SARS-CoV-2 Reinfection Cases in a Household-Based Prospective Cohort in Rio de Janeiro.

This was a household-based prospective cohort study conducted in Rio de Janeiro, in which people with laboratory-confirmed coronavirus disease 2019 (COVID-19) and their household contacts were followed from April 2020 through June 2022. Ninety-eight reinfections were identified, with 71 (72.5%) confirmed by genomic analyses and lineage definition in both infections. During the pre-Omicron period, 1 dose of any COVID-19 vaccine was associated with a reduced risk of reinfection, but during the Omicron period not even booster vaccines had this effect. Most reinfections were asymptomatic or milder in comparison with primary infections, a justification for continuing active surveillance to detect infections in vaccinated individuals. Our findings demonstrated that vaccination may not prevent infection or reinfection with severe acute respiratory syndrome coronavirus 2 (SARS CoV-2). Therefore we highlight the need to continuously update the antigenic target of SARS CoV-2 vaccines and administer booster doses to the population regularly, a strategy well established in the development of vaccines for influenza immunization programs.

Post-acute COVID-19 syndrome after reinfection and vaccine breakthrough by the SARS-CoV-2 Gamma variant in Brazil.

We describe a case of prolonged COVID-19 caused by the SARS-CoV-2 Gamma variant in a fully vaccinated healthcare worker, 387 days after an infection caused by lineage B.1.1.33. Infections were confirmed by whole-genome sequencing and corroborated by the detection of neutralizing antibodies in convalescent serum samples. Considering the permanent exposure of this healthcare worker to SARS-CoV-2, the waning immunity after the first infection, the low efficacy of the inactivated vaccine at preventing COVID-19, the immune escape of the Gamma variant (VOC), and the burden of post-COVID syndrome, this individual would have benefited from an additional dose of a heterologous vaccine.

Inflammatory Cytokine Patterns Associated with Neurological Diseases in Coronavirus Disease 2019.

Patients with coronavirus disease 2019 (COVID-19) can present with distinct neurological manifestations. This study shows that inflammatory neurological diseases were associated with increased levels of interleukin (IL)-2, IL-4, IL-6, IL-10, IL-12, chemokine (C-X-C motif) ligand 8 (CXCL8), and CXCL10 in the cerebrospinal fluid. Conversely, encephalopathy was associated with high serum levels of IL-6, CXCL8, and active tumor growth factor ß1. Inflammatory syndromes of the central nervous system in COVID-19 can appear early, as a parainfectious process without significant systemic involvement, or without direct evidence of severe acute respiratory syndrome coronavirus 2 neuroinvasion. At the same time, encephalopathy is mainly influenced by peripheral events, including inflammatory cytokines. ANN NEUROL 2021;89:1041-1045.

Hepatitis C virus and human T-cell lymphotropic virus type 1 co-infection: impact on liver disease, virological markers, and neurological outcomes.

OBJECTIVES: Human T-cell lymphotropic virus type 1 (HTLV-1) infection is associated with neurological abnormalities, such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and peripheral neuropathy (PN). Hepatitis C virus (HCV) infection is the leading cause of chronic liver disease worldwide, and causes PN in approximately 9% of patients. Because the interplay between these potentially neuropathogenic viruses in the same individual is still poorly understood, the clinical and laboratory outcomes of co-infected patients were evaluated and compared with those of controls. METHODS: The prevalence rates of neurological and laboratory abnormalities were evaluated in HCV/HTLV-1 co-infected patients (n=50), and in subjects with single HCV (n=46) or HTLV-1 (n=150) infection. RESULTS: A higher frequency of isolated PN was present in HCV-infected patients; this was not associated with cryoglobulinemia. No difference was found in the frequency of PN or HAM/TSP when co-infected subjects were compared to singly infected subjects. Hepatic involvement was present in HCV-infected subjects, as shown by increased levels of serum alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, and bilirubin, in addition to thrombocytopenia. On the other hand, HCV/HTLV-1 co-infected individuals presented a better prognosis for hepatic involvement when compared with singly HCV-infected subjects. CONCLUSIONS: These data suggest that HCV/HTLV-1 co-infection does not mutualistically alter the outcome with regard to neurological manifestations. Nonetheless, changes in the immunological environment induced by HTLV-1 infection could lead to a reduction in hepatic damage, even without significant HCV clearance.

