北京市1例内脏利什曼病病例的调查分析

EPIDEMIOLOGICAL INVESTIGATION AND ANALYSIS ON A VISCERAL LEISHMANIASIS CASE IN BEIJING

对北京市1例内脏利什曼病病例开展流行病学调查,确定感染来源,制定防控措施。收集病例就诊资料,在其感染地使用诱蛉灯开展白蛉监测、调查病犬信息,对病例和病犬骨髓液样本进行涂片、PCR检测、基因测序;对捕捉到的中华白蛉进行PCR检测。结果显示,病例以间断性发热、乏力就诊,医院以骨髓液涂片可见利什曼原虫无鞭毛体确诊为内脏利什曼病。感染地为门头沟王平镇,在该地区共捕获中华白蛉4520只,PCR结果阴性。病例、2只病犬骨髓液利什曼原虫PCR阳性,且基因序列与婴儿利什曼原虫序列同源性分别为94.44%、95.6%、93.23%,病犬骨髓液涂片查见利什曼原虫。结果表明,确定门头沟王平镇存在婴儿利什曼原虫感染传播链。需进一步开展白蛉、病犬分布范围调查,开展病例监测,多部门联合采取防控措施,防止内脏利什曼病疫情继续扩散。

A case of visceral leishmaniasis in Beijing was described following the determination of the infection source and reasonable prevention and control methods.The patient endured intermittent fever and fatigue and was confirmed in clinical diagnosis by bone marrow smear showing leishmaniasis amastigotes.To survey the potential infection source or reservoir hosts,dogs and sandflies were collected from the resident areas of the patient with sandfly trap lamp methods.The bone marrow from dogs and sandflies samples was also submitted to detect the pathogenic protozoan using morphological observation by microscopy,PCR,and sequences analysis,respectively.As a result,the patient was concluded to be infected in Wangping Town,Mentougou District,where a total of 4520 Phlebotomus chinensis and two dogs were sampled.The bone marrow samples from two dogs were shown positive for Leishmania infantum with typical leishmaniasis amastigotes on bone marrow smears,which were further confirmed by specific PCR detection and sequences identities ranged from 94.44%,95.6%,and 93.23%to referenced L.infantum.However,no positive results were achieved from all P.chinensis detected by the same PCR protocol.More wide surveys on sandflies in the endemic areas should be strengthened and rational prevention and control measures should be addressed by multiple departments to prevent the spread of visceral leishmaniasis in the future.