Mary Roach - Grunt

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 antibiotic-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.