Fungal Skin Infections Skyrocket After Missouri Tornado

July 29, 2011 — Outbreaks of necrotizing fungal soft-tissue infections have been reported after the deadly tornado that leveled a wide swath of Joplin, Missouri, on May 22. By June 10, eight patients were diagnosed with wound infections caused by Mucormycetes (formerly Zygomycetes). This represents the first known cluster of cutaneous mucormycosis associated with the disaster, the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, announced Thursday.

In the July 29 issue of the CDC’s Morbidity and Mortality Weekly Report, CDC investigators write that outbreaks of cutaneous mucormycosis, considered rare, were reported after the Indian Ocean tsunami of 2004 and a volcanic eruption in Armero, Colombia, in 1985.

Cutaneous mucormycosis, or zygomycosis, is caused by fungi of the order Mucorales, usually found in soil, rotting wood, and other organic matter. Individuals with weakened immune systems are at high risk, but immunocompetent individuals who have experienced skin trauma can also be at risk. The fungus enters through cuts, scrapes, puncture wounds, burns, and the like, such as might occur after a natural disaster.

The resulting infection may initially resemble a blister or ulcer, and the skin eventually becomes necrotic. Other symptoms are fever, localized tenderness, pain, heat, excessive redness, or swelling around the wound, according to the CDC.

Each Patient With Confirmed Case Averaged 4 Wounds

Skin trauma explained the origins of the Joplin outbreak of cutaneous mucormycosis. Twelve days after winds clocked at more than 200 miles per hour ripped through town, a local physician reported to the Missouri Department of Health and Senior Services that 2 patients hospitalized with tornado-related injuries were suspected of having necrotizing soft-tissue fungal infections.

The CDC dispatched a field team to Joplin and, as of July 19, identified 18 suspected cases of cutaneous mucormycosis. Thirteen cases were confirmed by a positive fungal culture or histopathology and genetic sequencing consistent with the mucormycete Apophysomyces trapeziformis.

The 13 patients with confirmed infections had sustained injuries from the tornado such as lacerations, fractures, and blunt trauma. Each patient averaged 4 wounds apiece upon arrival at the hospital emergency department. All 13 underwent surgical debridement of their wounds, and 6 required the removal of foreign bodies, such as wood splinters. Two patients were diabetic; none were immunocompromised.

Of the 13 patients, 10 were admitted to an intensive care unit, and 5 died. The CDC puts the total death toll from the tornado at 159 people. Another 1000 or so individuals were injured.

The CDC reports that no additional cases of cutaneous mucormycosis have been reported since June 17. It also states that the risk to relief workers in Joplin contracting the infection appears to be very low because none of the cases as of June 15 involved individuals who assisted in clean-up.

Depending on the infection’s severity and the patient’s underlying medical condition, the case fatality rate for cutaneous mucormycosis ranges from roughly 30% to 80%.

More information on the fungal infection is available on the CDC Web site.