Epidémies de Choléra en Afrique Sub-Saharienne: Revue documentaire de 2010 à 2016

Introduction: Cholera remains a major public health problem in many parts of the world and particularly in sub-Saharan African countries. The objective of this study is to review data on cholera epidemiology, risk, microbiological and disease control factors in sub-Saharan Africa from 2010 to 2016. Material and method: A literature review on cholera epidemics in sub-Saharan Africa from 2010 to 2016 was conducted using electronic databases from countries that have experienced epidemics. Annual cholera data for countries with outbreaks from 2010 to 2016 have been reported. Results: From 2010 through 2016, 35 of the 54 African countries have experienced cholera epidemics. An overall of 1268 outbreaks have been reported, of which 13.04% were recorded in Nigeria and 4.35% in Burundi. The number of cases reported was 801022 and 13232 deaths (overall CFR =1.65%). Vibrio cholerae O1 and O139 are the main etiological agents. The main risk factors are heavy rains, floods, contamination of water sources and lack ofsanitation. Conclusion: In addition to the suffering of patients, cholera outbreaks cause panic, disrupt economic and social structures and hinder the development of affected communities. Mobilization of the water, sanitation and hygiene sectors is essential to ensure the benefits of patient care and cholera vaccination.Introduction : Le choléra demeure un problème majeur de Santé Publique dans de nombreuses parties du monde et en particulier dans les pays d’Afrique subsaharienne. L’objectif de cette étude de faire une revue des donnéessur les épidémies de choléra, les facteurs de risques, microbiologiques et de lutte contre la maladie en Afrique sub-saharienne de 2010 à 2016. Materiels et méthode: Une revue de la littérature sur les épidémies de choléra en Afrique sub-saharienne de 2010 à 2016 a été conduite dans des banques de données ou bases de données et bibiothèques électroniques des pays ayant connu des épidémies. Les données annuelles de choléra dans les pays ayant connu des épidémies de 2010 à 2016 ont été rapportées. Résultats : Entre 2010 et 2016, 35 des 54 pays d'Afrique ont connu des épidémies de choléra. 1268 épisodes épidémiques ont été rapportés dont 13,04% au Nigeria et 4,35% au Burundi. Le nombre de cas notifiés était de 801022 dont 13232 décès (létalité globale =1,65%). Le Vibrio cholerae O1 et O139 sont les principaux agents étiologiques épidémiogènes. Les principaux facteurs de risques sont les pluies abondantes, les inondations, la contamination des sources d’eau et le manque d’assainissement. Conclusion : En dehors des souffrances éprouvées par les malades, les flambées de choléra provoquent la panique, désorganisent les structures économiques et sociales et freinent le développement des communautés touchées. Cependant, la mobilisation des secteurs de l’eau, de l’assainissement et de l’hygiène ainsi que le rensforcement des systemes de surveillance et riposte surtout au niveau transfrontalier sont des etapes essentielles pour la lutte contre les epidemies de cholera en Afrique subsaharienne

Prevalence of Mutations in the \u3ci\u3ePfdhfr\u3c/i\u3e, \u3ci\u3ePfdhps\u3c/i\u3e, and \u3ci\u3ePfmdr1\u3c/i\u3e Genes of Malarial Parasites Isolated from Symptomatic Patients in Dogondoutchi, Niger

