Tuesday, January 23, 2007

"The Invisible Enemy in Iraq"

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Wired News has a lengthy article, authored by Steve Silberman, about an antibiotic-resistant strain of bacteria that is killing hundreds of U.S. soldiers in Iraq and here in the States:

A homemade bomb exploded under a Humvee in Anbar province, Iraq, on August 21, 2004. The blast flipped the vehicle into the air, killing two US marines and wounding another - a soft-spoken 20-year-old named Jonathan Gadsden who was near the end of his second tour of duty. In previous wars, he would have died within hours. His skull and ribs were fractured, his neck was broken, his back was badly burned, and his stomach had been perforated by shrapnel and debris.

Gadsden got out of the war zone alive because of the Department of Defense's network of frontline trauma care and rapid air transport known as the evacuation chain. Minutes after the attack, a helicopter touched down in the desert. Combat medics stanched the marine's bleeding, inflated his collapsed lung, and eased his pain. He was airlifted to the 31st Combat Support Hospital in Baghdad, located in an old health care facility called the Ibn Sina, which had formerly catered to the Baathist elite. Army surgeons there repaired Gadsden's cranium, removed his injured spleen, and pumped him full of broad-spectrum antibiotics to ward off infection.

Three days later, he was flown to the Landstuhl Regional Medical Center in Germany, the largest American military hospital in Europe. He was treated for his burns, and his spine was stabilized for the 18-hour flight to the US. Just a week after nearly dying in the desert, Gadsden was recuperating at the National Naval Medical Center in Bethesda, Maryland, with his mother, Zeada, at his bedside.

The surgeons, nurses, medics, and pilots of the evacuation chain have saved thousands of lives. Soldiers wounded in Vietnam were six weeks of transit time away from US hospitals, and one out of every four of them died. By contrast, a soldier's odds of surviving battle injuries in Iraq are nine out of 10. Unfortunately, this remarkable advance in battlefield logistics has also resulted in an increase in the number of traumatically injured patients who are particularly susceptible to infections during their recovery. In Gadsden's case, from the moment he was carried into the Ibn Sina, the injured marine was in the crosshairs of an enemy he didn't even know was there.

This is one of those stories that has many more sub-story lines within it: the growing problem of antibiotic-resistant pathogens in general, even outside the context of war; the connection between the obsession in American culture with hygiene and "germs" and personal cleanliness and the fact that we are now seeing these "superbugs" that are impervious to any known antibiotics; the way public policy and budget priorities often focus on lesser threats or theoretical dangers and ignore much graver and more immediate problems until it's too late, or until the problem is much harder to manage.

One of the more striking of these sub-stories to me is the way the pathogen that is killing American soldiers in Iraq has been moving into the civilian population in Europe, and in the United States:

The first news that US troops had engaged an unforeseen enemy in Iraq appeared on a physicians' email list called ProMED on April 17, 2003. A communicable-disease expert in the Navy named Kyle Petersen posted a request for information about unusual infections he was seeing aboard the USNS Comfort, a 1,000-bed hospital ship off the coast of Kuwait.

The Comfort was taking in 50 new patients a day by helicopter, many of them Iraqi civilians and prisoners of war. Petersen told the ProMED list that he had seen "several cases of [multidrug-resistant] acinetobacter amongst Iraqi natives wounded by gunshots, shrapnel, burns or motor vehicle accidents." Reviewing the literature, he found reports of an outbreak in Turkish hospitals after an earthquake in 1999, which suggested to him that "acinetobacter species are fairly common pathogens in traumatic wounds, especially if they are dirty." The bugs on the Comfort, however, were more resistant than the Turkish strains. He continued: "Can anyone familiar with the soil biology of Iraq or the drug prescribing practices of the pre-regime medical system explain the severe drug resistance pattern we are seeing among our trauma victims medevaced from Iraq" Any comments would be greatly appreciated."

