Host age and Plasmodium falciparum multiclonality are associated with gametocyte prevalence: a 1-year prospective cohort study

Malaria Journal

Research

Matthew S. Chenoweth¹  Jennifer M. Anderson¹  Carole A. Long¹  Rick M. Fairhurst¹  Aaron M. Tocker¹  Yaw Adomako-Ankomah¹  Kazutoyo Miura¹  Saibou Doumbia²  Mory Doumbouya²  Drissa Konate²  Mahamadou Diakite²  Abdoul S. Keita² 

[1] Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA;Malaria Research and Training Center, Faculty of Medicine, Pharmacy, and Odontostomatology, University of Sciences, Techniques, and Technologies of Bamako, Bamako, Mali;

关键词: Plasmodium falciparum;    Malaria;    Gametocytes;    Longitudinal;    Multiclonality;    Mali;   

DOI  :  10.1186/s12936-017-2123-2

 received in 2017-07-17, accepted in 2017-11-15,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundSince Plasmodium falciparum transmission relies exclusively on sexual-stage parasites, several malaria control strategies aim to disrupt this step of the life cycle. Thus, a better understanding of which individuals constitute the primary gametocyte reservoir within an endemic population, and the temporal dynamics of gametocyte carriage, especially in seasonal transmission settings, will not only support the effective implementation of current transmission control programmes, but also inform the design of more targeted strategies.MethodsA 1-year prospective cohort study was initiated in June 2013 with the goal of assessing the longitudinal dynamics of P. falciparum gametocyte carriage in a village in Mali with intense seasonal malaria transmission. A cohort of 500 individuals aged 1–65 years was recruited for this study. Gametocyte prevalence was measured monthly using Pfs25-specific RT-PCR, and analysed for the effects of host age and gender, seasonality, and multiclonality of P. falciparum infection over 1 year.ResultsMost P. falciparum infections (51–89%) in this population were accompanied by gametocytaemia throughout the 1-year period. Gametocyte prevalence among P. falciparum-positive individuals (proportion of gametocyte positive infections) was associated with age (p = 0.003) but not with seasonality (wet vs. dry) or gender. The proportion of gametocyte positive infections were similarly high in children aged 1–17 years (74–82% on median among 5 age groups), while older individuals had relatively lower proportion, and those aged > 35 years (median of 43%) had significantly lower than those aged 1–17 years (p < 0.05). Plasmodium falciparum-positive individuals with gametocytaemia were found to have significantly higher P. falciparum multiclonality than those without gametocytaemia (p < 0.033 in two different analyses).ConclusionsTaken together, these results suggest that a substantial proportion of Pf-positive individuals carries gametocytes throughout the year, and that age is a significant determinant of gametocyte prevalence among these P. falciparum-positive individuals. Furthermore, the presence of multiple P. falciparum genotypes in an infection, a common feature of P. falciparum infections in high transmission areas, is associated with gametocyte prevalence.

【 授权许可】

CC BY   
© The Author(s) 2017