RESUMO
BackgroundIn observational studies, Alzheimers disease (AD) has been associated with an increased risk of Coronavirus disease 2019 (COVID-19), and the prognosis of COVID-19 can affect nervous systems. However, the causality between these conditions remains to be determined. MethodsThis study sought to investigate the bidirectional causal relations of AD with COVID-19 using two-sample Mendelian randomization (MR) analysis. ResultsWe found that genetically predicted AD was significantly associated with higher risk of severe COVID-19 (odds ratio [OR], 3.329; 95% confidence interval [CI], 1.139-9.725; P=0.028). Its interesting that genetically predicted severe COVID-19 was also significantly associated with higher risk of AD (OR, 1.004; 95% CI, 1.001-1.007; P=0.018). In addition, the two strong genetic variants associated with severe COVID-19 was associated with higher AD risk (OR, 1.018; 95% CI, 1.003-1.034; P=0.018). There is no evidence to support that genetically predicted AD was significantly associated with COVID-19 susceptibility, and vice versa. No obvious pleiotropy bias and heterogeneity were observed. ConclusionOverall, AD may causally affect severe COVID-19, and vice versa, performing bidirectional regulation through independent biological pathways.
RESUMO
Most common causative agents for hand, foot and mouth disease (HFMD) are enterovirus 71 (EV-A71) and coxsackievirus A16 (CV-A16). The symptomatic and asymptomatic cases could transmit the disease in population. Many sero-epidemiological surveys were launched to estimate the sero-incidence of EV-A71 and CV-A16 enterovirus, the susceptibility of different sub-population, and to observe the dynamics of neutralizing antibody. A literature search of sero-epidemiological study focused on EV-A71 or CV-A16 was conducted via PubMed and China Hospital Knowledge Database. Based on the 20 selected studies, the different age groups' antibody level, the susceptibility, the dynamics of antibody and sero-incidence of EV-A71 or CV-A16 were analyzed. From our results, the antibody level against EV-A71 or CV-A16 in neonates was associated with their mothers, which was similar with that of adults. The antibody level against EV-A71 or CV-A16 in neonates dropped to lowest level at one years-old, and started to dramatically increase until four years-old, and reached a plateau at five years-old. In conclusion, the infants aged 6-12 months were the priority group to receive vaccination when the EV-A71 vaccine is licensed in the future.
