International Journal of Antimicrobial Agents, Jun 1, 2017
In 2006, the Senegalese National Malaria Control Programme recommended artemisinin-based combinat... more In 2006, the Senegalese National Malaria Control Programme recommended artemisinin-based combination therapy as first-line treatment for uncomplicated malaria. In addition, intravenous (i.v.) injection of artesunate and artemether has gradually replaced quinine for the treatment of severe malaria. Mutations in the propeller domain of the Kelch 13 gene (K13-propeller, PF3D71343700), such as Y493H, R539T, I543T and C580Y, were recently associated with in vivo and in vitro resistance to artemisinin in Southeast Asia. However, these mutations were not identified in Africa. In total, 181 isolates of Plasmodium falciparum from 161 patients from Dakar, Senegal, were collected between August 2015 and January 2016. The K13-propeller gene of the isolates was sequenced. A search for non-synonymous mutations in the propeller region of K13 was performed in the 181 isolates collected from Dakar from 2015 to 2016. Three synonymous mutations were detected (D464D, C469C and R471R). Of 119 patients treated with i.v. artesunate or intramuscular artemether followed by artemether/lumefantrine, 9 patients were still parasitaemic on Day 3. Parasites from these nine patients were wild-type for K13-propeller. None of the polymorphisms known to be involved in artemisinin resistance in Asia were detected. These results suggest that K13 is not the best predictive marker for artemisinin resistance in Africa. More isolates from clinical failure cases or patients with delayed parasite clearance after treatment with artemisinin derivatives are necessary to identify new molecular markers.
bioRxiv (Cold Spring Harbor Laboratory), Jul 21, 2022
Molecular characterization of extended-spectrum beta-lactamase-producing extraintestinal pathogen... more Molecular characterization of extended-spectrum beta-lactamase-producing extraintestinal pathogenic Escherichia coli isolated in a university teaching hospital Dakar-Senegal
Objective: The present study aimed to determine the seroprevalence of HBs Ag in HIV-infected pati... more Objective: The present study aimed to determine the seroprevalence of HBs Ag in HIV-infected patients followed at the Maradi CHR. Methods: This is a retrospective study based on the records of the infectious diseases department of the CHR of Maradi. Included were all HIV-positive adults seen in consultation who received HBs Ag research between 2006 and 2018. The data was collected from patients' medical records. Results: In total, 2770 patients included in our study. The average age of the cohort was 38 years old. Of these patients, 159 had HBs Ag or a prevalence of 5.74% (95% CI: 4.93 - 6.67). HIV-HBV coinfections were higher in men (52.20%). HIV1 subtype was involved in 96.86% of cases. Two patients co-infected with HIV-HBV had HIV1 and HIV2 dual profile. Which represents 1.26% (95% CI: 0.15 - 4.47). Conclusion: This study confirms the high prevalence rate of HBV coinfection in HIV-infected patients. It is therefore necessary to screen all HIV-infected patients for better management.
International Journal of Antimicrobial Agents, Dec 1, 2020
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Distributed under a Creative Commons Attribution-NonCommercial| 4.0 International License
Purpose: Bacterial resistance to antibiotics has become a global public health problem. Enterobac... more Purpose: Bacterial resistance to antibiotics has become a global public health problem. Enterobacteriaceae ESBL is among the most incriminated in this emergence which reduces the therapeutic possibilities. Thus, the objective of this study is to determine the prevalence of the extended-spectrum betalactamase (ESBL) producing Enterobacteriaceae at ZNH and their antibiotic susceptibility profile. Materials and Methods: This is a prospective study carried out over 5 months in all hospitalized and non-hospitalized patients in whom a culture was taken for the diagnosis of an infection. The search for ESBL is done by the double disc diffusion method. Results: In total, 21 out of 45 of our strains are ESBL-producing, i.e. a frequency of 46.7%. The mean age is 41.62 (±22.90) with extremes of 2.6-78 years. The distribution of ESBL producing species showed a predominance of E. coli with 66.7% followed by K. pneumoniae and K. oxytoca each 9.5%. All ESBL strains were resistant to Amoxicillin, Cefalotin, Pipiracillin, Piperacillin + tazobactam, Ticarcillin, Ticarcillin + clavulanic acid. Resistance to C3G and Aztreonam was each 95.5%, to Amoxicillin/clavulanic acid 9.1%. All strains were sensitive to imipenem. E. coli strains showed resistance: 85.7% to ciprofloxacin, 50% to Amikacin, 57.1% to Gentamicin.