The effectiveness of artemisinin-based combination therapies (ACTs) depends not only on that of artemisinin but also on that of partner molecules. This study aims to evaluate the prevalence of mutations in the Pfdhfr, Pfdhps, and Pfmdr1 genes from isolates collected during a clinical study. Plasmodium genomic DNA samples extracted from symptomatic malaria patients from Dogondoutchi, Niger, were sequenced by the Sanger method to determine mutations in the Pfdhfr (codons 51, 59, 108, and 164), Pfdhps (codons 436, 437, 540, 581, and 613), and Pfmdr1 (codons 86, 184, 1034, and 1246) genes. One hundred fifty-five (155) pre-treatment samples were sequenced for the Pfdhfr, Pfdhps, and Pfmdr1 genes. A high prevalence of mutations in the Pfdhfr gene was observed at the level of the N51I (84.97%), C59R (92.62%), and S108N (97.39%) codons. The key K540E mutation in the Pfdhps gene was not observed. Only one isolate was found to harbor a mutation at codon I431V. The most common mutation on the Pfmdr1 gene was Y184F in 71.43% of the mutations found, followed by N86Y in 10.20%. The triple-mutant haplotype N51I/C59R/S108N (IRN) was detected in 97% of the samples. Single-mutant (ICS and NCN) and double-mutant (IRS, NRN, and ICN) haplotypes were prevalent at 97% and 95%, respectively. Double-mutant haplotypes of the Pfdhps (581 and 613) and Pfmdr (86 and 184) were found in 3% and 25.45% of the isolates studied, respectively. The study focused on the molecular analysis of the sequencing of the Pfdhfr, Pfdhps, and Pfmdr1 genes. Although a high prevalence of mutations in the Pfdhfr gene have been observed, there is a lack of sulfadoxine pyrimethamine resistance. There is a high prevalence of mutation in the Pfmdr184 codon associated with resistance to amodiaquine. These data will be used by Niger’s National Malaria Control Program to better monitor the resistance of Plasmodium to partner molecules in artemisinin-based combination therapies

A Fatal Case of COVID-19 in an Infant with Severe Acute Malnutrition Admitted to a Paediatric Ward in Niger

While there have been very few fatal cases, SARS-CoV-2 has been reported in paediatric patients. This study aims to describe a fatal case of COVID-19 in a child with severe acute malnutrition. The eight-month-old child presented with fever, diarrhoea, and difficulty in breathing. The mother of the child had fever and shortness of breath four weeks before she died. Physical examination revealed lethargy, dehydration, and severe weight loss with a weight of 5 kg at a height of 78 cm tall. The weight-for-height index was less than three Z-scores, which corresponds to severe acute malnutrition. The pulmonary examination revealed moderate respiratory distress, and the chest X-ray presented features suggestive of pneumonia in the right lung area. In the context of the COVID-19 outbreak in Niger and the circumstances of the mother’s death, a nasal swab was taken for laboratory confirmation. Treatment provided to the child included intranasal oxygen, antibiotics, and a dietary program with therapeutic milk. The child died 48 hours after his admission. The history of contact with a SARS-CoV-2 suspect or positive patient should lead to screening for infection by using RT-PCR. It is important to investigate malnutrition as a potential risk factor for severe SARS-CoV-2 infection and resultant mortality

Transfusional Malaria and Associated Factors at the National Blood Transfusion Center of Niamey-Niger

Summary. Problem. Transfusional malaria is an accidental transmission of Plasmodium via a blood transfusion. Its magnitude is underestimated and very little data on the assessment of this risk are available in Niger. Objective. This study aimed to determine the prevalence of plasmodial infection of blood bags at the National Blood Transfusion Center of Niamey (NBTC). Methodology. A cross-sectional study to diagnose Plasmodium infection by microscopy and Rapid Diagnostic Test (RDT) was carried out during the rainy season (September to November 2015). Blood grouping was performed by the BETH-VINCENT technique. Results. One thousand three hundred and fifty-seven (1357) blood bags were collected. One hundred and fifty-seven (11.6%) of the donors were infected with Plasmodium by microscopy and 2.4% (9/369) by rapid diagnostic test. All infections were with P. falciparum (100%). The mean parasite density was 197 parasites/μL (SD=281; [80: 2000]). There were no significant differences in infection prevalence between the ABO blood groups (p=0.3) or the rhesus positivity (p=08). There is also no significant difference in temporal (p=0.1) and spatial (p=0.6) distribution. Conclusion. The transmission of transfusional malaria during the rainy season is a fact in Niger. Such risks were independent of the ABO blood type and positivity for the rhesus antigen. Pretransfusion diagnosis or posttransfusion therapy should be instituted to prevent it

First identification of Microsporidia MB in Anopheles coluzzii from Zinder City, Niger

