Variabilités et Tendances des Paramètres Hydroclimatiques dans le Bassin Versant de la Rivière Banco au Sud de la Côte d’Ivoire

This study conducted in the basin of Banco river in Abidjan (5°20’ and 5°26’ at latitude north and between 4°1’ and 4°5’ at longitude west) in the south of Cote d’Ivoire aims at underlining the existence of climate variability on the basis of fluctuations and trends in hydro climatic data ( rainfalls, temperatures and discharges). To reach this goal, diverse data (pluviometric, thermometric and hydrometrical) and methods (Nicholson rating/index, Mann Kendall test; Cusum test; t-student test and Sen incline/slope estimator) are used. In light of the results, a climatic variability characterized by the alternation of humid, normal and dry years have been revealed in the area under study. The statistical indexes/ratings and methods show the continuity of the rainfall recession established since 1970 before a resumption of the pluviometry from the year 2000 onwards. Concerning the temperatures, we notice a slight fall of the annual average temperature triggered by the regression of minimal temperatures. The average temperature in the hole basin has decreased of 1.4°C in the last 34 years. The manifestations of this climate variability hardly impact on the flow of the river. An important increase in the superficial outflow appears in the basin with a rate of change of 71.25%, indicating therefore sufficient water availability.La présente étude menée sur le bassin versant de la rivière Banco à Abidjan (5°20’ et 5°26’ de latitude Nord et entre 4°1’et 4°5’ de longitude Ouest) dans le sud de la Côte d’Ivoire vise à mettre en exergue l'existence d'une variabilité climatique, à partir des fluctuations et des tendances dans les données hydroclimatiques (pluies, températures et débits). Pour atteindre cet objectif, diverses données (pluviométriques, thermométriques et hydrométriques) et méthodes (indice de Nicholson, tests de Cusum, de tstudent, de Mann-Kendall et de l’estimateur de la pente de Sen) ont été utilisées. A la lumière des résultats acquis, une variabilité climatique caractérisée par une alternance d’années humides, normales et sèches a été mise en évidence dans la zone d’étude. Les indices et méthodes statistiques montrent la continuité de la récession pluviométrique établie depuis 1970 avant une reprise pluviométrique à partir de l’année 2000. En ce qui concerne les températures, on assiste à une légère baisse de la température moyenne annuelle provoquée par la régression des températures minimales. La température moyenne dans le bassin versant a baissé de 1,4°C au cours des 34 dernières années. Les manifestations de cette variabilité climatique affectent peu le débit de la rivière. Une augmentation importante de l’écoulement superficielle apparaît dans le bassin avec un taux de changement de 71,25%, indiquant ainsi une bonne disponibilité en eau

Dynamics of antigenemia and transmission intensity of Wuchereria bancrofti following cessation of mass drug administration in a formerly highly endemic region of Mali

Background After seven annual rounds of mass drug administration (MDA) in six Malian villages highly endemic for Wuchereria bancrofti (overall prevalence rate of 42.7%), treatment was discontinued in 2008. Surveillance was performed over the ensuing 5 years to detect recrudescence. Methods Circulating filarial antigen (CFA) was measured using immunochromatographic card tests (ICT) and Og4C3 ELISA in 6–7 year-olds. Antibody to the W. bancrofti infective larval stage (L3) antigen, Wb123, was tested in the same population in 2012. Microfilaraemia was assessed in ICT-positive subjects. Anopheles gambiae complex specimens were collected monthly using human landing catch (HLC) and pyrethrum spray catch (PSC). Anopheles gambiae complex infection with W. bancrofti was determined by dissection and reverse transcriptase polymerase chain reaction (RT-PCR) of mosquito pools. Results Annual CFA prevalence rates using ICT in children increased over time from 0% (0/289) in 2009 to 2.7% (8/301) in 2011, 3.9% (11/285) in 2012 and 4.5% (14/309) in 2013 (trend χ 2  = 11.85, df =3, P = 0.0006). Wb123 antibody positivity rates in 2013 were similar to the CFA prevalence by ELISA (5/285). Although two W. bancrofti-infected Anopheles were observed by dissection among 12,951 mosquitoes collected by HLC, none had L3 larvae when tested by L3-specific RT-PCR. No positive pools were detected among the mosquitoes collected by pyrethrum spray catch. Whereas ICT in 6–7 year-olds was the major surveillance tool, ICT positivity was also assessed in older children and adults (8–65 years old). CFA prevalence decreased in this group from 4.9% (39/800) to 3.5% (28/795) and 2.8% (50/1,812) in 2009, 2011 and 2012, respectively (trend χ 2  = 7.361, df =2, P = 0.0067). Some ICT-positive individuals were microfilaraemic in 2009 [2.6% (1/39)] and 2011 [8.3% (3/36)], but none were positive in 2012 or 2013. Conclusion Although ICT rates in children increased over the 5-year surveillance period, the decrease in ICT prevalence in the older group suggests a reduction in transmission intensity. This was consistent with the failure to detect infective mosquitoes or microfilaraemia. The threshold of ICT positivity in children may need to be re-assessed and other adjunct surveillance tools considered

