Effects of Chinese provincial CDCs WeChat official account article features on user engagement during the COVID-19 pandemic.

Background: WeChat has become a potent medium for disseminating public health information, especially during the coronavirus disease 2019 (COVID-19) pandemic. WeChat is important for public health organizations when considering users' information needs and preferences to further explore factors that affect user engagement. Methods: We collected data from WeChat official accounts (WOAs) of the Chinese provincial Center for Disease Control and Prevention (CDC) to identify factors affecting and predicting the behavior of user engagement as measured by the level of reading and re-sharing during different phases of the COVID-19 pandemic between January 1, 2019, and December 31, 2020. We used multiple logistic regression analyses to identify features of articles with higher reading and re-sharing levels from 31 Chinese provincial CDCs. We developed a nomogram to predict the effect on user engagement. Results: We collected a total of 26 302 articles. Release position, title type, article content, article type, communication skills, marketing elements, article length, and video length were key determinants of user engagement. Although the feature patterns also varied between different pandemic stages, the article content, release position, and article type were still the most prominent features driving user engagement. Regarding article content, the COVID-19 pandemic report and guidance for public protection were more likely to obtain high-level reading (normalization: odds ratio (OR) = 12.340, 95% confidence interval (CI) = 9.357-16.274) and re-sharing (normalization: OR = 7.254, 95% CI = 5.554-9.473) than other contents throughout the pandemic. When we compared release position with secondary push, users who used main push were more likely to exhibit high-level reading and re-sharing during any period, especially during normalization (OR = 6.169, 95% CI = 5.554-6.851; OR = 4.230, 95% CI = 3.833-4.669). For article type, a combination of text, links and pictures was associated with a higher rate of reading (normalization: OR = 4.262, 95% CI = 3.509-5.176) and re-sharing level (normalization: OR = 4.480, 95% CI = 3.635-5.522) compared to text only. Simultaneously, the prediction model showed good discriminatory power and calibration. Conclusions: Discrepancies exist in article features between different pandemic stages. Public health agencies should make full use of official WOAs and consider the information needs and preferences of users in order to better carry out health education and health communication with the public when public health events occur.

Characteristics of Angiotensin I-converting enzyme 2, type II transmembrane serine protease 2 and 4 in tree shrew indicate it as a potential animal model for SARS-CoV-2 infection.

Angiotensin I-converting enzyme 2 (ACE2), type II transmembrane serine protease 2 and 4 (TMPRSS2 and TMPRSS4) are important receptors for SARS-CoV-2 infection. In this study, the full-length tree shrewACE2 gene was cloned and sequenced, and its biological information was analyzed. The expression levels of ACE2, TMPRSS2 and TMPRSS4 in various tissues or organs of the tree shrew were detected. The results showed that the full-length ACE2 gene in tree shrews was 2,786 bp, and its CDS was 2,418 bp, encoding 805 amino acids. Phylogenetic analysis based on the CDS of ACE2 revealed that tree shrews were more similar to rabbits (85.93%) and humans (85.47%) but far from mice (82.81%) and rats (82.58%). In silico analysis according to the binding site of SARS-CoV-2 with the ACE2 receptor of different species predicted that tree shrews had potential SARS-CoV-2 infection possibility, which was similar to that of rabbits, cats and dogs but significantly higher than that of mice and rats. In addition, various tissues or organs of tree shrews expressed ACE2, TMPRSS2 and TMPRSS4. Among them, the kidney most highly expressed ACE2, followed by the lung and liver. The esophagus, lung, liver, intestine and kidney had relatively high expression levels of TMPRSS2 and TMPRSS4. In general, we reported for the first time the expression of ACE2, TMPRSS2 and TMPRSS4 in various tissues or organs in tree shrews. Our results revealed that tree shrews could be used as a potential animal model to study the mechanism underlying SARS-CoV-2 infection.