Obboh Evans K, Okonu Ruth E, Amoah Linda E
Department of Microbiology and Immunology, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana.
Immunology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.
J Trop Med. 2020 Sep 22;2020:4125109. doi: 10.1155/2020/4125109. eCollection 2020.
Indicators of successful malaria control interventions include a reduction in the prevalence and densities of malaria parasites contained in both symptomatic and asymptomatic infections as well as a reduction in malaria transmission. Individuals harboring malaria parasites in asymptomatic infections serve as reservoirs for malaria transmission. This study determined the prevalence of asymptomatic malaria parasite carriage in afebrile children attending six different schools in two districts, the Cape Coast Metropolitan Assembly (CCMA) and the Komenda Edina Eguafo Abirem (KEEA) of the Central Region of Ghana.
This cross sectional study recruited afebrile children aged between 3 and 15 years old from six randomly selected schools in the Central Region of Ghana. Finger-pricked blood was collected and used to prepare thick and thin blood smears as well as spot a strip of filter paper (Whatman #3). Nested PCR was used to identify , , , and in DNA extracted from the filter paper spots. The multiplicity of infection was determined using merozoite surface protein 2 genotyping.
Out of the 528 children sampled, PCR identified 27.1% to harbor parasites in asymptomatic infections, whilst microscopy identified malaria parasites in 10.6% of the children. The overall PCR estimated prevalence of and was 26.6% and 1.3%, respectively, with no or identified by PCR or microscopy. The RDT positivity rate ranged from 55.8% in Simiw to 4.5% in Kuful. Children from the Simiw Basic School accounted for 87.5% of all the asymptomatic infections. The multiplicity of infection was predominantly monoclonal and biclonal.
The low prevalence of asymptomatic malaria parasite carriage by the children living in the Cape Coast Metropolis suggests that the malaria control interventions in place in CCMA are highly effective and that additional malaria control interventions are required for the KEEA district to reduce the prevalence of asymptomatic malaria parasite carriers. No molecular evidence of and was identified in the afebrile children sampled from the selected schools.
成功的疟疾控制干预指标包括有症状和无症状感染中所含疟原虫的流行率和密度降低，以及疟疾传播减少。无症状感染中携带疟原虫的个体是疟疾传播的储存宿主。本研究确定了在加纳中部地区开普海岸市议会（CCMA）和科门达埃迪纳埃瓜福阿比雷姆（KEEA）两个区的六所不同学校就读的无发热儿童中无症状疟原虫携带情况的流行率。
这项横断面研究从加纳中部地区六所随机选择的学校招募了3至15岁的无发热儿童。采集手指刺破的血液，用于制备厚血涂片和薄血涂片以及点样一条滤纸（Whatman #3）。巢式PCR用于从滤纸斑点中提取的DNA中鉴定恶性疟原虫、间日疟原虫、卵形疟原虫和三日疟原虫。使用裂殖子表面蛋白2基因分型确定疟原虫感染的多样性。
在528名抽样儿童中，PCR鉴定出27.1%的儿童在无症状感染中携带疟原虫，而显微镜检查在10.6%的儿童中发现了疟原虫。总体而言，PCR估计恶性疟原虫和间日疟原虫的流行率分别为26.6%和1.3%，PCR或显微镜检查均未发现卵形疟原虫或三日疟原虫。快速诊断检测阳性率从西米的55.8%到库富尔的4.5%不等。西米小学的儿童占所有无症状感染的87.5%。疟原虫感染的多样性主要为单克隆和双克隆。
居住在开普海岸市的儿童无症状疟原虫携带率较低，这表明CCMA实施的疟疾控制干预措施非常有效，而KEEA区需要额外的疟疾控制干预措施来降低无症状疟原虫携带者的流行率。在所选学校抽样的无发热儿童中未发现卵形疟原虫和三日疟原虫的分子证据。
