An outbreak of cutaneous anthraxcaused by slaughter sick cow in Xinjiang, China, 2016 / 中国人兽共患病学报

ABSTRACT

On June 6,2016,an outbreak of suspected cutaneous anthrax was reported by T County CDC,Xinjiang Uygur Autonomous,China.An investigation was carried out to determine the magnitude and risk factors and to recommend control measures.Suspected cases were defined as any villager in T county residents whose skin appeared rash,blisters,ulceration,swelling of black eschar or ulcer between May 1 and June 8.Confirmed case were defined as suspected case plus serological positive,real-time polymerase chain reaction (PCR) positive or Bacillus anthraci isolated.We interviewed clinicians and reviewed medical files in the township and city hospital,and visited all households searching for cases.A case-control study was conducted to investigate the risk factors of human anthrax infection.Three types of specimens were collected and tested by serological detection,real-time polymerase chain reaction (PCR) and bacterial culture.Through epidemiological investigation,15 families purchased beef of a sick cow on May 26,2016.Between 29 May and 3 June,ten people from these families were diagnosed as skin anthrax.Among them,six were confirmed cases and four were suspected cases.The attack rate was 20％.The incubation period was 3 to 7 days with average incubation 5 days.The nain clinical manifestations were hand skin anthrax carbuncle.Case control study showed that the incidences of people who exposing or not exposing to contaminated beefs significantly different,with 53％ and 0％ respectively.Blood serums from six patients showed that specific antibody titer appeared to increase more than 4 times.B.anthraci was isolated from herpes fluid of one patient.B.anthraci nucleic acid was detected from beef collected from four families.The outbreak was caused by the villagers exposed sick cow which infected by B.anthraci.Contaminated beef caused the infections.