[Evaluation of the Viral Hemorrhagic Fever Surveillance System in the Assaba region, Mauritania (2020-2022)]. / Évaluation du système de surveillance des fièvres hémorragiques virales dans la wilaya d'Assaba, Mauritanie (2020-2022).

Introduction: Several arboviral diseases have been known to be endemic (e.g., Crimean-Congo hemorrhagic fever, Rift Valley fever) or are emerging (dengue fever, chikungunya, O'nyong-nyong) in human populations in Mauritania, while others have become rare in recent years (e.g. yellow fever). Moreover, domestic animals, especially cattle, camels, goats, and sheep, are also known to be infected with some of these arboviruses (e.g. Crimean-Congo hemorrhagic fever, Rift Valley fever). For these reasons, viral hemorrhagic fever surveillance in Mauritania is part of the Integrated Disease Surveillance and Response (IDSR). However, limited information is available on the efficacy of the viral hemorrhagic fever surveillance system in the Assaba region of Mauritania. The aim of the present study was to assess the performance of the surveillance system, in particular its general utility, simplicity, flexibility, acceptability, and reactivity. Methods: A descriptive cross-sectional study was conducted from July to August 2022 in the Assaba region with the objective of evaluating the characteristics of the system by interviewing key actors involved in the surveillance of viral hemorrhagic fevers, with a focus on Rift Valley fever and Crimean-Congo hemorrhagic fever, using questionnaires developed following the guidelines of the Centers for Disease Control and Prevention (Atlanta, Georgia, USA). Data from 2020-2022 on viral hemorrhagic fevers from the National Institute of Public Health laboratory were analyzed. Medians, interquartile ranges, and proportions were calculated using Epi Info® 7.2.5.0 and Excel® 2021. Results: The questionnaire was answered by all twenty-six persons involved in the viral hemorrhagic fever surveillance system in Assaba region. The majority of survey respondents found the system to be useful (51%), simple (63%), acceptable (46%), responsive (64%), and flexible (46%). An analysis of the data revealed a positive predictive value of 28% for Rift Valley Fever. The weekly distribution of cases within the wilaya indicates that the moughataa of Kiffa recorded the highest number of cases in September, with a notable weekly peak during that month in 2020. According to the analysis of the National Institute of Public Health database, cases of viral hemorrhagic fevers were promptly handled. Survey responses and database analysis revealed issues related to data quality and data management mechanisms. These limitations in the surveillance system are likely to be due to insufficient resources and training of the personnel, in particular with regards to data collection and management, which in turn led to incomplete or missing data and invalid data entry. These weak points can be ascribed, at least in part, to financial constraints and inadequate attribution of priority to arboviral diseases. Despite these limitations, disease data generated by the surveillance system were generally reliable. Conclusion: The viral hemorrhagic fever surveillance system in the Assaba region adheres to the organization and functioning of the national viral hemorrhagic fever surveillance system, which is part of the IDSR. The characteristics of utility, simplicity, responsiveness, and flexibility of the viral hemorrhagic fever surveillance system are good, but acceptability and flexibility need further improvement. The earlier the first arboviral human or animal cases are detected, the more likely an active intervention can be organized in response to the emerging epidemic or epizootic and prevent the spread of the disease. An efficient viral surveillance system is the key to reducing the negative impact of arboviral diseases in Assaba region.

Genomic Characterization of SARS-CoV-2 Variants from Clinical Isolates during the COVID-19 Epidemic in Mauritania.

The rapid genetic evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the coronavirus disease 2019 (COVID-19) pandemic has greatly challenged public health authorities worldwide, including in Mauritania. Despite the presence of the virus in Mauritania, only one study described its genomic variation during the course of the epidemic. The purpose of the present study was to document the genomic pattern of SARS-CoV-2 variants from clinical isolates during the COVID-19 outbreak in Mauritania, from September to November 2021. The whole genomes from 54 SARS-CoV-2 strains detected in nasopharyngeal swabs with a cycle threshold value ≤ 30 were successfully sequenced using next-generation sequencing (NGS) and the Illumina protocol. The mean genome coverage (±standard deviation) was 96.8% (±3.7). The most commonly identified clade was 21J (57.4%), followed by 21D (16.7%), 20A (11.1%), and 20B (9.2%). At the level of lineages, the majority of the samples were Delta variants with the sub-lineage AY.34 (or B.1.617.2.34). Among the 54 SARS-CoV-2 isolates that were successfully sequenced, 33 (61.1%) came from vaccinated individuals, and 21 (38.9%) were from unvaccinated individuals. Several SARS-CoV-2 variants were present in Mauritania between September and November 2021. As Mauritania, like many West African countries, is resource-limited regarding viral genome sequencing facilities, establishment of mutualized sub-regional sequencing platforms will be necessary to ensure continuous monitoring of mutations in viral genomes and track potential reduction in COVID-19 vaccine efficacy, increased transmissibility, and disease severity.

[Delta hepatitis in Africa: epidemiological and clinical particularities]. / Hépatites Delta en Afrique: particularités épidémiologiques et cliniques.

In 2022, the World Health Organization (WHO) estimated that hepatitis B virus (HBV) infections caused 1.5 million deaths, mostly attributable to complications from chronic infections, cirrhosis and hepatocellular carcinoma (HCC). Despite the availability of a vaccine, 296 million people were chronically infected in 2019. Asia and Africa are the continents most affected by this infection, with around 100 million people infected in Africa as a whole.Hepatitis Delta or D virus (HDV), which is a "satellite" virus of HBV, is often misunderstood and its diagnosis remains neglected. However, it is associated with acute fulminant forms and chronic forms of hepatitis leading to a more rapid evolution towards cirrhosis and HCC than during HBV mono-infection. Research on these two viruses HBV and HDV has progressed a lot in recent years, and new treatments are currently in development.In people living with the human immunodeficiency virus (PlHIV), liver disease is a major cause of morbidity and mortality. Due to common modes of transmission, dual or triple HIV/HBV or HIV/HBV/HDV infections are relatively common, particularly in HBV endemic regions such as Africa. However, while today most co-infected patients benefit from effective treatment against both HIV and HBV, the latter is not active against HDV. In Africa, hepatitis B and D have already been the subject of several studies. However, the frequency and clinical consequences of these co-infections have been little studied in the general population and in PlHIV.This review seeks to update the epidemiological and clinical data and the therapeutic perspectives of HDV co-infections or triple infections (HIV-HBV-HDV) in Africa.

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

Investment in Africa over the past year with regards to SARS-CoV-2 genotyping has led to a massive increase in the number of sequences, exceeding 100,000 genomes generated to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence within their own borders, coupled with a decrease in sequencing turnaround time. Findings from this genomic surveillance underscores the heterogeneous nature of the pandemic but we observe repeated dissemination of SARS-CoV-2 variants within the continent. Sustained investment for genomic surveillance in Africa is needed as the virus continues to evolve, particularly in the low vaccination landscape. These investments are very crucial for preparedness and response for future pathogen outbreaks. One-Sentence SummaryExpanding Africa SARS-CoV-2 sequencing capacity in a fast evolving pandemic.