Clinical utility of quantifying hepatitis B surface antigen in African patients with chronic hepatitis B.

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 multicentre 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 disease progression and ii) those in need of antiviral therapy according to the 2017 EASL guidelines. We analysed 770 HBV mono-infected treatment-naïve patients, mainly males (61%) from West Africa (92%), median age 35 years (IQR: 30-44), median HBV DNA: 95.6 IU/ml (10.0-1,300.0), median qHBsAg 5,498 IU/ml (1,171-13,000) and HBeAg-pos 38 (5%). A total of 464/770 (60.2%) patients were classified as HBeAg-negative chronic infection (median age 36 years (31-46), median ALT 23 IU/l (18-28), median HBV-DNA 33.5 IU/ml (3.8-154.1), median LSM 4.8 kPa (4.1-5.8)) and qHBsAg levels had poor accuracy to identify these subjects with an AUROC at 0.58 (95%CI: 0.54-0.62), sensitivity 55.0% and specificity 55.6%; 118/770 (15.3%) patients were eligible for treatment according to the 2017 EASL criteria. qHBsAg correlated poorly with HBV DNA and had poor accuracy to select patients for antiviral therapy with an AUROC at 0.54 (0.49-0.60), sensitivity 46.6% and specificity 46.9%. In African treatment-naïve HBV-infected subjects, the clinical utility of qHBsAg to identify subjects in HBeAg-negative infection phase or subjects eligible for antiviral therapy seems futile. Whether qHBsAg levels can be used as a predictor of long-term liver complications in Africa needs to be further investigated.

Sibling status, home birth, tattoos and stitches are risk factors for chronic hepatitis B virus infection in Senegalese children: A cross-sectional survey.

Sub-Saharan Africa's hepatitis B virus (HBV) burden is primarily due to infection in infancy. However, data on chronic HBV infection prevalence and associated risk factors in children born post-HBV vaccination introduction are scarce. We estimated hepatitis B surface antigen (HBsAg) prevalence and risk factors in Senegalese children born during the HBV vaccination era. In 2018-2019, a community-based cross-sectional survey was conducted in Senegal among children born between 2004 and 2015 (ie after the three-dose HBV vaccine series was introduced (2004) but before the birth dose's introduction (2016)). HBsAg-positive children were identified using dried blood spots. A standardized questionnaire collected socioeconomic information. Data were age-sex weighted and calibrated to be representative of children living in the study area. Risk factors associated with HBsAg positivity were identified using negative binomial regression. Among 1,327 children, 17 were HBsAg-positive (prevalence = 1.23% (95% confidence interval [CI] 0.61-1.85)). Older age (adjusted incidence-rate ratio [aIRR] 1.31 per one-year increase, 95% CI 1.10-1.57), home vs healthcare facility delivery (aIRR 3.55, 95% CI 1.39-9.02), stitches (lifetime) (aIRR 4.79; 95% CI 1.84-12.39), tattoos (aIRR 8.97, 95% CI 1.01-79.11) and having an HBsAg-positive sibling with the same mother (aIRR 3.05, 95% CI 1.09-8.57) were all independently associated with HBsAg positivity. The low HBsAg prevalence highlights the success of the Senegalese HBV vaccination program. To further reduce HBV acquisition in children, high-risk groups, including pregnant women and siblings of HBsAg-positive individuals, must be screened. Vital HBV infection prevention measures include promoting delivery in healthcare facilities, and increasing awareness of prevention and control procedures.

Respective prevalence of high-risk HPVgenotypes in cervical neoplasia in Senegal.

