Dynamics of SARS-CoV-2 seroprevalence during the first year of the COVID-19 pandemic in the Northeast region of Brazil.

In this household-based seroepidemiological survey, we analyzed the dynamics of SARS-CoV-2 seroprevalence during the first year of the COVID-19 pandemic in Sergipe State, Northeast Brazil, the poorest region of the country. A total of 16,547 individuals were tested using a rapid IgM-IgG antibody test and fluorescence immunoassay (FIA). Seroprevalence rates were presented according to age, sex, and geographic region. A comparative analysis was performed between the results obtained in July 2020 (peak of the first wave), August - November 2020 (end of the first wave), and February - March 2021 (beginning of the second wave). Seroprevalence rates in the three phases were estimated at 9.3% (95% CI 8.5-10.1), 12.0% (95% CI 11.2-12.9) and 15.4% (95% CI 14.5-16.4). At the end of the first wave, there was a rise in seroprevalence in the countryside (p < 0.001). At the beginning of the second wave, we found an increase in seroprevalence among women (p < 0.001), adults aged 20 to 59 years (p < 0.001), and the elderly (p < 0.001). In this phase, we found an increase in estimates both in metropolitan areas and in the countryside (p < 0.001). This study showed an increase in SARS-CoV-2 seroprevalence over the first year of the pandemic, with approximately one in six people having anti-SARS-CoV-2 antibodies at the beginning of the second wave of COVID-19. Furthermore, our results suggest a rapid spread of COVID-19 from metropolitan areas to the countryside during the first months of the pandemic.

Hesperetin-Based Hydrogels Protect the Skin against UV Radiation-Induced Damage.

UV radiation can cause damages, such as erythema, skin photoaging, and carcinogenesis. The adoption of protective measures against sun exposure is essential to prevent these damages, and the interest in using natural substances as an alternative for photoprotection is growing. Thus, hesperetin with antioxidant, anti-inflammatory, and anticancer properties is a promising substance to be used with photochemopreventive action and to protect the skin from damage induced by UV radiation. Therefore, the present study aimed to develop a topical formulation based on AAMVPC gel containing hesperetin and evaluate its photoprotective effect on the skin of rats exposed to UVA-UVB radiation. The animals were submitted to the irradiation protocol UVA-UVB, and at the end, erythema, lipid peroxidation, and activity of the antioxidant enzyme catalase and superoxide dismutase were evaluated. Additionally, it evaluated the activity of myeloperoxidase and histological changes. The formulation presented a rheological and spreadability profile suitable for cutaneous application. In vivo results demonstrated that the topical formulation of AAMVPC gel containing hesperetin at a concentration of 10% protected the skin from damage induced by UVA-UVB radiation, with the absence of erythema, lipid lipoperoxidation, and inflammation (low myeloperoxidase activity), and increased catalase and superoxide dismutase activities. The morphology and architecture of the dermo-epidermal tissue of these animals were like those observed under normal conditions (non-irradiated animals). Thus, the results showed that hesperetin was able to protect the animals' skin against UV radiation-induced skin damage and the protection mechanisms may be related to the antioxidant and anti-inflammatory properties of this natural product.

Seroprevalence of SARS-CoV-2 antibodies in radio and television workers.

We investigated the seroprevalence of SARS-CoV-2 antibodies in individuals working in radio and television stations (TV) in Sergipe state, Northeast Brazil. This cross-sectional study was conducted from December 1 to December 20, 2020, a period which was considered as the beginning of the second wave of COVID-19 in the state. One hundred and thirteen professionals from the three largest media companies in the state were included in this study. Venous blood was collected using venipuncture and a fluorescence immunoassay for qualitative detection and differentiation of IgM and IgG antibodies against SARS-CoV-2 was performed. Twenty-eight media workers had detectable levels of SARS-CoV-2 antibodies (11 IgM+, 6 IgM+/ IgG+, and 11 IgG+) and the estimated seroprevalence was 24.8 % (95 % CI 17.7 - 33.5). Our findings showed a high seroprevalence of SARS-CoV-2 antibodies in radio and TV workers during the second wave of COVID-19 in Brazil.

Phytochemical screening and cardiovascular effects of the ethanol extract of Erythroxylum passerinum mart.

Species of Erythroxylum genus are popularly used as anti-inflammatories and in the treatment of renal and respiratory disorders. Although it has been reported that species from the Erythroxylum genus induce cardiovascular effects, E. passerinum had not been studied specifically in this respect. However, previous phytochemical studies of E. passerinum demonstrated the presence of compounds which can have potential activity on the cardiovascular system. In this study, phytochemical screening of the ethanol extract of E. passerinum (EEEP) detected polyphenols, but not alkaloids. EEEP caused hypotension, bradycardia and vasorelaxation in rats. The vasorelaxation was attenuated by Nw-nitro-L-arginine methyl ester (L-NAME) or L-NAME + indomethacin (INDO), but not by INDO alone. Vasorelaxation was also significantly attenuated after endothelium removal or after incubation with high K+, 4-aminopyridine, glibenclamide or tetraethylammonium, but was not affected by pre-contraction with serotonin. Thus, EEEP induces hypotension and endothelium-dependent and independent vasorelaxation, which seems to involve the nitric oxide and K+-channels.

Seroprevalence of SARS-CoV-2 antibodies in the poorest region of Brazil: results from a population-based study.

Population-based seroprevalence studies on coronavirus disease 2019 (COVID-19) in low- and middle-income countries are lacking. We investigated the seroprevalence of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) antibodies in Sergipe state, Northeast Brazil, using rapid IgM-IgG antibody test and fluorescence immunoassay. The seroprevalence was 9.3% (95% CI 8.5-10.1), 10.2% (95% CI 9.2-11.3) for women and 7.9% (IC 95% 6.8-9.1) for men (P = 0.004). We found a decline in the prevalence of SARS-CoV-2 antibodies according to age, but the differences were not statistically significant: 0-19 years (9.9%; 95% CI 7.8-12.5), 20-59 years (9.3%; 95% CI 8.4-10.3) and ≥60 years (9.0%; 95% CI 7.5-10.8) (P = 0.517). The metropolitan area had a higher seroprevalence (11.7%, 95% CI 10.3-13.2) than outside municipalities (8.0%, 95% CI 7.2-8.9) (P < 0.001). These findings highlight the importance of serosurveillance to estimate the real impact of the COVID-19 outbreak and thereby provide data to better understand the spread of the virus, as well as providing information to guide stay-at-home measures and other policies. In addition, these results may be useful as basic data to follow the progress of COVID-19 outbreak as social restriction initiatives start to be relaxed in Brazil.