High IFN-γ/IL-10 expression ratio and increased frequency of persistent human T-cell lymphotropic virus type 1-infected clones are associated with human T-cell lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis development.

BACKGROUND/AIMS: Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus that causes a persistent infection, and only 0.5-5% of infected individuals will develop HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Therefore, we investigated parameters to discriminate HTLV-1 asymptomatic carriers (ACs) with an increased chance to develop HAM/TSP. METHODS: We evaluated integration patterns of HTLV-1 provirus, the relative expression of HTLV-1 tax and HBZ mRNAs and of IFN-γ and IL-10 mRNAs, in addition to proviral load (PVL) levels. RESULTS: HAM/TSP patients presented a higher number of large persistent HTLV-1-carrying clones compared to ACs, and the expression of the HTLV-1 tax and HBZ genes by infected cells was detected at low levels and correlated positively with PVL. In addition, HAM/TSP patients and ACs with high PVL expressed higher levels of IFN-γ mRNA in comparison to IL-10, while ACs with low PVL presented an equilibrate IFN-γ/IL-10 ratio. CONCLUSIONS: The presence of large persistent HTLV-1-infected clones in association with viral gene expression, even at small levels, could stimulate the intense inflammatory response in HTLV-1-infected individuals. This was supported by a high ratio of IFN-γ/IL-10 relative expression in HAM/TSP patients and ACs with high PVL, indicating that these parameters could aid the identification of ACs with a high risk to develop HAM/TSP.

High frequencies of functionally competent circulating Tax-specific CD8+ T cells in human T lymphotropic virus type 2 infection.

Human T lymphotropic virus type 2 (HTLV-2) is characterized by a clinically asymptomatic persistent infection in the vast majority of infected individuals. In this study, we have characterized for the first time ex vivo specific CTL responses against the HTLV-2 Tax protein. We could detect CTL responses only against a single HLA-A*0201-restricted Tax2 epitope, comprising residues 11-19 (LLYGYPVYV), among three alleles screened. Virus-specific CTLs could be detected in most evaluated subjects, with frequencies as high as 24% of circulating CD8(+) T cells. The frequency of specific CTLs had a statistically significant positive correlation with proviral load levels. The majority of virus-specific CD8(+) T cells exhibited an effector memory/terminally differentiated phenotype, expressed high levels of cytotoxicity mediators, including perforin and granzyme B, and lysed in vitro target cells pulsed with Tax2((11-19)) synthetic peptide in a dose-dependent manner. Our findings suggest that a strong, effective CTL response may control HTLV-2 viral burden and that this may be a significant factor in maintaining persistent infection and in the prevention of disease in infected individuals.

Sindbis virus as a tool for quality control of viral inactivation of heated and chemically treated plasma-derived products.

Regulatory guidelines for production of plasma-derived products emphasize the need to document methods of viral inactivation and demonstrate the effectiveness of screening methods. Therefore, it is important to evaluate the kinetics of such processes. Togaviridae family virions may be considered as good tools for quality control of haemoderivatives, if they possess large amounts of cholesterol and saturated lipids and high structural lipid/protein ratio in their envelope composition, which give more resistance to classical treatments. The purpose of this study was to evaluate the efficiency of solvent-detergent and heat treatments adopted during the human haemoderivatives processment. Sindbis virus was used as a model for inactivation of enveloped viruses. Semi-processed human factor VIII (FVIII) product experimentally contaminated with Sindbis virus was used to test a solvent-detergent treatment with tri-N-butyl-phosphate (TNBP) and Tween 80. To evaluate thermal inactivation kinetics, lyophilized, and reconstituted samples of Sindbis virus-containing FVIII were incubated up to 30 h at 60 degrees C. The results showed that treatment with TNBP and Tween 80 reduced the infectivity of virus-contaminated FVIII in > or =5.5 log(10) and heat treatment was effective in all samples, although FVIII concentrate had reduced the rate of viral inactivation during a brief period of time.