Analysis of the epidemiological characteristics and risk factors of typhoid and paratyphoid outbreak in China, 2004 to 2007

Objective　The study was conducted to determine the epidemiological characteristics and risk factors of the outbreaks of typhoid and paratyphoid, provide the evidence for the improvement of predictive capacity and development of specific prevention and control strategies. Methods　Descriptive epidemiological analysis was conducted based on the report data of outbreaks of typhoid and paratyphoid from 2004 to 2007. Results　A total of 31 outbreaks of typhoid and 46 outbreaks of paratyphoid were reported from 2004 to 2007 in China, most of which occurred from May to September in a year (62.20%). The laboratory diagnosis proportion for typhoid outbreak was 29.03% and that for paratyphoid outbreak was 43.47%. Most outbreaks occurred in schools (33.77%) and in rural areas (44.16%), especially in township middle schools (53.84%). Bacillus paratyphosus A was the predominant causal agent（57.14%）. Drinking water contamination was the primary cause of the most outbreaks (54.55%), followed by food-borne factors (23.38%). Conclusion　It is necessary to strengthen the hygienic surveillance and management of drinking water in rural areas and the monitoring of fever-like symptom among risk groups including the students in order to effectively detect and control the infectious source. The information on risk factors associated with the outbreaks could be used as the evidence of the revision of relevant laws and regulations.