OBJECTIVES: With the perspective of prophylactic vaccination against high-risk human papillomavirus (HPV), we analyzed the viral epidemiology of cervical neoplasia in Senegal. METHODS: All patients were treated at the Institut Joliot Curie du Cancer in Dakar. HPV genotypes were characterized using a real-time polymerase chain reaction-based approach and sequencing. RESULTS: Histologically, there were 224 invasive carcinomas, 17 high-grade intraepithelial neoplasia (CIN), and five undetermined histologies. Molecular analysis was conclusive in 241 cases. HPV DNA was found in 207/241 (85.9%) cases while 34/241 (14.1%) remained HPV negative. There was one single genotype in 127/207 (61.4%) cases and several in 80/207 (38.6%) corresponding to 308 genotypes identified. Viral genotyping found HPV16 in 175 (56.8%) cases, HPV18 in 45 (14.6%), HPV45 in 40 (13.0%), HPV58 in 35 (11.4%), HPV33 in 6 (2.0%), HPV35 in 3 (1.0%), HPV31 in 2 (0.6%), HPV39 and HPV56 in one (0.3% each). CONCLUSION: Our analysis showed that 98.4% of the HPV-positive cases were associated with viral genotypes covered by the 9-valent HPV vaccine. However, 14.1% of cases remained HPV negative. Therefore, prophylactic vaccination using a 9-valent vaccine should dramatically reduce the incidence of HPV-associated neoplasia but the detection and treatment of CIN remain necessary for the optimal prevention of cervical cancer.

Contribution of the classical polymerase chain reaction in the diagnosis of a HIV-1 infected patient in Benin: a case report.

BACKGROUND: First ambitious target by 2020 of UNAIDS is that 90% of people living with HIV know their HIV status. In people older than 18 months of age, serological confirmation test is recommended to confirm HIV infection. CASE PRESENTATION: Here we report the case of a patient tested positive with HIV-1, ELISA, Murex® Ag/Ab Combination assay (OD450 = 0.802 and cutoff-OD = 0.279) and negative by using FIRST RESPONSE HIV1-2.O CARD TEST (version 2.0) RAPID HIV CARD TEST. Viral load performed with Cobas® TaqMan® 96/Cobas® Ampliprep® was 6.49log10. The virus could be sequenced in partial gag and pol genes and belonged to CRF02_AG clade. CONCLUSION: Conventional PCR is a complementary method for the diagnosis of inconclusive HIV-1 serologies by antibodies.

Associations Between Economic Factors and Condom Use Behavior Among Female Sex Workers in Dakar and Mbour, Senegal.

Condom use remains a mainstay of HIV prevention programs around the world. However, data characterizing economic determinants of condom use among female sex workers (FSW) are limited, including in Senegal. We recruited 718 FSWs via respondent-driven sampling. Bivariate and multivariable regressions were conducted to assess the associations between economic variables and condom use at last sex. Paying rent (aRR: 1.07, 95%CI 1.01-1.13) was positively associated with condom use at last sex with new clients. No statistically significant associations were found between condom use and financial responsibility for dependent children, having additional source of income, sharing sex work earnings, or the ability to borrow from other FSWs, regardless of sexual partner types. The relationship between economic marginalization and consistent condom use among sex workers is complex reinforcing the need for behavioral economic research and prevention to be integrated into HIV prevention and treatment research and programs.

Use and Acceptability of HIV Self-Testing Among First-Time Testers at Risk for HIV in Senegal.

HIV Self-Testing (HIVST) aims to increase HIV testing coverage and can facilitate reaching the UNAIDS 90-90-90 targets. In Senegal, key populations bear a disproportionate burden of HIV and report limited uptake of HIV testing given pervasive stigma and criminalization. In these contexts, HIVST may represent a complementary approach to reach populations reporting barriers to engagement with existing and routine HIV testing services. In this study, 1839 HIVST kits were distributed in Senegal, with 1149 individuals participating in a pre-test questionnaire and 817 participating in a post-test questionnaire. Overall, 46.9% (536/1144) were first-time testers and 26.2% (300/1144) had tested within the last year; 94.3% (768/814) reported using the HIVST, and 2.9% (19/651) reported a reactive result which was associated with first-time testers (p = 0.024). HIVST represents an approach that reached first-time testers and those who had not tested recently. Implementation indicators suggest the importance of leveraging existing community structures and programs for distribution.

High level of treatment failure and drug resistance to first-line antiretroviral therapies among HIV-infected children receiving decentralized care in Senegal.

