Birth asphyxia and its association with grand multiparity and referral among hospital births: A prospective cross-sectional study in Benin, Malawi, Tanzania and Uganda.

INTRODUCTION: Birth asphyxia is a leading cause of neonatal mortality in sub-Saharan Africa. The relationship to grand multiparity (GM), a controversial pregnancy risk factor, remains largely unexplored, especially in the context of large multinational studies. We investigated birth asphyxia and its association with GM and referral in Benin, Malawi, Tanzania and Uganda. MATERIAL AND METHODS: This was a prospective cross-sectional study. Data were collected using a perinatal e-Registry in 16 hospitals (four per country). The study population consisted of 80 663 babies (>1000 g, >28 weeks' gestational age) delivered between July 2021 and December 2022. The primary outcome was birth asphyxia, defined by 5-minute appearance, pulse, grimace, activity and respiration score <7. A multilevel and stratified multivariate logistic regression was performed with GM (parity ≥5) as exposure, and birth asphyxia as outcome. An interaction between referral (none, prepartum, intrapartum) and GM was also evaluated as a secondary outcome. All models were adjusted for confounders. CLINICAL TRIAL: Pan African Clinical Trial Registry 202006793783148. RESULTS: Birth asphyxia was present in 7.0% (n = 5612) of babies. More babies with birth asphyxia were born to grand multiparous women (11.9%) than to other parity groups (≤7.6%). Among the 76 850 cases included in the analysis, grand multiparous women had a 1.34 times higher odds of birth asphyxia (95% confidence interval [CI] 1.17-1.54) vs para one to two. Grand multiparous women referred intrapartum had the highest probability of asphyxiation (13.02%, 95% CI 9.34-16.69). GM increased odds of birth asphyxia in Benin (odds ratio [OR] 1.37, 95% CI 1.13-1.68) and Uganda (OR 1.29, 95% CI 1.02-1.64), but was non-significant in Tanzania (OR 1.44, 95% CI 0.81-2.56) and Malawi (OR 0.98, 95% CI 0.67-1.44). CONCLUSIONS: There is some evidence of an increased risk of birth asphyxia for grand multiparous women having babies at hospitals, especially following intrapartum referral. Antenatal counseling should recognize grand multiparity as higher risk and advise appropriate childbirth facilities. Findings in Malawi suggest an advantage of health systems configuration requiring further exploration.

Lung microenvironments harbor Mycobacterium tuberculosis phenotypes with distinct treatment responses.

Tuberculosis lung lesions are complex and harbor heterogeneous microenvironments that influence antibiotic effectiveness. Major strides have been made recently in understanding drug pharmacokinetics in pulmonary lesions, but the bacterial phenotypes that arise under these conditions and their contribution to drug tolerance are poorly understood. A pharmacodynamic marker called the RS ratio® quantifies ongoing rRNA synthesis based on the abundance of newly synthesized precursor rRNA relative to mature structural rRNA. Application of the RS ratio in the C3HeB/FeJ mouse model demonstrated that Mycobacterium tuberculosis populations residing in different tissue microenvironments are phenotypically distinct and respond differently to drug treatment with rifampin, isoniazid, or bedaquiline. This work provides a foundational basis required to address how anatomic and pathologic microenvironmental niches may contribute to long treatment duration and drug tolerance during the treatment of human tuberculosis.

Combination of Mycobacterium tuberculosis RS Ratio and CFU Improves the Ability of Murine Efficacy Experiments to Distinguish between Drug Treatments.

Murine tuberculosis drug efficacy studies have historically monitored bacterial burden based on CFU of Mycobacterium tuberculosis in lung homogenate. In an alternative approach, a recently described molecular pharmacodynamic marker called the RS ratio quantifies drug effect on a fundamental cellular process, ongoing rRNA synthesis. Here, we evaluated the ability of different pharmacodynamic markers to distinguish between treatments in three BALB/c mouse experiments at two institutions. We confirmed that different pharmacodynamic markers measure distinct biological responses. We found that a combination of pharmacodynamic markers distinguishes between treatments better than any single marker. The combination of the RS ratio with CFU showed the greatest ability to recapitulate the rank order of regimen treatment-shortening activity, providing proof of concept that simultaneous assessment of pharmacodynamic markers measuring different properties will enhance insight gained from animal models and accelerate development of new combination regimens. These results suggest potential for a new era in which antimicrobial therapies are evaluated not only on culture-based measures of bacterial burden but also on molecular assays that indicate how drugs impact the physiological state of the pathogen.

