"The largest recorded U.S. outbreak occurred in 1998, when 775 people were exposed to the disease. Of these, 110 became infected," according to the CDC. "Although the incidence in the United States is relatively low, leptospirosis is considered to be the most widespread zoonotic disease in the world."
Mycobacteria
After the tsunami in Thailand in 2004, 15 people who had crush traumatic injuries developed rapid-growing mycobacterial infections 20-105 days after the tsunami in undamaged skin near sutured wounds. Seven of the infections were from the organism Mycobacterium abscessus, six were from M. fortuitum, one was from M. peregrinum, and the last was from M. mageritense.
All of the patients were treated and free of infection after 12 months.
Mucormycosis
Mucormycosis (also known as zygomycosis) is a rare fungal infection that results from the fungi group Mucoromycotina found in the soil of decaying organic matter. In hospitals, infection is associated with the use of contaminated materials or organ transplantation and carries a mortality rate of 30%-80%, Dr. Bettencourt noted.
There was an outbreak of the rare infection in May, in Joplin, Mo., 12 days after a tornado plowed through the community causing mass destruction. The infection penetrated the open wounds of hospitalized tornado victims, resulting in five deaths. Contaminated tongue dispensers were the vector of transmission.
The first two patients diagnosed with mucormycosis presented with a necrotizing soft tissue fungal infection. Eighteen cases were suspected, with 13 confirmed. None of the patients with the infection were immunocompromised, but two had diabetes. No additional cases were reported after June 17.
Mucormycosis can take many clinical forms, including rhinocerebral, pulmonary, gastrointestinal, cutaneous, and disseminated (most commonly in the brain). The fungi move aggressively into the bloodstream, causing everything from sinus pain and fever to black pus drainage from the eyes and cutaneous necrosis, she reported.
Coccidiomycosis
Coccidiomycosis, also known as valley fever, is a fungus found in the soil of arid areas. Inhalation of conidia from dust stirred up by human activity or a natural disaster can cause infection, said Dr. Bettencourt.
California, Arizona, Nevada, New Mexico, Texas, and Utah are U.S. endemic areas, where 10%-50% of the population will have evidence of exposure to Coccidioides species, according to the CDC.
An earthquake was the cause of the 1994 outbreak of coccidiomycosis in Northridge, Calif., where 203 cases of infection and 3 deaths were reported (JAMA 1997;277:904-8).
Symptoms of acute infection are flulike, occurring 1-3 weeks after exposure, with fever, cough, headache, rash, and muscle ache being the most common events. However, 60% of infected individuals will have no symptoms. Severe infection can cause lung problems, meningitis, skin ulcers, and bone and joint infection, but most patients make a full recovery, Dr. Bettencourt noted. Chronic pulmonary coccidioidomycosis may develop 20 years or more after infection.
Disseminated infection can spread to the skin, brain, bones, and heart. Some of the symptoms of disseminated skin infection are nodules, papules, plaques, furuncles, abscesses, and ulcers. Erythema nodosum is the most common skin presentation, she said.
Other natural disaster–related disease outbreaks include measles. Thirty-five cases were reported after the 2004 tsunami in Indonesia, and 400 cases were reported after the 2005 earthquake in Pakistan. "Malaria outbreaks are directly associated with flooding, while dengue transmission is influenced by rainfall and humidity, but is not directly associated with flooding," reported Dr. Bettencourt. Tetanus, hepatitis, and diarrhea from cholera and salmonella also can affect people after natural disasters.
Dr. Bettencourt reported being on the speakers bureaus of PharmaDerm and Graceway and conducting clinical trials for 3M Pharmaceuticals.