We explore here how variation in the SARS-CoV-2 virus tropism could influence epidemic spread. We use a compartmental model fit to the existing data. The model indicates that Wuhan quarantine measures were effective but that alternative virus forms (gut tropism) and a second propagation route (through environment) was present. For Singapore and Shenzhen region the secondary route does not seem to be active yet. Adequate prevention measures taking into account both routes should be implemented.