Does discovery of differentially culturable M tuberculosis really demand a new treatment paradigm? Longitudinal analysis of DNA clearance from sputum.

BACKGROUND: According to the traditional tuberculosis (TB) treatment paradigm, the initial doses of treatment rapidly kill most Mycobacterium tuberculosis (Mtb) bacilli in sputum, yet many more months of daily treatment are required to eliminate a small, residual subpopulation of drug-tolerant bacilli. This paradigm has recently been challenged following the discovery that up to 90% of Mtb bacilli in sputum are culturable only with growth-factor supplementation. These "differentially culturable" bacilli are hypothesized to be more drug-tolerant than routinely culturable bacilli. This hypothesis implies an alternative paradigm in which TB treatment does not rapidly reduce the total Mtb population but only the small, routinely culturable subpopulation. To evaluate these competing paradigms, we developed a culture-independent method for quantifying the viable fraction of Mtb bacilli in sputum during treatment. METHODS: We used GeneXpert MTB/RIF to quantify Mtb DNA in sputa collected longitudinally from Ugandan adults taking standard 4-drug treatment for drug-susceptible pulmonary TB. We modeled GeneXpert cycle thresholds over time using nonlinear mixed-effects regression. We adjusted these models for clearance of DNA from killed-but-not-yet-degraded bacilli, assuming clearance half-lives ranging from 0 to 1.25 days. We used a convolution integral to quantify DNA from viable bacilli only, and converted cycle thresholds to Mtb genomic equivalents. We replicated our results in a South African cohort. RESULTS: We enrolled 41 TB patients in Uganda. Assuming a DNA-clearance half-life of 0 days, genomic equivalents of viable sputum bacilli decreased by 0.22 log/day until 8.8 days, then by 0.07 log/day afterwards. Assuming a DNA-clearance half-life of 1.25 days, genomic equivalents of viable bacilli decreased by 0.36 log/day until 5.0 days, then by 0.06 log/day afterwards. By day 7, viable Mtb had decreased by 97.2-98.8%. We found similar results for 19 TB patients in South Africa. DISCUSSION: Using a culture-independent method, we found that TB treatment rapidly eliminates most viable Mtb in sputum. These findings are incompatible with the hypothesis that differentially culturable bacilli are drug-tolerant. CONCLUSIONS: A culture-independent method for measuring viable Mtb in sputum during treatment corroborates the traditional TB treatment paradigm in which a rapid bactericidal phase precedes slow, elimination of a small, residual bacillary subpopulation.

Midwifery care providers' childbirth and immediate newborn care competencies: A cross-sectional study in Benin, Malawi, Tanzania and Uganda.

Evidence-based quality care is essential for reducing sub-Saharan Africa's high burden of maternal and newborn mortality and morbidity. Provision of quality care results from interaction between several components of the health system including competent midwifery care providers and the working environment. We assessed midwifery care providers' ability to provide quality intrapartum and newborn care and selected aspects of the working environment as part of the Action Leveraging Evidence to Reduce perinatal morTality and morbidity (ALERT) project in Benin, Malawi, Tanzania, and Uganda. We used a self-administered questionnaire to assess provider knowledge and their working environment and skills drills simulations to assess skills and behaviours. All midwifery care providers including doctors providing midwifery care in the maternity units were invited to take part in the knowledge assessment and one third of the midwifery care providers who took part in the knowledge assessment were randomly selected and invited to take part in the skills and behaviour simulation assessment. Descriptive statistics of interest were calculated. A total of 302 participants took part in the knowledge assessment and 113 skills drills simulations were conducted. The assessments revealed knowledge gaps in frequency of fetal heart rate monitoring and timing of umbilical cord clamping. Over half of the participants scored poorly on aspects related to routine admission tasks, clinical history-taking and rapid and initial assessment of the newborn, while higher scores were achieved in active management of the third stage of labour. The assessment also identified a lack of involvement of women in clinical decision-making. Inadequate competency level of the midwifery care providers may be due to gaps in pre-service training but possibly related to the structural and operational facility characteristics including continuing professional development. Investment and action on these findings are needed when developing and designing pre-service and in-service training. Trial registration: PACTR202006793783148-June 17th, 2020.

Transcriptional adaptation of drug-tolerant Mycobacterium tuberculosis in mice.