BACKGROUND: In Senegal in 2015, an estimated 4800 children were living with HIV, with 1200 receiving ARV treatment, of whom half had follow-up care in decentralized sites outside Dakar. However, until now no studies have determined the efficacy of pediatric treatment in decentralized settings, even though the emergence of viral resistance, particularly among children in Africa, is a well-known phenomenon. This study aimed to assess the virological status of HIV-infected children in all decentralized facilities to help improve access to quality care. METHODS: A cross-sectional epidemiological and virological study was conducted in all of Senegal's regions, except Dakar, between March and June 2015 and sought to include all HIV-infected children and adolescents (0-19 years), treated or not with ARVs. Socio-demographic and clinical data and a blood sample on blotting paper were collected for children from treatment sites. Samples were routed on public transportation, assisted by a network of community health workers. A viral load (VL) assay was performed for each child, followed by genotyping when it exceeded 1000 copies/mL (3 log10). RESULTS: Of the 851 identified children, 666 (78%) were enrolled in the study. Half of the children were girls, and the average age was 8 years (6 months-19 years). Most of the children (96.7%) were infected with HIV-1, and 90% were treated with ART, primarily with AZT + 3TC + NVP/EFV therapeutic regimen. The median duration of time on ART was 21 months (1-129). VL was measured for 2% of children before this study. Almost two-thirds (64%) of the children are experiencing virological failure. Among them, there was resistance to at least one drug for 86.5% of cases. Also, 25% children presented resistance to one drug and 40% to two out of three. For nearly one-third of the children presenting resistance, none of the three drugs of the treatment was active. Factors associated with virological failure were male sex, follow-up by a generalist rather than a specialist, and treatment interruptions. CONCLUSIONS: We observed a high level of virological failure and a high percentage of viral resistance among children receiving health care in decentralized facilities in Senegal.

Evaluation of Senegal's prevention of mother to child transmission of HIV (PMTCT) program data for HIV surveillance.

BACKGROUND: With the expansion of Prevention of Mother to Child Transmission (PMTCT) services in Senegal, there is growing interest in using PMTCT program data in lieu of conducting unlinked anonymous testing (UAT)-based ANC Sentinel Surveillance. For this reason, an evaluation was conducted in 2011-2012 to identify the gaps that need to be addressed while transitioning to using PMTCT program data for surveillance. METHODS: We conducted analyses to assess HIV prevalence rates and agreements between Sentinel Surveillance and PMTCT HIV test results. Also, a data quality assessment of the PMTCT program registers and data was conducted during the Sentinel Surveillance period (December 2011 to March 2012) and 3 months prior. Finally, we also assessed selection bias, which was the percentage difference from the HIV prevalence among all women enrolled in the antenatal clinic and the HIV prevalence among women who accepted PMTCT HIV testing. RESULTS: The median site HIV prevalence using routine PMTCT HIV testing data was 1.1% (IQR: 1.0) while the median site prevalence from the UAT HIV Sentinel Surveillance data was at 1.0% (IQR: 1.6). The Positive per cent agreement (PPA) of the PMTCT HIV test results compared to those of the Sentinel Surveillance was 85.1% (95% CI 77.2-90.7%), and the percent-negative agreement (PNA) was 99.9% (95% CI 99.8-99.9%). The overall HIV prevalence according to UAT was the same as that found for women accepting a PMTCT HIV test and those who refused, with percent bias at 0.00%. For several key PMTCT variables, including "HIV test offered" (85.2%), "HIV test acceptance" (78.0%), or "HIV test done" (58.8%), the proportion of records in registers with combined complete and valid data was below the WHO benchmark of 90%. CONCLUSIONS: The PPA of 85.1 was below the WHO benchmarks of 96.6%, while the combined data validity and completeness rates was below the WHO benchmark of 90% for many key PMTCT variables. These results suggested that Senegal will need to reinforce the quality of onsite HIV testing and improve program data collection practices in preparation for using PMTCT data for surveillance purposes.

Desulfovibrio senegalensis sp. nov., a mesophilic sulfate reducer isolated from marine sediment.