Abstract Background Malaria, a disease transmitted by Anopheles mosquitoes, is a major public health problem causing millions of deaths worldwide, mostly among children under the age of 5 years. Biotechnological interventions targeting parasite-vector interactions have shown that the microsporidian symbiont Microsporidia MB has the potential to disrupt and block Plasmodium transmission. Methods A prospective cross-sectional survey was conducted in Zinder City (Zinder), Niger, from August to September 2022, using the CDC light trap technique to collect adult mosquitoes belonging to the Anopheles gambiae complex. The survey focused on collecting mosquitoes from three neighborhoods of Zinder (Birni, Kangna and Garin Malan, located in communes I, II and IV, respectively). Collected mosquitoes were sorted and preserved in 70% ethanol. PCR was used to identify host species and detect the presence of Microsporidia MB and Plasmodium falciparum infection. Results Of the 257 Anopheles mosquitoes collected and identified by PCR, Anopheles coluzzii was the most prevalent species, accounting for 97.7% of the total. Microsporidia MB was exclusively detected in A. coluzzii, with a prevalence of 6.8% (17/251) among the samples. No significant difference in prevalence was found among the three neighborhoods. Only one An. coluzzii mosquito tested PCR-positive for P. falciparum. Conclusions The results confirm the presence of Microsporidia MB in Anopheles mosquitoes in Zinder, Niger, indicating its potential use as a biotechnological intervention against malaria transmission. However, further studies are needed to determine the efficacy of Microsporidia MB to disrupt Plasmodium transmission as well as its impact on vector fitness. Graphical Abstrac

Cours National de Paludologie du Niger : Bilan de cinq ans.

Le Cours National de Paludologie (CNP) est une formation organisée depuis 2011 par le Centre de Recherche Médicale et Sanitaire (CERMES) de Niamey en collaboration avec le Programme National de Lutte contre le Paludisme (PNLP) du Niger, la Faculté des Sciences de la Santé (FSS) de l’université Abdoul Moumouni et l’Hôpital National de Niamey.Objectif : L’objectif de ce cours est de renforcer l’aptitude des acteurs de la lutte contre le paludisme. Nous présentons le bilan de cinq ans d’animation du cours.Méthodologie et résultats : La méthodologie du cours est une approche interactive, basée sur le principe de l’andragogie et utilisant les nouvelles technologies de l’information et de la communication (NTIC). Cent quarante-six candidats ont postulé au CNP en 5 ans. Soixante-seize candidats ont été retenus par la commission de sélection des dossiers. 97,4% des candidats étaient de nationalité Nigérienne. Le taux de réussite était de 95,9% (N=74). Cinquante-trois conférences ont été animées par des chercheurs séniors venus de 7 pays différents. La moyenne générale au pré test était de 9,2/20 (D=6,2, [3 ; 16,5]) contre 14,9/20 (D=8,3 ; [7,5 ; 20]) au post test. L’analyse du questionnaire de satisfaction montre que 69,9% (N=44) des apprenants étaient satisfaits du cours.Conclusion : Le CNP s’est déroulé avec beaucoup de satisfaction durant ces cinq années consécutives. Les résultats d’évaluation de ce cours sont excellents. Le Réseau International des Instituts Pasteur (RIIP) auquel appartient le CERMES doit pérenniser ce cours en le transformant en un cours sous régional dénommé « Cours Ouest Africain de Paludologie (COAP) ».Mots clés : Formation, Paludisme, Bilan, Niger

Plasmodium falciparum kelch13 polymorphisms identified after treatment failure with artemisinin-based combination therapy in Niger

