Transfusion transmissible infections (TTIs), caused by hepatitis B virus (HBV), human immunode-ficiency virus (HIV), hepatitis C virus (HCV), and syphilis, have a high global impact, especially in sub-Saharan Africa. We evaluated the trend of these infections over time in blood donors in Angola. A retrospective cross-sectional study was conducted among blood donors in Angola from 2005 to 2020. Additionally, frozen samples obtained from blood donors in 2007 were investigated to identify chronic HCV carriers and possible occult HBV infection (OBI). The overall prevalence of HBV, HCV, HIV, and syphilis was 8.5, 3, 2.1, and 4.4%, respectively, among 57,979 blood donors. HBV was predominant among male donors, while the remaining TTIs were predominant among women. Donors >50 years had a significantly high prevalence for all TTIs. Chronic HCV infection was ab-sent in 500 samples tested and OBI was present in 3%. Our results show the continued high prev-alence of TTIs among blood donors in Angola. Most infections showed a significantly low preva-lence in years with campaigns seeking voluntary blood donors, thus, reinforcing the importance of this type of donor to ensure safe blood. Africa, with a high prevalence of diverse pathogens, should consider cost-effective pathogen reduction technologies, once they are commercially accessible, to increase the availability of safe blood.

Background: Alphaviruses are transmitted by arthropod vectors and can be found worldwide. Alphaviruses of the Semliki Forest complex such as chikungunya virus (CHIKV), Mayaro virus (MAYV) or Ross River virus (RRV) cause acute febrile illness and long-lasting arthralgia in humans, which cannot be clinically discriminated from a dengue virus or Zika virus infection. Alphaviruses utilize a diverse array of mosquito vectors for transmission and spread. For instance, adaptation of CHIKV to transmission by Aedes albopictus has increased its spread and resulted in large outbreaks in the Indian Ocean islands. For many alphaviruses commercial diagnostic tests are not available or show cross-reactivity among alphaviruses. Climate change and globalization will increase the spread of alphaviruses and monitoring of infections is necessary and requires virus-specific methods. Method: We established an alphavirus neutralization assay in a 384-well format by using pseudotyped lentiviral vectors. Results: MAYV-specific reactivity could be discriminated from CHIKV reactivity. Human plasma from blood donors infected with RRV could be clearly identified and did not cross-react with other alphaviruses. Conclusion: This safe and easy to use multiplex assay allows the discrimination of alphavirus-specific reactivity within a single assay and has potential for epidemiological surveillance. It might also be useful for the development of a pan-alphavirus vaccine.

Hepatitis B virus (HBV) subgenotypes may be related to clinical outcomes and response to antiviral therapy. Most Brazilian studies on HBV subgenotypes are restricted to some regions and to specific population groups. Here, we provide an insight about genetic diversity of HBV subgenotypes in 321 serum samples from all five geographical regions, providing a representative overview of their circulation among chronic carriers. Overall, HBV/A1 was the most prevalent subgenotype, being found as the major one in all regions except in South Brazil. Among HBV/D samples, subgenotype D3 was the most prevalent, found in 51.5%, followed by D2 (27.3%) and D4 (21.2%). D2 and D3 were the most prevalent subgenotypes in South region, with high similarity with European strains. D4 was found in North and Northeast region and clustered with strains from Cape Verde and India. For HBV/F, the most frequent subgenotype was F2 (84.1%), followed by F4 (10.1%) and F1 (5.8%), closely related with strains from Venezuela, Argentina and Chile, respectively. Phylogeographic analyses were performed using an HBV full-length genome obtained from samples infected with genotypes rarely found in Brazil (B, C, and E). According to Bayesian inference, HBV/B2 and HBV/C2 were probably introduced in Brazil through China, and HBV/E from Guinea, all of them mostly linked to recent events of human migration. In conclusion, this study provided a comprehensive overview of the current circulation of HBV subgenotypes in Brazil. Our findings might contribute to a better understand of the dynamics of viral variants, to establish a permanent molecular surveillance on the introduction and dispersion patterns of new strains and, thus, to support public policies to control HBV dissemination in Brazil.

Background: Cytokines play an important role in the regulation of the immune response. In hepatitis C virus (HCV) infection, cytokine levels may influence the outcome of acute HCV infection. Polymorphisms in cytokine genes have been associated to different expression levels in response to infection. This study was carried out to investigate the association of several cytokine gene polymorphisms with disease outcome in HCV-infected patients.Findings: Patients with chronic or spontaneously resolved HCV infection were included in a cross-sectional study. A comparative analysis was performed between the groups regarding frequency distribution of the following cytokines’ gene polymorphisms: IL-10 (−1082 A/G; -819 T/C; -592 A/C), IL-4 (+33C/T), IFN-γ (+874 T/A), TNF-α (−238 G/A and −308 G/A) and IL-28B (rs12979860 C/T and rs8099917 T/G). Results: Eighteen patients with spontaneous viral clearance and 161 with chronic HCV infection were included. In the comparative analysis, the GG genotype of the IL-10 polymorphism -1082A/G was more frequent in patients with spontaneous viral clearance when compared to patients with chronic HCV (41.2% vs 6.2%; p = 0.001). This association was also found for the CC genotype of the IL-4 polymorphism +33C/T (72.2% vs 36.7%; p = 0.017) and the CC and TT genotypes of the IL-28B polymorphisms rs 12979860 and rs 8099917 (88.9% vs 30.3%; p < 0.001 and 88.9% vs 49.6%; p = 0.002). The IL10 (A-1082 G) and IL-28B (Crs12979860T) gene polymorphisms showed odds ratios of 12.848 and 11.077, respectively, and thus may have a greater influence on HCV spontaneous viral clearance. The IFN-γ (+874 T/A), TNF-α (−238 G/A and −308 G/A) polymorphisms did not show significant association with spontaneous viral clearance or chronicity.Conclusion: The G allele for IL-10 (−1082 A/G), the C allele for IL-4 (+3 C/T) and the C and T alleles for IL-28B (rs12979860 and rs8099917, respectively) are associated with spontaneous viral clearance in hepatitis C infection.