Medjigbodo Adandé A, Djossou Laurette, Adoha Constantin J, Djihinto Oswald Y, Ogouyemi-Hounto Aurore, Donnelly Martin J, Weetman David, Djogbénou Luc S
Tropical Infectious Diseases Research Centre (TIDRC), University of Abomey-Calavi, 01BP 526 Cotonou, Benin.
Regional Institute of Public Health/ University of Abomey-Calavi, BP 384 Ouidah, Benin.
Parasite Epidemiol Control. 2023 Jan 19;21:e00285. doi: 10.1016/j.parepi.2023.e00285. eCollection 2023 May.
Understanding the contribution of asymptomatic carriers in malaria transmission might be helpful to design and implement new control measures. The present study explored the prevalence of asymptomatic and symptomatic infections (asexual and sexual stages) and the contribution of asymptomatic carriers to -mediated malaria transmission in Ouidah (Benin). Thick and thin blood smears were examined from finger-prick blood specimens using light microscopy, and the density of both asexual and sexual stages of species was calculated. Infectivity of gametocyte-infected blood samples to was assessed through direct membrane feeding assays. The prevalence of asymptomatic infections was 28.73% (289/1006). All the asymptomatic gametocyte-carriers (19/19), with gametocytaemia ranging from 10 - 1200 gametocytes/μL of blood, were infectious to mosquitoes. The mean oocyst prevalences varied significantly ( = 16.42, = 7, = 0.02) among laboratory mosquito strains (6.9 - 39.4%) and near-field mosquitoes (4.9 - 27.2%). Likewise, significant variation ( = 56.85, = 7, = 6.39 × 10) was observed in oocyst intensity. Our findings indicate that asymptomatic carriers could significantly contribute to malaria transmission. Overall, this study highlights the importance of diagnosing and treating asymptomatic and symptomatic infection carriers during malaria control programmes.
了解无症状携带者在疟疾传播中的作用可能有助于设计和实施新的控制措施。本研究探讨了贝宁维达地区无症状和有症状感染（无性和有性阶段）的流行情况以及无症状携带者对疟疾传播的作用。使用光学显微镜检查手指刺血标本的厚血膜和薄血膜，并计算疟原虫无性和有性阶段的密度。通过直接膜饲法评估感染配子体的血样对按蚊的感染性。无症状感染的流行率为28.73%（289/1006）。所有无症状配子体携带者（19/19），配子体血症范围为10 - 1200个配子体/微升血液，对按蚊具有感染性。实验室蚊株（6.9 - 39.4%）和近场蚊子（4.9 - 27.2%）之间的平均卵囊流行率差异显著（χ² = 16.42，df = 7，P = 0.02）。同样，在卵囊强度方面也观察到显著差异（χ² = 56.85，df = 7，P = 6.39 × 10⁻⁷）。我们的研究结果表明，无症状携带者可能对疟疾传播有显著贡献。总体而言，本研究强调了在疟疾控制计划中诊断和治疗无症状和有症状感染携带者的重要性。
