Ndeffo Mbah Martial L, Skrip Laura, Greenhalgh Scott, Hotez Peter, Galvani Alison P
School of Public Health, Yale University, New Haven, Connecticut, United States of America.
National School of Tropical Medicine, and Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, Texas, United States of America.
PLoS Negl Trop Dis. 2014 Oct 16;8(10):e3234. doi: 10.1371/journal.pntd.0003234. eCollection 2014 Oct.
Sub-Saharan Africa harbors the majority of the global burden of malaria and schistosomiasis infections. The co-endemicity of these two tropical diseases has prompted investigation into the mechanisms of coinfection, particularly the competing immunological responses associated with each disease. Epidemiological studies have shown that infection with Schistosoma mansoni is associated with a greater malaria incidence among school-age children.
We developed a co-epidemic model of malaria and S. mansoni transmission dynamics which takes into account key epidemiological interaction between the two diseases in terms of elevated malaria incidence among individuals with S. mansoni high egg output. The model was parameterized for S. mansoni high-risk endemic communities, using epidemiological and clinical data of the interaction between S. mansoni and malaria among children in sub-Saharan Africa. We evaluated the potential impact of the S. mansoni-malaria interaction and mass treatment of schistosomiasis on malaria prevalence in co-endemic communities.
Our results suggest that in the absence of mass drug administration of praziquantel, the interaction between S. mansoni and malaria may reduce the effectiveness of malaria treatment for curtailing malaria transmission, in S. mansoni high-risk endemic communities. However, when malaria treatment is used in combination with praziquantel, mass praziquantel administration may increase the effectiveness of malaria control intervention strategy for reducing malaria prevalence in malaria- S. mansoni co-endemic communities.
CONCLUSIONS/SIGNIFICANCE: Schistosomiasis treatment and control programmes in regions where S. mansoni and malaria are highly prevalent may have indirect benefits on reducing malaria transmission as a result of disease interactions. In particular, mass praziquantel administration may not only have the direct benefit of reducing schistosomiasis infection, it may also reduce malaria transmission and disease burden.
撒哈拉以南非洲地区承担着全球大部分疟疾和血吸虫病感染负担。这两种热带疾病的共同流行促使人们对共感染机制进行研究，特别是与每种疾病相关的相互竞争的免疫反应。流行病学研究表明，曼氏血吸虫感染与学龄儿童中较高的疟疾发病率相关。
我们建立了一个疟疾和曼氏血吸虫传播动力学的共流行模型，该模型考虑了两种疾病之间的关键流行病学相互作用，即曼氏血吸虫高虫卵排出量个体中疟疾发病率升高的情况。利用撒哈拉以南非洲儿童中曼氏血吸虫与疟疾相互作用的流行病学和临床数据，对该模型进行了参数化，以适用于曼氏血吸虫高风险流行社区。我们评估了曼氏血吸虫与疟疾相互作用以及血吸虫病大规模治疗对共流行社区疟疾患病率的潜在影响。
我们的结果表明，在没有大规模使用吡喹酮药物治疗的情况下，在曼氏血吸虫高风险流行社区，曼氏血吸虫与疟疾之间的相互作用可能会降低疟疾治疗在减少疟疾传播方面的效果。然而，当疟疾治疗与吡喹酮联合使用时，大规模使用吡喹酮可能会提高疟疾控制干预策略在降低疟疾-曼氏血吸虫共流行社区疟疾患病率方面的效果。
结论/意义：在曼氏血吸虫和疟疾高度流行的地区，血吸虫病治疗和控制项目可能因疾病相互作用而对减少疟疾传播产生间接益处。特别是，大规模使用吡喹酮不仅可能直接降低血吸虫病感染率，还可能减少疟疾传播和疾病负担。
