Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon.
Department of Microbiology and Immunology, Cornell College of Veterinary Medicine, Ithaca, NY, USA.
Malar J. 2021 Sep 26;20(1):382. doi: 10.1186/s12936-021-03916-7.
The Mount Cameroon area has experienced a 57.2% decline in confirmed malaria cases between 2006 and 2013 with the implementation of different control measures but, the disease is still of public health concern. The objective of the study was to assess the burden of asymptomatic and sub-microscopic Plasmodium infection, altitudinal influence on it, their effect on haematological parameters as well as identify the risk factors of infection.
A cross-sectional community-based survey involving 1319 children of both sexes aged 6 months to 14 years was conducted between July 2017 and May 2018. Malaria parasitaemia was confirmed by Giemsa-stained microscopy, sub-microscopic Plasmodium infection by 18S mRNA using nested PCR and full blood count analysis was done using an auto haematology analyser.
Malaria parasite, asymptomatic malaria parasitaemia and sub-microscopic Plasmodium infection and anaemia were prevalent in 36.4%, 34.0%, 43.8% and 62.3% of the children, respectively. The risk of having sub-microscopic Plasmodium infection was highest in children 5‒9 (OR = 3.13, P < 0.001) and 10‒14 years of age (OR = 8.18, P < 0.001), non-insecticide treated net users (OR = 1.69, P < 0.04) and those anaemic (OR = 9.01, P < 0.001). Children with sub-microscopic infection had a significantly lower mean haemoglobin (9.86 ± 1.7 g/dL, P < 0.001), red blood cell counts (4.48 ± 1.1 × 10/L, P < 0.001), haematocrit (31.92%, P < 0.001), mean corpuscular haemoglobin concentration (313.25 ± 47.36, P = 0.035) and platelet counts (280.83 ± 112.62, P < 0.001) than their negative counterparts. Children < 5 years old (73.8%), having asymptomatic (69.8%) and sub-microscopic Plasmodium infection (78.3%) as well as resident in the middle belt (72.7%) had a higher prevalence of anaemia than their peers.
The meaningful individual-level heterogeneity in the burden of asymptomatic and sub-microscopic Plasmodium infection in addition to its corollary on haematological variables among children in the different attitudinal sites of the Mount Cameroon Region accentuate the need for strategic context specific planning of malaria control and preventative measures.
2006 年至 2013 年期间，在实施了不同控制措施的情况下，喀麦隆山地区确诊的疟疾病例减少了 57.2%，但该疾病仍然是公共卫生关注的问题。本研究的目的是评估无症状和亚显微疟原虫感染的负担，海拔对其的影响，以及它们对血液参数的影响，并确定感染的危险因素。
2017 年 7 月至 2018 年 5 月期间，进行了一项基于社区的横断面研究，涉及 1319 名 6 个月至 14 岁的男女儿童。通过吉姆萨染色显微镜检查确认疟疾寄生虫感染，通过巢式 PCR 检测亚显微疟原虫感染，使用自动血液学分析仪进行全血细胞计数分析。
36.4%、34.0%、43.8%和 62.3%的儿童分别存在疟疾寄生虫、无症状疟疾寄生虫血症和亚显微疟原虫感染和贫血。5-9 岁（OR=3.13，P<0.001）和 10-14 岁（OR=8.18，P<0.001）儿童、未使用杀虫剂处理的蚊帐使用者（OR=1.69，P<0.04）和贫血儿童（OR=9.01，P<0.001）的亚显微疟原虫感染风险最高。患有亚显微感染的儿童的平均血红蛋白（9.86±1.7 g/dL，P<0.001）、红细胞计数（4.48±1.1×10/L，P<0.001）、血细胞比容（31.92%，P<0.001）、平均红细胞血红蛋白浓度（313.25±47.36，P=0.035）和血小板计数（280.83±112.62，P<0.001）明显低于阴性对照组。5 岁以下儿童（73.8%）、无症状（69.8%）和亚显微疟原虫感染（78.3%）以及居住在中带（72.7%）的儿童贫血患病率高于同龄人。
喀麦隆山地区不同海拔地区儿童无症状和亚显微疟原虫感染负担存在显著的个体差异，以及其对血液变量的影响，这突出了需要针对疟疾控制和预防措施进行战略性的具体情况规划。
