Epidemic Trichophyton mentagrophytes infections in servicemen. Source of infection, role of environment, host factors, and susceptibility.

Epidemic inflammatory dermatophytosis among US combat forces in Vietnam was caused by a pancreatopeptidase E-producing, small (a) mating type, zoophilic variety ofTrichophyton mentagrophytes,a variety not ordinarily isolated in the United States. An abundant reservoir of zoophilicT mentagrophyteswas discovered in commensal rats; carriage was frequent on normal-appearing perineal skin. Variations in prevalence and severity of infection were related to differences in clothing, wet terrain exposures, and duration of tropical service. Our findings suggest that (1) T mentagrophytes infections were acquired in Vietnam, possibly from rats; (2) risk of infection was directly related to degree of exposure to wet clothing; (3) Americans were distinctly more susceptible to T mentagrophytes infections than were adult Vietnamese.