Influence of micro-habitats on the distribution of macroinvertebrates in Burkina Faso (West Africa)

In this work, we assessed micro-habitat's influence on the distribution of macroinvertebrates in lake Ziga in Burkina Faso from July to December 2016. The water quality variables were measured in situ and the macroinvertebrates were collected with a hand net. The organisms were identified to the lower taxonomic resolution as possible. The results show that the temperature is globally warm, characteristic of tropical area, with a good oxygen content and pH close to neutral. We found five micro-habitats, mainly dominated by fine substrates (32.5%) and aquatic plants (25.83%). The stone, roots and dead woods represented less than 20%. In total, 3,773 individuals of macroinvertebrates were collected. These individuals belong to 33 taxa and three classes. The insects class is the most abundant (88.22%) and the most diversified (24 taxa, 72.72%). The highest taxonomic richness is observed in aquatic plants and root zones. The diversity and density of the macroinvertebrate community varies according to micro-habitats but not according to the size of their surface area. The results showed that coleopterans and hemipterans were strongly and positively correlated to transparency and conductivity (adjusted r>60%, P<0.05). In the local area, the results showed that macroinvertebrates' diversity and distribution are more linked to habitat availability. Our findings reveal a good habitat condition of the lake, and can be served as reference site and hostpot of aquatic biodiversity in the area

Plasmodium species occurrence, temporal distribution and interaction in a child-aged population in rural Burkina Faso.

International audienceBACKGROUND: Malaria can be caused by five Plasmodium species. Due to their higher prevalence, much of the research concentrates on Plasmodium falciparum and Plasmodium vivax. In Burkina Faso, where P. falciparum co-exists with Plasmodium malariae and Plasmodium ovale, there is not much data about the prevalence of the latter two species across human population. Moreover, interactions between co-infecting Plasmodium species are not documented. The aim of the current research is to determine species-specific prevalence and temporal distribution. The potential interactions between co-infecting Plasmodium species amongst the child-aged population in Burkina Faso are also discussed. METHODS: The study took place in the Sudanese savannah zone in Burkina Faso in a rural village, Laye. Surveys were conducted during the wet season across four years, 2007 to 2010. Volunteers aged three to 15 years with parental signed consent were enrolled. Ten children per week were screened for any history of pain, fever. Parasitological data were obtained by blood slide processing. RESULTS: Three sympatric Plasmodium species were recorded during this study with an average prevalence of 70.7%. Species temporal distribution showed an increase of P. malariae parasite prevalence from 0.9% in 2007 to 13.2% in 2010. Within a season, P. falciparum occurred in the overall study period while P. malariae and P. ovale were highly prevalent after the rainy part of this period. Species-specific infection analysis showed that in a comparison of mono-infections, P. malariae gametocyte prevalence and median density were higher than those of P. falciparum (88.9% vs 34.5% and 124.0 vs 40.0 gametocytes/μl, respectively). Likewise, in P. falciparum co-infections with P. malariae or P. ovale, gametocyte prevalence was also higher than in P. falciparum mono-infection. However, in P. falciparum mixed infection with P. malariae, P. falciparum gametocyte prevalence and median density as well as asexual form density decreased compared to P. falciparum mono-infection while for P. malariae mono-infection, only asexual form density significantly vary. CONCLUSION: These data revealed high gametocyte prevalence in other Plasmodium species than P. falciparum with a significant variation of P. malariae gametocyte carriers and gametocyte density across years. Molecular tools and entomological studies are needed to highly assess species-specific contribution to malaria transmission

Equivalent susceptibility of Anopheles gambiae M and S molecular forms and Anopheles arabiensis to Plasmodium falciparum infection in Burkina Faso