Transcriptome evaluation of Mycobacterium tuberculosis in the lungs of laboratory animals during long-term treatment has been limited by extremely low abundance of bacterial mRNA relative to eukaryotic RNA. Here we report a targeted amplification RNA sequencing method called SEARCH-TB. After confirming that SEARCH-TB recapitulates conventional RNA-seq in vitro, we applied SEARCH-TB to Mycobacterium tuberculosis-infected BALB/c mice treated for up to 28 days with the global standard isoniazid, rifampin, pyrazinamide, and ethambutol regimen. We compared results in mice with 8-day exposure to the same regimen in vitro. After treatment of mice for 28 days, SEARCH-TB suggested broad suppression of genes associated with bacterial growth, transcription, translation, synthesis of rRNA proteins and immunogenic secretory peptides. Adaptation of drug-stressed Mycobacterium tuberculosis appeared to include a metabolic transition from ATP-maximizing respiration towards lower-efficiency pathways, modification and recycling of cell wall components, large-scale regulatory reprogramming, and reconfiguration of efflux pumps expression. Despite markedly different expression at pre-treatment baseline, murine and in vitro samples had broadly similar transcriptional change during treatment. The differences observed likely indicate the importance of immunity and pharmacokinetics in the mouse. By elucidating the long-term effect of tuberculosis treatment on bacterial cellular processes in vivo, SEARCH-TB represents a highly granular pharmacodynamic monitoring tool with potential to enhance evaluation of new regimens and thereby accelerate progress towards a new generation of more effective tuberculosis treatment.

Transcriptional adaptation of Mycobacterium tuberculosis that survives prolonged multi-drug treatment in mice.

To address the ongoing global tuberculosis crisis, there is a need for shorter, more effective treatments. A major reason why tuberculosis requires prolonged treatment is that, following a short initial phase of rapid killing, the residual Mycobacterium tuberculosis withstands drug killing. Because existing methods lack sensitivity to quantify low-abundance mycobacterial RNA in drug-treated animals, cellular adaptations of drug-exposed bacterial phenotypes in vivo remain poorly understood. Here, we used a novel RNA-seq method called SEARCH-TB to elucidate the Mycobacterium tuberculosis transcriptome in mice treated for up to 28 days with standard doses of isoniazid, rifampin, pyrazinamide, and ethambutol. We compared murine results with in vitro SEARCH-TB results during exposure to the same regimen. Treatment suppressed genes associated with growth, transcription, translation, synthesis of rRNA proteins, and immunogenic secretory peptides. Bacteria that survived prolonged treatment appeared to transition from ATP-maximizing respiration toward lower-efficiency pathways and showed modification and recycling of cell wall components, large-scale regulatory reprogramming, and reconfiguration of efflux pump expression. Although the pre-treatment in vivo and in vitro transcriptomes differed profoundly, genes differentially expressed following treatment in vivo and in vitro were similar, with differences likely attributable to immunity and drug pharmacokinetics in mice. These results reveal cellular adaptations of Mycobacterium tuberculosis that withstand prolonged drug exposure in vivo, demonstrating proof of concept that SEARCH-TB is a highly granular pharmacodynamic readout. The surprising finding that differential expression is concordant in vivo and in vitro suggests that insights from transcriptional analyses in vitro may translate to the mouse. IMPORTANCE A major reason that curing tuberculosis requires prolonged treatment is that drug exposure changes bacterial phenotypes. The physiologic adaptations of Mycobacterium tuberculosis that survive drug exposure in vivo have been obscure due to low sensitivity of existing methods in drug-treated animals. Using the novel SEARCH-TB RNA-seq platform, we elucidated Mycobacterium tuberculosis phenotypes in mice treated for with the global standard 4-drug regimen and compared them with the effect of the same regimen in vitro. This first view of the transcriptome of the minority Mycobacterium tuberculosis population that withstands treatment in vivo reveals adaptation of a broad range of cellular processes, including a shift in metabolism and cell wall modification. Surprisingly, the change in gene expression induced by treatment in vivo and in vitro was largely similar. This apparent "portability" from in vitro to the mouse provides important new context for in vitro transcriptional analyses that may support early preclinical drug evaluation.

Lessons Learnt From the Experiences of Primary Care Physicians Facing COVID-19 in Benin: A Mixed-Methods Study.

