Grunt: The Curious Science of Humans at War

by Mary Roach

  William Baer likened clusters of feeding maggots to litters of puppies. “So voracious are they in their struggle for food that they will stand upright on their heads with their tails in the air, as puppies do . . . around a basin of food where the basin is too small for the number of puppies.” Baer had dogs on the brain. To me, they look like a set of tiny accordion buttons being played by some ghost polka virtuoso. The important thing, especially for someone being treated with them, is that they don’t look like maggots. So if a patient peeked beneath the trademarked Monarch Labs LeFlap dual-layered maggot cage dressing, he would not be slammed with a squirming Halloween horror visual.

  Peck transfers three outliers to the tip of my index finger. They rear up and wave their heads like happy Sesame Street puppets. Peck says they’re searching for food. Now two are lifting the third up above them. They remind me of jubilant teammates after a sporting victory.

  Peck isn’t reading joy in the scene. “They do cannibalize,” he says gently.

  Upon closer inspection, they are, yes, attacking—eating!—their clutch mate. They were away from the liver for maybe two minutes! The maggot lives to eat. That is what it does, all it does, for the four or so days before beginning the energy-intensive, deeply sci-fi project of rearranging itself into a fly.

  Peck puts a maggot under the microscope he has set up on the kitchen table, so I can get a closer look at the mouthparts: the showpiece of maggot anatomy. They are rasping, curved scythe-like things. They’re the only piece of the maggot formed from chitin, hard and brown in contrast with the creature’s moist, pale, flexible self. Fortunately for maggot debridement therapy patients, the tissue deep inside a wound—dead or alive—has no sensory nerves; those are up in top layers of skin. Provided the Medical Maggots recommended “dosage”—5 to 8 maggots per square centimeter of wound surface—hasn’t been exceeded, there should be enough dead tissue to go around, and no ravenous maggot will shift its gaze to live skin.

  “Those little mandibles,” Peck says as I look through the eyepiece, “can do what no surgeon or scalpel can do. No robotic laser can bend its light into a hidden crevice from an IED blast like that can. That is the master surgeon.” If you want to destroy every last bacterium and shred of dead tissue, a maggot is your man. He’s a small man, though, so it takes a while. A course of maggot debridement therapy—up to six rounds of fresh larvae—may take weeks. Whereas surgical debridement can be done in a matter of hours. And if a patient’s immune system is healthy, as a young soldier’s tends to be, it’s not necessary to get every last cell of bacteria and necrotic flesh.

  But Peck never suggested that maggots be used for the initial debridement of a blast wound. For military personnel, maggots would come into play further down the road, should a recalcitrant infection set in—some antibiotic-resistant strain, perhaps something exotic and stubborn that lurked in the dirt that was blasted so deeply and voluminously into the wound. These complications set in often enough that Peck received military funding for a rodent study to measure the effectiveness of maggot debridement therapy for soil-infected IED wounds. The experimental protocol presented challenges. It required Peck’s team to surgically mimic, in a rat, the typical injuries caused by a bomb blast. To meet the requirements of the animal review board—and Peck’s own personal ethics—no part of the process could be painful to the rat. The nerves supplying feeling to that portion of the body had to be identified and severed.

  Peck’s funding was not renewed, for reasons that are fairly easy to guess at. Modern hospital culture is technology-driven and forward-looking. To those unfamiliar with the studies and success rates, maggot therapy sounds primitive, anachronistic. Peck recalls presenting some promising preliminary findings to a roomful of colleagues and listening while a disapproving colonel talked about the thirty years of advancements he’d seen in his time at WRAIR. The man shook his head. “And we’re using maggots.”

  A 2012 survey of US Army physicians suggests that the colonel’s opinions are not those of the majority. While only 10 percent of those surveyed had prescribed maggot debridement therapy, 85 percent felt that having access to practitioners would be a good resource. Their reservations were mostly just practical: They didn’t know where to obtain the maggots or how to use them or what the billing code might be.§ In a smaller survey, practitioners voiced concerns that the medical facility they worked for wouldn’t allow maggots, and that patients would be likely to balk.