Several strains of sulfate-reducing bacteria were isolated from marine sediments recovered from Hann Bay (Senegal). All were related to members of the genus Desulfovibrio. A strictly anaerobic, mesophilic and moderately halophilic strain designated BLaC1T was further characterized. Cells of strain BLaC1T stained Gram-negative and were 0.5 µm wide and 2-4 µm long, motile, rod-shaped and non-spore-forming. The four major fatty acids were anteiso-C15 : 0, iso-C15 : 0, iso-C17 : 0 and anteiso-C17 : 0. Growth was observed from 15 to 45 °C (optimum 40 °C) and at pH 5.5-8 (optimum pH 7.5). The salinity range for growth was 5-65 g NaCl l-1 (optimum 30 g l-1). Yeast extract was required for growth. Strain BLaC1T was able to grow on lactate and acetate in the presence of sulfate as an electron acceptor. Sulfate, thiosulfate and sulfite could serve as terminal electron acceptors, but not fumarate, nitrate or elemental sulfur. The DNA G+C content was 55.8 mol%. 16S rRNA gene sequence analysis assigned strain BLaC1T to the family Desulfovibrionaceae; its closest relative was Desulfovibrio oxyclinae DSM 19275T (93.7 % similarity). On the basis of 16S rRNA gene sequence comparisons and physiological characteristics, strain BLaC1T is proposed as representing a novel species of Desulfovibrio, with the name Desulfovibrio senegalensis sp. nov. The type strain is BLaC1T (=DSM 101509T=JCM 31063T).

HBV carriage in children born from HIV-seropositive mothers in Senegal: The need of birth-dose HBV vaccination.

Hepatitis B is a major public health problem in Senegal, a country with high prevalence and a transmission occurring mainly during infancy. Only, one 6-8 weeks vaccination campaign was initiated in 2005 and it was part of the expanded program of immunization. The aim of this study was to determine the prevalence of HBsAg in children born from HIV-seropositive mothers by using dried blood specimens. Specimens were collected between July 2007 and November 2012 from children aged 2-48 weeks in Dakar and decentralized sites working on HIV mother-to-child transmission prevention. HBsAg detection was performed using Architect HBsAg Qualitative II kit (Abbott Diagnostics, Ireland) and for all reactive samples confirmation was done using Architect HBsAg Qualitative II Confirmatory kit (Abbott Diagnostics, Ireland). Nine hundred thirty samples were collected throughout the country with 66% out of Dakar, the capital city. The median age was 20 weeks and 88% of children were less than 1 year of age with a sex ratio of 1.27 in favor of boys. HBsAg was detected in 28 cases giving a global prevalence of 3%. According to age, HBsAg prevalences were 5.1% for children less than 6 weeks, 4.1% and 4.6%, respectively, for those aged 12-18 weeks and 18-24 weeks of age. The HIV prevalence was 2.6% with no HIV/HBV co-infection. This study showed a high rate of HBV infection in children under 24 months, highlighting the need to promote birth-dose HBV vaccination as recommended by WHO.

Prevalence of hepatitis B markers in Senegalese HIV-1-infected patients.

The study aimed to estimate the prevalence of Hepatitis B virus (HBV) infection and to describe the HBV virological profiles among Senegalese HIV-1-infected patients. We conducted a retrospective study between 2006 and 2010 among Senegalese HIV-1-infected patients from the antiretroviral therapy cohort. Samples were screened using Determine(®) HBsAg or MONOLISA(®) POC test. The HBsAg positivity status was confirmed by Architect(®) HBsAg. Detection of HBeAg, anti-HBe Ab, and HBV DNA load were done for the HBsAg-positive samples. Then, Anti-HBcAb was tested for the HBsAg-negative samples. Microsoft Excel was used for data collection and statistical analyses were performed using Epi info 3.5.1. Overall, 466 HIV-infected patients were enrolled including 271 women (58.4%), and 193 men (41.6%) with a median age of 39 years (19-74 years). The global prevalence of HIV/HBV coinfection (HBsAg positive) was 8.8% (41/466). For HBsAg positives samples, the prevalence of HBeAg and the anti-HBeAb were, respectively, 24.4 and 69.2% and the median of HBV DNA viral load, for 27 HBsAg-positive samples, was 3.75 log10 copies/ml. The virological profiles were the following: 7, 15, and 5 patients infected, respectively, by a replicative virus, an inactive virus and a probably mutant virus. For HBsAg-negative samples, 83 out of 109 were positive for anti-HBcAb. This study showed a significant decrease of the prevalence of HBV/HIV coinfection between 2004 and 2014 (P = 0.003), which highlighted the performance of the Senegalese HBV vaccine program. However, implementing a systematic quantification of HBV DNA viral load could improve the monitoring of HBV-infected patient.

