The first report of a human autochthonous in Brazil contributes with new information for hepatitis E epidemiology in Latin America and to considerate further broadly epidemiological studies.
Background
The natural outcome of infection with hepatitis C virus (HCV) varies substantially among individuals. However, little is known about host and viral factors associated with a self-limiting or chronic evolution of HCV infection.
Methods
From 1 January 2001 through 31 December 2008, a consecutive series of 65 patients from Rio de Janeiro, Brazil, with a well-documented diagnosis of acute HCV infection, acquired via various routes, were enrolled in this study. Patients were prospectively followed up for a median of 40 months after the estimated date of HCV infection with serial measurements of serum alanine aminotransferase, HCV RNA, and anti-HCV antibodies. Spontaneous viral clearance (SVC) was defined as undetectable levels of HCV RNA in serum, in the absence of treatment, for 3 consecutive HCV polymerase chain reaction tests within the first 6 months of follow-up. Cox proportional hazards regression was used to identify host and viral predictors of SVC.
Results
The cumulative rate of SVC was 44.6% (95% confidence interval, 32.3%–57.5%). Compared with chronic HCV evolution, patients with self-limiting disease had significantly lower peak levels of anti-HCV antibodies (median, 109.0 vs 86.7 optical density–to–cutoff ratio [od/co]; P < .02), experienced disease symptoms more frequently (69.4% vs 100%; P < .001), and had lower viral load at first clinical presentation (median, 4.3 vs 0.0 log copies; P =.01). In multivariate analyses, low peak anti-HCV level (<93.5 od/co) was the only independent predictor for SVC; the hazard ratio compared with high anti-HCV levels (≥93.5 od/co) was 2.62 (95% confidence interval, 1.11–6.19; P =.03).
Conclusion
Our data suggest that low levels of anti-HCV antibodies during the acute phase of HCV infection are independently related to spontaneous viral clearance.
Zika virus (ZIKV) is a Flavivirus closely related to other human pathogens such as Dengue virus (DENV) 1. Primary transmission usually involves Aedes aegypti, which has expanded its distribution range significantly 2 , though rarer infection routes including mother-to-fetus transmission, sexual contact and blood transfusion have also been observed 3-7. Primary ZIKV infection is usually asymptomatic or mild in adults, with quickly resolved blood viremia, but ZIKV might persist for months in saliva, urine, semen, breast milk and the central nervous system 8-12. During a recent ZIKV outbreak in South America, significant numbers of neurological complications such as Guillain-Barré syndrome were reported 13,14 , together with cases of microcephaly and associated developmental problems in infants born to women infected with ZIKV during pregnancy 15-20 , raising the clinical significance of this Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:
In 2019, a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is transmitted via the airborne route, caused a new pandemic namely, “coronavirus disease 2019” (COVID-19). Although the effectiveness of face masks to prevent the transmission of SARS-CoV-2 is debated, no study has evaluated the virus-blocking efficacy of masks used by patients. We aimed to evaluate this efficacy of masks used by SARS-CoV-2-infected individuals. Data, masks used, and nasopharyngeal swab samples were obtained from these patients. Forty-five paired samples of nasopharyngeal swabs and masks were obtained and processed; the majority of masks were woven. Viral RNAs were amplified using quantitative reverse‐transcription polymerase chain reaction and detected only on the inner parts of masks. Median viral load (VL) values of swabs and masks were 1.954x106 and 2,51x103, respectively. Statistically, there was a difference of approximately 1000 RNA copies/mL between swabs and masks and no significant difference in VL values among different types of masks. There were statistically significant differences in VL values between men and women and between symptomatic and asymptomatic patients. Our findings suggest the blocking of virus transmission by different types of masks and reinforce the use of masks by both infected and non-infected individuals.
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