Abstract Background Artemisinin-based combination therapy (ACT) is the most effective treatment for malaria, and has significantly reduced morbimortality. Polymorphisms associated with the Plasmodium falciparum Kelch gene (Pfkelch13) have been associated with delayed parasite clearance even with ACT treatment. Methods The Pfkelch13 gene was sequenced from P. falciparum infected patients (n = 159) with uncomplicated malaria in Niger. An adequate clinical and parasitological response (ACPR) was reported in 155 patients. Four (n = 4) patients had treatment failure (TF) that were not reinfections—two of which had late parasitological failures (LPF) and two had late clinical failures (LCF). Results Thirteen single nucleotide polymorphisms (SNPs) were identified of which seven were non-synonymous (C469R, T508S, R515T, A578S, I465V, I437V, F506L,), and three were synonymous (P443P, P715P, L514L). Three SNP (C469R, F506L, P715P) were present before ACT treatment, while seven mutations (C469R, T508S, R515T, L514L, P443P, I437V, I465V) were selected by artemether/lumefantrine (AL)—five of which were non-synonymous (C469R, T508S, R515T, I437V, I465V). Artesunate/amodiaquine (ASAQ) has selected any mutation. One sample presented three cumulatively non-synonymous SNPs—C469R, T508S, R515T. Conclusions This study demonstrates intra-host selection of Pfkelch13 gene by AL. The study highlights the importance of LCF and LPF parasites in the selection of resistance to ACT. Further studies using gene editing are required to confirm the potential implication of resistance to ACT with the most common R515T and T508S mutations. It would also be important to elucidate the role of cumulative mutations

Prevalence of Plasmodium falciparum haplotypes associated with resistance to sulfadoxine-pyrimethamine and amodiaquine before and after upscaling of seasonal malaria chemoprevention in seven African countries: a genomic surveillance study.

BACKGROUND: Seasonal malaria chemoprevention is used in 13 countries in the Sahel region of Africa to prevent malaria in children younger than 5 years. Resistance of Plasmodium falciparum to seasonal malaria chemoprevention drugs across the region is a potential threat to this intervention. METHODS: Between December, 2015, and March, 2016, and between December, 2017, and March, 2018, immediately following the 2015 and 2017 malaria transmission seasons, community surveys were done among children younger than 5 years and individuals aged 10-30 years in districts implementing seasonal malaria chemoprevention with sulfadoxine-pyrimethamine and amodiaquine in Burkina Faso, Chad, Guinea, Mali, Nigeria, Niger and The Gambia. Dried blood samples were collected and tested for P falciparum DNA by PCR. Resistance-associated haplotypes of the P falciparum genes crt, mdr1, dhfr, and dhps were identified by quantitative PCR and sequencing of isolates from the collected samples, and survey-weighted prevalence and prevalence ratio between the first and second surveys were estimated for each variant. FINDINGS: 5130 (17·5%) of 29 274 samples from 2016 and 2176 (7·6%) of 28 546 samples from 2018 were positive for P falciparum on quantitative PCR. Among children younger than 5 years, parasite carriage decreased from 2844 of 14 345 samples (19·8% [95% CI 19·2-20·5]) in 2016 to 801 of 14 019 samples (5·7% [5·3-6·1]) in 2018 (prevalence ratio 0·27 [95% CI 0·24-0·31], p<0·0001). Genotyping found no consistent evidence of increasing prevalence of amodiaquine resistance-associated variants of crt and mdr1 between 2016 and 2018. The dhfr haplotype IRN (consisting of 51Ile-59Arg-108Asn) was common at both survey timepoints, but the dhps haplotype ISGEAA (431Ile-436Ser-437Gly-540Glu-581Ala-613Ala), crucial for resistance to sulfadoxine-pyrimethamine, was always rare. Parasites carrying amodiaquine resistance-associated variants of both crt and mdr1 together with dhfr IRN and dhps ISGEAA occurred in 0·05% of isolates. The emerging dhps haplotype VAGKGS (431Val-436Ala-437Gly-540Lys-581Gly-613Ser) was present in four countries. INTERPRETATION: In seven African countries, evidence of a significant reduction in parasite carriage among children receiving seasonal malaria chemoprevention was found 2 years after intervention scale-up. Combined resistance-associated haplotypes remained rare, and seasonal malaria chemoprevention with sulfadoxine-pyrimethamine and amodiaquine is expected to retain effectiveness. The threat of future erosion of effectiveness due to dhps variant haplotypes requires further monitoring. FUNDING: Unitaid