Michel Makoutodé

Migraine Among University Students in Cotonou (Benin)

Background.— Few data are available on migraine among students in Africa. The aim of this study was to estimate the prevalence of migraine and describe its clinical features and associated conditions among students of the Faculty of Health Sciences of Abomey‐Calavi University, in Cotonou, Benin.

Effect of three larval diets on larval development and male sexual performance of Anopheles gambiae s.s.

Population replacement/elimination strategies based on mass-release of sterile or otherwise genetically modified (male) mosquitoes are being considered in order to expand the malaria vector control arsenal on the way to eradication. A challenge in this context, is to produce male mosquitoes that will be able to compete and mate with wild females more efficiently than their wild counterparts, i.e. high fitness males. This study explored the effect of three larval food diets developed by the International Atomic Energy Agency on the overall fitness and mating performance of male Anopheles gambiae s.s. mosquitoes (Kisumu strain). Larval development (pupation and emergence rate, development time) was monitored, and adult wing length and energy reserves at emergence (i.e. lipids, sugars, glycogen and proteins) were measured. Male sexual performance was assessed through an insemination test whereby one male and 10 virgin females were maintained together in the same cage in order to record the number of inseminated females per 24h. Our results show that males reared on Diets 2 and 3 performed best during larval development. Males provided with treatment 2.2 had a shorter development time and performed best in insemination tests. However, these males had the lowest overall lifespan, suggesting a trade-off between longevity and sexual performances which needs to be taken into consideration when planning release. The results from this work were discussed in the context of sterile insect techniques or genetic control methods which is today one of the strategy in the overall mosquito control and elimination efforts.

Characterization of swarming and mating behaviour between Anopheles coluzzii and Anopheles melas in a sympatry area of Benin.

The swarm structure of two sibling species, Anopheles gambiae coluzzii and Anopheles melas, was characterize to explore the ecological and environmental parameters associated with the formation of swarms and their spatial distribution. Swarms and breeding sites were searched and sampled between January and December 2010, and larval and adult samples were identified by PCR. During the dry season, 456 swarms of An. gambiae s.l. were sampled from 38 swarm sites yielding a total of 23,274 males and 76 females. Of these 38 swarming sites, 18 were composed exclusively of An. gambiae coluzzii and 20 exclusively of An. melas, presenting clear evidence of reproductive swarm segregation. The species makeup of couples sampled from swarms also demonstrated assortative mating. The swarm site localization was close to human dwellings in the case of the An. gambiae coluzzii and on salt production sites for An. melas. At the peak of the rainy season, swarms of An. melas were absent. These findings offer evidence that the ecological speciation of these two sibling species of mosquitoes is associated with spatial swarm segregation and assortative mating, providing strong support for the hypothesis that mate recognition is currently maintaining adaptive differentiation and promoting ecological speciation. Further studies on the swarming and mating systems of An. gambiae, with the prospect of producing a predictive model of swarm distribution, are needed to inform any future efforts to implement strategies based on the use of GMM or SIT.

An ace-1 gene duplication resorbs the fitness cost associated with resistance in Anopheles gambiae, the main malaria mosquito.

Widespread resistance to pyrethroids threatens malaria control in Africa. Consequently, several countries switched to carbamates and organophophates insecticides for indoor residual spraying. However, a mutation in the ace-1 gene conferring resistance to these compounds (ace-1R allele), is already present. Furthermore, a duplicated allele (ace-1D) recently appeared; characterizing its selective advantage is mandatory to evaluate the threat. Our data revealed that a unique duplication event, pairing a susceptible and a resistant copy of the ace-1 gene spread through West Africa. Further investigations revealed that, while ace-1D confers less resistance than ace-1R, the high fitness cost associated with ace-1R is almost completely suppressed by the duplication for all traits studied. ace-1 duplication thus represents a permanent heterozygote phenotype, selected, and thus spreading, due to the mosaic nature of mosquito control. It provides malaria mosquito with a new evolutionary path that could hamper resistance management.

