Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland.
Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland.
Epidemics. 2022 Dec;41:100639. doi: 10.1016/j.epidem.2022.100639. Epub 2022 Oct 20.
Malaria persists at low levels on Zanzibar despite the use of vector control and case management. We use a metapopulation model to investigate the role of human mobility in malaria persistence on Zanzibar, and the impact of reactive case detection. The model was parameterized using survey data on malaria prevalence, reactive case detection, and travel history. We find that in the absence of imported cases from mainland Tanzania, malaria would likely cease to persist on Zanzibar. We also investigate potential intervention scenarios that may lead to elimination, especially through changes to reactive case detection. While we find that some additional cases are removed by reactive case detection, a large proportion of cases are missed due to many infections having a low parasite density that go undetected by rapid diagnostic tests, a low rate of those infected with malaria seeking treatment, and a low rate of follow up at the household level of malaria cases detected at health facilities. While improvements in reactive case detection would lead to a reduction in malaria prevalence, none of the intervention scenarios tested here were sufficient to reach elimination. Imported cases need to be treated to have a substantial impact on prevalence.
尽管桑给巴尔岛一直在使用病媒控制和病例管理措施，但疟疾仍在低水平持续存在。我们使用了一个复合种群模型来研究人类流动性在桑给巴尔岛疟疾持续存在中的作用，以及反应性病例检测的影响。该模型使用疟疾患病率、反应性病例检测和旅行史的调查数据进行了参数化。我们发现，如果没有来自坦桑尼亚大陆的输入病例，疟疾很可能会在桑给巴尔岛停止流行。我们还研究了可能导致消除的潜在干预情景，特别是通过改变反应性病例检测。虽然我们发现反应性病例检测可以消除一些额外的病例，但由于许多感染的寄生虫密度较低，快速诊断检测无法检测到，感染疟疾的人寻求治疗的比例较低，以及在医疗机构检测到的疟疾病例在家庭层面的随访率较低，因此很大一部分病例被漏检。虽然改善反应性病例检测会导致疟疾患病率降低，但这里测试的任何干预情景都不足以达到消除的目的。需要对输入性病例进行治疗，才能对发病率产生重大影响。
