The epidemiology of human trichinellosis in China during 2000-2003

The endemic foci of trichinellosis continue to be mainly located in the southwestern, the central and northeastern China. The seroepidemiological surveys of T. spiralis infection in humans were carried out in six Provinces or Municipals (P/M) of China during 2000-2003, the overall seroprevalence was 3.57%. From 2000 to 2003, 17 outbreaks of human trichinellosis, with 828 cases and 11 deaths, were recorded in 8 P/A of China. All of 11 deaths occurred in the southwestern China (1 case in Sichuan, 4 cases in Tibet and 6 cases in Yunnan), where the ethnic groups have the habit of eating raw meat. Pork is the predominant source of outbreaks of human trichinellosis in China. Out of 17 outbreaks, 13 (76.47%) outbreaks were caused by eating raw or poorly cooked pork, 2 (11.77%) outbreaks caused by eating raw dog meat and 2 (11.77%) outbreaks by eating game meat (wild boar and bear), suggesting the increasing significance of dog and game meat as source of infection for human trichinellosis. The partial effects of health education interventions for control of trichinellosis have been achieved in some counties of Yunnan province. The number of inhabitants eating raw meat has decreased from 72.74% (1561/2146) before interventions to 47.43% (489/1031) after interventions. The decrease of incidence of trichinellosis in China during the past 4 years was probably due to a combination of factors, including the reduction in the prevalence of Trichinella infection in domestic swine, the strengthened meat inspection, the increased use of home freezers and the development of heath education practice.