Surgical-site infection is the most frequent health care-associated infection in the developing world, with a strikingly higher prevalence than in developed countries We studied the prevalence of resistance to antibiotics in Enterobacteriaceae isolates from surgical-site infections collected in three major tertiary care centres in Bangui, Central African Republic. We also studied the genetic basis for antibiotic resistance and the genetic background of third-generation cephalosporin-resistant (3GC-R) Enterobacteriaceae. Between April 2011 and April 2012, 195 patients with nosocomial surgical-site infections were consecutively recruited into the study at five surgical departments in three major tertiary care centres. Of the 165 bacterial isolates collected, most were Enterobacteriaceae (102/165, 61.8%). Of these, 65/102 (63.7%) were 3GC-R, which were characterized for resistance gene determinants and genetic background. The bla CTX-M-15 and aac(6′)-Ib-cr genes were detected in all strains, usually associated with qnr genes (98.5%). Escherichia coli, the most commonly recovered species (33/65, 50.8%), occurred in six different sequence types, including the pandemic B2-O25b-ST131 group (12/33, 36.4%). Resistance transfer was studied in one representative strain of the resistance gene content in each repetitive extragenic palindromic and enterobacterial repetitive intergenic consensus sequence-PCR banding pattern. Plasmids were characterized by PCR-based replicon typing and sub-typing schemes. In most isolates (18/27, 66.7%), bla CTX-M-15 genes were found in incompatibility groups F/F31:A4:B1 and F/F36:A4:B1 conjugative plasmids. Horizontal transfer of both plasmids is probably an important mechanism for the spread of bla CTX-M-15 among Enterobacteriaceae species and hospitals. The presence of sets of antibiotic resistance genes in these two plasmids indicates their capacity for gene rearrangement and their evolution into new variants. Diverse modes are involved in transmission of resistance, plasmid dissemination probably playing a major role.

Shigella is a major cause of severe diarrhea in children less than the age of 5 years in sub-Saharan Africa. The aim of this study was to describe the (sub-)serotype distribution and antimicrobial susceptibility of Shigella serogroups from Centrafrican patients with diarrhea between 2002 and 2013. We collected 443 Shigella isolates in total. The most common serogroups were Shigella flexneri (N = 243, 54.9%), followed by Shigella sonnei (N = 90, 20.3%) and Shigella dysenteriae (N = 72, 16.3%). The high diversity of (sub-)serotypes of S. flexneri and S. dysenteriae may impede the development of an efficient vaccine. Rates of resistance were high for ampicillin, chloramphenicol, tetracycline, and cotrimoxazole but low for many other antimicrobials, confirming recommendations for the use of third-generation cephalosporins (only one organism resistant) and fluoroquinolones (no resistance). However, the detection of one extended-spectrum beta-lactamase–producing Shigella organism highlights the need for continued monitoring of antimicrobial drug susceptibility.

Since its outbreak, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spread rapidly, causing the Coronavirus Disease 19 (COVID-19) pandemic. Even with the vaccines’ administration, the virus continued to circulate due to inequal access to prevention and therapeutic measures in African countries. Information about COVID-19 in Africa has been limited and contradictory, and thus regional studies are important. On this premise, we conducted a genomic surveillance study about COVID-19 lineages circulating in Bangui, Central African Republic (CAR). We collected 2687 nasopharyngeal samples at four checkpoints in Bangui from 2 to 22 July 2021. Fifty-three samples tested positive for SARS-CoV-2, and viral genomes were sequenced to look for the presence of different viral strains. We performed phylogenetic analysis and described the lineage landscape of SARS-CoV-2 circulating in the CAR along 15 months of pandemics and in Africa during the study period, finding the Delta variant as the predominant Variant of Concern (VoC). The deduced aminoacidic sequences of structural and non-structural genes were determined and compared to reference and reported isolates from Africa. Despite the limited number of positive samples obtained, this study provides valuable information about COVID-19 evolution at the regional level and allows for a better understanding of SARS-CoV-2 circulation in the CAR.