Introduction: In sub-Saharan Africa, there is a need to better understand and guide the practice of primary care physicians (PCPs), especially in a crisis context like the COVID-19 pandemic. This study analyses the experiences of PCPs facing COVID-19 in Benin and draws policy lessons. Methods: The study followed a fully mixed sequential dominant status design. Data were collected between April and August 2020 from a sample of PCPs in Benin. We performed descriptive analyses on the quantitative data. We also performed bivariate analyses for testing associations between various outcomes and the public/private status of the PCPs, their localization within or outside the cordon sanitaire put in place at the beginning of COVID-19, and their practice' category. A thematic content analysis was done on qualitative data. Results from both analyses were triangulated. Results: Ninety PCPs participated in the quantitative strand, and 14 in the qualitative. The median percentage of the COVID-19 control measures implemented in the health facilities, as reported by the PCPs, was 77.8% (interquartile range = 16.7%), with no difference between the various groups. While 29.4% of the PCPs reported being poorly/not capable of helping the communities to deal with COVID-19, 45.3% felt poorly/not confident in dealing with an actual case. These percentages were bigger in the private sector. The PCP's experiences were marked by anxiety and fear, with 80.2% reporting stress. Many PCPs (74.1%) reported not receiving support from local health authorities, and 75.3% felt their concerns were not adequately addressed. Both percentages were higher in the private sector. The PCPs especially complained of insufficient training, insufficient coordination, and less support to private providers than the public ones. For 72.4 and 79.3% of the PCPs, respectively, the pandemic impacted services utilization and daily work. There were negative impacts (like a decrease in the services utilization or the quality of care), but also positive ones (like improved compliance to hygiene measures and new opportunities). Conclusion: Our study highlighted the need for more structured support to PCPs for optimizing their contribution to epidemics control and good primary healthcare in Benin. Efforts in this direction can build on several good practices and opportunities.

Factors associated with COVID-19 vaccine intention in Benin in 2021: A cross-sectional study.

Introduction: The development of COVID-19 vaccines has brought considerable hope for the control of the pandemic. With a view to promoting good vaccine coverage, this study aimed to measure vaccine intention against COVID-19 and to understand the factors that promote it. Method: In April 2021, we conducted a cross-sectional and analytical study at the national level through a telephone survey of Beninese aged 18 years or older. We used a marginal quota sampling method (n = 865) according to age, gender, and department. We constructed the questionnaire using a theoretical framework of health intention. We determined the factors associated with intention to vaccinate against COVID-19 in Benin using a multinomial logistic regression at the 5 % significance level. Results: The intention to vaccinate was 64.7 %; 10.9 % of the population were hesitant, and 24.4 % did not want to vaccinate. Thinking that it was important to get vaccinated (AOR = 0.274; CI = 0.118-0.638) or that getting vaccinated will help protect loved ones from the virus (AOR = 0.399; CI = 0.205-0.775) increased the intention to vaccinate. Having a high level of education (AOR = 1.988; CI = 1.134-3.484), thinking that the vaccine could put one's health at risk (AOR = 2.259; CI = 1.114-4.578), and hearing something negative about the vaccine (AOR = 1.765; CI = 1.059-2.941) reduced intention to vaccinate. In addition, believing that the creators of the vaccine had ensured its safety (AOR = 0.209; CI = 0.101-0.430), and believing that it was unlikely to be infected after vaccination (AOR = 0.359; CI = 0.183-0.703) decreased hesitancy in favour of the intention to vaccinate. Conclusion: In April 2021, vaccine intention was high, but maintaining this high rate requires building confidence in the vaccine and combating misinformation about the vaccine.

MOVER approximated CV: A tool for quantifying precision in ratiometric droplet digital PCR assays.

Droplet digital PCR is a particularly valuable tool for ratiometric assays because it provides simultaneous absolute quantification of two target sequences in a single assay. This manuscript addresses a challenge in establishing a new ratiometric droplet digital PCR assay for use in sputum, the rRNA synthesis ratio. In principle, the methods established to evaluate precision and determine the limit of quantification for a single measurand cannot be applied to a ratiometric assay. The precision of a ratio depends on precision in both the numerator and denominator. Here, we evaluated the MOVER approximated coefficient of variation as indicator of assay precision that does not require technical replicates. We estimated the MOVER approximated coefficient of variation in dilution series and routine assays and evaluated its agreement with the traditional coefficient of variation. We found that the MOVER approximated coefficient of variation was able to recapitulate the traditional coefficient of variation without the requirement for replicate assays. We also demonstrated that the MOVER approximated coefficient of variation threshold can be used to define the limit of quantification of the rRNA synthesis Ratio. In conclusion, the MOVER approximated coefficient of variation may be useful not only for the rRNA synthesis ratio but for other assays that measure ratios via droplet digital PCR.

