Mortality in sea lions is associated with the introduction of the H5N1 clade 2.3.4.4b virus in Brazil October 2023: whole genome sequencing and phylogenetic analysis.

Clade 2.3.4.4b highly pathogenic avian influenza (HPAI) H5N1 virus was detected in the South American sea lions found dead in Santa Catarina, Brazil, in October 2023. Whole genome sequencing and comparative phylogenetic analysis were conducted to investigate the origin, genetic diversity, and zoonotic potentials of the H5N1 viruses. The H5N1 viruses belonged to the genotype B3.2 of clade 2.3.4.4b H5N1 virus, which was identified in North America and disseminated to South America. They have acquired new amino acid substitutions related to mammalian host affinity. Our study provides insights into the genetic landscape of HPAI H5N1 viruses in Brazil, highlighting the continuous evolutionary processes contributing to their possible adaptation to mammalian hosts.

Incursion of Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Virus, Brazil, 2023.

We report 4 highly pathogenic avian influenza A(H5N1) clade 2.3.4.4.b viruses in samples collected during June 2023 from Royal terns and Cabot's terns in Brazil. Phylodynamic analysis revealed viral movement from Peru to Brazil, indicating a concerning spread of this clade along the Atlantic Americas migratory bird flyway.

Inhibition of severe acute respiratory syndrome coronavirus 2 replication by hypertonic saline solution in lung and kidney epithelial cells

An unprecedented global health crisis has been caused by a new virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We performed experiments to test if a hypertonic saline solution was capable of inhibiting virus replication. Our data show that 1.2% NaCl inhibited virus replication by 90%, achieving 100% of inhibition at 1.5% in the nonhuman primate kidney cell line Vero, and 1.1% of NaCl was sufficient to inhibit the virus replication by 88% in human epithelial lung cell line Calu-3. Furthermore, our results indicate that the inhibition is due to an intracellular mechanism and not to the dissociation of the spike SARS-CoV-2 protein and its human receptor. NaCl depolarizes the plasma membrane causing a low energy state (high ADP/ATP concentration ratio) without impairing mitochondrial function, supposedly associated with the inhibition of the SARS-CoV-2 life cycle. Membrane depolarization and intracellular energy deprivation are possible mechanisms by which the hypertonic saline solution efficiently prevents virus replication in vitro assays.

Effectiveness of direct-acting antivirals for hepatitis C virus infection in hepatitis C/HIV coinfected individuals: A multicenter study

In a hepatitis C virus (HCV)/HIV-positive Brazilian cohort, evaluate the safety and efficacy of HCV DAAs, the frequency of resistance substitutions in the HCV NS5A and NS5B genes and identify predictors of treatment failure. Retrospective multicenter study of HCV/HIV patients treated with sofosbuvir (SOF)-based regimens at 10 reference centers in Brazil. Clinical and virological data were collected. Genetic diversity in the NS5A and NS5B genes was assessed by direct nucleotide sequencing. The primary outcome was sustained virological response (SVR) 12 weeks after DAA completion. Of 643HCV/HIV patients analyzed, 74.7% were male, median CD4+ T cell count was 617cells/mm3, 90% had an undetectable HIV viral load. HCV genotype 1 was detected in 80.2%, and 60% were taking at least 1 medication other than antiretroviral drugs during their DAA therapy. Cirrhosis was present in 42%. An SOF/daclatasvir (DCV) regimen was used in most patients (98%). The frequency of NS5A polymorphisms associated with clinically relevant resistance to DCV was 2%; no relevant NS5B variants were identified. The SVR12 rate was 92.8% in an intention to treat (ITT) analysis and 96% in a modified ITT (m-ITT) analysis. AE occurred in 1.6% of patients. By multivariate analysis, therapeutic failure was associated, in the m-ITT analysis, with concomitant use of anticonvulsant drugs (P=.001), age (P=.04), and female gender (P=.04). SOF/DCV regimens were associated with a high SVR rate in an HCV/HIV population. The use of concurrent anticonvulsant drugs and DAAs decreases the chances of achieving an SVR

Soroprevalência da hepatite B e avaliação da resposta imunológica à vacinação contra a hepatite B por via intramuscular e intradérmica em profissionais de um laboratório de saúde pública / Hepatitis B seroprevalence and evaluation of immune response to hepatitis B vaccination using intramuscular and intradermal routes in public health laboratory employees

OBJETIVOS: Determinar a prevalência dos marcadores da hepatite B (HBsAg e anti-HBs) e avaliar a resposta à vacinação contra hepatite B por via intradérmica (ID) em profissionais de saúde que não responderam à vacinação por via intramuscular (IM). MÉTODO: Todos os funcionários do Instituto Adolfo Lutz (IAL) foram convidados a participar do estudo. Amostras de soro foram colhidas no momento da administração da primeira dose de vacina (Engerix® B) e o HBsAg e o anti-HBs foram pesquisados, utilizando-se kits comerciais (Laboratórios Abbott®). Aos funcionários que não responderam à vacinação convencional (três doses por via IM) foram oferecidas doses de 5µg da mesma vacina por via ID. RESULTADOS: Foram envolvidos nesse estudo 404 funcionários do IAL, dos quais dois (0,5 por cento) eram HBsAg e 42 (10,5 por cento), anti-HBs reagentes. Dos 360 voluntários com sorologia negativa, 316 (87,8 por cento) receberam três doses de vacina (IM) e, desses, 259 colheram soros para avaliação pós-vacinal. Do total, 242 (93,4 por cento) apresentaram anticorpos acima de 10 UI/L após completarem o esquema inicial. Foram administradas duas doses de reforço, porém sete funcionários permaneceram sem resposta imunológica. A vacinação intradérmica foi realizada em cinco voluntários, e todos produziram anticorpos após a utilização dessa via de administração. CONCLUSÕES: A prevalência da hepatite B não foi maior nessa população do que na população geral. A vacinação por via intradérmica pode ser uma boa alternativa na imunização de pessoas que não respondem ao esquema convencional.

OBJECTIVES: To determine the prevalence of HBsAg and anti-HBs and to evaluate the response of intradermal hepatitis vaccination in healthcare workers non-responsive to previous repeated intramuscular vaccination. MATERIAL AND METHOD: All of the employees from Instituto Adolfo Lutz were invited to participate on this study. Serum samples were obtained and HBsAg and anti-HBs were detected using commercial kits (Abbott® Laboratories). Employees were submitted to the conventional three-dose vaccination by intramuscular route. To those employees who did not respond to intramuscular vaccination, 5 µg doses of Engerix® B were then administered by intradermal route up to nine doses. RESULTS: Four hundred and four healthcare workers were enrolled in this study. Initially, two (0.5 percent) and 42 (10.4 percent) were HBsAg and anti-HBs reagent, respectively. Among the 360 negative volunteers, 316 (87.8 percent) received three vaccine doses and in 259 of them, serum samples were collected to evaluate vaccine efficacy. Among them, 242 (93.4 percent) showed antibodies titer higher than 10 UI/l. Intradermal vaccination was carried out in five volunteers and all of them responded to this vaccine administration route. CONCLUSION: The prevalence of hepatitis B was not higher than in general population. Intradermal vaccine administration could be a good alternative in people that did not respond to previous intramuscular route.