ABSTRACT
BACKGROUND Patients with severe coronavirus disease 2019 (COVID-19) often present with coagulopathies and have high titres of circulating antibodies against viral proteins. OBJECTIVES Herein, we evaluated the association between D-dimer and circulating immunoglobulin levels against viral proteins in patients at different clinical stages of COVID-19. METHODS For this, we performed a cross-sectional study involving patients of the first wave of COVID-19 clinically classified as oligosymptomatic (n = 22), severe (n = 30), cured (n = 27) and non-infected (n = 9). Next, we measured in the plasma samples the total and fraction of immunoglobulins against the nucleoprotein (NP) and the receptor-binding domain (RBD) of the spike proteins by enzyme-linked immunosorbent assay (ELISA) assays. FINDINGS Patients with severe disease had a coagulation disorder with high levels of D-dimer as well as circulating IgG against the NP but not the RBD compared to other groups of patients. In addition, high levels of D-dimer and IgG against the NP and RBD were associated with disease severity among the patients in this study. MAIN CONCLUSIONS Our data suggest that IgG against NP and RBD participates in the worsening of COVID-19. Although the humoral response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is partially understood, and more efforts are needed to clarify gaps in the knowledge of this process.
ABSTRACT
Abstract Aedes (Stegomyia) aegypti (A. aegypti) transmits arboviral diseases of high public health importance, including those caused by Zika virus (ZIKV), Dengue virus (DENV), Chikungunya virus (CHIKV) and Yellow fever virus (YFV). Barreiras is a city with 157,638 inhabitants in the West of the State of Bahia, Northeast of Brazil. The climate is dry, with well-determined and concentrated seasons of rains. The city is crossed by a Federal Highway and by the Rio Grande river. In this study, we aimed to understand the dynamics of mosquito vectors and arboviral diseases in Barreiras. We used correlation statistics to investigate a possible relationship among rains, mosquito abundance and transmission of diseases. In addition, as a preliminary population genetics estimate, we used geometric morphometrics to compare mosquitoes from areas limited by a highway and a river. We found that i) infestation occurs in rain-dependent cycles and that ii) both, the river and the highway segregate populations of A. aegypti in different areas of the studied city. Our results indicate that it is necessary to treat anthropic containers with mosquito breading capacity during both, the dry and rain seasons in urban areas similar to Barreiras.