L’appendagite aiguë : une étiologie rare à ne pas méconnaître dans les douleurs abdominales: Acute appendagitis: a rare etiology not to be overlooked in abdominal pain

Acute appendagitis is a rare cause of abdominal pain. Its diagnosis is based on medical imaging and its treatment is medical. We report a case of acute appendagitis diagnosed on the abdominal CT scan in the context of epigastralgia. L’appendagite aiguë est une cause rare de douleurs abdominales. Son diagnostic repose sur l’imagerie médicale et son traitement est médical. Nous rapportons un cas d’appendagite aiguë diagnostiquée au scanner abdominal au décours d’une mise au point d’épigastralgies

BMC Public Health

BACKGROUND: The extent of SARS-CoV-2 circulation in African countries is still unclear. Seroprevalence studies are a common approach to epidemiological surveillance, allowing estimation of the proportion of people who have had contact with the virus. We aimed at estimating the seroprevalence of anti-SARS-CoV-2 antibodies and associated factors in Togo at the national level in 2021 according to age groups, gender, and place of residence (rural or urban). METHODS: From 15 May to 31 June 2021, we conducted a nationally representative cross-sectional serological survey in 12 health districts (two districts per health region) in the > 5 years old population in Togo. The Wantai SARS-CoV-2 total antibody assay S protein receptor-binding domain-based ELISA (Wantai Biological Pharmacy Enterprise Co.; Beijing, China) was used to determine the presence of SARS-CoV-2 total antibodies in plasma. Crude and weighted seroprevalences (weighted by age, sex and place of residence) were calculated and then weighted seroprevalences were adjusted according to sensitivity and specificity of the ELISA test. Finally, logistic regression models were performed in order to describe factors associated. RESULTS: Of the 7593 participants, the overall weighted and adjusted seroprevalence of total anti-SARS-CoV-2 antibodies was 65.5% (CI95%: 18.9-21.1). Urban dwellers, young adults (30-49 years) and vaccinated individuals were significantly more likely to be seropositive. CONCLUSION: The high seroprevalence we observed is consistent with observations across West Africa. Quantification of the level of immunity in the population is needed to know how close we are to herd immunity. In the meantime, vaccination against the COVID-19 remains necessary

BMC Public Health

The original publication [1] of this paper contained a typo in the abstract. The value "CI95%: 18.9–21.1" should have been "95%CI: 64.3–66.6". This was correct elsewhere in the article. The original article has been updated to correct this

Comparison of Different Sampling Methods to Catch Lymphatic Filariasis Vectors in a Sudan Savannah Area of Mali

There is a need for better tools to monitor the transmission of lymphatic filariasis and malaria in areas undergoing interventions to interrupt transmission. Therefore, mosquito collection methods other than human landing catch (HLC) are needed. This study aimed to compare the Ifakara tent trap type C (ITTC) and the Biogents sentinel trap (BGST) to the HLC in areas with different vector densities. Mosquitoes were collected in two villages in Mali from July to December in 2011 and 2012. The three methods were implemented at each site with one ITTC, one BGST, and one HLC unit that consisted of one room with two collectors—one indoor and the other outdoor. The Anopheles collected in 2011 were individually dissected, whereas those from 2012 were screened in pools using reverse transcription-polymerase chain reaction (RT-PCR) to determine the maximum infection prevalence likelihood (MIPL) for Wuchereria bancrofti and Plasmodium falciparum. The dissection of the females also allowed to assess the parity rates, as well its results. Over the 2 years, the HLC method collected 1,019 Anopheles, yields that were 34- and 1.5-fold higher than those with the BGST and ITTC, respectively. None of the dissected Anopheles were infected. The RT-PCR results showed comparable MIPL between HLC and ITTC for W. bancrofti with one infected pool from each trap’s yield (respectively 0.03% [0.0009–0.2%] and 0.04% [0.001–0.2%]). For P. falciparum, no infected pool was recovered from BGST. The ITTC is a good alternative to HLC for xenomonitoring of program activities