  They are wrong about the patients. The surgeon who runs the Southern Arizona Limb Salvage Alliance,¶ David Armstrong, has applied maggots to more than a thousand patients. “I can count on one hand the number of people who have refused,” he told me. The Medical Maggots FDA approval summary cited a “complaint and adverse event” rate of 1 percent, many of these occasioned by “late or lost” (or perhaps hurled into a Dumpster by the driver) FedEx shipments. The yuck factor of these wounds—and their resistance to more conventional treatment—well overrides the yuck factor of hosting live blowfly larvae. Also, Medical Maggots are less off-putting than you might imagine. Straight out of the vial, they’re the size of cupcake sprinkles. When they’re not eating each other alive, they’re kind of adorable. They move like inchworms, like something you might see humping along the pages of a children’s book.

  “People take an interest in the cute little guys,” Armstrong said, quickly amending his statement with “. . . and gals.” You mean, I asked him, the way one might follow the progress of seedlings one has planted, or guppies one is raising? “Exactly,” he said. “And then, in turn, the progress of the healing going on. It’s hard to describe it, but the larvae draw people into the wound emotionally.” Medical Maggots patients, some anyway, are sufficiently positive and cavalier about their infestations that they go around wearing Monarch Labs t-shirts that proclaim, “Maggots on Board!”

  Hospital staff are less charmed. “A lot of doctors and nurses find it repulsive,” Armstrong told me. Colonel Pete Weina, former director of the Complex Wound and Limb Salvage Center at WRAIR and now their chief of research programs, agrees. Around 2009, Weina had a William Baer moment. “I had a patient who’d passed out in an alley and flies had come by and laid eggs in his wound. The nurses were all, ‘Oh my God, this is terrible, get the maggots out of there!’” Recalling what he’d read about the blowfly larvae’s talent for debridement, Weina improvised a cage dressing to keep them from straying and left them in. The wounds healed nicely, but Weina backed away from the practice. “The entire hospital was pretty much grossed out by what I was doing.”

  While not discounting what he calls “the gross factor,” George Peck sees cost as the main hurdle. How is it, you might ask, that maggots are more expensive than surgeons? It’s not the creatures themselves; a vial of Monarch Labs maggots is priced at $150. It’s the time demands on medical staff—staff who have to be trained to monitor the maggots and change the dressings. Peck shows me a second bowl of liver and maggots, hatched two days earlier. “See how foamy and goamy it is in there?” With, say, a hundred maggots, he explains, the breathable mesh of the cage dressing quickly becomes nonbreathable. The larvae suffocate. The nurses are repulsed.

  Changing a maggot dressing is trickier—and creepier, and goamier—than changing other kinds of wound dressings, because you are also changing the insects. Each dose must be completely wiped out—literally, with a piece of gauze—before the next is introduced. Overlooked maggots that continue growing will soon be gripped by an urge to pupate. After a few days of gorging, fly larvae abandon the juicy chaos of their childhood home and set out to find a dry, quiet place in which to build a cocoonlike “puparium” and become a fly.

  There is an understated line in the Medical Maggots package insert: “Escaping maggots have been known to upset the hospital staff . . .” One, they’re maggots. Two, they’re about to be flies. Flies in the medical center. Flies in the operating room. Landing on open wounds. Vomiting and defecating. Moving on to other wounds, spreading the antibioti
c-resistant pathogens they’ve picked up on their feet. Physician Ron Sherman, Monarch Labs’ founder, started out raising maggots in a closet at the VA hospital in Long Beach—a closet that “became quite spacious once everyone found out what I was doing.” The moment a fly would get loose, the administration jumped on him. Sherman has since moved his “living medicine” operation to a warehouse near the Irvine airport, where he raises maggots, leeches, and fecal bacteria (for transplants). I can imagine the company’s Schedule C taxable expense form simultaneously attracting and deflecting a visit from the IRS.

  FILTH FLIES are lured by the odor of decay: a whole body or sometimes just a part. A moist, rank, infected body opening—be it a wound or a natural cavity—is a VACANCY sign to a gravid female. When maggot infestation shows up in a medical journal, it’s generally accompanied by the technical term for it, “myiasis,” and a revolting photographic close-up of the infected, infested part: gums, a nostril, genitals.