Reproducibility of the Ribosomal RNA Synthesis Ratio in Sputum and Association with Markers of Mycobacterium tuberculosis Burden.

There is a critical need for improved pharmacodynamic markers for use in human tuberculosis (TB) drug trials. Pharmacodynamic monitoring in TB has conventionally used culture or molecular methods to enumerate the burden of Mycobacterium tuberculosis organisms in sputum. A recently proposed assay called the rRNA synthesis (RS) ratio measures a fundamentally novel property, how drugs impact ongoing bacterial rRNA synthesis. Here, we evaluated RS ratio as a potential pharmacodynamic monitoring tool by testing pretreatment sputa from 38 Ugandan adults with drug-susceptible pulmonary TB. We quantified the RS ratio in paired pretreatment sputa and evaluated the relationship between the RS ratio and microbiologic and molecular markers of M. tuberculosis burden. We found that the RS ratio was highly repeatable and reproducible in sputum samples. The RS ratio was independent of M. tuberculosis burden, confirming that it measures a distinct new property. In contrast, markers of M. tuberculosis burden were strongly associated with each other. These results indicate that the RS ratio is repeatable and reproducible and provides a distinct type of information from markers of M. tuberculosis burden. IMPORTANCE This study takes a major next step toward practical application of a novel pharmacodynamic marker that we believe will have transformative implications for tuberculosis. This article follows our recent report in Nature Communications that an assay called the rRNA synthesis (RS) ratio indicates the treatment-shortening of drugs and regimens. Distinct from traditional measures of bacterial burden, the RS ratio measures a fundamentally novel property, how drugs impact ongoing bacterial rRNA synthesis.

Mycobacterium tuberculosis precursor rRNA as a measure of treatment-shortening activity of drugs and regimens.

There is urgent need for new drug regimens that more rapidly cure tuberculosis (TB). Existing TB drugs and regimens vary in treatment-shortening activity, but the molecular basis of these differences is unclear, and no existing assay directly quantifies the ability of a drug or regimen to shorten treatment. Here, we show that drugs historically classified as sterilizing and non-sterilizing have distinct impacts on a fundamental aspect of Mycobacterium tuberculosis physiology: ribosomal RNA (rRNA) synthesis. In culture, in mice, and in human studies, measurement of precursor rRNA reveals that sterilizing drugs and highly effective drug regimens profoundly suppress M. tuberculosis rRNA synthesis, whereas non-sterilizing drugs and weaker regimens do not. The rRNA synthesis ratio provides a readout of drug effect that is orthogonal to traditional measures of bacterial burden. We propose that this metric of drug activity may accelerate the development of shorter TB regimens.

Development of vegetable farming: a cause of the emergence of insecticide resistance in populations of Anopheles gambiae in urban areas of Benin.

BACKGROUND: A fast development of urban agriculture has recently taken place in many areas in the Republic of Benin. This study aims to assess the rapid expansion of urban agriculture especially, its contribution to the emergence of insecticide resistance in populations of Anopheles gambiae. METHODS: The protocol was based on the collection of sociological data by interviewing vegetable farmers regarding various agricultural practices and the types of pesticides used. Bioassay tests were performed to assess the susceptibility of malaria vectors to various agricultural insecticides and biochemical analysis were done to characterize molecular status of population of An. gambiae. RESULTS: This research showed that:(1) The rapid development of urban agriculture is related to unemployment observed in cities, rural exodus and the search for a balanced diet by urban populations;(2) Urban agriculture increases the farmers' household income and their living standard;(3) At a molecular level, PCR revealed the presence of three sub-species of An. gambiae (An. gambiae s.s., Anopheles melas and Anopheles arabiensis) and two molecular forms (M and S). The kdr west mutation recorded in samples from the three sites and more specifically on the M forms seems to be one of the major resistance mechanisms found in An. gambiae from agricultural areas. Insecticide susceptibility tests conducted during this research revealed a clear pattern of resistance to permethrin (76% mortality rate at Parakou; 23.5% at Porto-Novo and 17% at Cotonou). CONCLUSION: This study confirmed an increase activity of the vegetable farming in urban areas of Benin. This has led to the use of insecticide in an improper manner to control vegetable pests, thus exerting a huge selection pressure on mosquito larval population, which resulted to the emergence of insecticide resistance in malaria vectors.

