Vitamin C and D supplementation and the severity of COVID-19: A protocol for systematic review and meta-analysis.

BACKGROUND: The COVID-19 pandemic has rapidly spread to other countries, causing numerous deaths and challenges for organizations and health professionals. Diet and nutrition invariably influence the competence of the immune system and determine the risk and severity of infections. Studies have already been published on the relationships through which vitamins C and D can mitigate the severity of infections such as COVID-19. In this context, this protocol describes a systematic review intended to analyze if vitamin C and D supplementation can reduce the severity of Covid-19. METHODS: This protocol was developed based on the recommendations of PRISMA-P. In order to accomplish the systematic review, we will carry out searches in the PubMed, Web of Science, Scopus, Cochrane, and ScienceDirect databases in the quest for control case studies that analyze the supplementation and evolution of patients with COVID-19. There will be no limitations related to language or publication time. The searches will be carried out by 2 independent researchers who will select the articles, and then the duplicate studies will be removed, while the suitable ones will be selected using the Rayyan QCRI application. In order to assess the risk of bias, we will use the instrument proposed by the National Heart, Lung and Blood Institute. Moreover, we will carry out metaanalyses and subgroup analyses according to the conditions of the included data. RESULTS: This review will assess the association between vitamin C and D supplementation and the reduction in the severity of COVID-19. CONCLUSION: The findings of this systematic review will summarize the latest evidence for the association between vitamin C and D supplementation and COVID-19 through a systematic review and meta-analysis. RECORD OF SYSTEMATIC REVIEW: CRD42021255763.

Association between ocular toxoplasmosis and APEX1 and MYD88 polymorphism.

Ocular toxoplasmosis (OT) is the most common form of posterior uveitis, and in some countries, it is the most frequent cause of visual impairment. Studies demonstrate that the polymorphism in genes involved with the immune response can be related both to the occurrence and to the recurrence of OT. Thus, the present study aimed to analyze the association between OT and the polymorphism of the APEX1 (rs1130409) and MyD88 (rs7744) genes. The studied sample consisted of 48 volunteers with OT and 96 asymptomatic volunteers, but positive for anti - T. gondii IgG (control group). Blood collection was performed for serological analysis (ELISA) and DNA extraction. Genotyping of the polymorphism was performed using real-time PCR. To analyze the association between gene polymorphism and OT, logistic regression was performed. The results showed no association between the MYD88 gene polymorphism and the development of OT. However, a significant association was found between OT and APEX1 gene polymorphism, indicating that individuals expressing polymorphic (GG) or heterozygous (GT) alleles are more likely to develop the disease (P-value = 0.02 and 0.03 respectively). These results suggest that APEX1 (rs1130409) polymorphism is a risk factor for the occurrence of ocular toxoplasmosis in the studied population.

Seroprevalence and risk factors for human toxoplasmosis in northeastern Brazil

Toxoplasmosis is one of the most prevalent parasitic infections in humans, causing severe clinical complications in immunocompromised patients or in foetuses. Estimates on the toxoplasmosis seroprevalence in human populations vary widely, even within the same region. This study aimed to estimate the prevalence of Toxoplasma gondii infection in the municipality of Santa Cruz, State of Rio Grande do Norte, Brazil, and identify the risk factors for toxoplasmosis. T. gondii IgG antibodies were measured in 66.2% of the studied population. The factors associated with infection were as follows: age above 45 years (OR = 7.4; 95% CI = 3.7-14.8); illiteracy (OR = 2.8; 95% CI = 1.6-5.0); the presence of more than three cats in the home (OR 2.0; 95% CI = 1.2-3.5); no water tank (OR = 2.0; 95% CI = 1.4-3.1); and consumption of raw or unpasteurized milk (OR = 2.0; 95% CI = 1.3-3.0). The risk factors identified were predominantly related to the ingestion of oocysts. This study may contribute to public health knowledge of toxoplasmosis and the definition of control programs, particularly for pregnant women from regions similar to the area studied.