Fabien Niama | Université Marien Ngouabi (original) (raw)

Papers by Fabien Niama

Open Journal of Epidemiology, Dec 31, 2023

BMC research notes, Jan 5, 2017

In this work, we investigated the genetic diversity of HIV-1 and the presence of mutations confer... more In this work, we investigated the genetic diversity of HIV-1 and the presence of mutations conferring antiretroviral drug resistance in 50 drug-naïve infected persons in the Republic of Congo (RoC). Samples were obtained before large-scale access to HAART in 2002 and 2004. To assess the HIV-1 genetic recombination, the sequencing of the pol gene encoding a protease and partial reverse transcriptase was performed and analyzed with updated references, including newly characterized CRFs. The assessment of drug resistance was conducted according to the WHO protocol. Among the 50 samples analyzed for the pol gene, 50% were classified as intersubtype recombinants, charring complex structures inside the pol fragment. Five samples could not be classified (noted U). The most prevalent subtypes were G with 10 isolates and D with 11 isolates. One isolate of A, J, H, CRF05, CRF18 and CRF37 were also found. Two samples (4%) harboring the mutations M230L and Y181C associated with the TAMs M41L an...

Journal of Biosciences and Medicines, 2023

Staphylococci strains, like the majority of bacterial strains, have developed the resistance to s... more Staphylococci strains, like the majority of bacterial strains, have developed the resistance to several antibiotics, including Quinolones and Fluoroquinolones In the Republic of the Congo, cases of resistance leading to treatment failures have been observed during the treatment of staphylococcal infections with antibiotics in hospitals. The objective of this study was to identify the Quinolones/Fluoroquinolones resistance genes from staphylococci strains isolated in hospitals. A total of 51 strains of Staphylococci were isolated, including 16 (31.37%) community strains, and 35 (68.62%) clinical strains. 46 strains of Staphylococcus aureus (S. aureus) and 5 SCNs were identified. A total of 34 DNA fragments from different strains resistant to Quinolones/Fluoroquinolones, including 21 (61.67%) DNA fragments from clinical S. aureus and 13 (38.23%) from community SCN strains were analyzed by the molecular method (genotypic detection) by PCR. The genotypic results made it possible to identify the gyrA, grLA and norA genes and to show that these genes are involved in the resistance of the strains to the various antibiotics used. The grLA gene was the most identified gene with a frequency of 75%. The gyrA and grLA genes have been identified in Staphylococcus aureus and Coagulase Negative Staphylococci. The norA gene, on the other hand, has only been

Advances in microbiology, 2022

The improper use of antimicrobials against infectious diseases has allowed microorganisms to deve... more The improper use of antimicrobials against infectious diseases has allowed microorganisms to develop defense mechanisms that give them insensitivity to these agents. All bacteria are concerned by this phenomenon. This work aimed to assess prevalence of beta-lactamase produced by enterobacterial isolates. Then, disc diffusion, double disc synergy test (DDST) and combined disc test (CDT) were respectively used for antimicrobial resistance, detection of Extended-Spectrum Beta-Lactamases (ESBL) and Metallo-Beta-Lactamases (MBL). bla genes were detected by PCR. A total of 132 enterobacterial strains were studied. Resistance to antibiotic families was observed with a greater frequency than 50%. Gentamicin was the least active beta-lactam antibiotic, with a resistance rate of 88%. 40.9% of strains show an ESBL phenotype and 16.6% were MBL. An overall prevalence of 74% (40/54) and respectively rates of 29.6%, 27.7% and 16.7% for blaSHV, blaCTX and blaTEM genes were observed. SHV, CTX, CTX/SHV/TEM, CTX/TEM, SHV/TEM and CTX/SHV were different ESBL genotypes observed. ESBL-producing enterobacteria isolation worried about the future of antimicrobial therapy in the Republic of Congo. This is a public health problem that requires careful monitoring and implementation of a policy of rational antibiotics use.

