Epidemiology of butchers' warts.

Studies were carried out in two slaughter-houses in different cities differing in the degree of work automation and, for comparison, in workers of nearby factories of the same two cities. There was a high incidence of warts (49.2%) in a slaughterhouse where the workers had direct contact with animals and meat, while a significantly lower incidence (9%) was observed in a modern slaughterhouse where the work was almost completely automated. The types of human papillomaviruses (HPVs) were similar in warts of butchers from these slaughterhouses and of 63 butchers from various slaughterhouses all over the country. All cutaneous HPVs were present in butchers' warts. The so-called butchers' wart virus HPV-7 was found in about 30% of the butchers from all slaughterhouses. Cell-mediated immunity of the butchers was found to be unimpaired. There was no correlation between the incidence of infection and the frequency of antibodies against HPV-1, HPV-2, or HPV-3.