Rotavirus vaccines in Africa and Norovirus genetic diversity in children aged 0 to 5 years old: a systematic review and meta-analysis : Rotavirus vaccines in Africa and Norovirus genetic diversity.

Noroviruses are the second leading cause of death in children under the age of 5 years old. They are responsible for 200 million cases of diarrhoea and 50,000 deaths in children through the word, mainly in low-income countries. The objective of this review was to assess how the prevalence and genetic diversity of noroviruses have been affected by the introduction of rotavirus vaccines in Africa. PubMed, Web of Science and Science Direct databases were searched for articles. All included studies were conducted in Africa in children aged 0 to 5 years old with gastroenteritis. STATA version 16.0 software was used to perform the meta-analysis. The method of Dersimonian and Laird, based on the random effects model, was used for the statistical analyses in order to estimate the pooled prevalence's at a 95% confidence interval (CI). Heterogeneity was assessed by Cochran's Q test using the I2 index. The funnel plot was used to assess study publication bias. A total of 521 studies were retrieved from the databases, and 19 were included in the meta-analysis. The pooled norovirus prevalence's for pre- and post-vaccination rotavirus studies were 15% (95 CI, 15-18) and 13% (95 CI, 09-17) respectively. GII was the predominant genogroup, with prevalence of 87.64% and 91.20% respectively for the pre- and post-vaccination studies. GII.4 was the most frequently detected genotype, with rates of 66.84% and 51.24% respectively for the pre- and post-vaccination studies. This meta-analysis indicates that rotavirus vaccination has not resulted in a decrease in norovirus infections in Africa.

Performance of Molecular Tests in the Diagnosis of Syphilis From 2009 to 2019: A Systematic Review and Meta-Analysis.

BACKGROUND: Syphilis continues to be a public health problem, and its diagnosis still has limitations. Molecular diagnosis provides an alternative for rapid and effective management. The objective is to determine the accuracy of tests in the molecular diagnosis of syphilis. METHODS: We searched PubMed and Web of Sciences for articles related to molecular detection of syphilis from January 1, 2009, to December 31, 2019. The bivariate Reitsma model and the hierarchical receiver operating characteristic curve model were used to evaluate the diagnostic performance of molecular tests at a 95% confidence interval. A subgroup meta-analysis was performed to explore sources of heterogeneity. RESULTS: Forty-seven articles were identified for qualitative synthesis, of which 23 met the inclusion criteria for meta-analysis. The pooled sensitivities in conventional polymerase chain reaction (PCR) and real-time PCR were 77.52 (59.50-89.01) and 68.43 (54.96-79.39), respectively. The pooled specificities were 98.00 (90.73-99.59) and 98.84 (97.55-99.46), respectively. Ulcer samples had a better performance (sensitivity of 79.88 [69.00-87.62] and specificity of 98.58 [97.25-99.27]), and the major target genes were the polymerase A gene and tpp47 gene. CONCLUSIONS: Our work showed that conventional PCR was more widely used than real-time PCR in the diagnosis of syphilis, and ulcers were the best specimens. Sample types and target genes are factors that may influence the quality of the different tests. These results could provide evidence for further work in the direction of providing a more efficient diagnostic test.

Residual risk of HIV, HCV, and HBV transmission by blood transfusion between 2015 and 2017 at the Regional Blood Transfusion Center of Ouagadougou, Burkina Faso.

INTRODUCTION: In sub-Saharan Africa, the high endemicity of blood-borne infections is a serious threat to transfusion safety. In order to improve transfusion safety, Burkina Faso has undertaken in recent years a reorganization of its blood-transfusion system through the creation of a National Blood Transfusion Center, which is the only blood operator in the whole country. This study aimed to estimate the residual risk of transmission of HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV) by blood transfusion at the Regional Blood Transfusion Center (RBTC) of Ouagadougou. METHODS: This was a retrospective study conducted at the RBTC of Ouagadougou between 2015 and 2017. Prevalence of infectious markers was calculated for first-time donors and incidence rates calculated for repeat donors who had made at least two donations of blood over the study period. Residual risks were estimated for the three viruses (HIV, HBV, and HCV) by multiplying the incidence rate per 100,000 person-years by the respective durations of serological windows. RESULTS: Between 2015 and 2017, of a total of 84,299 blood donors, 68,391 (81.13%) were first-time donors compared to 15,908 (18.87%) repeat donors. The seroprevalence of HBV (8.56%) was twice that of HCV (4.40%) and fourfold that of HIV (1.80%). Incidence rates were 1,215, 2,601, and 1,599 per 100,000 donations for HIV, HCV, and HBV, respectively. In contrast, the estimated residual risk for HCV (1 in 213 donations) was double that of HBV (1 in 408 donations) and four times that of HIV (1 in 1,366). CONCLUSION: The residual risk of transmission of these viruses by blood transfusion remains high in repeat donors. An effective donor-retention and education policy could help to reduce this residual risk.

