广西SARS来源的流行病学研究

Epidemiological Analysis of SARS in Guangxi Province

目的研究SARS来源,掌握其发生原因、发展和分布规律,为制定预防控制对策和措施提供科学依据。方法建立主动和被动监测系统监测SARS疫情,对SARS病例进行现场流行病学问卷调查,分析其分布规律和特征。采集病例、密切接触者、野生动物和人工饲养果子狸的血清、咽漱液、咽拭子等标本分别采用ELISA方法和荧光定量PCR检测IgG、IgM抗体和RNA,进行血清学和病原学研究,并结合流行病学、病原学和血清学结果探讨SARS的来源。结果于2002年12月17日到2003年5月上旬,出现两个流行高峰,共报告病人22例,发病率0.046/10万,病死率为13.64%。呈局部爆发和高度点状散发,具有高度家庭聚集性,大多分布在农村,以外出广东务工青壮年民工为主,男女性别比为1.75∶1。主要症状为发热、咳嗽,伴有畏寒、咽痛、胸闷、气促、胸痛、全身乏力、恶心、呕吐和腹泻等其它的症状。91%的病人胸片检查呈现单侧或双侧肺部片状阴影。病例血白细胞正常或减少,病人血清IgG和IgM阳性率分别为100%和81.8%,1例病人血浆中检出SARS病毒核酸。密切接触者IgG抗体阳性率为1.11%。野生动物山瑞鳖、眼镜蛇、蛤蚧和鹰血清SARS病毒抗体阳性。结论从流行病学、临床表现、血清学和病原学均证实SARS在广西流行,具有输入性、续发性和自然疫源性三个来源。病人为重要的传染源,野生动物可能是SARS的源头。

Objective To identify the source and epidemic characteristic of SARS in Guangxi, and provide basis for SARS prevention and control. Method Active and passive surveillance systems were used. Questionnaire surveys were conducted among SARS patients to study the characteristics of SARS epidemic. Serological method （ELISA） and PCR were used to test for the SARS virus in sera and throat secretions collected from patients, individuals with a close contact with patients, wild animals, and domestic animals. Result 22 SARS patients were reported in Guangxi between 17 December 2002 and 10 May 2003. The incidence rate was 0.046 per 100 thousand. The fatality rate was 13.64%. The epidemic patterns were outbreak in the families and sporadic. Most of the patients were farmers and had a history of working in Guangdong province. The ratio of male to female was 1.75：1, The main signs and symptoms were fever, cough, throat or chest ache, cold, nausea, vomit, and fatigue. X-ray check of the lungs showed that 91% of the patients had shadows in one or both side of the lung. Number of white blood cell count was ranged from normal to reduced. The positive rates of anti-SARS IgG and IgM from thc patient sera were 100% and 81.8% respectively. SAPS viral RNA was found in the plasma of one serum sample. 1% of the serum samples from individual with a close contact with SARS patients had anti-SARS IgG. Samples from some wild animals such as sanrui turtle, cobra, and eagle had antibodies against the SARS virus. Conclusion There are 3 major sources of SARS, namely imported from the nearby regions, local and secondary. SARS patients are the major source of infection. Wild animals are probably the origin of SRAS.