Validation of rapid point-of-care (POC) tests for detection of hepatitis B surface antigen in field and laboratory settings in the Gambia, Western Africa.

Hepatitis B virus (HBV) infection is a leading cause of death in sub-Saharan Africa (SSA). Point-of-care tests for hepatitis B surface antigen (HBsAg) could be an ideal tool for a large-scale HBV screening/treatment program in SSA. Using data from the PROLIFICA (Prevention of Liver Fibrosis and Cancer in Africa) program, we conducted a cross-sectional study to assess the diagnostic accuracy of three point-of-care tests (Determine, Vikia, and Espline) for the detection of HBsAg in the field or a laboratory setting in the Gambia. In the field, we used finger-prick whole blood for the Determine and Vikia tests and dried blood spots for the reference standard test (AxSYM HBsAg enzyme-linked immunosorbent assay [ELISA]). In the laboratory we used serum for the Determine, Espline, and reference test (Architect chemiluminescent microparticle immunoassay). Of 773 participants recruited at the community and 227 known chronic HBV carriers (1,000 subjects in total), 293 were positive for HBsAg. The sensitivity and specificity of the Determine test were 88.5% and 100% in the field and 95.3% and 93.3% in the laboratory setting, respectively. The sensitivity and specificity were 90.0% and 99.8% for the Vikia test (in the field) and 93.9% and 94.7% for the Espline test (in the laboratory). There was no evidence that one kit was better than another. Most of the patients with false-negative results (18/19) were classified as inactive chronic carriers. In summary, the three point-of-care tests had acceptable ranges of diagnostic accuracy. These tests may represent accurate, rapid, and inexpensive alternatives to serology testing for the screening of HBV infection at field level in SSA.

Extraordinary heterogeneity of virological outcomes in patients receiving highly antiretroviral therapy and monitored with the World Health Organization public health approach in sub-saharan Africa and southeast Asia.

BACKGROUND: The limited access to virological monitoring in developing countries is a major weakness of the current antiretroviral treatment (ART) strategy in these settings. We conducted a large cross-sectional study in Burkina Faso, Cameroon, Cote d'Ivoire, Senegal, Togo, Thailand, and Vietnam to assess virological failure and drug resistance mutations (DRMs) after 12 or 24 months of ART. METHODS: Between 2009 and 2011, we recruited adults attending ART centers 10-14 months (the M12 group) or 22-26 months (M24 group) after initiating ART. Demographic and clinical data were collected on site, and viral load was measured. Samples with a viral load of ≥ 1000 copies/mL, considered as the failure threshold, were genotyped for drug resistance assessment. RESULTS: Overall, 3935 patients were recruited (2060 at M12 and 1875 at M24). Median ages varied from 32 to 42 years. Median CD4(+) T-cell counts at ART initiation were low (99-172 cells/µL). The main ART regimens included stavudine/zidovudine plus lamivudine plus nevirapine/efavirenz. Overall, virological failure frequency was 11.1% for M12 patients and 12.4% for M24 patients, and 71.0% to 86.1% of these patients, respectively, had drug-resistant virus. Across sites, virological failure varied from 2.9% to 20.6% in M12 patients and from 3.7% to 26.0% in M24 patients. Predominant DRMs were associated with ART regimens, but virus in several patients accumulated DRMs to drugs not received, such as abacavir, didanosine, tenofovir, etravirine, and rilpivirine. CONCLUSIONS: Our findings show heterogeneous virological failure and illustrate that, in addition to routine access to viral load, good management of ART programs is even more critical to improve treatment outcomes in resource-limited countries.

Field evaluation of dried blood spots for routine HIV-1 viral load and drug resistance monitoring in patients receiving antiretroviral therapy in Africa and Asia.

