Hamainza Busiku, Moonga Hawela, Sikaala Chadwick H, Kamuliwo Mulakwa, Bennett Adam, Eisele Thomas P, Miller John, Seyoum Aklilu, Killeen Gerry F
Ministry of Health, National Malaria Control Centre, Chainama Hospital College Grounds, off Great East road, P,O, Box 32509, Lusaka, Zambia.
Malar J. 2014 Mar 31;13:128. doi: 10.1186/1475-2875-13-128.
Active, population-wide mass screening and treatment (MSAT) for chronic Plasmodium falciparum carriage to eliminate infectious reservoirs of malaria transmission have proven difficult to apply on large national scales through trained clinicians from central health authorities.
Fourteen population clusters of approximately 1,000 residents centred around health facilities (HF) in two rural Zambian districts were each provided with three modestly remunerated community health workers (CHWs) conducting active monthly household visits to screen and treat all consenting residents for malaria infection with rapid diagnostic tests (RDT). Both CHWs and HFs also conducted passive case detection among residents who self-reported for screening and treatment.
Diagnostic positivity was higher among symptomatic patients self-reporting to CHWs (42.5%) and HFs (24%) than actively screened residents (20.3%), but spatial and temporal variations of diagnostic positivity were highly consistent across all three systems. However, most malaria infections (55.6%) were identified through active home visits by CHWs rather than self-reporting to CHWs or HFs. Most (62%) malaria infections detected actively by CHWs reported one or more symptoms of illness. Most reports of fever and vomiting, plus more than a quarter of history of fever, headache and diarrhoea, were attributable to malaria infection. The minority of residents who participated >12 times had lower rates of malaria infection and associated symptoms in later contacts but most residents were tested <4 times and high malaria diagnostic positivity (32%) in active surveys, as well as incidence (1.7 detected infections per person per year) persisted in the population. Per capita cost for active service delivery by CHWs was US$5.14 but this would rise to US$10.68 with full community compliance with monthly testing at current levels of transmission, and US$6.25 if pre-elimination transmission levels and negligible treatment costs were achieved.
Monthly active home visits by CHWs equipped with RDTs were insufficient to eliminate the human infection reservoir in this typical African setting, despite reasonably high LLIN/IRS coverage. However, dramatic impact upon infection and morbidity burden might be attainable and cost-effective if community participation in regular testing could be improved and the substantial, but not necessarily prohibitive, costs are affordable to national programmes.
通过中央卫生当局培训的临床医生在全国范围内对慢性恶性疟原虫携带者进行积极的、全人群大规模筛查和治疗（MSAT），以消除疟疾传播的感染源，已证明难以实施。
在赞比亚两个农村地区，以卫生设施（HF）为中心的14个人口集群，每个集群约有1000名居民，每个集群配备了三名报酬适中的社区卫生工作者（CHW），他们每月进行一次主动的家庭访视，使用快速诊断测试（RDT）对所有同意的居民进行疟疾感染筛查和治疗。CHW和HF还对自我报告进行筛查和治疗的居民进行被动病例检测。
自我报告给CHW（42.5%）和HF（24%）的有症状患者的诊断阳性率高于主动筛查的居民（20.3%），但在所有三个系统中，诊断阳性率的空间和时间变化高度一致。然而，大多数疟疾感染（55.6%）是通过CHW的主动家访发现的，而不是自我报告给CHW或HF。CHW主动检测到的大多数（62%）疟疾感染报告了一种或多种疾病症状。大多数发热和呕吐报告，以及超过四分之一的发热、头痛和腹泻病史，都归因于疟疾感染。参与超过12次检测的少数居民在后续接触中疟疾感染率和相关症状较低，但大多数居民检测次数少于4次，主动调查中的疟疾诊断阳性率较高（32%），并且人群中的发病率（每人每年检测到1.7例感染）仍然存在。CHW提供主动服务的人均成本为5.14美元，但如果社区完全按照当前传播水平每月进行检测，这一成本将升至10.68美元，如果达到消除前的传播水平且治疗成本可忽略不计，则为6.25美元。
在这种典型的非洲环境中，配备RDT的CHW每月进行主动家访不足以消除人类感染源，尽管长效驱虫蚊帐/室内滞留喷洒覆盖率相当高。然而，如果能够提高社区对定期检测的参与度，并且国家项目能够承担得起可观但不一定过高的成本，那么对感染和发病负担可能会产生巨大影响且具有成本效益。