Role of Killer cell immunoglobulin-like receptors (KIR) genes in stages of HIV-1 infection among patients from Burkina Faso.

Objectives A cluster of specialized KIR genes of specialized KIR genes has been shown to be associated with susceptibility or resistance to viral infections in humans. Therefore, this pilot study, this pilot investigation sought to determine the frequencies of KIR genes human immunodeficiency virus type 1( HIV-1) patients and establish their potential clinical involvement in disease progression and staging. Methods HIV-1 infected and healthy individuals were selected for this study. Hepatitis B surface antigen (HBsAg), anti-HCV antibodies and anti-HIV-1/2 antibody/ antigen were screened using a 4th generation ELISA assay (Cobas e 411 Analyzer, Roche Diagnostics GmbH Mannheim, Germany). SSP-PCR was used to evaluate the frequencies of KIR genes. CD4+ T counts and HIV-1 viral load were measured in patients using respectively BD FACSCount and Abbott m2000rt instruments. Results We found a significant association between the frequencies of KIR2DL2 (OR=4.41; p < 0.001), KIR2DS2 (OR=4.76; p < 0.001), KIR2DS3 (OR=2.27; p=0.004), KIR2DS4 (OR=1.76; p=0.026), KIR3DS1 (OR=2.43; p=0.016) and HIV-1 infection; whilst the KIR3DL1 gene (OR= 0.39; p < 0.001) was associated with protection against HIV-1 infection. HIV-1 replication was found to be associated with the presence of KIR2DS2 (OR=6.08, p = 0.024). In contrary the pseudogene KIR2DP1 (OR=0.39; p=0.026) were linked to a protective status with the highest number of lymphocyte T CD4 counts. Conclusion Our data showed that KIR2DL2, KIR2DS2, KIR2DS3, KIR2DS4, and KIR3DS1 were significantly associated with HIV-1 infection whereas KIR3DL1 was associated with protection against HIV-1 infection. Further investigations are needed to fully comprehend the clinical significance of KIR genes in HIV disease progression.

Importance of extending the use of polymerase chain reaction in the diagnosis of venereal syphilis in a blood transfusion center in Burkina Faso, West Africa.

INTRODUCTION: Due to the existence of a variety of types of non-venereal syphilis caused by the related T. pallidum, regular serological testing such as Rapid Plasma Reagin (RPR) and Chemiluminescent Microparticle Immunoassay Technique (CMIA) are often unable to differentiate venereal syphilis from the non- venereal one, hence, the interest in the use of molecular biology testing for a confirmation diagnosis of syphilis caused by Treponema pallidum subspecies pallidum. OBJECTIVE: The study is designed to assess the effectiveness of PCR testing and serological methods in the diagnosis of Treponema pallidum subsp pallidum among blood donors in Burkina Faso. METHODS: The study included 6375 samples of volunteer blood donors from the regional blood transfusion center of Ouagadougou (CRTS/O). Among samples, 183 positive and 59 negative in RPR were analyzed to detect antibodies anti-T. pallidum subsp pallidum with a immunoassay method (CMIA) and were confirmed using the Polymerase Chain Reaction testing. RESULTS: In RPR, we obtained a prevalence rate of 2.9% (183/6375) for treponematosis. From the 183 RPR+ specimen, 108 (59%) were found CMIA+ and 11 (6%) were confirmed PCR+. While the 59 pattern RPR-; 31 (52.5%) were CMIA + including 3 (5.1%) tested PCR+. Seventy-five (75) samples RPR + /CMIA-; 2 (2.7%) were confirmed positive by PCR. All 28 samples RPR-/CMIA- were confirmed negative by PCR. CONCLUSION: PCR testing confirmed a low distribution of T. pallidum subsp pallidum in comparison to serological methods. Cross-reactions, existence of non-venereal treponemal or immunological scars could account for the discrepancy between the results obtained.