目的 探讨广西上林县赴非务工回国人员的疟疾感染危险因素。方法 2018年采用病例对照研究方法进行疟疾感染因素进行调查,将上林县赴非回国人员中镜检或PCR检测阳性者纳入病例组,阴性者纳入对照组。对病例组和对照组进行问卷调查,调查内容包括一般情况、既往病史和治疗史、境外工作居住情况、疟疾防控知识及行为认知等。对病例组和对照组各因素进行统计学分析,然后以病例组作结果变量,其他因素作解释变量,对疟疾感染的潜在危险因素进行非条件多因素logistic分析。结果 2018年共调查上林县非洲务工回国人员465人,其中病例组149例,对照组316例。单因素分析结果显示,病例组和对照组共5个变量之间差异有统计学意义（P < 0.05）,分别是年龄（< 30：17.5%、7.6%,30~39：40.3%、40.8%,40~49：24.2%、32.6%,≥ 50：18.1%、19.0%）,居住点周边主要生态环境（森林：41.6%、43.4%,丛林：41.6%、26.3%,草地：5.4%、3.5%,荒地：10.7%、22.8%,综合生境：0.7%、4.1%）,当地农作物类型（水稻：95.3%、89.9%,其他：4.7%、10.1%）,傍晚是否经常在户外活动（是：56.4%、62.0%,否：43.6%、38.0%）和户外活动时间（无外出：43.6%、38.0%;有外出,1~30 min：8.1%、17.4%,31 min~1 h：1.3%、2.9%,1~2 h：0.7%、1.6%,≥ 2 h：46.3%、40.8%）。非条件多因素logistic回归分析结果显示：病例组、对照组（依次）国外居住地类型（城市：4.0%、2.2%,农村：7.4%、3.5%,野外：87.3%、91.8%,综合类型：1.3%、2.5%）的OR值为1.8（1.1~2.8）,所住房屋安装纱门纱窗情况（有：7.4%、12.0%;无：92.6%、88.0%）的OR值为 0.2（0.1~0.8）。结论 广西上林县赴非人群在非洲居住房屋无纱门纱窗、傍晚经常到户外活动及户外活动时间长是患疟疾的重要危险因素;居住地类型影响患疟疾感染危险程度的大小,与居住在野外相比,居住在综合生境的疟疾感染风险较高。

Objective To identify the risk factors related to malaria infection in those who traveled to Africa and returned to Shanglin County of Guangxi. Methods An epidemiological investigation and Plasmodium detection were done using a case-control study method in 2018. The cases with Plasmodium positive examined by microscopy or PCR test were grouped as case group, while those with negative results were grouped as a control group. The malaria infection risk factors were investigated by a questionnaire answered by those returned from a travel to Africa, with and without malaria infection. The questionnaire included general information, past medical history and anti-malaria treatment, working and living conditions when abroad, knowledge of malaria prevention and control and behavioral awareness related to malaria infection and so on. The collected information was analyzed to compare the difference of each factor between the case group and the control group. The potential risk factors related to malaria infection were analyzed using an unconditional multivariate logistic regression analysis method by setting the case group as the result variable and other factors as the explanation variable. Results Total 465 people returned from a travel to Africa were enrolled in the investigation related to the malaria infection in Africa, among them 149 were identified as Plasmodium infection positive and 316 as negative. Univariate analysis showed that there were significant differences for the five variables between the case group and the control group (P ≤ 0.05), including age (< 30: 17.5% and 7.6%, 30-39: 40.3% and 40.8%, 40-39: 24.2% and 32.6%, ≥ 50: 18.1% and 19.0%）, living ecological environment (forest: 41.6% and 43.4%, jungle: 41.6% and 26.3%, meadow: 5.4% and 3.5%, uncultivated: 10.7% and 22.8%, mixed: 0.7% and 4.1%), the cultivated crop type (rice: 95.3% and 89.9%, other: 4.7% and 10.1%), outdoor activities in the evening (yes: 56.4% and 62.0%, no: 43.6% and 38.0%), and outdoor activity spent time (no: 43.6% and 38.0%, 1-30 min: 8.1% and 17.4%, 31 min-1 h: 1.3% and 2.9%, 1-2 h: 0.7% and 1.6%, ≥ 2 h: 46.3% and 40.8%), respectively. Multivariate logistic regression analysis showed that the living environment in Africa for case group and control group was in city： 4.0%, 2.2%; in countryside: 7.4%, 3.5%; in the wild: 87.3%, 91.8%; and mixed： 1.3%, 2.5%, respectively, with OR = 1.8(1.0-2.8). The living house for case group contained less percentage of window and door screen (7.4%) than control group (12.0%) with OR = 0.2 (0.1-0.8). Conclusion The results conclude that people who lived in houses without door and window screens, went outdoors in the evening, and spent longer time outdoors had higher chance to get malaria and these activities are the important risk factors for malaria infection in Africa. Interestingly, people living in the city or integrated areas had the higher risk to get infected than those living in the field.