Dried blood spots (DBS) can be used in developing countries to alleviate the logistic constraints of using blood plasma specimens for viral load (VL) and HIV drug resistance (HIVDR) testing, but they should be assessed under field conditions. Between 2009 and 2011, we collected paired plasma-DBS samples from treatment-experienced HIV-1-infected adults in Burkina Faso, Cameroon, Senegal, Togo, Thailand, and Vietnam. The DBS were stored at an ambient temperature for 2 to 4 weeks and subsequently at -20°C before testing. VL testing was performed on the plasma samples and DBS using locally available methods: the Abbott m2000rt HIV-1 test, generic G2 real-time PCR, or the NucliSENS EasyQ version 1.2 test. In the case of virological failure (VF), i.e., a plasma VL of ≥1,000 copies/ml, HIVDR genotyping was performed on paired plasma-DBS samples. Overall, we compared 382 plasma-DBS sample pairs for DBS VL testing accuracy. The sensitivities of the different assays in different laboratories for detecting VF using DBS varied from 75% to 100% for the m2000rt test in labs B, C, and D, 91% to 93% for generic G2 real-time PCR in labs A and F, and 85% for the NucliSENS test in lab E. The specificities varied from 82% to 97% for the m2000rt and NucliSENS tests and reached only 60% for the generic G2 test. The NucliSENS test showed good agreement between plasma and DBS VL but underestimated the DBS VL. The lowest agreement was observed for the generic G2 test. Genotyping was successful for 96/124 (77%) DBS tested, and 75/96 (78%) plasma-DBS pairs had identical HIVDR mutations. Significant discrepancies in resistance interpretations were observed in 9 cases, 6 of which were from the same laboratory. DBS can be successfully used as an alternative to blood plasma samples for routine VL and HIVDR monitoring in African and Asian settings. However, the selection of an adequate VL measurement method and the definition of the VF threshold should be considered, and laboratory performance should be monitored.

Drug resistance mutations and genetic diversity in adults treated for HIV type 1 infection in Mauritania.

The aim of this cross-sectional study was to evaluate the drug resistance mutationprofile observed in patients receiving antiretroviral therapy with virological failure and to document the HIV-1 genetic diversity in Mauritania. Eighty-six subjects were included and 65 samples were amplified successfully and sequenced. HIV-1 genotyping was performed using the Agence Nationale de Recherche sur le SIDA AC11 resistance procedure. The median treatment duration was 32 months (range: 6-88) and the median viral load, 5 log10 copies/ml (range: 3.13-7). Fifty-nine patients (90.8%) were on first line regimens including 32.0% (19/59) on triomune fixed-dose and six on second-line therapy with NonNucleoside Reverse Transcriptase plus a protease inhibitor. Forty-seven patients (72.3%) had at least one drug resistance mutation including 73.0% (43/59) on first-line therapy. For the second-line, one out of six patients presented resistance mutations and only one presented PI DRM. Overall, the most common DRMs detected were M184V/I (n = 32; 49.2%), K103N (n = 28; 43%), and Y181C (n = 13; 20%). Thymidine Analog Mutations (TAMs) were found in 26.0% (n = 17) of strains and the most common was T215Y (n = 11, 16.9%). Phylogenetic analysis revealed 17 HIV-1 variants with the predominance of CRF02_AG (n = 42; 64.6%). A high rate of DRM was found in this study and shows the potential need for a structured virological surveillance including viral load quantification and genotyping. Further studies may also be needed in regards to the great variability of HIV-1 strains in Mauritania.

Genomic epidemiology of SARS-CoV-2 in Senegal in 2020-2021.

INTRODUCTION: In Senegal, molecular diagnosis was widely used for the detection and management of COVID-19 patients. However, genomic surveillance was very limited in the public sector. This study aimed to share the experience of a Senegalese public sector laboratory in response to the COVID-19 pandemic, and to describe the distribution of variants circulating in 2020 and 2021. METHODOLOGY: From July 2020 to December 2021, SARS-CoV-2 qRT-PCR was performed on nasopharyngeal samples from travelers and symptomatic patients at the Bacteriology and Virology Laboratory (LBV) of the Aristide le Dantec University Teaching Hospital. Samples with a cycle threshold (Ct) ≤ 30 were selected for whole-genome sequencing (WGS) using the Nanopore technology. In-house scripts were developed to study the spatial and temporal distribution of SARS-CoV-2 variants in Senegal, using our sequences and those retrieved from the GISAID database. RESULTS: Of 8,207 patients or travelers screened for SARS-CoV-2, 970 (11.8%) were positive and 386 had a Ct ≤ 30. WGS was performed on 133 samples. Concomitantly with high-quality sequences deposited in the GISAID database covering nine cities in Senegal in 2020 and 2021 (n = 1,539), we observed a high circulation of the 20A (B.1, B.1.416 and B.1.620) and 20B (B.1.1.420) lineages in 2020, while most of the samples belonged to Delta variants (AY34 and AY.34.1, 22%) in 2021. CONCLUSIONS: Despite its late involvement, COVID-19 diagnosis was routinely performed in LBV, but genomic characterization remained challenging. The genomic diversity of SARS-CoV-2 strains in Senegal reflected that observed worldwide during the first waves of the pandemic.