Microbiology research journal international, Nov 24, 2022
Background: Bacterial vaginosis (BV) is associated with a high risk of complications, particularl... more Background: Bacterial vaginosis (BV) is associated with a high risk of complications, particularly during pregnancy. Objectives: The aims of this study were to determine the prevalence of BV in pregnant women in Dakar, Senegal, and to identify its associated risk factors. Patients and Methods: This prospective cross-sectional study was conducted from July 2020 to March 2021 in pregnant women with 34 to 38 weeks of gestation and seen for their routine prenatal consultation at the Nabil Choucair health center in Dakar, Senegal. Vaginal swabs were taken and examined using the Nugent scoring system for the diagnosis of the BV. Data analysis on SPSS (version 25) was done using the chi-square test to measure the strength of association. A value of p ≤ 0.05 was considered statistically significant. Results: BV was found in 28.0% (112/400) of the screened women with a median age 24 (21-29) years. A pH >4.5 predictive of BV was found in 80.4% (90/112) of samples. BV was associated with vaginal candidiasis in 49.1% (55/112) while Trichomonas vaginitis was found in 1.8% (02/112). In 80.4% (90/112) of affected women, BV was caused by Gardnerella vaginalis. Mobiluncus spp. was found in 19.6% (22/112) pregnant women in association with G. vaginalis. Symptoms characterized by episodes of pruritus, pelvic pain, burning and/or dyspareunia were seen among 59.8% (67/112) of these women with BV while 40.1% (45/112) of them reported no symptoms. Conclusion: In view of these results and in order to reduce gestational complications and adverse outcomes in the newborn, screening for BV in pregnant women should be favored in developing countries.
Investment in Africa over the past year with regards to SARS-CoV-2 genotyping has led to a massiv... more 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.
Purpose: Real-time reverse-transcription polymerase chain reaction (RT-PCR)-based testing remains... more Purpose: Real-time reverse-transcription polymerase chain reaction (RT-PCR)-based testing remains the gold standard for the diagnosis of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Due to the high diagnosis demand of SARS-CoV-2 and the limited resources for RT-PCR testing, especially in Low-Income Countries (LICs), antigen-based methods are being considered as an option. The aim of this study was to assess the performance of LumiraDx SARS-CoV-2 antigen assay for large population screening compared to RT-PCR. Methods: This evaluation was conducted on 4146 participants including travelers and participants under household survey and vaccine evaluation studies before injection of the first dose. Oropharyngeal and nasopharyngeal swaps were collected from each participant into 2 mL of viral transport medium (VTM) and 400 μl of VTM were used to assess the performance of LumiraDx SARS-CoV-2 antigen assay, compared to RT-PCR. Results: The prevalence of SARS-CoV-2 of the...
The clinical utility of quantifying hepatitis B surface antigen (qHBsAg) levels in African subjec... more The clinical utility of quantifying hepatitis B surface antigen (qHBsAg) levels in African subjects with chronic hepatitis B virus (HBV) infection has been poorly documented.From a multicenter cohort of 944 HBV-infected African patients we aimed to assess whether qHBsAg alone can accurately identify i) those in a HBeAg-negative chronic HBV infection phase at low risk of liver
Clinics and Research in Hepatology and Gastroenterology, Mar 1, 2021
BACKGROUND AND AIMS Sub-Saharan Africa (SSA) is the region with the most patients co-infected wit... more BACKGROUND AND AIMS Sub-Saharan Africa (SSA) is the region with the most patients co-infected with the human immunodeficiency virus (HIV) and the hepatitis B virus (HBV) worldwide. However, few studies have focused on SSA children who are at a higher risk of developing a chronic infection than adults. Furthermore, children on first-line antiretroviral therapy (ART) including low genetic barrier drugs may develop both HBV and HIV resistance mutations. The aim of this work was to document HIV-HBV co-infection and to characterize the HBV isolates in children in Senegal. METHODS This is a retrospective study of 613 children infected with HIV on