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 compared with 9.64 ± 4.34 ul in sickle cell crisis subjects. Hb and HCT levels were significantly higher in controls compared with sickle cell subjects in crisis. During crisis, total bilirubin, direct bilirubin, triglycerides, LDH, AST, and CRP were significantly elevated. Hematological parameters such as Hb and HCT were elevated in controls, while the mean WBC value and RET were higher in sickle cell patients in steady state. The mean values of the biochemical parameters were higher in sickle cell patients in steady state. Conclusion: Evaluation of the influence of sickle cell trait on biochemical and hematological parameters showed significant differences between sickle cell and control subjects.

Poliovirus (PV), the virus that causes both acute poliomyelitis and post-polio syndrome, is classified within the Enterovirus C species, and there are three wild PV serotypes: WPV1, WPV2 and WPV3. The launch of the Global Polio Eradication Initiative (GPEI) in 1988 eradicated two of the three serotypes of WPV (WPV2 and WPV3). However, the endemic transmission of WPV1 persists in Afghanistan and Pakistan in 2022. There are cases of paralytic polio due to the loss of viral attenuation in the oral poliovirus vaccine (OPV), known as vaccine-derived poliovirus (VDPV). Between January 2021 and May 2023, a total of 2141 circulating VDPV (cVDPV) cases were reported in 36 countries worldwide. Because of this risk, inactivated poliovirus (IPV) is being used more widely, and attenuated PV2 has been removed from OPV formulations to obtain bivalent OPV (containing only types 1 and 3). In order to avoid the reversion of attenuated OPV strains, the new OPV, which is more stable due to genome-wide modifications, as well as sabin IPV and virus-like particle (VLP) vaccines, is being developed and offers promising solutions for eradicating WP1 and VDPV.

Background: Hepatitis D virus (HDV) is a defective virus that requires the presence of hepatitis B virus (HBV) for replication. It is a major cause of severe acute and chronic hepatitis B. The objective of this study was to determine the prevalence and risk factors of HDV in blood donors. Methods: This was a descriptive, cross-sectional study involving HBsAg-positive blood donors covering the period from July to December 2020. Testing for HDV RNA was performed by conventional two-step RT-PCR. Data were analysed using SPSS version 22 software. Result: Of 113 HBsAg positive samples included in the study 22 or 19.5% were HDV positive. The prevalence of HDV was higher in the age group 31 -45 years (45.5%), in male donors (71.4%) and in donors with secondary education (50.0%). Furthermore, 55.4% belonged to the family donor category. A significant statistical difference was observed between HDV infection, tattoos, piercings and multiple sexual partners. Conclusion: This study shows a high prevalence of HDV among blood donors in Brazzaville.

Corona Virus Disease 2019 (COVID-19) is a highly transmissible and pathogenic viral infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which erupted in Wuhan, China, in 2019 and has spread worldwide [1]. The objective of this study was to assess the seroprevalence of SARS-CoV-2 among blood donors in the Republic of Congo. Method: This is an analytical and cross-sectional study that was carried out during the period from July to December 2021. Biological analyses were performed with the serological tests n2019 rapid IgG/IgM from Beijing Diagreat Biotechnologies and antigen tests from Abbot using the serum for the detection of anti-SARS-Cov-2 antibodies and nasal mucus for the detection of SARS-Cov-2 antigens. Statistical analysis was performed using SPSS version 22. The Results: Out of 2553 donors recruited in our study, we observed a predominance of male sex with 86.1% or a ratio of 6.19, the age group of 18 -30 years was dominant with 45.9%, family donation represented 59.2%, the dominant profession was workers with 46.9% and the dominant blood group was O Rh positive with 54%. The prevalence of anti-SRAS-CoV-2 antibodies and antigens were respectively 31.4% for anti-SRAS CoV-2 IgG antibodies, 36.7% for anti-SRAS CoV-2 IgM antibodies and 2.93% for SARS-CoV-2 antigen.