Cook Jackie, Xu Weiping, Msellem Mwinyi, Vonk Marlotte, Bergström Beatrice, Gosling Roly, Al-Mafazy Abdul-Wahid, McElroy Peter, Molteni Fabrizio, Abass Ali K, Garimo Issa, Ramsan Mahdi, Ali Abdullah, Mårtensson Andreas, Björkman Anders
Department of Microbiology and Tumor and Cell Biology.
Zanzibar Malaria Elimination Programme, Ministry of Health.
J Infect Dis. 2015 May 1;211(9):1476-83. doi: 10.1093/infdis/jiu655. Epub 2014 Nov 26.
Seasonal increases in malaria continue in hot spots in Zanzibar. Mass screening and treatment (MSAT) may help reduce the reservoir of infection; however, it is unclear whether rapid diagnostic tests (RDTs) detect a sufficient proportion of low-density infections to influence subsequent transmission.
Two rounds of MSAT using Plasmodium falciparum-specific RDT were conducted in 5 hot spots (population, 12 000) in Zanzibar in 2012. In parallel, blood samples were collected on filter paper for polymerase chain reaction (PCR) analyses. Data on confirmed malarial parasite infections from health facilities in intervention and hot spot control areas were monitored as proxy for malaria transmission.
Approximately 64% of the population (7859) were screened at least once. P. falciparum prevalence, as measured by RDT, was 0.2% (95% confidence interval [CI], .1%-.3%) in both rounds, compared with PCR measured prevalences (for all species) of 2.5% (95% CI, 2.1%-2.9%) and 3.8% (95% CI, 3.2%-4.4%) in rounds 1 and 2, respectively. Two fifths (40%) of infections detected by PCR included non-falciparum species. Treatment of RDT-positive individuals (4% of the PCR-detected parasite carriers) did not reduce subsequent malaria incidence, compared with control areas.
Highly sensitive point-of-care diagnostic tools for detection of all human malaria species are needed to make MSAT an effective strategy in settings where malaria elimination programs are in the pre-elimination phase.
桑给巴尔的疟疾高发地区，疟疾季节性发病率持续上升。大规模筛查和治疗（MSAT）可能有助于减少感染源；然而，尚不清楚快速诊断检测（RDT）能否检测出足够比例的低密度感染以影响后续传播。
2012年在桑给巴尔的5个疟疾高发地区（人口12,000）开展了两轮使用恶性疟原虫特异性RDT的MSAT。同时，采集滤纸血样进行聚合酶链反应（PCR）分析。监测干预地区和疟疾高发对照地区卫生机构确诊的疟原虫感染数据，作为疟疾传播的替代指标。
约64%的人口（7859人）至少接受了一次筛查。两轮筛查中，通过RDT检测的恶性疟原虫患病率均为0.2%（95%置信区间[CI]，0.1%-0.3%），而第一轮和第二轮通过PCR检测的患病率（所有疟原虫种类）分别为2.5%（95%CI，2.1%-2.9%）和3.8%（95%CI，3.2%-4.4%）。PCR检测出的感染中有五分之二（40%）为非恶性疟原虫种类。与对照地区相比，对RDT检测呈阳性的个体（占PCR检测出的寄生虫携带者的4%）进行治疗并未降低后续疟疾发病率。
在疟疾消除计划处于消除前阶段的地区，需要高灵敏度的即时诊断工具来检测所有人类疟原虫种类，以使MSAT成为一项有效的策略。