HEALTH SCIENCES AND DISEASES, Apr 3, 2017

Objectif. La transfusion sanguine est une thérapeutique salvatrice, mais qui comporte un risque n... more Objectif. La transfusion sanguine est une thérapeutique salvatrice, mais qui comporte un risque non négligeable de transmission de maladies infectieuses. Pour quantifier ce risque, nous avons évalué la prévalence du VHB, VHC, VIH, CMV et de la syphilis dans un groupe d'enfants et son évolution après transfusion. Méthodologie. Nous avons réalisé une étude longitudinale concernant des enfants âgés de 0 à 15 ans, hospitalisés et transfusés dans les services de pédiatrie du Centre Hospitalier et Universitaire de Brazzaville (CHUB) durant la période allant de février à septembre 2010. Les analyses sérologiques ont été réalisées par les tests ELISA avant la transfusion sanguine et trois mois après. Résultats. Nous avons recruté 75 enfants (34 de sexe féminin et 41 de sexe masculin). Leur âge moyen était de cinq ans avec des extrêmes de un mois et quinze ans. La tranche d'âge de un à cinq ans était la plus représentée (58,7%). Sur la base de critères cliniques, quarante sept enfants (62%) ont été transfusés ; la principale pathologie en cause était le paludisme (49,3%). La distribution des sérologies positives avant la transfusion était : VIH : 9,3% ; VHC : 4% ; VHB : 6,7% ; CMV IgM : 9,3% ; CMV IgG : 32% et syphilis : 0%. Les cas de séroconversion après transfusion concernaient le VHC (un cas soit 1,3%), le CMV IgM (4 cas soit 5,3%) et le CMV IgG (7 cas soit 9,3%). Conclusion. Un pourcentage élevé d'enfants ayant besoin de transfusion sont déjà porteurs de maladies infectieuses virales graves. D'autre part, les séroconversions post transfusionnelles observées montrent l'importance de renforcer les mesures de sécurité transfusionnelle.

We present the first videos depicting the consumption of bats by rusty-spotted genets (Genetta ma... more We present the first videos depicting the consumption of bats by rusty-spotted genets (Genetta maculata) inside a cave in the Republic of Congo. Following the implementation of a camera-trap monitoring protocol of interactions between cave bats and wildlife, we identified important genet activity in one of the caves in our study. Between 2022 and 2023, we recorded four events of bat or rodent consumption (including two with certainty on bats), one hunting attempt on bats and three feeding behaviors on insects. We detail the various behaviors and discuss the potential implications of genets consuming bats, rodents and insects, and in particular scavenging on dead bats. Finally, we address the potential implications of zoonotic pathogen transmission from bats to humans via genets through the bushmeat trade.

Open Journal of Gastroenterology, 2018

Hepatitis B virus (HBV) infection is a major public health problem in the world. In Congo, studie... more Hepatitis B virus (HBV) infection is a major public health problem in the world. In Congo, studies on the prevalence of HBV infection are common but HDV infection is rare. Objective: Contribute to improve the management and prevention of HBV and HDV infections. Patients and Methods: This was a descriptive and cross-sectional study conducted from January to August 2016 in the health services of the various departments of Congo and at the national public health laboratory in Brazzaville. All patients with HBsAg surface antigen who were at least 18 years old and who consented to the study were included. The HBs antigen was first tested by a rapid test then confirmed by ELISA. All HBsAg positive patients were subsequently subjected to a second ELISA test for Delta antibody. The techniques of extraction and conventional and specific gene amplification were carried out on plasma for the identification of the genotypes of the two viruses. The data analysis was done with EpiInfo V7 software. The proportions were compared using the Chi-square test or the Fisher test at the significance level of 5%. Results: 1618 subjects were included, of whom 180 were positive for HBsAg, a frequency of 11.12%. The sex ratio (M/F) was 0.77%, the mean age was 40.2 ± 15.6 years with extremes ranging from 18 to 88 years. Of the 180 HBsAg positive, 22 were anti-VHD positive, a frequency of 12.22%. HBV DNA was amplified in 83.8% (151/180), HDV RNA in 63.6% (14/22). For HBV, three genotypes were identified: E (46.9%), A (43.7%) and D (9.4%), however for VHD three genotypes D1, D5, D8 were identified. Conclusion: Co-infection of hepatitis

In this study, we used a predator-enabled metagenomics strategy to sample the virome of a remote ... more In this study, we used a predator-enabled metagenomics strategy to sample the virome of a remote and difficult-to-access densely forested African tropical region. Specifically, we focused our study on the use of army ants of the genusDorylusthat are obligate collective foragers and group predators that attack and overwhelm a broad array of animal prey. Using 209 army ant samples collected from 29 colonies and the virion-associated nucleic acid-based metagenomics approach, we showed that a broad diversity of bacterial, plant, invertebrate and vertebrate viral sequences were accumulated by army ants: including sequences from 157 different viral genera in 56 viral families. This suggests that using predators and scavengers such as army ants to sample broad swathes of tropical forest viromes can shed light on the composition and the structure of viral populations of these complex and inaccessible ecosystems.

