Assessment of occupational risk for hantavirus infection in Arizona and New Mexico

Differentiating occupational exposure from other potential domestic or recreational exposure(s) for Sin Nombre virus (SNV) infection is an epidemiologic challenge. Interviews on work-related activities were conducted, and serum specimens were obtained from 494 workers in Arizona and New Mexico. These workers may have been exposed to rodents and rodent excreta at work, but their primary occupation did not require rodent contact (National Park Service [n = 193]; Navajo Agricultural Product Industry [n = 65], utility companies [n = 169] and plumbing and heating contractors [n = 67]. Within each occupational group (farm workers [n = 57], laborers [n = 20], professionals [n = 70], repairers [n = 211], service industry workers [n = 83], and technicians [n = 53], the majority of workers reported working in areas that had rodent droppings (range, 75 to 95%); 70% of laborers and 64% of service industry workers reported handling rodents. More than 60% of workers in each group, except technicians, reported reopening and cleaning or working in closed spaces. Approximately 90% of laborers, repairers, and farm workers reported hand-plowing. Although the risk for occupationally related SNV infection appears to be low, workers frequently performed risk activities associated with hantavirus pulmonary syndrome (HPS). All workers were seronegative for SNV by enzyme-linked immunoassay or Western blot testing. These findings, the known occupational exposure of some HPS cases, and the high HPS case-fatality rate (52%) support the need for recommendations to reduce human contact with rodents in the workplace. Increased understanding of hantavirus transmission to humans will help focus future recommendations to minimize human exposures effectively.