International audienceBackgroundThe Anopheles gambiae sensu lato (s.l.) species complex in Burkina Faso consists of Anopheles arabiensis, and molecular forms M and S of Anopheles gambiae sensu stricto (s.s.). Previous studies comparing the M and S forms for level of infection with Plasmodium falciparum have yielded conflicting results.MethodsMosquito larvae were sampled from natural pools, reared to adulthood under controlled conditions, and challenged with natural P. falciparum by experimental feeding with blood from gametocyte carriers. Oocyst infection prevalence and intensity was determined one week after infection. DNA from carcasses was genotyped to identify species and molecular form.ResultsIn total, 7,400 adult mosquitoes grown from wild-caught larvae were challenged with gametocytes in 29 experimental infections spanning four transmission seasons. The overall infection prevalence averaged 40.7% for A. gambiae M form, 41.4% for A. gambiae S form, and 40.1% for A. arabiensis. There was no significant difference in infection prevalence or intensity between the three population groups. Notably, infection experiments in which the population groups were challenged in parallel on the same infective blood displayed less infection difference between population groups, while infections with less balanced composition of population groups had lower statistical power and displayed apparent differences that fluctuated more often from the null average.ConclusionThe study clearly establishes that, at the study site in Burkina Faso, there is no difference in genetic susceptibility to P. falciparum infection between three sympatric population groups of the A. gambiae s.l. complex. Feeding the mosquito groups on the same infective blood meal greatly increases statistical power. Conversely, comparison of the different mosquito groups between, rather than within, infections yields larger apparent difference between mosquito groups, resulting from lower statistical power and greater noise, and could lead to false-positive results. In making infection comparisons between population groups, it is more accurate to compare the different groups after feeding simultaneously upon the same infective blood

List of amphibian species (Vertebrata, Tetrapoda) of Burkina Faso

Ayoro, Halamoussa Joëlle, Segniagbeto, Gabriel Hoinsoudé, Hema, Emmanuel Midibahaye, Penner, Johannes, Oueda, Adama, Dubois, Alain, Rödel, Mark-Oliver, Kabré, Gustave Boureima, Ohler, Annemarie (2020): List of amphibian species (Vertebrata, Tetrapoda) of Burkina Faso. Zoosystema 42 (28): 547-582, DOI: 10.5252/zoosystema2020v42a2

<it>Plasmodium falciparum </it>genotypes diversity in symptomatic malaria of children living in an urban and a rural setting in Burkina Faso

<p>Abstract</p> <p>Background</p> <p>The clinical presentation of malaria, considered as the result of a complex interaction between parasite and human genetics, is described to be different between rural and urban areas. The analysis of the <it>Plasmodium falciparum </it>genetic diversity in children with uncomplicated malaria, living in these two different areas, may help to understand the effect of urbanization on the distribution of <it>P. falciparum </it>genotypes.</p> <p>Methods</p> <p>Isolates collected from 75 and 89 children with uncomplicated malaria infection living in a rural and an urban area of Burkina Faso, respectively, were analysed by a nested PCR amplification of <it>msp1 </it>and <it>msp2 </it>genes to compare <it>P. falciparum </it>diversity.</p> <p>Results</p> <p>The K1 allelic family was widespread in children living in the two sites, compared to other <it>msp1 </it>allelic families (frequency >90%). The MAD 20 allelic family of <it>msp1 </it>was more prevalent (<it>p </it>= 0.0001) in the urban (85.3%) than the rural area (63.2%). In the urban area, the 3D7 alleles of <it>msp2 </it>were more prevalent compared to FC27 alleles, with a high frequency for the 3D7 300_bpallele (>30%). The multiplicity of infection was in the range of one to six in the urban area and of one to seven in the rural area. There was no difference in the frequency of multiple infections (p = 0.6): 96.0% (95% C.I: 91.6–100) in urban versus 93.1% (95%C.I: 87.6–98.6) in rural areas. The complexity of infection increased with age [p = 0.04 (rural area), p = 0.06 (urban area)].</p> <p>Conclusion</p> <p>Urban-rural area differences were observed in some allelic families (MAD20, FC27, 3D7), suggesting a probable impact of urbanization on genetic variability of <it>P. falciparum</it>. This should be taken into account in the implementation of malaria control measures.</p