Artemether–lumefantrine with or without single-dose primaquine and sulfadoxine–pyrimethamine plus amodiaquine with or without single-dose tafenoquine to reduce Plasmodium falciparum transmission: a phase 2, single-blind, randomised clinical trial in Ouelessebougou, Mali

Background: Artemether–lumefantrine is widely used for uncomplicated Plasmodium falciparum malaria; sulfadoxine–pyrimethamine plus amodiaquine is used for seasonal malaria chemoprevention. We aimed to determine the efficacy of artemether–lumefantrine with and without primaquine and sulfadoxine–pyrimethamine plus amodiaquine with and without tafenoquine for reducing gametocyte carriage and transmission to mosquitoes. Methods: In this phase 2, single-blind, randomised clinical trial conducted in Ouelessebougou, Mali, asymptomatic individuals aged 10–50 years with P falciparum gametocytaemia were recruited from the community and randomly assigned (1:1:1:1) to receive either artemether–lumefantrine, artemether–lumefantrine with a single dose of 0·25 mg/kg primaquine, sulfadoxine–pyrimethamine plus amodiaquine, or sulfadoxine–pyrimethamine plus amodiaquine with a single dose of 1·66 mg/kg tafenoquine. All trial staff other than the pharmacist were masked to group allocation. Participants were not masked to group allocation. Randomisation was done with a computer-generated randomisation list and concealed with sealed, opaque envelopes. The primary outcome was the median within-person percent change in mosquito infection rate in infectious individuals from baseline to day 2 (artemether–lumefantrine groups) or day 7 (sulfadoxine–pyrimethamine plus amodiaquine groups) after treatment, assessed by direct membrane feeding assay. All participants who received any trial drug were included in the safety analysis. This study is registered with ClinicalTrials.gov, NCT05081089. Findings: Between Oct 13 and Dec 16, 2021, 1290 individuals were screened and 80 were enrolled and randomly assigned to one of the four treatment groups (20 per group). The median age of participants was 13 (IQR 11–20); 37 (46%) of 80 participants were female and 43 (54%) were male. In individuals who were infectious before treatment, the median percentage reduction in mosquito infection rate 2 days after treatment was 100·0% (IQR 100·0–100·0; n=19; p=0·0011) with artemether–lumefantrine and 100·0% (100·0–100·0; n=19; p=0·0001) with artemether–lumefantrine with primaquine. Only two individuals who were infectious at baseline infected mosquitoes on day 2 after artemether–lumefantrine and none at day 5. By contrast, the median percentage reduction in mosquito infection rate 7 days after treatment was 63·6% (IQR 0·0–100·0; n=20; p=0·013) with sulfadoxine–pyrimethamine plus amodiaquine and 100% (100·0–100·0; n=19; p<0·0001) with sulfadoxine–pyrimethamine plus amodiaquine with tafenoquine. No grade 3–4 or serious adverse events occurred. Interpretation: These data support the effectiveness of artemether–lumefantrine alone for preventing nearly all mosquito infections. By contrast, there was considerable post-treatment transmission after sulfadoxine–pyrimethamine plus amodiaquine; therefore, the addition of a transmission-blocking drug might be beneficial in maximising its community impact. Funding: Bill & Melinda Gates Foundation

The transmission blocking activity of artemisinin-combination, non-artemisinin, and 8-aminoquinoline antimalarial therapies: A pooled analysis of individual participant data.

