Microscopic and Submicroscopic Asymptomatic Plasmodium falciparum Infections in Ghanaian Children and Protection against Febrile Malaria.
Microscopic and Submicroscopic Asymptomatic Plasmodium falciparum Infections in Ghanaian Children and Protection against Febrile Malaria.
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DOI：
10.1128/iai.00125-20
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发表时间：
2020-09-18
影响因子：
3.1
通讯作者：
Dodoo D
中科院分区：
文献类型：
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作者：
Adu B;Issahaque QA;Sarkodie-Addo T;Kumordjie S;Kyei-Baafour E;Sinclear CK;Eyia-Ampah S;Owusu-Yeboa E;Theisen M;Dodoo D
对恶性疟原虫疟疾的自然获得性免疫被认为是非不育的，并通过低水平寄生虫血症的持续存在而持续。本研究评估了基线显微镜和亚显微镜下无症状恶性疟原虫感染与抗疟抗体水平之间的关系，以及这些寄生虫血症是否改变了加纳儿童抗体水平与疟疾之间的保护性联系。健康儿童（N = 973，年龄0。人们认为，对恶性疟原虫疟疾的自然获得性免疫是非无菌的，并且通过持续存在低水平寄生虫血症来维持。本研究评估了基线显微镜和亚显微镜下无症状恶性疟原虫感染与抗疟抗体水平之间的关系，以及这些寄生虫血症是否改变了加纳儿童抗体水平与疟疾之间的保护性联系。2016年1月至2017年1月，健康儿童（N = 973，年龄0.5至12岁）被招募到一项为期50周的纵向疟疾队列研究中。通过显微镜检查（显微寄生虫血症）和PCR（亚显微寄生虫血症）确定基线无症状寄生虫血症，并通过酶限制性免疫吸附试验（ELISA）测量针对粗抗原的抗体水平。在基线无症状的显微镜或亚显微镜或无恶性疟原虫感染的儿童中，比较了抗体水平、寄生虫多样性和随后传播季节的疟疾风险。在99例无症状基线感染中，46例（46.5%）为显微镜感染，53例（53.5%）为亚显微镜感染。调整年龄组、性别和社区的考克斯回归分析发现，基线显微镜检查和（风险比[HR] = 0.36，95%置信区间[95% CI] = 0.21至0.63; P < 0.001）和亚显微镜下（HR = 0.22，95%CI = 0.11 - 0.44; P < 0.001）与基线时未感染的患者相比，无症状寄生虫血症和发热性疟疾风险降低。基线无症状亚显微寄生虫血症对抗疟原虫抗体和预防发热性疟疾之间的关联有显著影响（P < 0.001;似然比检验）。该研究发现，基线恶性疟原虫无症状的显微镜下感染和更强烈的亚显微镜下感染与随后的传播季节预防发热性疟疾有关。这可能对疟疾血清流行病学研究和疫苗试验产生重要影响。
Naturally acquired immunity to Plasmodium falciparum malaria is thought to be nonsterile and sustained by persistence of low-level parasitemia. This study assessed the association between baseline microscopic and submicroscopic asymptomatic P. falciparum infections and antimalarial antibody levels and whether these parasitemia modify protective associations between antibody levels and malaria in Ghanaian children. Healthy children (N = 973, aged 0. Naturally acquired immunity to Plasmodium falciparum malaria is thought to be nonsterile and sustained by persistence of low-level parasitemia. This study assessed the association between baseline microscopic and submicroscopic asymptomatic P. falciparum infections and antimalarial antibody levels and whether these parasitemia modify protective associations between antibody levels and malaria in Ghanaian children. Healthy children (N = 973, aged 0.5 to 12 years) were recruited into a 50-week longitudinal malaria cohort study from January 2016 to January 2017. Baseline asymptomatic parasitemia were determined by microscopy (microscopic parasitemia) and PCR (submicroscopic parasitemia), and antibody levels against crude schizont antigens were measured by enzyme-limited immunosorbent assay (ELISA). Antibody levels, parasite diversity, and risk of malaria in the ensuing transmission season were compared among children who had baseline asymptomatic microscopic or submicroscopic or no P. falciparum infections. Of the 99 asymptomatic baseline infections, 46 (46.5%) were microscopic and 53 (53.5%), submicroscopic. Cox regression analysis adjusting for age group, sex and community found a strong association between both baseline microscopic (hazard ratio [HR] = 0.36, 95% confidence interval [95% CI] = 0.21 to 0.63; P < 0.001) and submicroscopic (HR = 0.22, 95% CI = 0.11 to 0.44; P < 0.001) asymptomatic parasitemia and a reduced risk of febrile malaria compared to those who were uninfected at baseline. Baseline asymptomatic submicroscopic parasitemia had a significant effect on associations between antischizont antibodies and protection against febrile malaria (P < 0.001; likelihood ratio test). The study found both baseline P. falciparum asymptomatic microscopic and more strongly submicroscopic infections to be associated with protection against febrile malaria in the ensuing transmission season. This could have important implications for malaria seroepidemiological studies and vaccine trials.