Relationship between meteorological factors, air pollutants and hand, foot and mouth disease from 2014 to 2020.

BACKGROUND: Meteorological factors and air pollutants have been reported to be associated with hand, foot, and mouth disease (HFMD) epidemics before the introduction of vaccine. However, there is limited evidence for studies with long-term dimensions. METHODS: We collected the daily HFMD counts, weather and air pollution data from 2014 to 2020 in Chengdu. Distributed lag non-linear models (DLNM) were used to assess the associations of meteorological factors and air pollutants on HFMD cases. RESULTS: From 2014-2020, high relative humidity and precipitation and extremely high and low levels of PM10, O3, SO2 and CO increased the risk of HFMD. In pre-vaccination period, extreme high and low temperatures, PM10 and NO2, low precipitation and high concentrations of PM2.5 and O3 significantly increase the risk of HFMD; In post-vaccination period, high relative humidity and low level of CO can significantly increase the incidence of HFMD; During the period of COVID-19, only low temperature will significantly increase the risk of HFMD; Low concentration of air pollutants has the greatest impact on the 6-14 age group, while the high concentration of air pollutants has the greatest impact on the 0-1 age group. CONCLUSIONS: Our study suggest that high relative humidity and precipitation and extremely high and low levels of PM10, O3, SO2 and CO increased the risk of HFMD from 2014 to 2020. The results of this study provide a reference for local authorities to formulate intervention measures and establish an environment-based disease early warning system.

Effect of early oxygen therapy and antiviral treatment on disease progression in patients with COVID-19: A retrospective study of medical charts in China.

BACKGROUND: Until now, no antiviral treatment has been proven to be effective for the coronavirus disease 2019 (COVID-19). The timing of oxygen therapy was considered to have a great influence on the symptomatic relief of hypoxemia and seeking medical intervention, especially in situations with insufficient medical resources, but the evidence on the timing of oxygen therapy is limited. METHODS AND FINDINGS: Medical charts review was carried out to collect the data of hospitalized patients with COVID-19 infection confirmed in Tongji hospital, Wuhan from 30th December 2019 to 8th March 2020. In this study, the appropriate timing of oxygen therapy and risk factors associated with severe and fatal illness were identified and the effectiveness of antivirus on disease progression was assessed. Among 1362 patients, the prevalence of hypoxia symptoms was significantly higher in those patients with severe and fatal illness than in those with less severe disease. The onset of hypoxia symptoms was most common in the second to third week after symptom onset, and patients with critical and fatal illness experienced these symptoms earlier than those with mild and severe illness. In multivariable analyses, the risk of death increased significantly when oxygen therapy was started more than 2 days after hypoxia symptoms onset among critical patients (OR, 1.92; 95%CI, 1.20 to 3.10). Compared to the critically ill patients without IFN-a, the patients who were treated with IFN-a had a lower mortality (OR, 0.60; 95%CI, 0.39 to 0.91). CONCLUSIONS: Early initiation of oxygen therapy was associated with lower mortality among critical patients. This study highlighted the importance of early oxygen therapy after the onset of hypoxia symptoms. Our results also lend support to potentially beneficial effects of IFNα on critical illness.