Mwesigwa Julia, Achan Jane, Di Tanna Gian Luca, Affara Muna, Jawara Musa, Worwui Archibald, Hamid-Adiamoh Majidah, Kanuteh Fatoumatta, Ceesay Sainey, Bousema Teun, Drakeley Chris, Grietens Koen Peeters, Lindsay Steve W, Van Geertruyden Jean-Pierre, D'Alessandro Umberto
Medical Research Council Unit The Gambia, Banjul, The Gambia.
Department of Global Health, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.
PLoS One. 2017 Nov 2;12(11):e0187059. doi: 10.1371/journal.pone.0187059. eCollection 2017.
Over the last decades, malaria has declined substantially in The Gambia but its transmission has not been interrupted. In order to better target control interventions, it is essential to understand the dynamics of residual transmission. This prospective cohort study was conducted between June 2013 and April 2014 in six pairs of villages across The Gambia. Blood samples were collected monthly during the transmission season (June-December) from all residents aged ≥6 months (4,194 individuals) and then in April (dry season). Entomological data were collected monthly throughout the malaria transmission season. Ownership of Long-Lasting Insecticidal Nets was 71.5% (2766/3869). Incidence of malaria infection and clinical disease varied significantly across the country, with the highest values in eastern (1.7/PYAR) than in central (0.2 /PYAR) and western (0.1/PYAR) Gambia. Malaria infection at the beginning of the transmission season was significantly higher in individuals who slept outdoors (HR = 1.51, 95% CI: 1.02-2.23, p = 0.04) and in those who had travelled outside the village (HR = 2.47, 95% CI: 1.83-3.34, p <0.01). Sub-patent infections were more common in older children (HR = 1.35, 95% CI: 1.04-1.6, p <0.01) and adults (HR = 1.53, 95% CI: 1.23-1.89, p<0.01) than in younger children. The risk of clinical malaria was significantly higher in households with at least one infected individual at the beginning of the transmission season (HR = 1.76, p<0.01). Vector parity was significantly higher in the eastern part of the country, both in the south (90.7%, 117/129, p<0.01) and the north bank (81.1%, 227/280, p<0.01), than in the western region (41.2%, 341/826), indicating higher vector survival. There is still significant residual malaria transmission across The Gambia, particularly in the eastern region. Additional interventions able to target vectors escaping Long-Lasting Insecticidal Nets and indoor residual spraying are needed to achieve malaria elimination.
在过去几十年中，冈比亚的疟疾发病率大幅下降，但其传播尚未被阻断。为了更好地确定控制干预措施的目标，了解残余传播的动态至关重要。这项前瞻性队列研究于2013年6月至2014年4月在冈比亚的六对村庄中进行。在传播季节（6月至12月）每月从所有年龄≥6个月的居民（4194人）中采集血样，然后在4月（旱季）采集。在整个疟疾传播季节每月收集昆虫学数据。长效驱虫蚊帐的拥有率为71.5%（2766/3869）。疟疾感染和临床疾病的发病率在全国范围内差异显著，东部地区（1.7/人年发病率）高于中部地区（0.2/人年发病率）和西部地区（0.1/人年发病率）。在传播季节开始时，睡在户外的个体（风险比=1.51，95%置信区间：1.02-2.23，p=0.04）和出过村的个体（风险比=2.47，95%置信区间：1.83-3.34，p<0.01）的疟疾感染率显著更高。亚临床感染在大龄儿童（风险比=1.35，95%置信区间：1.04-1.6，p<0.01）和成年人（风险比=1.53，95%置信区间：1.23-1.89，p<0.01）中比在小龄儿童中更常见。在传播季节开始时，至少有一名感染者的家庭中临床疟疾的风险显著更高（风险比=1.76，p<0.01）。该国东部地区的媒介成蚊率显著高于西部地区，南部（90.7%，117/129，p<0.01）和北岸（81.1%，227/280，p<0.01）均高于西部地区（41.2%，341/826），表明媒介生存率更高。冈比亚各地仍存在显著的残余疟疾传播，特别是在东部地区。需要采取额外的干预措施来针对那些避开长效驱虫蚊帐和室内滞留喷洒的媒介，以实现消除疟疾的目标。
