Rek John, Katrak Shereen, Obasi Hannah, Nayebare Patience, Katureebe Agaba, Kakande Elijah, Arinaitwe Emmanuel, Nankabirwa Joaniter I, Jagannathan Prasanna, Drakeley Chris, Staedke Sarah G, Smith David L, Bousema Teun, Kamya Moses, Rosenthal Philip J, Dorsey Grant, Greenhouse Bryan
Infectious Diseases Research Collaboration, Kampala, Uganda.
Department of Medicine, University of California San Francisco, San Francisco, USA.
Malar J. 2016 Sep 15;15:470. doi: 10.1186/s12936-016-1519-8.
Parasite prevalence is a key metric used to quantify the burden of malaria and assess the impact of control strategies. Most published estimates of parasite prevalence are based on microscopy and likely underestimate true prevalence.
Thick smear microscopy was performed in cohorts of children (aged 6 month to 10 years) and adults every 90 days over 2 years, at three sites of varying transmission intensity in Uganda. Microscopy-negative samples were tested for sub-microscopic parasitaemia using loop-mediated isothermal amplification (LAMP). Generalized estimating equation models were used to evaluate associations between age and parasitaemia, factors associated with sub-microscopic infection and associations between parasitaemia and haemoglobin.
A total of 9260 samples were collected from 1245 participants. Parasite prevalence among children across the three sites was 7.4, 9.4 and 28.8 % by microscopy and 21.3, 31.8 and 69.0 % by microscopy plus LAMP. Parasite prevalence among adults across the three sites was 3.1, 3.0 and 5.2 % by microscopy and 18.8, 24.2 and 53.5 % by microscopy plus LAMP. Among those with parasitaemia, adults and persons recently treated with anti-malarial therapy had the highest prevalence of sub-microscopic infection. Children with sub-microscopic or microscopic parasitaemia had lower mean haemoglobin levels compared to children with no detectable parasites.
Across a range of transmission intensities in Uganda, microscopy vastly underestimated parasite prevalence, especially among adults.
寄生虫感染率是用于量化疟疾负担和评估防控策略效果的关键指标。大多数已发表的寄生虫感染率估计值基于显微镜检查，可能低估了实际感染率。
在乌干达三个传播强度不同的地点，对儿童（6个月至10岁）和成人群体每90天进行一次厚涂片显微镜检查，持续2年。对显微镜检查阴性的样本，使用环介导等温扩增技术（LAMP）检测亚显微水平的寄生虫血症。采用广义估计方程模型评估年龄与寄生虫血症之间的关联、与亚显微感染相关的因素以及寄生虫血症与血红蛋白之间的关联。
共从1245名参与者中采集了9260份样本。三个地点儿童的寄生虫感染率，显微镜检查分别为7.4%、9.4%和28.8%，显微镜检查加LAMP分别为21.3%、31.8%和69.0%。三个地点成人的寄生虫感染率，显微镜检查分别为3.1%、3.0%和5.2%，显微镜检查加LAMP分别为18.8%、24.2%和53.5%。在有寄生虫血症的人群中，成人和近期接受抗疟治疗的人亚显微感染率最高。与未检测到寄生虫的儿童相比，有亚显微或显微寄生虫血症的儿童平均血红蛋白水平较低。
在乌干达不同传播强度范围内，显微镜检查极大地低估了寄生虫感染率，尤其是在成人中。