ART or not. Dried blood spot (DBS) specimens were used to detect hepatitis B surface antigen (HBsAg) with a rapid diagnostic test (RDT). Confirmation of HBsAg status and hepatitis B e antigen (HBeAg) detection was performed on an automated platform using the chemiluminescence assay technology. HBV viral DNA was quantified by real-time polymerase chain reaction (PCR) and the preS1/preS2/HBsAg region was genotyped by nested PCR followed by sequencing using the Sanger technique. RESULTS The prevalence of HIV-HBV co-infection was 4.1% (25/613). The median age of co-infected children was 13 years (2 years-16 years) and 40% (10/25) were girls. Almost all 19/20 (95%) were infected with HIV-1 and 79% (19/24) were treated with 3TC-based triple combination ART. The median duration of time on ART was 15 months (3 months-80 months). More than half of the children 53% (9/17) were experiencing HIV virologic failure and 75% (6/8) had at least one HIV-related resistance-associated mutation (RAM). Of the six children with resistance, none of the three administered treatments were effective on HIV. Of the 25 co-infected children, 82% (18/22) were HBeAg-positive, while the median HBV viral load (VL) was 6.20 log10 IU/mL (24/25 patients), and 62,5% (10/16) of the children had a persistent HBV viremia. Combination of ART was the only factor associated with HBV viremia persistence. Amplification was successful in 15 out of 16 patients (rate of 94%), and the ensuing phylogenetic analysis revealed that eight strains (53%) belonged to genotype A and seven (47%) to genotype E. HBV-related 3TC RAMs were uncovered in 20% of these patients (3/15). HBsAg escape mutations were found in 20% of the children (3/15). CONCLUSIONS Our results showed a high level of drug resistance mutations to both HIV and HBV, a significant level of HBsAg escape mutations, HBV DNA persistence and HIV virologic failure in co-infected children in Senegal. The HBV genotypes found were A and E.
Background Bacterial virulence is a key factor determining the outcome of each bacterial infectio... more Background Bacterial virulence is a key factor determining the outcome of each bacterial infection and virulent bacteria are often associated to high-risk infections. Extraintestinal pathogenic Escherichia coli (ExPEC) is the most implicated bacterium in human bacterial infections and its virulence factors are classi ed into ve categories: adhesins, toxins, iron capture systems, protectins and invasins. Furthermore, bacterial bio lms are the main cause of hospital-acquired infections like urinary catheter-associated infections, valve endocarditis, Otitis and cystic brosis. Results For the sixteen virulence genes sought by standard polymerase chain reaction (PCR), all the 78 ExPECs isolates carried at least four virulence genes. Following prevalences of virulence genes were reported: adhesins genes mH (98.7%), mrkD (98.7%), papC (46.2%), afaC (9%), sfa / focDE (1.3%); iron acquisition systems genes entB (98.7%), fepA (98.7%), ybtS (93.6%), fyuA (91%), iucA (91%), iucB (91%), iutA (34.6), iroB (6.4%), iroN (6.4%) and toxins genes hlyA (10.3%), cnf (1 & 2) (10.3%). Seventy-ve out of 78 isolates (96.2%) carried at least the combination of two adhesins genes and two iron capture systems genes whereas 8 out of 78 (10.3%) harbored the combination of (adhesins genes + iron acquisition systems genes + toxins genes). Among the 78 strains studied, one hospital-acquired strain isolated from urine harbored 15 virulence genes out of 16 sought. The evaluation of bio lm-formation capacity revealed that all (29/29) hospital-acquired isolates were bio lm producers with (6/29; 20.7%) strong bio lm producers, (15/29; 51.7%) moderate bio lm producers and (8/29; 27.6%) weak bio lm producers. Isolates carrying papC had greater bio lm formation capacity than those not carrying papC (p < 0.001). Conclusions Most of our strains had moderate bio lm-formation capacity and carried an average of 9 virulence genes out of 16 sought. These eight strains carrying a combination of genes (adhesins + iron acquisition systems genes + toxins genes) may be hypervirulent isolates. Additional studies may con rm this. The deepening of this kind of study on bacterial virulence and hospital bacterial bio lms could lead to the improvement of infections investigation, prevention and therapeutic protocols.
