RESUMEN
In this comprehensive study of 15 deceased patients with confirmed SARS-CoV-2 infection, spanning a time frame of 1 to 68 days from confirmation to death, autopsies were meticulously conducted with stringent safety measures. Clinical, laboratory, histopathological, and molecular analyses were integrated, shedding light on diverse pulmonary lesions, including acute inflammatory changes, vascular abnormalities, and aberrant regenerative processes. Immunohistochemical analysis, utilizing various markers, successfully identified the SARS-CoV-2 nucleocapsid antigen within infected tissue cells and also revealed what type of inflammatory cells are involved in COVID-19 pathogenesis. Molecular investigations through rt-qPCR revealed the persistent presence and varying quantities of viral genes, even after 68 days. Moreover, the viral nucleocapsid was present even in patients who died after 50 days of infection onset. Employing statistical analyses such as Chi-square and phi coefficient tests, significant associations among microscopic lesions and their correlation with molecular and immunohistochemical findings were elucidated. We could draw a map of what kind of lesions were a direct consequence of viral invasion and what lesions where secondary to the acute immunological response. This integrative approach enhances our understanding of the intricate relationships between pathological features, providing valuable insights into the multifaceted landscape of COVID-19 pathogenesis.
RESUMEN
Despite the large number of studies on rodent ectoparasites-most of them vectors of epidemiologically important pathogens-infestation patterns remain poorly understood in various ecological contexts, such as the highly patchy agricultural landscapes. We aimed to relate the infestation of rodents to temporal, habitat, and host variables. We assessed the difference in parasite prevalence and mean abundance depending on host sex, age, and body weight, season, and land use intensity. Furthermore, we analysed the effect of host species abundance and the differential responses of parasites in main and minor host species. The field survey was conducted in a rural landscape in southern Transylvania (Romania) between June and September 2010-2011. We live-trapped small mammals, collected the ticks and fleas, and recorded the presence of lice and mites. Overall, we found the same infestation patterns largely reported in the literature: higher prevalence and mean abundance in heavier adult males, significant seasonality and differences among host species, and evidence of the dilution effect. The uniqueness of our study system was the negative effect of the land use intensity on the prevalence and mean abundance of parasites, explained by the highly patchy mosaic landscape.
RESUMEN
Water is a risk factor for epidemics of waterborne diseases with effects on human health. In 2019, new viral pneumonia cases occurred in China and spread worldwide. The aim of this study was to assess the feasibility and accuracy of a wastewater-based epidemiological (WBE) monitoring tool in a SARS-CoV-2 hot spot (Sibiu City metropolitan area), namely to highlight the correlation between the number of infections on the days of sampling and the amount of viral RNA detected in wastewater. Wastewater samples were collected once a week, and viral RNA was extracted and quantified. In parallel, the daily number of SARS-CoV-2 infections was obtained from the local council. The correlation between the number of infections and viruses detected in sewage was measured by Pearson correlation coefficients. The results show the amount of viral RNA in the wastewater is directly correlated with the number of infections reported in the week up to the sampling day and also the number of infections reported for the sampling day. Moreover, correlation coefficients show the amount of viral RNA in wastewater increases in advance of the increase in reported infection cases. Therefore, WBE can be used as a tool for monitoring virus spread trends in human communities and can help anticipate the trend of this type of viral infection.
