Low Prevalence of Antibodies to SARS-CoV-2 and Undetectable Viral Load in Seropositive Blood Donors from South-Eastern Italy.

Recently, a significant cluster of pneumonia caused by a novel betacoronavirus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) was described initially in China and then spread throughout the world. Like other coronaviridae, the viral transmission occurs mainly through droplets. In addition, the virus has been detected in different clinical specimens, suggesting a potential transmission by other routes, including blood transfusion. However, the potential risk of transmission of SARS-CoV-2 via blood products is still unclear. The aim of our study was to investigate the prevalence of antibodies against SARS-CoV-2 among blood donors from South-Eastern Italy. Moreover, in the seropositive donors, we searched for the presence of the virus in nasopharyngeal swabs and in plasma samples. Overall, 1,797 blood donors from the Apulia region were tested for anti-SARS-CoV-2 antibodies, using a commercially available assay. Only 18/1,797 donors (1.0%) tested positive for anti-SARS-CoV-2 antibodies; in none of them SARS-CoV-2 viral RNA was detected in nasopharyngeal swabs and in plasma samples. Our results indicate that most of the blood donors in Apulia remained uninfected during this wave of the pandemic; further, none had detectable virus both in nasopharyngeal swabs and in blood samples. The risk to carry and transmit the virus by healthy and asymptomatic blood donors is probably very low.

Resistance Associated Mutations in HCV Patients Failing DAA Treatment.

Currently, treatment of chronic hepatitis C is based on a combination of direct-acting antiviral agents (DAAs) which achieve HCV clearance in more than 95% of patients. Despite this high rate of cure, treatment failures can occur in about 3-5% of treated patients. Resistance associated substitutions (RAS) are commonly detected after virological failure, although their role in real-life DAA failures is still debated. This study aimed to evaluate in real-life DAA-failing patients the prevalence of clinically relevant RASs for the different DAA classes and to identify possible predictors. Fifty consecutive HCV-infected patients who experienced a virological failure to a DAA-containing regimen were included in the study. Direct sequencing of HCV regions involved in DAA resistance (NS3, NS5A and NS5B) was performed with Sanger-based homemade protocols. The presence of mutations in the NS3 and NS5A regions was statistically associated with regimens containing protease inhibitors (p<0.0032) and NS5A inhibitors (p<0.0006), respectively. On the contrary, for the NS5B region, the known mutations associated with the NS5B RNA polymerase inhibitors were detected in treated HCV patients, although there was no statistical significance (p>0.5). A significant correlation was found between the presence of RASs and advanced fibrosis/cirrhosis, but not with age, sex and viral load. Our study demonstrates a high frequency of RASs in patients with DAA failure, thus highlighting the usefulness of genotypic tests in this setting. The identification of RASs may guide the choice of the most appropriate drugs for HCV re-treatment.