  Here again, some words from the Armed Forces Pest Management Board: “Vaginal myiasis is a concern of increased importance because of the larger numbers of women serving in deployed units. . . . Egg laying may be stimulated by discharges from diseased genitals.” In a hot climate, there might be a temptation to sleep outside uncovered, the board points out. And the kind of soldier who sleeps outside with no underpants would also, I suppose, be the kind of soldier with a genital disease. The kind headed for “dishonorable discharge” of one kind or another.

  And finally, there is “accidental myiasis,” typically of the intestines. The tale unfolds like this: The patient espies maggots in or near his daily evacuation and assumes he has shat them out. He further assumes—as does his doctor—that he accidentally ate some food infested with fly eggs. One hyperventilating MD, writing in a 1947 issue of British Medical Journal, claimed that the “resistant chitinous coating of the egg” survives the acids and enzymes of the stomach, enabling the larvae inside to travel unharmed to the less hostile environment of the intestines, where they would hatch and set up camp.

  To the rescue, in the form of a letter to the editor, comes F. I. van Emden, of the Imperial Institute of Entomology. Does it not make more sense that the larvae were hatched not inside the patient but inside—as Van Emden put it, giving toilets and bedpans the ring of religious sacrament—“a vessel used for receiving . . . the excrements”? Furthermore, Van Emden points out, insect eggs are not made of chitin. The “shell” is a fine, thin, permeable membrane. To prove his point, Emden set up an experimental tabletop stomach, a mixture of warmed gastric juices and chewed bread, into which he placed eggs and larvae of the species in question. The larvae, including those inside eggs, were killed.

  To any in need of further reassurance, I give you Michael Kenney, of Governmental Medical Services for the city of Katanga in the Belgian Congo, circa 1945. Presumably the GMS was an agency providing health care for indigents. “Sixty human volunteers . . . ,” Kenney wrote, in Proceedings of the Society for Experimental Biology and Medicine, “were fed living maggots” of the common housefly, encased in large gelatin capsules. It’s unclear whether the larvae—twenty per subject!—were encapsulated individually or inhabited one large community capsule, but either way it took two glasses of water to get them down. A third of the time, the capsules were vomited up shortly after they were swallowed, their passengers still for the most part alive. In the remaining two-thirds of the subjects, diarrhea with dead maggots ensued. An “occasional” maggot survived the odyssey, but that doesn’t mean the volunteer was infested. A brief transit through the alimentary canal is different from settling in and passing your childhood there. All the volunteers’ symptoms cleared up within forty-eight hours and no further maggots appeared. This suggested that, first, fly larvae “do not produce a true intestinal myiasis in man.” And second, there’s no such thing as free health care.

  It’s almost 8:00 p.m. at the Peck residence. George has brought out a tray of pinned insect specimens. I’m distracted at the moment by a live one.

  “George?”

  “Mm?”

  “You have a large, somewhat frightening insect on your shoulder.”

  Peck doesn’t bother to confirm this. Without removing his gaze from the tray, he says, “It’s probably a brown marmorated stink bug.” This time of year they’re apparently everywhere. He explains that the name derives from the smell released when the bug is crushed. This one isn’t crushed but carefully escorted out the screen door into the deepening Maryland dusk. Peck sits back down at the kitchen table. “They’re beautiful under a microscope.”

  SETTING ASIDE George Peck—an act I’ve put off for as long as possible—most of the military’s filth fly researchers are down in Florida. The Navy Entomology Center of Excellence (NECE) is located in Jacksonville, about an hour’s drive from colleagues at the US Department of Agriculture Mosquito and Fly Research Unit. NECE serves as the military’s pest control arm. It is a job that will go on forever. Because new generations come and go in a matter of weeks, flies quickly evolve resistance to whatever new pesticide they’re hit with. There will always be some with a mutation that helps them survive, and those survivors and their rapidly proliferating spawn will repopulate the area, laughing at the humans with their misters and foggers and truck-mounted sprayers.

  The flies of the Gulf wars are recalled as maddeningly persistent, a function of food’s relative scarcity in the desert. During Operation Desert Shield, Navy entomologist Joe Conlon camped with a light infantry battalion in the Saudi Arabian desert near the Kuwait border. The flies served as an unpleasant but effective alarm clock. “You’d be asleep with your mouth open. Soon as dawn came the flies would be out, looking for food and moisture. They’d fly right in your mouth. You’d wake up to the sound of Marines coughing and cursing.” USDA fly researcher Jerry Hogsette told me about a team of entomologists in Operation Desert Storm who drove off into the empty desert until they could no longer see the base, stopped, and opened a can of sardines. Within seconds, there were flies.

