中缅边境地区恶性疟配子体易显影响因素分析

Analysis of factors influencing gametocytogenesis in Plasmodium falciparum in areas along the China-Myanmar border

目的分析中缅边境地区恶性疟配子体携带危险因素,探讨恶性疟配子体形成的影响因素以阻断多重抗药性恶性疟传播。方法采用单因素和多因素非条件logistic回归分析同一研究小组2002~2010年在中缅边境地区纳入研究的恶性疟病例资料。结果分析567例恶性疟病例13项信息,其中77例携带配子体,配子体携带率为13.58%,几何平均配子体密度为（140.15±3.58）个/μl。单因素非条件Logistic回归分析体温、对数无性体原虫密度、有疟史者末次发病时间、病程和2周内用药史为危险因素,血红蛋白含量为可能的危险因素;多因素非条件Logistic回归分析对数无性体原虫密度为主要危险因素（OR=0.322,OR95%CI为0.146~0.712）。结论近期获得疟疾保护性免疫力、不规范治疗和中重度贫血可能促进恶性疟配子体形成,配子体携带率随病程的延长和随无性体原虫密度的降低而升高。早发现、早诊断、早规范治疗,使用高效速效抗疟药和配子体杀灭药是减少配子体形成及阻断多重抗药性恶性疟传播的必要措施。

Objectives To analyze the risk factors for gametocyte carriage of falciparum malaria and to explore the factors influencing gametocytogenesis in order to block the transmission of multi-drug-resistant Plasmodium falciparumin areas along the China-Myanmar border. Methods Data were collected from case records of falciparum malaria created by the same research team as it conducted several research projects in areas along the China-Myanmar border from 2002to2010.Data were subjected to unconditional univariate and multivariate logistic regression analysis. Results A total of567 cases of falciparum malaria and 13 factors were analyzed.Seventy-seven of the patients in those cases carried gametocytes,so patients carried gametocytes at a rate of 13.58%.The geometric mean density of gametocytes was 140.15±3.58/μl.A model for unconditional univariate logistic regression analysis identified body temperature,the log-transformed asexual parasite density,the date of the last episode if a patient had a history of malaria,the duration of malaria,and medication taken 2weeks prior to consulting a doctor as risk factors.Hemoglobin levels were also a potential risk factor.Only the log-transformed asexual parasite density was kept in the final model,and the log-transformed asexual parasite density was identified as main risk factor in a model for unconditional multivariate logistic regression analysis（OR=0.322,OR95%CI：0.146-0.712,P=0.005）. Conclusion Gametocytogenesis of P.falciparumis possibly affected and promoted by recently acquired protective immunity from malaria,non-standard treatment,and moderate and severe anemia.The rate of gametocyte carriage increases with a prolonged bout of malaria and decrease in the density of asexual parasites.Early diagnosis and prompt provision of standard treatment with a gametocidal agent and highly efficacious and quick-action antimalarials are needed to reduce the gametocytogenesis and block the transmission of multi-drug-resistant P.falciparum.