Background Hepatitis B virus (HBV) infection is a major global health problem. In Chad, the preva... more Background Hepatitis B virus (HBV) infection is a major global health problem. In Chad, the prevalence is estimated at 19% in the overall population. Control hepatitis B among pregnant women may help to break the chain of transmission. However, the prevalence and risk factors of hepatitis B among pregnant women in N'Djamena are not documented. The aim of this study was to establish the HBV prevalence and identify the risk factors associated with hepatitis B in pregnant women in N'Djamena. Methods We conducted a cross-sectional study in eight health facilities in the city of N'Djamena (Chad) from April 4 to August 2, 2021. HBV surface antigen was determined using the SD Bioline HBsAg WB rapid test. We performed a Chi-squared test and an adjusted logistic regression to identify risk factors associated with hepatitis B infection. Results A total of 458 pregnant women were included in the study. The average age of participants was 25 years (95% CI: 20-30). Among risk factors, being older (age > 35 years) and having been tested for HBsAg increase the likelihood of being HBsAg+ (OR = 1.22, 95% CI: 0.33-3.92, p = 0.001, and OR = 4.93, 95% CI: 2.05-12.0, p < 0.001).). Pregnant women whose mothers were AgHBs + were also more likely to be HBsAg+ (OR = 27.8; 95% CI: 4.17-192; P = 0.004). Conclusion The prevalence of hepatitis B shows intermediate endemicity in pregnant women in Chad. Age, HBsAg carrier mother, and history of HBsAg screening are associated with HBV infection.). Thus, to avoid mother to child transmission of HBV, here is a need to improve the health education of pregnant women and the access to routine prenatal screening and vaccination of newborns at birth. It is also important to increase the immunization coverage of the population, through children vaccination campaigns.
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: The emergence and spread of carbapenem-resistant Acinetobacter baumannii are critical... more Background: The emergence and spread of carbapenem-resistant Acinetobacter baumannii are critical in hospitals, particularly in intensive care units (ICUs), which represents a public health concern worldwide. In this study, we investigated the molecular epidemiology of multi-drug resistant A. baumannii (MDR-AB) in Dakar, Senegal. Methods. The A. baumannii was isolated from Eosin Methylene Blue Agar culture and identified using API 20NE strip test and MALDI-TOF. The antimicrobial susceptibility testing was performed using the disk diffusion method. Simplex and multiplex-polymerase chain reactions with appropriate primers were used to detect and sequence the following β-lactamase genes: Two class D carbapenem hydrolyzing oxacillinases (bla OXA-51 and bla OXA-23), three class B metallo-β-lactamase genes (bla IMP , bla VIM and bla NDM), and five class A β-lactamase genes (bla PER , bla SHV , bla VEB , bla TEM , and bla GES).
International Journal of Antimicrobial Agents, Jun 1, 2017
In 2006, the Senegalese National Malaria Control Programme recommended artemisinin-based combinat... more In 2006, the Senegalese National Malaria Control Programme recommended artemisinin-based combination therapy as first-line treatment for uncomplicated malaria. In addition, intravenous (i.v.) injection of artesunate and artemether has gradually replaced quinine for the treatment of severe malaria. Mutations in the propeller domain of the Kelch 13 gene (K13-propeller, PF3D71343700), such as Y493H, R539T, I543T and C580Y, were recently associated with in vivo and in vitro resistance to artemisinin in Southeast Asia. However, these mutations were not identified in Africa. In total, 181 isolates of Plasmodium falciparum from 161 patients from Dakar, Senegal, were collected between August 2015 and January 2016. The K13-propeller gene of the isolates was sequenced. A search for non-synonymous mutations in the propeller region of K13 was performed in the 181 isolates collected from Dakar from 2015 to 2016. Three synonymous mutations were detected (D464D, C469C and R471R). Of 119 patients treated with i.v. artesunate or intramuscular artemether followed by artemether/lumefantrine, 9 patients were still parasitaemic on Day 3. Parasites from these nine patients were wild-type for K13-propeller. None of the polymorphisms known to be involved in artemisinin resistance in Asia were detected. These results suggest that K13 is not the best predictive marker for artemisinin resistance in Africa. More isolates from clinical failure cases or patients with delayed parasite clearance after treatment with artemisinin derivatives are necessary to identify new molecular markers.