  The fly’s tenacious commitment to humans and their filth explains the military’s enduring commitment to extermination: Soldiers constantly waving off flies are soldiers poorly focused on their job. When the job involves shooting and not getting shot, that’s a hazardous distraction. With livestock, too, the distraction can be lethal. Hogsette says a cow can become so focused on shooing flies that it forgets about eating and starves. The agricultural community uses the term “fly worry.”

  The Gulf wars saw a related condition: insecticide sprayer worry. Shortly after the United States arrived in Kuwait, military intelligence determined that Saddam Hussein had purchased forty insecticide sprayers. With all the talk of “weapons of mass destruction,” paranoia was running high. Joe Conlon was brought in to assess the likelihood—and the danger—of the devices’ being used to disperse chemical or biological weapons. He deemed it unlikely. “You can’t control where the cloud goes. You’re just as likely to poison your own troops.” Conlon’s professional opinion was that Saddam Hussein wanted to kill some flies.

  High-volume fly traps are a popular tool on military bases, because they’re low-maintenance. Here the artistry is in the lure. NECE has tested different wavelengths of ultraviolet light, varied background colors, and all manner of chemical attractants. There was a fleeting moment, during World War II, when fly attractants played a more strategic battlefield role. Nazis had poured into a Spanish enclave of Morocco with the aim of cutting off the Allied supply line to troops fighting Erwin Rommel’s Afrika Korps. The Pentagon called upon Stanley Lovell, director of research and development for the Office of Strategic Services or OSS (precursor to today’s CIA), to devise a way to quietly, as Lovell put it in his memoir, “take out Spanish Morocco.”

  “I evolved a simulated goat dung,” Lovell wrote, improbably. Spanish Morocco being a land with “more goats than people,” the decoy dung would, he reasoned, fail to arouse suspicion. The plan was to spike the turds with both a powerf
ul fly attractant and a cocktail of pestilent microorganisms and then drop them from planes during the night. Filth flies would take over from there: landing on the dung, picking up pathogens, and delivering their deadly payload to the Nazis’ meals.

  The OSS files in the National Archives and Records Administration include dozens of entries for gadgets and weapons dreamed up by staff,# but I found nothing under “goats,” “dung,” or Lovell’s name for the project, Operation Capricious. Lovell wrote that he and his colleagues were “well along” with it when word arrived that the Germans had withdrawn from Spanish Morocco. Perhaps. I suspected that the killing shit never made it further than the drawing board. Or, more likely, the cocktail napkin.

  And then I came upon an OSS file labeled “Who, Me?” And it was clear I had underestimated Stanley Lovell.

  ___________

  * Insect shit.

  † Post-Vietnam-era mortuary practice forbids this, as the pesticides could interfere with the chemical and genetic analyses done as part of an autopsy. Also verboten in morgues: electric fly zappers. They cause the flies to explode, scattering their DNA and the DNA of whatever bodies they’ve been crawling on. Military morgues rely on “air curtains” to keep flies out. The air curtain is a high-tech version of the “fly curtain,” the beaded strands that hang in doorways in Middle Eastern homes, allowing breezes, but not flies, to pass. Who among the thousands of youthful 1970s doofs who hung these in their bedrooms had any clue as to the beads’ provenance as fly control? Not this doof.

  ‡ Tobin Rowland, the man who now holds the job, gave me the WRAIR Insect Kitchen recipe for sandfly larvae food. Mix rabbit feces, alfalfa, and water, and pour into nine large round pans. Soak for two weeks, or until mold covers entire surface, yielding what WRAIR entomology director Dan Szumlas calls a “lemon-meringue feces” appearance. Let dry and grind. Rabbit dung is used because it smells better than cow dung, not because it’s cheap. Rabbit turds are more expensive than rabbits. WRAIR’s supplier, which holds a monopoly by virtue of no one else’s having wanted or thought to compete, charges $35 a gallon.