen of them is their tail ends. Insects take in oxygen through openings in the exoskeleton called spiracles. In the larvae, these are, specifically, anal spiracles. On top of its other charms, the maggot breathes through its ass. It is a handy evolutionary adaptation if, as Peck puts it, “you spend your whole day with your head buried in slimy dead flesh.” Compared to lungs and a diaphragm, it’s an inefficient system, which is one reason the Insecta class never evolved to be as large as Mammalia. Having several minutes ago viewed a fly under George Peck’s home microscope, I assure you that’s a good thing.