The prevalence and density of asymptomatic Plasmodium falciparum infections among children and adults in three communities of western Kenya.
The prevalence and density of asymptomatic Plasmodium falciparum infections among children and adults in three communities of western Kenya.
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DOI：
10.1186/s12936-021-03905-w
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发表时间：
2021-09-17
期刊：
影响因子：
3
通讯作者：
Tran TM
中科院分区：
文献类型：
--
作者：
Salgado C;Ayodo G;Macklin MD;Gould MP;Nallandhighal S;Odhiambo EO;Obala A;O'Meara WP;John CC;Tran TM
随着越来越多的国家接近消除疟疾，要进一步减少疟疾发病率，就需要识别和治疗携带可促进疟疾传播的蚊子感染性疟原虫配子细胞的无症状个体。在实地调查中评估总寄生虫血症和配子体血症之间的关系，可以深入了解用敏感的分子方法检测低密度、无症状的恶性疟原虫感染是否能够充分检测出大多数有可能继续传播的感染者。在对肯尼亚西部三个不同疟疾传播梯度（Ajigo、Webuye和Kapsisywa-Kipsamoite）的1354名健康儿童和成人进行的横断面调查中，通过快速诊断测试、血液涂片和针对基因组DNA中varATS基因的干血斑点的定量PCR筛查无症状恶性疟原虫感染。我们还开发了一种针对雌性和雄性配子细胞基因（pfs25、pfs230p）、一个转录模式仅限于无性血阶段的基因（piesp2）和人类GAPDH的多重定量逆转录酶PCR方法，以确定寄生个体的寄生虫和配子细胞总密度。Ajigo的varats检测无症状感染患病率最高（42%），其次是Webuye（10%）。在卡普西西瓦只发现了两例感染。在基普萨莫伊特没有发现感染。在所有社区中，11-15岁儿童占总感染和亚微观无症状感染的最大比例。在较年轻的年龄组中，大多数感染可通过显微镜检测到，而68%的无症状感染成人（bb0 - 21岁）患有亚显微镜寄生虫病。与基于varats的检测相比，piesp2衍生的寄生虫密度与显微镜下确定的专利感染寄生虫密度相关性较差。一般来说，雄性和雌性配子细胞血症都随着varats引起的总寄生虫血症的增加而增加。相当大比例（41.7%）有可能继续传播的个体，其qPCR估计的寄生虫密度低于显微镜检测的极限，但高于varATS qPCR的检测极限。对三个传播强度不同的社区寄生虫病和配子体血症的评估显示，在无症状的恶性疟原虫携带者中存在大量亚显性感染库的证据。需要进行实验研究，以明确确定Ajigo和Webuye等社区的低密度感染是否对疟疾传播有重大贡献。在线版本包含补充材料，可在10.1186/s12936-021-03905-w获得。
Further reductions in malaria incidence as more countries approach malaria elimination require the identification and treatment of asymptomatic individuals who carry mosquito-infective Plasmodium gametocytes that are responsible for furthering malaria transmission. Assessing the relationship between total parasitaemia and gametocytaemia in field surveys can provide insight as to whether detection of low-density, asymptomatic Plasmodium falciparum infections with sensitive molecular methods can adequately detect the majority of infected individuals who are potentially capable of onward transmission. In a cross-sectional survey of 1354 healthy children and adults in three communities in western Kenya across a gradient of malaria transmission (Ajigo, Webuye, and Kapsisywa–Kipsamoite), asymptomatic P. falciparum infections were screened by rapid diagnostic tests, blood smear, and quantitative PCR of dried blood spots targeting the varATS gene in genomic DNA. A multiplex quantitative reverse-transcriptase PCR assay targeting female and male gametocyte genes (pfs25, pfs230p), a gene with a transcriptional pattern restricted to asexual blood stages (piesp2), and human GAPDH was also developed to determine total parasite and gametocyte densities among parasitaemic individuals. The prevalence of varATS-detectable asymptomatic infections was greatest in Ajigo (42%), followed by Webuye (10%). Only two infections were detected in Kapsisywa. No infections were detected in Kipsamoite. Across all communities, children aged 11–15 years account for the greatest proportion total and sub-microscopic asymptomatic infections. In younger age groups, the majority of infections were detectable by microscopy, while 68% of asymptomatically infected adults (> 21 years old) had sub-microscopic parasitaemia. Piesp2-derived parasite densities correlated poorly with microscopy-determined parasite densities in patent infections relative to varATS-based detection. In general, both male and female gametocytaemia increased with increasing varATS-derived total parasitaemia. A substantial proportion (41.7%) of individuals with potential for onward transmission had qPCR-estimated parasite densities below the limit of microscopic detection, but above the detectable limit of varATS qPCR. This assessment of parasitaemia and gametocytaemia in three communities with different transmission intensities revealed evidence of a substantial sub-patent infectious reservoir among asymptomatic carriers of P. falciparum. Experimental studies are needed to definitively determine whether the low-density infections in communities such as Ajigo and Webuye contribute significantly to malaria transmission. The online version contains supplementary material available at 10.1186/s12936-021-03905-w.
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DOI：
10.1016/j.ijbiomac.2021.02.145
发表时间：
2021-02-27
影响因子：
8.2
作者：
Liu, Xuewu;Wu, Yongming;Liang, Jiao
通讯作者：
Liang, Jiao
对疟疾寄生虫基因组的深入比较分析揭示了恶性疟原虫基因组中与人类疾病相关的蛋白质编码基因。
影响因子：
4.4
作者：
Liu X;Wang Y;Liang J;Wang L;Qin N;Zhao Y;Zhao G
通讯作者：
Zhao G
影响因子：
3
作者：
Apat DO;Gachohi JM;Karama M;Kiplimo JR;Sachs SE
通讯作者：
Sachs SE
影响因子：
3
作者：
Bousema, JT;Gouagna, LC;Sauerwein, RW
通讯作者：
Sauerwein, RW
影响因子：
3.7
作者：
Obala, Andrew A.;Mangeni, Judith Nekesa;O'Meara, Wendy Prudhomme
通讯作者：
O'Meara, Wendy Prudhomme