bioRxiv (Cold Spring Harbor Laboratory), Jul 21, 2022
Molecular characterization of extended-spectrum beta-lactamase-producing extraintestinal pathogen... more Molecular characterization of extended-spectrum beta-lactamase-producing extraintestinal pathogenic Escherichia coli isolated in a university teaching hospital Dakar-Senegal
Objective: The present study aimed to determine the seroprevalence of HBs Ag in HIV-infected pati... more Objective: The present study aimed to determine the seroprevalence of HBs Ag in HIV-infected patients followed at the Maradi CHR. Methods: This is a retrospective study based on the records of the infectious diseases department of the CHR of Maradi. Included were all HIV-positive adults seen in consultation who received HBs Ag research between 2006 and 2018. The data was collected from patients' medical records. Results: In total, 2770 patients included in our study. The average age of the cohort was 38 years old. Of these patients, 159 had HBs Ag or a prevalence of 5.74% (95% CI: 4.93 - 6.67). HIV-HBV coinfections were higher in men (52.20%). HIV1 subtype was involved in 96.86% of cases. Two patients co-infected with HIV-HBV had HIV1 and HIV2 dual profile. Which represents 1.26% (95% CI: 0.15 - 4.47). Conclusion: This study confirms the high prevalence rate of HBV coinfection in HIV-infected patients. It is therefore necessary to screen all HIV-infected patients for better management.
International Journal of Antimicrobial Agents, Dec 1, 2020
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Distributed under a Creative Commons Attribution-NonCommercial| 4.0 International License
Purpose: Bacterial resistance to antibiotics has become a global public health problem. Enterobac... more Purpose: Bacterial resistance to antibiotics has become a global public health problem. Enterobacteriaceae ESBL is among the most incriminated in this emergence which reduces the therapeutic possibilities. Thus, the objective of this study is to determine the prevalence of the extended-spectrum betalactamase (ESBL) producing Enterobacteriaceae at ZNH and their antibiotic susceptibility profile. Materials and Methods: This is a prospective study carried out over 5 months in all hospitalized and non-hospitalized patients in whom a culture was taken for the diagnosis of an infection. The search for ESBL is done by the double disc diffusion method. Results: In total, 21 out of 45 of our strains are ESBL-producing, i.e. a frequency of 46.7%. The mean age is 41.62 (±22.90) with extremes of 2.6-78 years. The distribution of ESBL producing species showed a predominance of E. coli with 66.7% followed by K. pneumoniae and K. oxytoca each 9.5%. All ESBL strains were resistant to Amoxicillin, Cefalotin, Pipiracillin, Piperacillin + tazobactam, Ticarcillin, Ticarcillin + clavulanic acid. Resistance to C3G and Aztreonam was each 95.5%, to Amoxicillin/clavulanic acid 9.1%. All strains were sensitive to imipenem. E. coli strains showed resistance: 85.7% to ciprofloxacin, 50% to Amikacin, 57.1% to Gentamicin.
Microbiology research journal international, Nov 24, 2022
Background: Bacterial vaginosis (BV) is associated with a high risk of complications, particularl... more Background: Bacterial vaginosis (BV) is associated with a high risk of complications, particularly during pregnancy. Objectives: The aims of this study were to determine the prevalence of BV in pregnant women in Dakar, Senegal, and to identify its associated risk factors. Patients and Methods: This prospective cross-sectional study was conducted from July 2020 to March 2021 in pregnant women with 34 to 38 weeks of gestation and seen for their routine prenatal consultation at the Nabil Choucair health center in Dakar, Senegal. Vaginal swabs were taken and examined using the Nugent scoring system for the diagnosis of the BV. Data analysis on SPSS (version 25) was done using the chi-square test to measure the strength of association. A value of p ≤ 0.05 was considered statistically significant. Results: BV was found in 28.0% (112/400) of the screened women with a median age 24 (21-29) years. A pH >4.5 predictive of BV was found in 80.4% (90/112) of samples. BV was associated with vaginal candidiasis in 49.1% (55/112) while Trichomonas vaginitis was found in 1.8% (02/112). In 80.4% (90/112) of affected women, BV was caused by Gardnerella vaginalis. Mobiluncus spp. was found in 19.6% (22/112) pregnant women in association with G. vaginalis. Symptoms characterized by episodes of pruritus, pelvic pain, burning and/or dyspareunia were seen among 59.8% (67/112) of these women with BV while 40.1% (45/112) of them reported no symptoms. Conclusion: In view of these results and in order to reduce gestational complications and adverse outcomes in the newborn, screening for BV in pregnant women should be favored in developing countries.
Investment in Africa over the past year with regards to SARS-CoV-2 genotyping has led to a massiv... more 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.