Development and field evaluation in African and Asian countries of an hepatitis B virus PCR on open polyvalent platforms to determine treatment eligibility: results from the "Agence Nationale de Recherche sur le Sida et les hépatites" 12327 study.

OBJECTIVES: Widespread testing and treatment are essential to eliminate hepatitis B virus (HBV) infection as a public health concern. However, in resource-limited countries, access to HBV PCR is limited. In this study, we developed a quantitative HBV PCR assay on open molecular platforms and evaluate its performance in diagnosing clinically significant HBV DNA thresholds as defined by the WHO (2000 IU/mL, 20 000 IU/mL, and 200 000 IU/mL). METHODS: We implemented our HBV PCR test in seven African and Asian countries and France, using either an in-house laboratory method or a European conformity for in vitro diagnostic (CE-IVD) marked version of the PCR (Generic HBV Charge Virale, Biocentric). Results were compared with reference tests (Roche Cobas AmpliPrep/Cobas TaqMan and Abbott RealTime on Abbott m2000). RESULTS: There was a good agreement between the HBV DNA results of 1015 samples tested by the PCR on open polyvalent platforms and the results from reference tests (mean difference (bias ± standard deviation [SD]): -0.3 ± 0.7 log10 IU/mL and -0.2 ± 0.9 log10 IU/mL when compared with Roche and Abbott tests, respectively). Kappa-Cohen agreements between the HBV PCR on open polyvalent platforms and the Roche/Abbott assays appeared almost perfect for HBV DNA levels ranged from >20 000 to 200 000 IU/mL and >200 000 IU/mL, substantial and moderate for HBV DNA levels ranged from 2000 to 20 000 IU/mL when compared with Abbott and Roche, respectively. The assay's performance was consistent across genotypes A, B, C, D, and E. DISCUSSION: This field evaluation showed that our HBV PCR test is a valuable alternative to proprietary PCR systems. PCR assays on open platforms contribute to expanding clinical laboratory solutions for diagnosing individuals who meet the viral load criteria for antiviral therapy (>20 000 IU/mL) and mother-to-child prophylaxis (>200 000 IU/mL).

Immunoprophylaxis failure and vaccine response in infants born to mothers with chronic hepatitis B infection in Djibouti.