The bug's emergence on the Comfort made a tough job even tougher. In infected burn victims, skin grafts failed. Two Iraqi patients died. Luckily, the acinetobacter on the Comfort was still susceptible to imipenem, one of the carbapenem-based "magic bullets" kept in reserve for the day when nothing else works. The staff quickly ran through its stock of the drug, firing off urgent requests for more. By isolating carriers in an area of the ship nicknamed Acinetobacter Alley and maxing out the imipenem, the medics finally brought the spread of the bacteria under control.

Soon, however, the bug started popping up in other hospitals along the evacuation chain. More than 70 patients at Walter Reed eventually contracted acinetobacter infections of the blood. Other infected patients and carriers surfaced at Landstuhl, Bethesda, and Balad Air Base, the embarkation point for troops on their way out of Iraq. By early 2005, nearly one-third of the wounded soldiers admitted to the National Naval Medical Center had been colonized by the bacteria. Only a handful of the early cases could be traced directly to the bugs on the Comfort, because the ship steamed out of the Gulf three months into the war. But almost all of the infected patients and carriers had received medical care at field hospitals in Iraq.

Known as combat support hospitals or CSHs, these facilities had been hastily erected in tents and other temporary structures, in keeping with the Pentagon's goal of a lean and mobile fighting force. Maintaining sterile conditions in the desert required creative efforts. Sand blew through every available opening in the walls, and the 130-degree days took their toll on drugs, power supplies, and diagnostic equipment. To move trauma care closer to the action, the DOD deployed modified shipping containers called ISO boxes as portable operating rooms. It was standard procedure to have a dozen nurses, surgeons, and anesthesiologists in each box crowded around two patients undergoing surgery simultaneously - an infection risk in any hospital.

At the 28th CSH near Camp Dogwood - home to more than 4,000 US and British soldiers - there was only one washer and dryer to launder all of the linen, including the surgical scrubs. Army nurses reported to the DOD that "sheets were more often than not soaked with blood and other body fluids - linen that covered the patients who were transferred back to Germany was not replaced." When hospital-grade disinfectants ran low, which was often, the supply crew stocked up on bleach from a local bazaar.

The derelict infrastructure of the Ibn Sina, where Jonathan Gadsden was treated during his evacuation, bedeviled the staff's best infection-control efforts. Rainwater dripped into operating rooms and supply closets, and pigeons roosted in the ventilation system, wafting the smell of droppings into the surgical suites. (A request was filed to the Iraqi Ministry of Health in September 2003 to "eliminate bird feces" from the air ducts.) Clean sheets and scrubs were scarce at the Ibn Sina as well, because the civilian laundry contractor was apparently selling them on the black market.

"When you're interested in immediate lifesaving, you can't be thinking about every infection-control nuance," says microbiologist Roberta Carey, branch chief of epidemiology at the CDC. "In any emergency room that deals with trauma patients, there's a limit - if they get too many patients from a car crash, they put the others on bypass and send them to another institution. But there is no bypass in a war zone."

The most effective way to curtail the development of multidrug-resistant bacteria is to limit the use of broad-spectrum antibiotics. But these drugs were dispensed widely in the CSHs. For wounded soldiers en route to Germany, they were employed as a kind of antimicrobial body armor to forestall future infection. But injured Iraqis would linger on antibiotic IV drips for weeks because the local medical facilities were overwhelmed or under rubble.

In the summer of 2003, civilian patients started getting sick at the Saarland University Hospital, one of the German facilities that admitted US troops evacuated from Iraq. A few months later, an elderly woman being treated for chronic lung disease at Landstuhl died suddenly of antibiotic-resistant acinetobacter pneumonia and bacteremia. DOD investigators found a perfect genetic match between the bug that caused her death and one infecting a military patient down the hall. Eventually, more than 30 civilian patients picked up acinetobacter infections at Walter Reed.

The bacteria was spreading beyond the theater of war.

Which raises yet another issue: how these health issues are going to affect our society and culture, even after American troops leave Iraq.

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