Hepatitis B Virus (HBV) Infection in Patients at Pasteur Institute of Dakar in Senegal from 2016 to 2020: Prevalence and Seroprotection Level

Hepatitis B virus (HBV) infection is highly endemic in Senegal. Vaccination of all children against HBV was introduced in 1999 and included in Expanded Programme on Immunisation in 2005. The aim of this study was to assess the prevalence and immune status against HBV in patients received at Pasteur Institut in Dakar, Senegal. Methods: Between January 2016 and December 2020, patients aged between 1 and 96 years received laboratory were included in the study. Serum samples were analysed for HBV serology (HBs antigen: HBsAg, HBs antibody: HBsAb and HBc antibody: HBcAb) using ARCHITECT? analyser. Patients with anti-HBs antibody levels (HBsAb ≥ 10 IU/l) were considered seroprotected against HBV. Results: A total of 5629 patients were analysed with a mean age of 39 years and extremes from 1 to 96 years. The most represented age group was 31 - 45 years with 38.4%. HBsAg was present in 520 patients (9.2%) and was signed by sex and age group. Anti-HBc antibodies were found in 52.7% of patients and 1603 (28.48%) had isolated anti-HBs antibodies reflecting proportion of people vaccinated at the time of the study. However, 2143 patients (41.9%) had no seroprotection (HBsAb 10 IU/L) and 640 (12.6%) had strong seroprotection defined as HBsAb > 1000 IU/L. Conclusion: Our results show a significant presence of virus in Senegalese population and low vaccination coverage, especially in adults. Evaluation of HBsAb levels and provision of HBV booster shots should be considered for children in Senegal.

Prevalence and Factors Associated with Positivity of Antinuclear Antibodies (ANA) Patterns, Native Anti-DNA and Extractable Nuclear Antigens (ENA) Antibodies: Experience from a Laboratory in Dakar

Background: Diagnosis of autoimmune diseases (AID) is challenging, due to overlapping features with other non-immune disorders. Anti-nuclear antibodies (ANA) are sensitive screening tests but anti-deoxyribonucleic acid-antibody (anti-DNA), and anti-extractable nuclear antigens (anti-ENA) are specific for AIDs. We aimed to look at ANA patterns in our patients and correlated them with anti-ENA for proper interpretation and better patient management cost-effectively. Methods: A retrospective study was conducted over 1 year from January to December 2022 who were tested for ANA at biology medical laboratory of Pasteur Institute of Dakar. Anti-ENA and anti-DNA results were also analyzed for ANA-positive patients. Statistical analysis was performed using STATA 14.0, p Results: 216 patients were analyzed. Women predominated at 79.2% and mean age was 48 years [CI 95%, 46 - 50], with extremes of 10 and 89. Most represented age group was [41 - 60] with 38%. ANA was positive in 27 (12.5%) of patients, 59.2% of whom were strongly positive (titer of 1/1000, 1/3200 or 1/6400). The most common pattern was nuclear speckled, which was found in 77.8% of samples. Anti-ENA and anti-DNA positivity in ANA-positive patients was found respectively in 63% (17/27) and 1.4% (3/27) of the samples analyzed. Most commonly identified anti-ENA was anti-Sm 29.6%, anti-SSA 29.6%, anti-Ro-52 25.9%, anti-RNP 18.5% and anti-SSB 14.8% which was associated with speckled pattern. Association results indicated a significant relationship between both tests and between ANA titer in the anti-ENA- and ANA-positive patients (p 0.001). Conclusions: ANA, Anti-ENA and anti-DNA antibodies are essential for AIDS diagnosis. However, the testing repertoire should follow an algorithm comprising of clinical features, followed by ANA results with nuclear, mitotic, and cytoplasmic patterns, anti-ENA, and anti-DNA for a more meaningful, and cost-effective diagnostic approach.

