贵州省从江县疟疾局部暴发的影响因素分析

目的 为确定2006年7月贵州省从江县局部疟疾暴发的影响因素。 方法 在疟疾暴发点进行流行病学调查，对495名常住居民采集滤纸干血滴，用间接荧光抗体试验（IFAT）检测人群抗体水平。对其中423人进行问卷调查，内容包括两年内疟史、疟防知识知晓情况、蚊帐使用情况、露宿习惯等。收集乡卫生院门诊发热病人登记资料，分析发热病人就医行为。复查上报的42例疟疾病例阳性血片和同期普查的部分阴性血片。按蚊调查仅做半通宵人饵诱捕和人、牛房密度调查，分析该地传播媒介组成和叮人率等。 结果 42张阳性血片经复查确定12张阳性均为间日疟原虫，18 d的疟疾罹患率为2.1%(16/753，包括4例临床诊断病例）。居民平均荧光抗体阳性率为8.7%（43/495），阳性几何平均滴度倒数（GMRT）为20.6，总的GMRT为10.6，其中5岁以下组抗体阳性率为7.5%（3/40），阳性GMRT为25.1。发热病人就诊率为81.3%（118/145），平均发热后3.9 d就诊。疟防知识知晓率平均为25.5%（108/423），文盲组、小学组和中学组分别为17.1%、29.2%和40.0%，组间差异有统计学意义（P＜0.01）。蚊帐使用率平均为31.0%（131/423），露宿率平均为40.7%（172/423）。2004和2005年休根治疗率分别为68.2%（15/22）和48.3%（14/29）。当地传疟媒介除中华按蚊外还存在嗜人按蚊和微小按蚊，人房帐内捕获嗜人按蚊和微小按蚊，叮人率分别为0.0566和0.0755。 结论 当地存在我国重要传疟媒介，因灾后居民居住条件简陋，自我保护意识薄弱，且有露宿习惯，疟疾病例的发现和治疗均不及时等，是促成了该起疟疾暴发的主要原因。

Factors Affecting Malaria Outbreak in Congjiang County of Guizhou Province

Objective To make a field investigation on the affecting factors of malaria outbreak in a village of Congjiang County, Guizhou Province. Methods The investigation was made in August, 2006. Filter paper dry blood samples were taken for indirect fluorescent antibody test (IFAT) from all the 495 residents above 1 year-old in the village where an outbreak of malaria was reported. Questionnairing was conducted in 423 villagers over 10 years-old, covering malaria history in the past 2 years, knowledge on malaria and its control, use of mosquito nets, and out-door sleeping habit. Data on febrile outpatients were collected from the records of the township health center for analyzing the compliance of the patients in seeking medical services. Mosquito collecting by human-bait before mid-night, and in mosquito nets and cattle pens in early morning was performed for mosquito composition and man-biting rate. Results Re-examination of the 42 positive blood smears confirmed 12 positives of P.vivax infection. The malaria incidence in 18 d was 2.1%,including 4 cases clinically diagnosed. The antibody positive rate of IFAT in the population was 8.7% (43/495) with a positive GMRT of 20.6, overall GMRT of 10.6; the IFAT positive rate in the age group of under 5 was 7.5% (3/40) with a GMRT of 25.1. The rate of seeking medical advice among febrile patients was 81.3% (118/145), 78.8% (93/118) of which being in the village clinic. The average time of going to a doctor after fever was 3.9 days, 37.4% (195/521) and 3.3% (17/521) were in 4-6 days and over 10 days respectively, with the longest 26 days. The average knowledge rate on malaria was 25.5% (108/423), with 17.1%, 29.2% and 40.0% in the groups of illiteracy, primary school and high school education respectively. A statistical significance was found between primary school/high school education and the illiteracy (P<0.01). The average rate of using mosquito nets was 31.0% (131/423), out-door sleeping rate was40.7% (172/423). The radical cure rate in 2004 and 2005 was 68.2% (15/22) and 48.3% (14/29) respectively. In addition to Anopheles sinensis, An. anthropophagus and An. minimus also existed in rooms and nets with a man-biting rate of 0.0566 and 0.0755 respectively. Conclusions Three species of anopheline mosquitoes are the important transmitting vectors. Poor self-protection, outdoor sleeping habit, delayed examination and treatment, and irregular chemotherapy among the residents are the main factors resulting malaria outbreak.