Genetic complexity and gametocyte production of Plasmodium falciparum in Fulani and Mossi communities in Burkina Faso

Abstract

We have examined Plasmodium falciparum gametocyte prevalence, density and their genetic complexity among children of 2 sympatric ethnic groups (Mossi and Fulani) in villages in Burkina Faso. The 2 groups are known to have distinct differences in their susceptibility and immune responses to malaria. We used RT-PCR and sequence-specific probes to detect and type RNA of the gametocyte-specific protein Pfs48/45. There were no differences in detection rates of asexual forms and gametocytes among the 2 groups, using PCR and RT-PCR, respectively. However, there were significant differences in densities of asexual forms and gametocytes, which were both higher among Mossi than Fulani. Both asexual forms and gametocyte densities were influenced by age and ethnicity. Multiple-clone infections with more than 1 gametocyte genotype were equally prevalent among Fulani and Mossi. These differences can most probably be attributed to genetic differences in malaria susceptibility in the 2 ethnic groups.

Epidemiology and Infectivity of Plasmodium falciparum and Plasmodium vivax Gametocytes in Relation to Malaria Control and Elimination

“…Lower gametocyte densities were observed in Fulani than in Mossi tribes in Burkina Faso, an observation that may not be explained completely by differences in asexual stage immunity (340). Gametocyte carriage and malaria transmission potential were also related to human genetic variation at the ␤-globin locus, with a higher gametocyte density and/or higher infection rate for individuals with the HbAS, HbAC, or HbCC genotype than for those with the HbAA ␤-globin genotype (164,387).…”

“…In areas of very low endemicity in Tanzania and Sudan, gametocytes were detected in 0 to 6% of the population by microscopy but in 12 to 52% of the population by molecular tools (1, 314,413). In areas of more intense seasonal transmission in the Gambia and Burkina Faso, gametocyte prevalences ranged from 3 to 30% by microscopy and from 49 to 70% by use of molecular tools (319,337,340). These findings indicate that gametocyte carriage is consistently underestimated by microscopy.…”

Molecular evidence for the localization of Plasmodium falciparum immature gametocytes in bone marrow

“…[5][6][7][8] However, these studies are of limited scale and used standard light microscopy as the only method for gametocyte detection and stage differentiation; standard light microscopy is known to have low sensitivity compared with molecular tools 9,10 and to miss a substantial proportion of P falciparum infections in surveys of endemic populations. [11][12][13] The information on gametocyte stages detected by molecular techniques such as polymerase chain reaction (PCR) is scarce for P falciparum infections in peripheral blood and absent for infections in the bone marrow. Such a lack of data limits the accurate assessment of malaria transmission at a community level, which is critical to enabling rational development of a transmission-blocking vaccine 14 and to support elimination and eradication of P falciparum and P vivax.…”

Longitudinal study on Plasmodium falciparum gametocyte carriage following artemether-lumefantrine administration in a cohort of children aged 12–47 months living in Western Kenya, a high transmission area

“…Gametocyte carriage in naturally infected individuals in a population is influenced by many factors such as the age group [5,11-13], transmission settings [5,14,15], seasons [5,16-18] and the human host genetic factors [19-21]. Other important risk factors for gametocyte carriage include anaemia [22], durations of the infections, recrudescent infections [23], fever [24], mixed infections [23,25] and drug treatment [26,27].…”