Scientists from the Translational Genomics Research Institute (TGen) and the U.S. Centers for Disease Control and Prevention (CDC) decoded the DNA of a fast-growing flesh-eating fungus that killed five people last year. The deaths followed a huge tornado that had devastated Joplin, Mo.
The TGen researchers, who used whole-genome sequencing techniques, concluded that the Joplin infections represented the largest documented cluster of Apophysomyces infections, according to a study published PLOS One. Health officials should be aware of infections caused by the fungus, according to the scientists, who tracked 13 people infected by the pathogen during the Class EF-5 tornado, which initially killed 160 and injured more than 1,000.
The common fungus, which lives in soil, wood, or water, usually has no effect on people. But once it is introduced deep into the body through a blunt-trauma puncture wound, it can grow quickly if the proper medical response is not immediate, the studies said. Five of the 13 people infected through injuries suffered during the Joplin tornado died within two weeks.
“This is one of the most severe fungal infections that anyone’s ever seen,” said David Engelthaler, director of programs and operations for TGen’s pathogen genomics division. Engelthaler was the senior author of the PLOS One study, and a contributing author of a paper in the New England Journal of Medicine.
Benjamin Park, M.D., chief of the epidemiology team at the CDC’s mycotic diseases branch, said the victims were infected when their injuries from the tornado were contaminated with debris from the storm. Without the multiple and deep wounds caused the by the storm, cases involving fungal infection are rare, said Dr. Park, the senior author of the NEJM study and a contributing author of the PLOS One study. “A typical hospital might normally see one case in a year.”
Engelthaler said Apophysomyces infections rapidly ravage the body, quickly sealing off capillaries, shutting off the blood supply and leaving tissue to rot. Physicians try to get ahead of the infection by surgically removing sections of dead, damaged, or infected tissue, a process called debridement. For example, he continued, one victim who suffered a deep wound to the upper right chest required a new titanium rib cage after the fungus rapidly destroyed skin and bones.
“It’s unlike anything you’ve ever seen before,” said Engelthaler, a former State of Arizona epidemiologist and former Arizona Biodefense Coordinator. “It’s unreal. It looks like there is no way this person can be alive.”
The studies show the need for rapid and accurate identification of the exact mold causing an infection, since only two FDA-approved drugs, amphotericin B and posaconazole, are commonly used against mucormycetes, the group of molds that includes Apophysomyces and causes mucormycosis.
Both the NEJM and PLOS One studies said whole-genome sequencing could lead to better diagnosis and a better understanding of this pathogen.
Earlier this year a study led by Russell R. Russo, M.D., a third-year orthopedic surgery resident at the LSU Health Sciences Center New Orleans School of Medicine, identified a new source of life-threatening necrotizing bacteria—“bath salts.” The study, which described the first known case of necrotizing fasciitis from an intramuscular injection of the street drug known as bath salts, was published in the January 2012 issue of Orthopedics. The analysis revealed bacterial isolates including alphahemolytic Streptococcus, Streptococcus viridans, Peptostreptococcus micros, Gemella morbillorum, and Actinomyces odontolyticus.