上海市一例三日疟病例的溯源调查

Tracing Investigation of a Quartan Malaria Case in Shanghai

目的对上海市1例三日疟病例进行溯源调查,以明确其传染来源。方法收集该病例的临床、实验室和流行病学资料,并对病例所在居民点进行相关人群的流行病学调查和现场快速诊断试纸条(RDT)检测,以及环境生物媒介调查。结果临床血涂片查见三日疟原虫;骨髓穿刺显示,骨髓增生活跃,粒细胞、红细胞、巨核细胞增生活跃。RDT检测结果为疟原虫阳性;巢式PCR结果显示,患者血样扩增出144 bp特异性条带,与三日疟原虫阳性对照条带大小一致。患者确诊后,服用双氢青蒿素哌喹片2片/次×bid×2 d进行治疗。流行病学溯源调查结果显示,患者发病前3年内无手术史,无输血史,2005年和2013年曾有海南、海门旅行史;患者居住地(上海杨浦区)5年内无本地感染病例。对居民点人群调查结果显示,共调查25户居民,计35人,RDT检测结果均显示阴性,35人在2周内均未出现发热。环境病媒生物调查未查见蚊幼虫孳生。结论患者为长潜伏期三日疟病例,其传染源为外省疫区。

Objective To find out the infection source of a quartan malaria case. Methods The clinical, laboratory and epidemiological information of the patient was collected. The epidemiological investigation and rapid diagnostic test （RDT） were conducted in the surrounding population. Vectors were investigated. Results Blood film test showed the presense of Plasmodium malariae. Bone marrow aspiration revealed active proliferation of bone marrow as well as granulocytes, red blood cells and giant cells. RDT test showed positive result for Plasmodium. Nested PCR resulted in a specific band of 144 bp, consistent with the positive control. The patient was treated with dihydroartemisinin piperaquine phosphate tablet（2 tab×bid×2 d, po）. Tracing investigation showed that the patient had no history of surgery or blood transfusion within 3 years before the disease onset, and had travelling history in Hainan Province and Haimen City in 2005 and 2013 respectively. There was no case of local infection within 5 years in the patient’s area of residence. Twenty-five families including 35 individuals in the area where the patient lived were investigated and all had negative results for the RDT test. In addition, none showed symptom of fever within the past 2 weeks. No Anopheles sinensis was found in the vector investigation. Conclusion This is a case of quartan malaria with a long latency, and the patient has been infected in other provinces.