Epizootic vesicular stomatitis in Colorado, 1982: infection in occupational risk groups.

This research article investigates an outbreak of vesicular stomatitis that occurred in 1982-1983 in the western United States, focusing on how the disease was transmitted among veterinarians, researchers, and regulatory personnel. Key outcomes reveal that the risk of infection was higher for those who had direct contact with infected animals, particularly horses, and those with exposed wounds or contact with animal saliva.

Background

• The study takes a detailed look into an epidemic of vesicular stomatitis that took place in the western United States in the period of 1982-1983.
• Vesicular stomatitis is a viral disease that primarily affects horses, cattle, and pigs, but can also infect humans, especially those in occupations involving close contact with infected animals.

Participants and Methodology

• The study examined veterinarians, research workers, and regulatory personnel who had been exposed to the vesicular stomatitis virus (VSNJ).
• It sought to identify patterns of infection and the prevalence of vesicular stomatitis New Jersey serotype neutralizing antibody, which helps in understanding immunity against the virus.
• Participants were divided into two groups, those with the presence (antibody-positive) and absence (antibody-negative) of neutralizing antibodies.

Findings

• Through comparing the activities of the two groups, the study identified that a significant risk factor for infection was when infected animals sneezed in the face of the participants.
• Other activities found to escalate the risk include examination of the oral cavity of the diseased animals, presence of open wounds on hands or arms, and exposure to animal saliva through either the skin or eye.
• The study emphasizes that intimate direct contact was necessary for transmission, with a higher risk associated with examining horses as compared to cattle.

Relation between Infection and Immunity

• Neutralizing antibody prevalence was found to be significantly higher among the participants who fell ill (23%) than among those who were exposed to the virus but did not show signs of illness (7%).
• This suggests that infection triggers a more robust immune response.

Infectivity and Risk

• The general conclusion of the paper was that VSNJ’s infectivity for humans during this outbreak was low, indicating that while certain activities may increase risk, overall the transmission rate to humans was low.