Mawuli Mawusi Adepa, Amoah Linda Eva, Sraku Isaac Kwame, Donu Dickson, Abagna Hamza B, Acquah Festus K, Quashie Neils Ben, Afrane Yaw Asare
West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana.
Department of Pathology, College of Health Sciences, University of Ghana Medical School, University of Ghana, Korle-Bu, Accra, Ghana.
Sci Rep. 2025 Jul 2;15(1):22561. doi: 10.1038/s41598-025-06844-7.
Asymptomatic carriage of malaria parasite is a major public health issue in Ghana and sub-Saharan Africa. These infections are mostly sub-microscopic and not detected by routine malaria screening methods. Asymptomatic malaria infection carriers serve as an infectious reservoir for malaria transmission. This study assessed the infectivity of asymptomatic children to Anopheles gambiae mosquitoes in a high transmission area in Ghana. Ninety-eight (98) healthy children were screened for malaria parasites by microscopy and PCR. Sub-microscopic gametocytes carriage was also determined using RT-PCR. Blood samples from asymptomatic parasite carriers were used in membrane feeding assays of laboratory colonies of An. gambiae mosquitoes. Infectivity was assessed by dissection of mosquito midguts and the mosquito infection rate and oocyst densities were recorded. The total participants that were asymptomatic for malaria was 73/98 (74.49%). Malaria parasite prevalence was 13.7% by microscopy and 78.08% by PCR. Sub-microscopic infections accounted for 64.38% (47/73) of the asymptomatic parasite carriers. No gametocytes were detected, however, the Pfg377 gene was observed in 33.33% (19/57) of the asymptomatic parasite carriers. Blood from 4 out of 19 asymptomatic carriers, associated with carriage of sub-microscopic gametocytes, were found to be infectious to the An. gambiae mosquitoes. The average oocyst density observed was 0.01, with an overall mosquito infection rate of 0.07. This data will be helpful in improving current malaria control efforts in Ghana.
疟原虫的无症状携带是加纳和撒哈拉以南非洲的一个主要公共卫生问题。这些感染大多是亚显微的，常规疟疾筛查方法无法检测到。无症状疟疾感染携带者是疟疾传播的传染源。本研究评估了加纳一个高传播地区无症状儿童对冈比亚按蚊的感染性。通过显微镜检查和聚合酶链反应（PCR）对98名健康儿童进行疟原虫筛查。还使用逆转录聚合酶链反应（RT-PCR）测定亚显微配子体携带情况。无症状寄生虫携带者的血样用于冈比亚按蚊实验室群体的膜饲试验。通过解剖蚊子中肠评估感染性，并记录蚊子感染率和卵囊密度。疟疾无症状的总参与者为73/98（74.49%）。显微镜检查疟原虫患病率为13.7%，PCR检测为78.08%。亚显微感染占无症状寄生虫携带者的64.38%（47/73）。未检测到配子体，然而，在33.33%（19/57）的无症状寄生虫携带者中观察到Pfg377基因。在19名与亚显微配子体携带相关的无症状携带者中，有4人的血液被发现对冈比亚按蚊具有感染性。观察到的平均卵囊密度为0.01，总体蚊子感染率为0.07。这些数据将有助于改善加纳目前的疟疾控制工作。