Open Journal of Blood Diseases, 2021

Introduction: Sickle cell disease is a public health problem in the Republic of Congo where the p... more Introduction: Sickle cell disease is a public health problem in the Republic of Congo where the prevalence of sickle cell trait is estimated at 1.25%. The objective of this study is to describe the variations of hematological and biochemical parameters of hemolysis in sickle cell patients in critical and inter-critical periods. Methods: This is a descriptive cross-sectional study including sickle cell patients followed regularly at the National Reference Center for Sickle Cell Disease (CNRDr) from November 2019 to March 2020. A sample of 167 patients (sickle cell subjects in crisis and in steady state as well as control subjects) was randomly selected during the study period. The blood count was performed using a Sysmex-XN 350 automated system and the biochemical parameters were determined using the Cobas e 311 automated system. Statistical analysis was performed with SPSS version 22 software. Results: The study showed that the mean cholesterol level in controls was 4.16 ± 0.77 ul c...

Viruses, Apr 9, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Background: Acute gastroenteritis due to Rotavirus A infection is common in both developing and d... more Background: Acute gastroenteritis due to Rotavirus A infection is common in both developing and developed countries and is responsible for approximately 215,000 annual deaths especially in developing countries. In 2014, the Republic of Congo joined the immunization program recommended by WHO and introduced Rotarix (GlaxoSmithKline Biologicals, Belgium) into its national immunization schedule. However, information on the genetic diversity of Rotavirus strains in Congo is derived from a single pre-vaccination study conducted in the southern Brazzaville area. To determine RVA prevalence and genotype distribution in Brazzaville and Pointe-Noire before and after the Rotarix vaccine introduction. Methods: From February to September 2013 and from August 2017 to February 2018, stool samples were collected from children under 5 years of age suffering from gastroenteritis in Congolese hospitals before and after vaccine introduction. RVA was detected using the ELISA and the VP7 and VP4 genes w...

EcoHealth

Orbiviruses are arthropod borne viruses of vertebrates, with some of them being important pathoge... more Orbiviruses are arthropod borne viruses of vertebrates, with some of them being important pathogens of veterinary, conservation and economic importance, while others are occasionally associated with human disease. Some apparently bat specific orbiviruses have been detected, but little is known about their distribution and diversity. We thus sampled and screened 52 bats living in the Congo Basin, and detected RNA indicative of a novel orbivirus in a single banana serotine (Afronycteris nanus) by PCR. The detected RNA clusters with epizootic haemorrhagic disease virus, bluetongue virus, and others. The findings highlight the need for more studies into arbovirus presence and diversity in bat species.

Open Journal of Epidemiology

We conducted a study to evaluate the sensitivity (Se), specificity (Sp), positive predictive valu... more We conducted a study to evaluate the sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) of five serologic tests. Subjects with negative or positive COVID-19 polymerase chain reaction (PRC) test results were tested with each of the serological tests. The results were compared with the reference PCR test. For the five tests evaluated, the Se ranged from 55.0% to 70.0% and the Sp ranged from 67.2% to 86.2%. PPV ranged from 53.2% to 80% and NPV from 75.0% to 86.2%. One test, the Wantai, had better specificity and sensitivity. None of the five tests had performance values of more than 90% in the entire sample. In symptomatic positive cases, the Wantai test reported excellent sensitivity. Overall, the low level of diagnostic performance of these tests does not support their use as an alternative to PCR for COVID-19 diagnostic. Test with better performance can be used for mass screening in low prevalence populations, to limit the indiscriminate use of PCR in context of resource-limited countries. Given the excellent sensitivity of Wantai in symptomatic cases, this test could be used as a referral test only in health facilities to discriminate suspected cases before PCR confirmation.

PLOS Neglected Tropical Diseases

On the 8th of May, 2018, an outbreak of Ebola virus disease (EVD) was declared, originating in th... more On the 8th of May, 2018, an outbreak of Ebola virus disease (EVD) was declared, originating in the Bikoro region of the Democratic Republic of the Congo (DRC) near the border with neighboring Republic of the Congo (ROC). Frequent trade and migration occur between DRC and ROC-based communities residing along the Congo River. In June 2018, a field team was deployed to determine whether Zaire ebolavirus (Ebola virus (EBOV)) was contemporaneously circulating in local bats at the human-animal interface in ROC near the Bikoro EVD outbreak. Samples were collected from bats in the Cuvette and Likouala departments, ROC, bordering the Équateur Province in DRC where the Bikoro EVD outbreak was first detected. EBOV genomic material was not detected in bat-derived samples by targeted quantitative reverse transcription-polymerase chain reaction or by family-level consensus polymerase chain reaction; however, serological data suggests recent exposure to EBOV in bats in the region. We collected ser...