Purpose: Real-time reverse-transcription polymerase chain reaction (RT-PCR)-based testing remains... more Purpose: Real-time reverse-transcription polymerase chain reaction (RT-PCR)-based testing remains the gold standard for the diagnosis of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Due to the high diagnosis demand of SARS-CoV-2 and the limited resources for RT-PCR testing, especially in Low-Income Countries (LICs), antigen-based methods are being considered as an option. The aim of this study was to assess the performance of LumiraDx SARS-CoV-2 antigen assay for large population screening compared to RT-PCR. Methods: This evaluation was conducted on 4146 participants including travelers and participants under household survey and vaccine evaluation studies before injection of the first dose. Oropharyngeal and nasopharyngeal swaps were collected from each participant into 2 mL of viral transport medium (VTM) and 400 μl of VTM were used to assess the performance of LumiraDx SARS-CoV-2 antigen assay, compared to RT-PCR. Results: The prevalence of SARS-CoV-2 of the...
The clinical utility of quantifying hepatitis B surface antigen (qHBsAg) levels in African subjec... more The clinical utility of quantifying hepatitis B surface antigen (qHBsAg) levels in African subjects with chronic hepatitis B virus (HBV) infection has been poorly documented.From a multicenter cohort of 944 HBV-infected African patients we aimed to assess whether qHBsAg alone can accurately identify i) those in a HBeAg-negative chronic HBV infection phase at low risk of liver
Clinics and Research in Hepatology and Gastroenterology, Mar 1, 2021
BACKGROUND AND AIMS Sub-Saharan Africa (SSA) is the region with the most patients co-infected wit... more BACKGROUND AND AIMS Sub-Saharan Africa (SSA) is the region with the most patients co-infected with the human immunodeficiency virus (HIV) and the hepatitis B virus (HBV) worldwide. However, few studies have focused on SSA children who are at a higher risk of developing a chronic infection than adults. Furthermore, children on first-line antiretroviral therapy (ART) including low genetic barrier drugs may develop both HBV and HIV resistance mutations. The aim of this work was to document HIV-HBV co-infection and to characterize the HBV isolates in children in Senegal. METHODS This is a retrospective study of 613 children infected with HIV on ART or not. Dried blood spot (DBS) specimens were used to detect hepatitis B surface antigen (HBsAg) with a rapid diagnostic test (RDT). Confirmation of HBsAg status and hepatitis B e antigen (HBeAg) detection was performed on an automated platform using the chemiluminescence assay technology. HBV viral DNA was quantified by real-time polymerase chain reaction (PCR) and the preS1/preS2/HBsAg region was genotyped by nested PCR followed by sequencing using the Sanger technique. RESULTS The prevalence of HIV-HBV co-infection was 4.1% (25/613). The median age of co-infected children was 13 years (2 years-16 years) and 40% (10/25) were girls. Almost all 19/20 (95%) were infected with HIV-1 and 79% (19/24) were treated with 3TC-based triple combination ART. The median duration of time on ART was 15 months (3 months-80 months). More than half of the children 53% (9/17) were experiencing HIV virologic failure and 75% (6/8) had at least one HIV-related resistance-associated mutation (RAM). Of the six children with resistance, none of the three administered treatments were effective on HIV. Of the 25 co-infected children, 82% (18/22) were HBeAg-positive, while the median HBV viral load (VL) was 6.20 log10 IU/mL (24/25 patients), and 62,5% (10/16) of the children had a persistent HBV viremia. Combination of ART was the only factor associated with HBV viremia persistence. Amplification was successful in 15 out of 16 patients (rate of 94%), and the ensuing phylogenetic analysis revealed that eight strains (53%) belonged to genotype A and seven (47%) to genotype E. HBV-related 3TC RAMs were uncovered in 20% of these patients (3/15). HBsAg escape mutations were found in 20% of the children (3/15). CONCLUSIONS Our results showed a high level of drug resistance mutations to both HIV and HBV, a significant level of HBsAg escape mutations, HBV DNA persistence and HIV virologic failure in co-infected children in Senegal. The HBV genotypes found were A and E.