Risk Factors for COVID-19 Related Death during the First Three Waves of the Pandemic in an Epidemic Treatment Center at Dakar, Senegal

Introduction-Objective: COVID-19 is a highly transmissible but often mild viral infection. However, some patients can present severe COVID-19 and subsequently die. The aim of the present study was to assess the risk factors for COVID-19 related death during the first three waves of the disease at the Epidemic Treatment Center (ETC) of Dakar Principal Hospital (DPH). Method: We conducted a descriptive and analytical perspective survival study from April 4, 2020 to September 25, 2021, including adult patients with COVID-19, hospitalized at the ETC of DPH. Log Rank test and multivariate Cox model were performed to identify risk factors for death. Results: We included 556 COVID-19 patients with mean age of 57 ± 17 years and a male-to-female ratio of 1.26. The number of deaths during one month of follow-up was 41, representing a cumulative risk of 7.4%. The log Rank test showed that being from the third wave (p = 0.0056), advanced age (p = 0.00098), presence of at least one comorbidity (p = 0.034), High blood pressure (p = 0.024), d-dimer level ≥ 1000 IU/L (p Conclusion: Our study showed that elderly and third-wave of COVID-19 patients were more at risk to die. Knowledge of risk factors for COVID-19 related death could improve the prognosis of these patients.

Phenotypic Detection of Enterobacterales Strains Susceptible of Producing OXA-48 Carbapenemase

Background: Nowadays, emergence of Carbapenemase-Producing Enterobacterales (CPE) throughout the world has become a public health problem, especially in countries with limited resources. In recent years, CPE of type OXA-48 (Ambler class D) have been identified in Dakar. The aim of this study was to evaluate the phenotypic detection of OXA-48 CPE using a temocillin disc (30 μg). Methodology: A retrospective study was carried out at Medical Biology Laboratory of Pasteur Institute in Dakar on Ertapenem-Resistant Enterobacterales (ERE) strains isolated from 2015 to 2017. These strains were then tested with a 30 μg temocillin disc. Any strain resistant to temocillin (inhibition diameter Results: Forty-one ERE isolated during the study period were tested, of which 34 (82.9%) were OXA-48 based on phenotypic detection using temocillin disc and confirmed by PCR (100%). OXA-48 CPE strains detected were composed of Klebsiella pneumoniae (n = 14;41.2%), Enterobacter cloacae (n = 8;23.5%), Escherichia coli (n = 7, 20.5%), Citrobacter freundii (n = 3;8.8%), Cronobacter sakazakii (n = 1;3%) and Morganella morganii (n = 1;3%). Conclusion: Temocillin resistance has a good positive predictive value for detecting OXA-48 CPE by phenotypic method, confirmed by PCR. Temocillin is therefore a good marker for detection of OXA-48 CPE except Hafnia alvei.

Vaginal Carriage of Group B Streptococcus in Pregnant Women in Rural Areas in Senegal

Vaginal carriage of Group B Streptococcus (GBS) is a maternal and child health issue. Our objective was to determine the prevalence of GBS carriage;identify the factors associated with this carriage and determine the antibiotic sensitivity of the isolated strains. We conducted a cross-sectional and prospective study in rural Senegal (in the health district of Sokone). Socio-demographic, clinical and gynaeco-obstetrical data were collected. Vaginal swabs were taken by the midwives on specific settings in order to test for GBS and other High Risk Vaginal Bacteria (HRVB). Antibiotic susceptibility testing was done according to the recommendations of the CA SFM/EUCAST 2020. In total, 100 pregnant women were targeted and 97 pregnant women were included. Their age ranged from 18 to 40 years with 64.9% (63/97) of participants belonging to the “20 - 30” age group. The overall prevalence of Group B Streptococcus carriage was 15.5% (15/97). However, the proportion of women with at least one high risk infectious bacteria was 29.89% (29/97). No statistically significant differences were found between GBS carriage and the potential factors studied. However, the study also looked for the presence of other high-risk bacteria and coinfections were indeed found between GBS and E. coli and Staphylococcus aureus. Antibiotic susceptibility testing shows that GBS strains were fully susceptible to penicillin G, erythromycin, clindamycin, chloramphenicol, rifampicin and vancomycin. Sensitivities to norfloxacin and gentamycin were 73.3% and 86.7% respectively. In contrast, high resistance to tetracycline (86.7%) was observed. GBS carriage remains a major public health issue because of its consequences for the mother and the newborn. Correct screening and proper monitoring of strain susceptibility remain one of the most effective means of patient management and care.