BACKGROUND: In endemic areas, vertical transmission of hepatitis B virus (HBV) remains a major source of the global reservoir of infected people. Eliminating mother-to-child transmission (MTCT) of HBV is at the heart of World Health Organization's goal of reducing the incidence of HBV in children to less than 0.1% by 2030. Universal screening for hepatitis B during pregnancy and neonatal vaccination are the main preventive measures. AIM: To evaluate the efficacy of HBV vaccination combined with one dose of immunoglobulin in children born to hepatitis B surface antigen (HBsAg)-positive mothers in Djibouti city. METHODS: We conducted a study in a prospective cohort of HBsAg-positive pregnant women and their infants. The study ran from January 2021 to May 2022, and infants were followed up to 7 mo of age. HBV serological markers and viral load in pregnant women were measured using aVidas microparticle enzyme-linked immunosorbent assay (Biomérieux, Paris, France) and the automated Amplix platform (Biosynex, Strasbourg, France). All infants received hepatitis B immunoglobulin and were vaccinated against HBV at birth. These infants were closely monitored to assess their seroprotective response and for failure of immunoprophylaxis. Simple logistic regression was also used to identify risk factors associated with immunoprophylaxis failure and poor vaccine response. All statistical analyses were performed with version 4.0.1 of the R software. RESULTS: Of the 50 pregnant women recruited, the median age was 31 years, ranging from 18 years to 41 years. The MTCT rate in this cohort was 4% (2/50) in HBsAg-positive women and 67% (2/3) in hepatitis B e antigen-positive women with a viral load > 200000 IU/mL. Of the 48 infants who did not fail immunoprophylaxis, 8 (16%) became poor responders (anti-HB < 100 mIU/mL) after HBV vaccination and hepatitis B immunoglobulin, while 40 (84%) infants achieved a good level of seroprotection (anti-HB > 100 mIU/mL). Factors associated with this failure of immunoprophylaxis were maternal HBV DNA levels (> 200000 IU/mL) and hepatitis B e antigen-positive status (odds ratio = 158, 95% confidence interval: 5.05-4958, P < 0.01). Birth weight < 2500 g was associated with a poor immune response to vaccination (odds ratio = 34, 95% confidence interval: 3.01-383.86, P < 0.01). CONCLUSION: Despite a failure rate of immunoprophylaxis higher than the World Health Organization target, this study showed that the combination of immunoglobulin and HBV vaccine was effective in preventing MTCT of HBV. Therefore, further studies are needed to better understand the challenges associated with immunoprophylaxis failure in infants in Djibouti city.

Detection of Hepatitis E Virus (HEV) in Pork Sold in Saint-Louis, the North of Senegal.

The hepatitis E virus (HEV) is a zoonotic pathogen with various hosts, including pigs, which act as reservoirs. In industrialized countries, sporadic cases caused by genotype 3, contracted by ingesting contaminated uncooked or undercooked meat, have been reported. However, in developing countries, HEV infection is mainly dominated by genotype 2 and often associated with poor hygiene conditions and drinking water supplies. HEV infection and its circulation in domestic fauna in West Africa are poorly documented. This study aimed to assess the presence of HEV in pork sold in Saint-Louis, Senegal. Meat products (250 g samples, n = 74) were purchased in August 2022 from three locations. Then, 2 g/sample was minced to extract total nucleic acids using the Purelink™ Viral DNA/RNA kit. RT-PCR reactions were performed using the One-Taq™ One-Step RT-PCR kit targeting the HEV ORF2 genomic region. The products obtained were visualized on a 1% agarose gel. Of a total of 74 samples, divided into pork meat (n = 65) and pork liver (n = 9), 5.4% (n = 4) tested positive for HEV. In both cases, two samples were positive, representing a rate of 3.1% and 22.2% for meat and pork liver, respectively. All new viral sequences were obtained from a monophyletic group within HEV genotype 3. This study is the first to report the presence of HEV in pork sold in Senegal and the results reveal a potential circulation of HEV in the pig population. The high proportion of contamination in the pork liver samples highlights a major risk associated with their consumption.

A metagenomic assessment of bacterial community in spices sold open-air markets in Saint-Louis, Senegal.

Natural spices play an essential role in human nutrition and well-being. However, their processing on different scales can expose them to potential sources of contamination. This study aimed to describe the bacterial community genomic footprint in spices sold in Senegal. Spice samples were collected in August 2022 in Saint-Louis, Senegal. The genomic region coding bacterial 16S rRNA was then amplified and sequenced using Oxford Nanopore Technology (ONT). Sequencing was carried out on two batches of samples, one containing part of the "Local Spices or Herbs" (n = 10), and the other, a mixture of 7 spices, Curcuma, Thyme and the other part of the "Local Spices or Herbs" (n = 39). Results showed high bacterial diversity and the predominance of Escherichia coli and Salmonella enterica in samples, with total reads of 65,744 and 165,325 for the two batches, respectively. The sample category "Homemade mixture of food condiments ", which includes all "Local Spices or Herbs" samples, showed remarkable bacterial diversity. These were followed by Curcuma, a blend of 7 spices and thyme. Also, the different categories of spices studied show similarities in their bacterial composition. These results highlight the microbial community's highly diverse genomic profile, including pathogenic bacteria, in spice samples.