介毛蚶传播甲型肝炎爆发流行调查报告

1988年1月20日至4月30日宁波市发生病毒性肝炎爆发,报告病例47 313例,死亡4例,发病率为949.78/10万,病死率为0.03‰;病人血清抗-HAV IgM阳性率为95.55%;82.56%的病例有食蚶史;流行病学调查表明食蚶居民发病率(8.53%)与未食蚶居民发病率(0.77%)有极显著性差异(χ²=39.49,P<0.01、RR=11.08),食蚶的归因危险性百分比(AR%)为90.97%。病原学检测(用细胞培养法和核酸杂交试验)证实经在本市海涂放养59天后的启东毛蚶 其体内仍携带HAV。因此,认为启东毛蚶是本次甲型肝炎爆发的传播媒介。

Hepatitis A Outbreak with Area as the Vehicle of Transmission

An outbreak of hepatitis A occurred during the period from January 20th to April 30 1988 in Ningbo City. 47,313 patients were reported and four patients died. Morbidity rate was 949.78 per 1,000,000 and fatality rate was 0.08 per 1,000. The positivity rate of anti-HAV IgM in the patient's sera was 95.55%. The history of eating Arca was 82.56% among the patients. Retrospective cohort studies showed that the morbidity of the residents who had eaten Arca was 8.53%, and that of the residents who had not eaten Arca was 0.77%. The difference was highly significant (P less than 0.01, chi 2 = 39.49, RR = 11.08). The attributable risk percent (AR%) of the resident eating Arca was 90.97%. HAV and HAV RNA have been observed in the body of Arca bought from Qidong County, Jiangsu Province, bred in the seashore of Ningbo City for 59 days, by the method of tissue-culture and DNA hybridization assay.