Evidence of multiple insecticide resistance mechanisms in Anopheles gambiae populations in Bangui, Central African Republic.

BACKGROUND: Knowledge of insecticide resistance status in the main malaria vectors is an essential component of effective malaria vector control. This study presents the first evaluation of the status of insecticide resistance in Anopheles gambiae populations from Bangui, the Central African Republic. METHODS: Anopheles mosquitoes were reared from larvae collected in seven districts of Bangui between September to November 2014. The World Health Organisation's bioassay susceptibility tests to lambda-cyhalothrin (0.05%), deltamethrin (0.05%), DDT (4%), malathion (5%), fenitrothion (1%) and bendiocarb (0.1%) were performed on adult females. Species and molecular forms as well as the presence of L1014F kdr and Ace-1 R mutations were assessed by PCR. Additional tests were conducted to assess metabolic resistance status. RESULTS: After 1 h exposure, a significant difference of knockdown effect was observed between districts in all insecticides tested except deltamethrin and malathion. The mortality rate (MR) of pyrethroids group ranging from 27% (CI: 19-37.5) in Petevo to 86% (CI: 77.6-92.1) in Gbanikola; while for DDT, MR ranged from 5% (CI: 1.6-11.3) in Centre-ville to 39% (CI: 29.4-49.3) in Ouango. For the organophosphate group a MR of 100% was observed in all districts except Gbanikola where a MR of 96% (CI: 90-98.9) was recorded. The mortality induced by bendiocarb was very heterogeneous, ranging from 75% (CI: 62.8-82.8) in Yapele to 99% (CI: 84.5-100) in Centre-ville. A high level of kdr-w (L1014F) frequency was observed in all districts ranging from 93 to 100%; however, no kdr-e (L1014S) and Ace-1 R mutation were found in all tested mosquitoes. Data of biochemical analysis showed significant overexpression activities of cytochrome P450, GST and esterases in Gbanikola and Yapele (χ 2 = 31.85, df = 2, P < 0.001). By contrast, esterases activities using α and ß-naphthyl acetate were significantly low in mosquitoes from PK10 and Ouango in comparison to Kisumu strain (χ 2 = 17.34, df = 2, P < 0.005). CONCLUSIONS: Evidence of resistance to DDT and pyrethroids as well as precocious emergence of resistance to carbamates were detected among A. gambiae mosquitoes from Bangui, including target-site mutations and metabolic mechanisms. The co-existence of these resistance mechanisms in A. gambiae may be a serious obstacle for the future success of malaria control programmes in this region.

Impact of land-use on malaria transmission in the Plateau region, southeastern Benin.

BACKGROUND: The goal of the study is to investigate if local agricultural practices have an impact on malaria transmission in four villages located in the same geographical area within a radius of 15 kilometers. Among the villages, one (Itassoumba) is characterized by the presence of a large market garden and fishpond basins, the three others (Itakpako, Djohounkollé and Ko-koumolou) are characterized by traditional food-producing agriculture. METHODS: Malaria transmission was evaluated using human-landing catches, both indoors and outdoors, two nights per month for 12 months. Field collected females An. gambiae s.l. were exposed for 1 hour to 0.75% permethrin and 0.05% deltamethrin using WHO insecticide susceptibility test kits and procedures. The presence of the kdr mutation was analyzed by PCR. RESULTS: Anopheles gambiae s.s form M (93.65%), was identified as the main malaria vector. Its susceptibility level to pyrethroids was the same (p > 0.05) in all villages. kdr mutation frequencies are 81.08 in Itakpako, 85 in Itassoumba, 79.73 in Djohounkollé and 86.84 in Ko-Koumolou (p = 0.63). The entomological inoculation rate ranged from 9.62 to 21.65 infected bites of An. gambiae per human per year in Djohounkollé, Itakpako and Ko-Koumolou against 1159.62 in Itassoumba (p < 0.0001). CONCLUSION: The level of resistance of An. gambiae to pyrethroids was the same in the four villages. The heterogeneous character of malaria epidemiology was confirmed. The creation of fishponds basins and the development of market-gardening activities increased drastically the malaria transmission in Itassoumba.