Lifestyle and Dietary Factors Associated with the Evolution of Cardiometabolic Risk over Four Years in West-African Adults: The Benin Study

Aim. To assess in adults from Benin changes in cardiometabolic risk (CMR) using both the Framingham risk score (FRS) and metabolic syndrome (MetS) and to examine the effects of diet, and lifestyles, controlling for location and socioeconomic status. Methods. Apparently healthy subjects (n = 541) aged 25–60 years and randomly selected in the largest city, a small town, and rural areas were included in the four-year longitudinal study. Along with CMR factors, socioeconomic, diet and lifestyle data were collected in individual interviews. A food score based on consumption frequency of four “sentinel” food groups (meat and poultry, dairy, eggs, and vegetables) was developed. Lifestyle included physical activity, alcohol and tobacco use. Education and income (proxy) were the socioeconomic variables. Results. Among the subjects with four-year follow-up data (n = 416), 13.5% were at risk at baseline, showing MetS or FRS ≥ 10%. The incidence of MetS and FRS ≥ 10% during follow-up was 8.2% and 5%, respectively. CMR deteriorated in 21% of subjects. Diet and lifestyle mediated location and income effects on CMR evolution. Low food scores and inactivity increased the likelihood of CMR deterioration. Conclusion. Combining MetS and FRS might be appropriate for surveillance purposes in order to better capture CMR and inform preventive measures.

Phenotypic effects of concomitant insensitive acetylcholinesterase (ace-1 R ) and knockdown resistance (kdr R ) in Anopheles gambiae: a hindrance for insecticide resistance management for malaria vector control

BackgroundMalaria is endemic in sub-Saharan Africa with considerable burden for human health. Major insecticide resistance mechanisms such as kdrR and ace-1Ralleles constitute a hindrance to malaria vector control programs. Anopheles gambiae bearing both kdr and ace-1 resistant alleles are increasingly recorded in wild populations. In order to maintain the efficacy of vector control strategies, the characterization of concomitant kdr and ace-1 resistance, and their pleiotropic effects on malaria vector phenotype on insecticide efficacy are important.MethodsLarval and adult bioassays were performed with different insecticide classes used in public health following WHO standard guidelines on four laboratory Anopheles gambiae strains, sharing the same genetic background but harboring distinct resistance status: KISUMU with no resistance allele; ACERKIS with ace-1R allele; KISKDR with kdrR allele and ACERKDRKIS with both resistance alleles’ ace-1R and kdrR.ResultsLarval bioassays indicate that the homozygote resistant strain harboring both alleles (ACERKDRKIS) displayed slightly but significantly higher resistance level to various insecticides like carbamates (bendiocarb, p < 0.001; propoxur, p = 0.02) and organophosphates (chlorpyriphos-methyl, p = 0.002; fenitrothion, p < 0.001) when compared to ACERKIS strain. However, no differences were recorded between ACERKDRKIS and KISKDR resistance level against permethrin (Pyrethroid, p = 0.7) and DDT (Organochlorine, p = 0.24). For adult bioassays, the percentages of mosquitoes knocked down were significantly lower for ACERKDRKIS than for KISKDR with permethrin (p = 0.003) but not with deltamethrin. The percentage of mortality from adult bioassays was similar between ACERKDRKIS and ACERKIS with carbamates and organophosphates, or between ACERKDRKIS and KISKDR with pyrethroid and DDT. Concerning acetylcholinesterase enzyme, ACERKDRKIS strain showed similarAChE1 activity than that of ACERKIS.ConclusionThe presence of both kdrR and ace-1R alleles seems to increase the resistance levels to both carbamate and organophosphate insecticides and at operational level, may represent an important threat to malaria vector control programs in West Africa.

Facteurs associés à la qualité de l’eau de puits et prévalence des maladies hydriques dans la commune d’Abomey-Calavi (Bénin)

The objective of this work is to assess the factors associated with the water quality of household wells, suggest solutions to improve it, and study the prevalence of water-borne diseases in this community. The quality of well water and the prevalence of waterborne diseases in the municipality were studied by analysis of the microbiological indicators currently used to assess drinking-water quality and the retrospective study of waterborne diseases treated in the local health centres. The wells surveyed were contaminated by Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, Salmonella spp, Clostridium perfringens and fecal streptococci, at prevalences of 12.5, 12.2, 12.2, 12.1, 12 and 11.1%, respectively. The high rates of diarrhea, urinary infections, typhoid fever and abdominal pain found in the retrospective study were consistent with the results of the well-water quality assessment. These results showed that human activity has strongly influenced water quality, especially the lack of sanitation in the different districts and neighbourhoods. Other factors affecting the vulnerability of well water include poor waste management by households, the low depth of the water table, the nature of the soil, and the permeability of the aquifer used. Improvement in water quality, sanitation, and personal hygiene will make it possible to reduce considerably the propagation of these diseases and several others. It is therefore important to provide these populations with the necessary equipment for an adequate drinking water supply, but also to promote health education to avoid water pollution. The search for solutions to these problems will lead to a plan for future action.

