RESUMEN
Population surveillance in COVID-19 Pandemic is crucial to follow up the pace of disease and its related immunological status. Here we present a cross-sectional study done in Maricá, a seaside town close to the city of Rio de Janeiro, Brazil. Three rounds of study sampling, enrolling a total of 1134 subjects, were performed during May to August 2021. Here we show that the number of individuals carrying detectable IgG antibodies and the neutralizing antibody (NAb) levels were greater in vaccinated groups compared to unvaccinated ones, highlighting the importance of vaccination to attain noticeable levels of populational immunity against SARS-CoV-2. Moreover, we found a decreased incidence of COVID-19 throughout the study, clearly correlated with the level of vaccinated individuals as well as the proportion of individuals with detectable levels of IgG anti-SARS-CoV-2 and NAb. The observed drop occurred even during the introduction of the Delta variant in Maricá, what suggests that the vaccination slowed down the widespread transmission of this variant. Overall, our data clearly support the use of vaccines to drop the incidence associated to SARS-CoV-2.
Asunto(s)
COVID-19 , Cobertura de Vacunación , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Brasil/epidemiología , COVID-19/epidemiología , COVID-19/prevención & control , Estudios Transversales , Humanos , Inmunoglobulina G , Incidencia , Pandemias , SARS-CoV-2RESUMEN
Successive periods of reactivation of Trypanosoma cruzi in the myocardium may contribute to chronic, progressive myocardial damage and fibrosis, indicating that viable parasites are still present in the host, although the infection may remain quiescent or inapparent. Identifying the presence of active infection as well as the intensity of the inflammatory process can lead to the administration of more effective chemotherapeutic agents to exterminate the parasite. We investigated the use of Tc-99m-mononuclear leukocytes as a complementary tool for the diagnosis of active chagasic myocarditis. Using the stannous chloride labeling method, previously reported by us, 22 patients underwent Tc-99m-leukocyte scintigraphy. Planar images were obtained after 30 minutes, 3 and 24 hours of endovenous administration of approximately 444MBq (12 mCi) of the labeled cells. There was abnormal cardiac uptake in 3 of the 22 patients. These findings suggest the presence of markedly Chagas' disease activity with important clinical implications.