John T Redd1, Ronald E Voorhees, Thomas J Török. 1. Epidemic Intelligence Service, assigned to the New Mexico Department of Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA. john.redd@ihs.gov
Abstract
BACKGROUND: Lepidopterism refers to moth- or butterfly-associated illness, including contact dermatitis, urticaria, and occasional systemic reactions. Lepidopterism outbreaks are rare. OBJECTIVE: To investigate a lepidopterism outbreak associated with caterpillars of the Douglas-fir tussock moth (DFTM; Orgyia pseudotsugata) among Boy Scouts attending summer camp in New Mexico. METHODS: Retrospective cohort analysis; environmental investigation. RESULTS: Attendees were primarily male (100/107; 94%) and less than 18 years old (82/107; 77%). Itch, rash, or hives were reported by 56 of 102 (55%) of campers. Patients were more likely to report direct caterpillar contact (relative risk [RR]: 2.7; 95% confidence interval [CI], 1.3-5.5); playing a caterpillar-flicking game (RR: 1.9; 95% CI, 1.1-3.4); and sleeping at campsite 6, where caterpillars were most numerous (RR: 1.7; 95% CI, 1.3-2.4). All patients recovered. LIMITATIONS: Data on disease status and risk factors were collected retrospectively. CONCLUSION: Modifying behaviors associated with lepidopterism and avoiding areas of heavy infestation can reduce illness risk.
BACKGROUND: Lepidopterism refers to moth- or butterfly-associated illness, including contact dermatitis, urticaria, and occasional systemic reactions. Lepidopterism outbreaks are rare. OBJECTIVE: To investigate a lepidopterism outbreak associated with caterpillars of the Douglas-fir tussock moth (DFTM; Orgyia pseudotsugata) among Boy Scouts attending summer camp in New Mexico. METHODS: Retrospective cohort analysis; environmental investigation. RESULTS: Attendees were primarily male (100/107; 94%) and less than 18 years old (82/107; 77%). Itch, rash, or hives were reported by 56 of 102 (55%) of campers. Patients were more likely to report direct caterpillar contact (relative risk [RR]: 2.7; 95% confidence interval [CI], 1.3-5.5); playing a caterpillar-flicking game (RR: 1.9; 95% CI, 1.1-3.4); and sleeping at campsite 6, where caterpillars were most numerous (RR: 1.7; 95% CI, 1.3-2.4). All patients recovered. LIMITATIONS: Data on disease status and risk factors were collected retrospectively. CONCLUSION: Modifying behaviors associated with lepidopterism and avoiding areas of heavy infestation can reduce illness risk.