INTRODUCTION: the National Laboratory of Clinical Biology and Public Health (NLBPH) in Bangui in the Central African Republic (CAR) carries out the vast majority of molecular screening tests for SARS-CoV-2 infection nationwide. TThis study aimed to show the contribution of molecular diagnosis and genomic surveillance in monitoring the evolution of longitudinal variations of the SARS-CoV-2 infection epidemic in CAR between 2020 and the end of 2022. METHODS: this is an observational study on the variations in the prevalence of detection of SARS-CoV-2 by RT-PCR at the NLCBPH from nasopharyngeal samples taken prospectively over a period of 3 years since the beginning of the Covid-19 epidemic. A subgroup of SARS-CoV-2 positive samples was selected for molecular sequencing performed by Illumina® and MinIon® at the National Institute for Biomedical Research in Kinshasa, Democratic Republic of the Congo. RESULTS: from March 2020 to December 31, 2022, 88,442 RT-PCR tests were carried out (4/5 of the country) and detected 9,156 cases of SARS-CoV-2 infection in 5 successive waves. The average age of the patients was 39.8 years (extremes ranging from to 92 years). Age(P=0.001), sex(P=0.001) and symptom presentation(P=0.001) were significantly associated with RT-PCR test positivity. Among the different variants identified during successive waves, the Omicron variant predominated during the last two waves. CONCLUSION: this prospective study over a period of 3 years, marked by 5 successive waves, made it possible to report that age, sex and the presence of clinical symptoms are associated with RT-PCR positivity. Among the different variants identified during successive waves, the Omicron variant predominated during the last two waves.

Objective : In a context of increasing cases despite vaccination campaigns, a survey was conducted in the Bangui population in January 17 to 26, 2022 to evaluate the strains of Severe Acute Respiratory Infection Coronavirus 2 (SARS-Cov-2) circulating in a healthy population by taking nasopharyngeal samples in 2,554 randomly selected volunteers. Antigen detection was performed systematically and RT-PCR was done on the positive samples. Thirty samples were found RT-PCR positive (1.2%) and sent for viral genome sequencing. Twenty eight SARS-Cov-2 strains belong to Omicron type and solely 2 to Delta type. Thus, infection were uncommon in the tested population but the presence of Omicron and Delta types make fear than vaccination will not be efficient to fight against the virus and newly designed vaccine should be implemented to better protect the population who is at risk of infection and re-infection by these variants.

Objective: The Covid-19 pandemic has highlighted the need to strengthen diagnosis and genomic surveillance capacities. The Central African Republic was able to manage 5 waves during health monitoring and integrated genomic surveillance as a surveillance tool in 2021. The aim of this study is to report surveillance data from the National Laboratory of Clinical Biology and Public Health and describe the landscape of circulation of SARS-CoV-2 variants. Materials and methods: This is a retrospective, descriptive observational study over a period of 3 years (ranging from April 2020 to November 2023) carried out on a population of consenting volunteers, from throughout the CAR, tested by RT -PCR on nasopharyngeal samples with sufficient information in the LNBCSP databases. Sequencing is largely carried out at the INRB in KINSHASA and from May 2023 at the LNBCSP. Results and discussion: Out of 97,864 RT-PCR tests carried out, 9,764 came back positive, which corresponds to a prevalence of 9.98%. The average age of the patients was 39.97 years ± 13.76 and the sex ratio M/F was 2.12. The positivity of RT-PCR tests was significantly associated with age (p=0.001), sex (p=0.013) and clinical manifestations. Ten variants circulated during the 5 waves recorded. The landscape of circulating variants was dominated by the Omicron (B.1.1.529), Delta (B.1.617.2) variants and especially by B.1.620 and B.640 which marked the second wave in CAR. Conclusion: This retrospective series provides key information for understanding the history of the Covid-19 pandemic in the CAR. Risk factors are identified and the variant circulation landscape described. Strengthening national genomic surveillance capacities would help the country adopt a better response against this pandemic.