Estimation of allele-specific Ace-1 duplication in insecticide-resistant Anopheles mosquitoes from West Africa

AbstractBackground Identification of variation in Ace-1 copy number and G119S mutation genotype from samples of Anopheles gambiae and Anopheles coluzzii across West Africa are important diagnostics of carbamate and organophosphate resistance at population and individual levels. The most widespread and economical method, PCR–RFLP, suffers from an inability to discriminate true heterozygotes from heterozygotes with duplication. MethodsIn addition to PCR–RFLP, in this study three different molecular techniques were applied on the same mosquito specimens: TaqMan qPCR, qRTPCR and ddPCR. To group heterozygous individuals recorded from the PCR–RFLP analysis into different assumptive genotypes K-means clustering was applied on the Z-scores of data obtained from both the TaqMan and ddPCR methods. The qRTPCR analysis was used for absolute quantification of copy number variation.ResultsThe results indicate that most heterozygotes are duplicated and that G119S mutation must now be regarded as a complex genotype ranging from primarily single-copy susceptible Glycine homozygotes to balanced and imbalanced heterozygotes, and multiply-amplified resistant Serine allele homozygotes. Whilst qRTPCR-based gene copy analysis suffers from some imprecision, it clearly illustrates differences in copy number among genotype groups identified by TaqMan or ddPCR. Based on TaqMan method properties, and by coupling TaqMan and ddPCR methods simultaneously on the same type of mosquito specimens, it demonstrated that the TaqMan genotype assays associated with the K-means clustering algorithm could provide a useful semi-quantitative estimate method to investigate the level of allele-specific duplication in mosquito populations.ConclusionsAce-1 gene duplication is evidently far more complex in An. gambiae and An. coluzzii than the better-studied mosquito Culex quinquefasciatus, which consequently can no longer be considered an appropriate model for prediction of phenotypic consequences. These require urgent further evaluation in Anopheles. To maintain the sustained effectiveness carbamates and organophosphates as alternative products to pyrethroids for malaria vector control, monitoring of duplicated resistant alleles in natural populations is essential to guide the rational use of these insecticides.

Data quality assessment in the routine health information system: an application of the Lot Quality Assurance Sampling in Benin

Health information systems in developing countries are often faulted for the poor quality of the data generated and for the insufficient means implemented to improve system performance. This study examined data quality in the Routine Health Information System in Benin in 2012 and carried out a cross-sectional evaluation of the quality of the data using the Lot Quality Assurance Sampling method. The results confirm the insufficient quality of the data based on three criteria: completeness, reliability and accuracy. However, differences can be seen as the shortcomings are less significant for financial data and for immunization data. The method is simple, fast and can be proposed for current use at operational level as a data quality control tool during the production stage.

Insulin resistance status and four-year changes in other cardiometabolic risk factors in West-African adults: the Benin study

Background: The association of insulin resistance (IR) with other cardiometabolic risk (CMR) factors in sub-Saharan Africans is poorly documented. This study examined the links between IR and the evolution of blood pressure (BP), glycaemia, serum lipids and abdominal obesity in the population of Benin. Design: Population-based longitudinal study. Methods: This study initially included 541 apparently healthy Beninese adults (50% women) aged 25–60 years who were randomly selected in a large city, a small town and a rural area. After a baseline survey, our subjects were followed up after 2 years, and again at 4 years. IR based on homeostasis model assessment (HOMA), blood glucose, BP, waist circumference (WC), triglycerides, total cholesterol and HDL-cholesterol were measured. Complete data at the end of the follow-up periods was available for 416 subjects. Results: IR was more prevalent in women than in men (33.2% versus 17.8%) and it was generally associated with more adverse values of CMR factors, excepting BP. In controlling for baseline age, sex, WC, diet, lifestyle variables and WC changes; the relative risk (RR) of hyperglycemia over 4 years was as least 3-fold in IR subjects, compared to normal subjects. The RR of abdominal obesity was 5.3 (1.04–26.93) in IR women, compared to non-IR. The association of IR with the evolution of dyslipidemia was inconsistent, but IR tended to exacerbate low HDL-cholesterol. Conclusion: Over 4 years, IR exacerbated hyperglycemia in both men and women, and abdominal obesity in women, but IR did not affect blood pressure. Further research on the link found between IR and dyslipidemia, particularly low HDL-C, is needed in sub-Saharan Africa.