RESUMEN
Objective:To analyze the cause and epidemiological characteristics of an outbreak of cutaneous anthrax in Caoxian County, Heze City, Shandong Province, and to provide scientific basis for anthrax prevention and control.Methods:Using on-site epidemiological investigation methods and the "Anthrax Epidemiological Case Investigation Form", case investigations were conducted based on the epidemiological contact history and close contacts of suspected anthrax cases reported by the national health care system ( n = 83). Scorched skin smears, diseased cattle tissues, soil samples from the slaughter site and smears from slaughter utensils were collected from cases for Real-time PCR testing and pathogenic bacteria isolation and culture, respectively. Anthrax determination criteria were carried out with reference to "Anthrax Diagnosis" (WS 283-2020). Results:A total of 13 cases of cutaneous anthrax were found in this outbreak, including 12 clinically diagnosed cases and one confirmed case (positive Real-time PCR test and isolation of a strain of Bacillus anthracis). The epidemiological investigation determined that the source of infection in this outbreak was diseased cattle, the transmission route was through slaughter of diseased cattle, contact with contaminated utensils and related cattle products, and the patients were mainly engaged in occupations related to cattle slaughter or cattle product collection and sale. A total of 84 samples were collected, including 13 skin scabs, 64 environmental samples and 7 beef samples. Thirty-six positive PCR tests were performed, with a positive rate of 42.86% (36/84). Among them, 100.00% (13/13) were positive for skin scab smear specimens, 29.69% (19/64) for environmental samples and 4/7 for beef samples. A total of 8 strains of Bacillus anthracis were isolated, including 6 environmental specimens, 1 suspected case and 1 beef strain, with an overall detection rate of 9.52% (8/84). Eighty-three close contacts were investigated. Thirteen households involved in the epidemic were disinfected by spraying (200 ml/m 2) with chlorine-containing disinfectant (5 000 mg/L), and a total of 40 households involved in the epidemic were disinfected, covering an area of about 10 765 m 2. Forty-five pieces of suspected contaminated clothing were burned and disposed of, and 152 pieces of kitchenware were soaked. Conclusions:Slaughter of infected cattle, contact with contaminated utensils and related cattle products are the main causes of this skin anthrax outbreak. Strengthening market supervision, deepening inter-animal epidemic prevention, carrying out publicity and education on anthrax prevention and control, and enhancing practitioners' awareness of disease prevention is the key to prevent anthrax from occurring.