From Philadelphia, at a meeting of the American Society of Tropical Medicine and Hygiene
Mysterious skin infections that have plagued residents of the Micronesian island of Satowan are traceable to swimming in the stagnant waters that fill bomb craters left over from World War II, a study shows. Scientists have successfully treated these infections with antibiotics but are still trying to determine what the specific pathogen in these waters might be.
Japanese soldiers held tiny Satowan during the war, and U.S. bombing raids left craters that filled with water, expanding the island’s mosquito population. The Japanese introduced nonnative fish called medaka (Oryzias latipes) into the freshwater ponds in hopes that the fish would eat the mosquito larvae.
Physician Vernon E. Ansdell of the University of Hawaii had heard about an affliction on Satowan known as “spam disease,” marked by mottled rashes that resemble the canned-meat product. On a recent trip to the island, he and his colleagues identified 37 people with the infection. On average, these people had lived with the skin problems for 13 years. The islanders had tried a host of traditional treatments on the infections, including bleach, lime juice, and ashes—without success.
A survey of 150 islanders revealed that swimming in the bomb craters increased a person’s infection risk eightfold. After finding that doxycycline or other antibiotics healed the infections within 2 months, Ansdell lays the blame on a water-borne microbe called Mycobacterium marinum. A previous study had found that medaka fish can become infected with this microbe and tolerate it, he notes. Although the infections abated with treatment, some scarring remained.
Initial tests of diseased tissue couldn’t pin down M. marinum as the culprit. Ansdell plans more tests and a return to Satowan next year.