2010-2016年溧阳市消除疟疾监测效果评价

Evaluation of malaria elimination surveillance in Liyang City from 2010 to 2016

目的评价溧阳市消除疟疾监测效果,为制定消除疟疾防控策略和措施提供依据。方法收集2010-2016年溧阳市疟疾疫情、发热病人血检和疟疾病例个案流行病学调查表等监测资料,采用描述性流行病学方法进行分析。结果2010-2016年共报告疟疾病例67例,血检发热病人39 196人次,镜检检出阳性65例,阳性率为0.17%。另有2例镜检阴性病例为出现发热症状后自行服用抗疟药,镜检未查见疟原虫,但疟疾快速诊断试剂盒(RDTs)检测显示阳性。67例疟疾病例中,恶性疟49例、卵形疟13例、间日疟5例。67例病例均为境外输入性疟疾病例,来自非洲的病例占94.03%(63/67)。67例病例中,男性占97.01%(65/67),30~49岁占73.13%(49/67),农民占病例数的80.60%(54/67)。全市10个镇均有病例分布,发病时间无明显季节特征。病例报告及时率、血片复核及时率、规范治疗率、流行病学个案调查率、疫点调查与处置率均达100%。主动病例侦查18 076人,未查见疟原虫阳性携带者。采用诱蚊灯法和人饵半通宵诱捕法进行蚊媒监测,分别捕获按蚊187只和78只,均为中华按蚊。2012-2016年溧阳市疾病预防控制中心门诊采用镜检与RDTs检测,共检测88人次,镜检查出疟原虫阳性35人次,其中恶性疟28人次、卵形疟7人次,恶性疟和卵形疟镜检阳性率差异无统计学意义(校正χ~2=0.05,P> 0.05);RDTs检测阳性为34例,其中恶性疟14例,恶性疟或混合感染其他3种疟疾17例,除恶性疟以外的3种疟疾单一或混合感染3例,RDTs检测阳性率差异有统计学意义(校正χ~2=13.75,P <0.05)。结论溧阳市境外输入性疟疾病例仍有再传播风险,今后还需加强疟疾监测工作,强化传染源管理,巩固消除疟疾成果。

Objective To evaluate the effect of malaria elimination monitoring in Liyang City, so as to provide the evidence for formulating control strategies and measures of malaria elimination. Methods The monitoring data about the epidemic situation, blood tests of feverish patients and epidemiology investigation of individual malaria patients in Liyang City from 2010 to 2016 were collected and analyzed by the descriptive epidemiology method. Results From 2010 to 2016, there were 67 malaria cases in total. Totally 39 196 feverish patients had blood tests for Plasmodium, and 65 of them showed positive and the positive rate was 0.17%. The other 2 cases of microscopy negative were treated with anti-malarial drugs by themselves after the onset of fever, and no Plasmodium was detected in the microscopy, but the tests with malaria rapid diagnostic kit(RDTs) were positive.Among all the 67 cases, there were 49 falciparum malaria cases, 13 ovale malaria cases and 5 vivax malaria cases. All the 67 malaria cases were imported, and the number of cases from Africa was 63(94.03%). Totally 97.01%(65/67) of the malaria patients were male and most of them were young adults. The patients aged 30 to 49 years accounted for 73.13%(49/67) and 80.60%(54/67) of them were farmers. There were malaria cases in all the 10 towns of the city, and the time of onset had no obvious seasonal characteristics. The timely rate of case report, timely rate of blood film review, standardized treatment rate, epidemiological case investigation rate, and epidemic focus investigation and disposal rate were all 100%. There were 18 076 people with the active case investigation, but no malaria parasite positive carriers were found. The mosquito vector monitoring was performed with the methods of mosquito trap lamp and human bait half night trap, and 187 and 78 Anopheles mosquitoes were captured respectively, and all the parasites were Anopheles sinensis. A total of 88 person-times were performed for the Plasmodium examinations with microscopy and RDTs(one blood sample, two detections) in Liyang City Center for Disease Prevention and Control from 2012 to 2016, and 35 person-times were positive, including 28 person-times of Plasmodium falciparum and 7 person-times of P. ovale, and there was no statistically significant difference between the detection rates of P. falciparum, and P. ovale(adjusted χ~2=0.05, P > 0.05). There were 34 RDTs positive cases, including 14 cases of malignant malaria, and 17 cases of malignant malaria or mixed infections of P. falciparum with other three kinds of Plasmodium parasites, and 3 cases of single infection or mixed infections of other three kinds of Plasmodium parasites, and there was a statistically significant difference among them in the positive RDTs detection rates(adjusted χ~2 = 13.75, P < 0.05). Conclusions There are still imported malaria cases and there is the risk of malaria retransmission in Liyang City. Therefore, it is necessary to strengthen the malaria surveillance work and the management of infectious sources, so as to consolidate the achievements of malaria elimination in the future.