BACKGROUND: Interrupting human-to-mosquito transmission is important for malaria elimination strategies as it can reduce infection burden in communities and slow the spread of drug resistance. Antimalarial medications differ in their efficacy in clearing the transmission stages of Plasmodium falciparum (gametocytes) and in preventing mosquito infection. Here, we present a retrospective combined analysis of six trials conducted at the same study site with highly consistent methodologies that allows for a direct comparison of the gametocytocidal and transmission-blocking activities of 15 different antimalarial regimens or dosing schedules. METHODS AND FINDINGS: Between January 2013 and January 2023, we conducted six clinical trials evaluating antimalarial treatments with transmission endpoints at the Clinical Research Centre of the Malaria Research and Training Centre of the University of Bamako in Mali. These trials tested Artemisinin-Combination Therapies (ACTs), non-ACT regimens and combinations with 8-aminoquinolines. Participants were males and non-pregnant females, between 5 and 50 years of age, who presented with P. falciparum mono-infection and gametocyte carriage by microscopy. We collected blood samples before and after treatment for thick film microscopy, infectivity assessments by mosquito feeding assays and molecular quantification of gametocytes. To combine direct and indirect effects of treatment groups across studies, we performed a network meta-analysis. This analysis quantified changes in mosquito infection rates and gametocyte densities within treatment groups over time and between treatments. In a pooled analysis of 422 participants, we observed substantial differences between antimalarials in gametocytocidal and transmission-blocking activities. Artemether-lumefantrine (AL) was significantly more potent at reducing mosquito infection rates within 48 h than dihydroartemisinin-piperaquine (p = 0.0164) and sulfadoxine-pyrimethamine plus amodiaquine (p = 0.0451), while this difference was near-significant for artesunate-amodiaquine (p = 0.0789) and pyronaridine-artesunate (p = 0.0519). The addition of single low-dose primaquine (SLD PQ) accelerated gametocyte clearance for any ACT and led to a substantially greater reduction in mosquito infection rate within 48 h of treatment for all ACTs except AL, while an SLD of the 8-aminoaquinoline tafenoquine showed a delayed activity, compared to SLD PQ, but was similarly effective. The main limitations of the study include the inclusion of highly infectious individuals, which may not reflect the broader malaria patient population with lower or undetectable gametocyte densities and the small sample sizes in some treatment groups, which resulted in wide confidence intervals and reduced the certainty of effect estimates. CONCLUSIONS: We found marked differences among ACTs and single low-dose 8-aminoquinoline drugs in their ability and speed to block transmission. The findings from this analysis can support treatment policy decisions for malaria elimination and be integrated into mathematical models to improve the accuracy of predictions regarding community transmission and the spread of drug resistance under varying treatment guidelines

Strengthening and utilizing response groups for emergencies flagship: a narrative review of the roll out process and lessons from the first year of implementation

The World Health Organization Regional Office for Africa (WHO/AFRO) faces members who encounter annual disease epidemics and natural disasters that necessitate immediate deployment and a trained health workforce to respond. The gaps in this regard, further exposed by the COVID-19 pandemic, led to conceptualizing the Strengthening and Utilizing Response Group for Emergencies (SURGE) flagship in 2021. This study aimed to present the experience of the WHO/AFRO in the stepwise roll-out process and the outcome, as well as to elucidate the lessons learned across the pilot countries throughout the first year of implementation. The details of the roll-out process and outcome were obtained through information and data extraction from planning and operational documents, while further anonymized feedback on various thematic areas was received from stakeholders through key informant interviews with 60 core actors using open-ended questionnaires. In total, 15 out of the 47 countries in WHO/AFRO are currently implementing the initiative, with a total of 1,278 trained and validated African Volunteers Health Corps-Strengthening and Utilizing Response Groups for Emergencies (AVoHC-SURGE) members in the first year. The Democratic Republic of Congo (DRC) has the highest number (214) of trained AVoHC-SURGE members. The high level of advocacy, the multi-sectoral-disciplinary approach in the selection process, the adoption of the one-health approach, and the uniqueness of the training methodology are among the best practices applauded by the respondents. At the same time, financial constraints were the most reported challenge, with ongoing strategies to resolve them as required. Six countries, namely Botswana, Mauritania, Niger, Rwanda, Tanzania, and Togo, have started benefiting from their trained AVoHC-SURGE members locally, while responders from Botswana and Rwanda were deployed internationally to curtail the recent outbreaks of cholera in Malawi and Kenya

Long-term cellular immunity of vaccines for Zaire Ebola Virus Diseases

Recent Ebola outbreaks underscore the importance of continuous prevention and disease control efforts. Authorized vaccines include Merck’s Ervebo (rVSV-ZEBOV) and Johnson & Johnson’s two-dose combination (Ad26.ZEBOV/MVA-BN-Filo). Here, in a five-year follow-up of the PREVAC randomized trial (NCT02876328), we report the results of the immunology ancillary study of the trial. The primary endpoint is to evaluate long-term memory T-cell responses induced by three vaccine regimens: Ad26–MVA, rVSV, and rVSV–booster. Polyfunctional EBOV-specific CD4+ T-cell responses increase after Ad26 priming and are further boosted by MVA, whereas minimal responses are observed in the rVSV groups, declining after one year. In-vitro expansion for eight days show sustained EBOV-specific T-cell responses for up to 60 months post-prime vaccination with both Ad26-MVA and rVSV, with no decline. Cytokine production analysis identify shared biomarkers between the Ad26-MVA and rVSV groups. In secondary endpoint, we observed an elevation of pro-inflammatory cytokines at Day 7 in the rVSV group. Finally, we establish a correlation between EBOV-specific T-cell responses and anti-EBOV IgG responses. Our findings can guide booster vaccination recommendations and help identify populations likely to benefit from revaccination