Background Bacterial virulence is a key factor determining the outcome of each bacterial infectio... more Background Bacterial virulence is a key factor determining the outcome of each bacterial infection and virulent bacteria are often associated to high-risk infections. Extraintestinal pathogenic Escherichia coli (ExPEC) is the most implicated bacterium in human bacterial infections and its virulence factors are classi ed into ve categories: adhesins, toxins, iron capture systems, protectins and invasins. Furthermore, bacterial bio lms are the main cause of hospital-acquired infections like urinary catheter-associated infections, valve endocarditis, Otitis and cystic brosis. Results For the sixteen virulence genes sought by standard polymerase chain reaction (PCR), all the 78 ExPECs isolates carried at least four virulence genes. Following prevalences of virulence genes were reported: adhesins genes mH (98.7%), mrkD (98.7%), papC (46.2%), afaC (9%), sfa / focDE (1.3%); iron acquisition systems genes entB (98.7%), fepA (98.7%), ybtS (93.6%), fyuA (91%), iucA (91%), iucB (91%), iutA (34.6), iroB (6.4%), iroN (6.4%) and toxins genes hlyA (10.3%), cnf (1 & 2) (10.3%). Seventy-ve out of 78 isolates (96.2%) carried at least the combination of two adhesins genes and two iron capture systems genes whereas 8 out of 78 (10.3%) harbored the combination of (adhesins genes + iron acquisition systems genes + toxins genes). Among the 78 strains studied, one hospital-acquired strain isolated from urine harbored 15 virulence genes out of 16 sought. The evaluation of bio lm-formation capacity revealed that all (29/29) hospital-acquired isolates were bio lm producers with (6/29; 20.7%) strong bio lm producers, (15/29; 51.7%) moderate bio lm producers and (8/29; 27.6%) weak bio lm producers. Isolates carrying papC had greater bio lm formation capacity than those not carrying papC (p < 0.001). Conclusions Most of our strains had moderate bio lm-formation capacity and carried an average of 9 virulence genes out of 16 sought. These eight strains carrying a combination of genes (adhesins + iron acquisition systems genes + toxins genes) may be hypervirulent isolates. Additional studies may con rm this. The deepening of this kind of study on bacterial virulence and hospital bacterial bio lms could lead to the improvement of infections investigation, prevention and therapeutic protocols.
Background Hepatitis B virus (HBV) infection is a major global health problem. In Chad, the preva... more Background Hepatitis B virus (HBV) infection is a major global health problem. In Chad, the prevalence is estimated at 19% in the overall population. Control hepatitis B among pregnant women may help to break the chain of transmission. However, the prevalence and risk factors of hepatitis B among pregnant women in N'Djamena are not documented. The aim of this study was to establish the HBV prevalence and identify the risk factors associated with hepatitis B in pregnant women in N'Djamena. Methods We conducted a cross-sectional study in eight health facilities in the city of N'Djamena (Chad) from April 4 to August 2, 2021. HBV surface antigen was determined using the SD Bioline HBsAg WB rapid test. We performed a Chi-squared test and an adjusted logistic regression to identify risk factors associated with hepatitis B infection. Results A total of 458 pregnant women were included in the study. The average age of participants was 25 years (95% CI: 20-30). Among risk factors, being older (age > 35 years) and having been tested for HBsAg increase the likelihood of being HBsAg+ (OR = 1.22, 95% CI: 0.33-3.92, p = 0.001, and OR = 4.93, 95% CI: 2.05-12.0, p < 0.001).). Pregnant women whose mothers were AgHBs + were also more likely to be HBsAg+ (OR = 27.8; 95% CI: 4.17-192; P = 0.004). Conclusion The prevalence of hepatitis B shows intermediate endemicity in pregnant women in Chad. Age, HBsAg carrier mother, and history of HBsAg screening are associated with HBV infection.). Thus, to avoid mother to child transmission of HBV, here is a need to improve the health education of pregnant women and the access to routine prenatal screening and vaccination of newborns at birth. It is also important to increase the immunization coverage of the population, through children vaccination campaigns.
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: The emergence and spread of carbapenem-resistant Acinetobacter baumannii are critical... more Background: The emergence and spread of carbapenem-resistant Acinetobacter baumannii are critical in hospitals, particularly in intensive care units (ICUs), which represents a public health concern worldwide. In this study, we investigated the molecular epidemiology of multi-drug resistant A. baumannii (MDR-AB) in Dakar, Senegal. Methods. The A. baumannii was isolated from Eosin Methylene Blue Agar culture and identified using API 20NE strip test and MALDI-TOF. The antimicrobial susceptibility testing was performed using the disk diffusion method. Simplex and multiplex-polymerase chain reactions with appropriate primers were used to detect and sequence the following β-lactamase genes: Two class D carbapenem hydrolyzing oxacillinases (bla OXA-51 and bla OXA-23), three class B metallo-β-lactamase genes (bla IMP , bla VIM and bla NDM), and five class A β-lactamase genes (bla PER , bla SHV , bla VEB , bla TEM , and bla GES).
Uploads
Papers by Gora Lo