Malaria case clinical profiles and Plasmodium falciparum parasite genetic diversity: a cross sectional survey at two sites of different malaria transmission intensities in Rwanda
Malaria case clinical profiles and Plasmodium falciparum parasite genetic diversity: a cross sectional survey at two sites of different malaria transmission intensities in Rwanda
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DOI：
10.1186/s12936-016-1287-5
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发表时间：
2016-04-26
期刊：
影响因子：
3
通讯作者：
van Vugt, Michele
中科院分区：
文献类型：
--
作者：
Kateera, Fredrick;Nsobya, Sam L.;van Vugt, Michele
背景：疟疾仍然是撒哈拉以南非洲地区的一个公共卫生挑战，恶性疟原虫是疟疾疾病发病率和死亡率的主要原因。恶性疟原虫的毒力部分归因于其群体水平的遗传多样性，这一特征尚未在卢旺达进行研究。为了更好地了解疟疾传播并为疟疾控制策略的选择提供信息，需要描述一个地区恶性疟原虫的分子流行病学特征。方法：在这项基于卫生机构的调查中，比较了在卢旺达不同疟疾传播强度的两个地点发现的恶性疟原虫感染患者的疟疾病例临床特征和寄生虫密度以及寄生虫遗传多样性。收集了人口统计和临床特征的数据以及用于显微镜检查和寄生虫基因分型的指尖血样。使用巢式 PCR 对 FC27 和 3D7 的 msp-2 等位基因进行基因分型。 结果：发现患者的年龄组、性别、发烧（通过患者报告和测量的鼓室温度）、寄生虫密度和蚊帐使用等变量在高流行区 (Ruhuha) 和低流行区 (Mubuga) 之间分布存在差异。恶性疟原虫感染的总体复数 (MOI) 为 1.73，但发现平均 MOI 在鲁胡哈 (Ruhuha) 的 2.13 和穆布加 (Mubuga) 的 1.29 之间存在显着差异 (p < 0.0001)。在鲁胡哈，FC27 和 3D7 等位基因的预期杂合度 (E-H) 分别为 0.62 和 0.49，而在穆布加，FC27 和 3D7 等位基因的预期杂合度 (E-H) 分别为 0.26 和 0.28。 结论：在这项研究中，在较高的条件下观察到较高的几何平均寄生虫计数、更多的多克隆感染、较高的 MOI 和较高的等位基因频率。疟疾流行区 (Ruhuha) 与疟疾流行较低区 (Mubuga) 相比。在选择特定环境的疟疾控制策略、评估 p.1 时，应考虑疟疾风险和 MOI 的这些差异。恶性疟相关参数，例如耐药性、免疫力和所用干预措施的影响，以及疟疾疫苗研究的正确解释。
Background: Malaria remains a public health challenge in sub-Saharan Africa with Plasmodium falciparum being the principal cause of malaria disease morbidity and mortality. Plasmodium falciparum virulence is attributed, in part, to its population-level genetic diversity-a characteristic that has yet to be studied in Rwanda. Characterizing P. falciparum molecular epidemiology in an area is needed for a better understand of malaria transmission and to inform choice of malaria control strategies.Methods: In this health-facility based survey, malaria case clinical profiles and parasite densities as well as parasite genetic diversity were compared among P. falciparum-infected patients identified at two sites of different malaria transmission intensities in Rwanda. Data on demographics and clinical features and finger-prick blood samples for microscopy and parasite genotyping were collected. Nested PCR was used to genotype msp-2 alleles of FC27 and 3D7.Results: Patients' variables of age group, sex, fever (both by patient report and by measured tympanic temperatures), parasite density, and bed net use were found differentially distributed between the higher endemic (Ruhuha) and lower endemic (Mubuga) sites. Overall multiplicity of P. falciparum infection (MOI) was 1.73 but with mean MOI found to vary significantly between 2.13 at Ruhuha and 1.29 at Mubuga (p < 0.0001). At Ruhuha, expected heterozygosity (E-H) for FC27 and 3D7 alleles were 0.62 and 0.49, respectively, whilst at Mubuga, E-H for FC27 and 3D7 were 0.26 and 0.28, respectively.Conclusions: In this study, a higher geometrical mean parasite counts, more polyclonal infections, higher MOI, and higher allelic frequency were observed at the higher malaria-endemic (Ruhuha) compared to the lower malariaendemic (Mubuga) area. These differences in malaria risk and MOI should be considered when choosing setting-specific malaria control strategies, assessing p. falciparum associated parameters such as drug resistance, immunity and impact of used interventions, and in proper interpretation of malaria vaccine studies.