China is lying. Wuhan has bio lab very near to where first cases were. First victims were NOT at the sea food that supposedly caused the outbreak. I read China bio labs have more mishaps than any other country and supposedly laboratory animals that should be destroyed sometimes end up on the black market and then someone's dinner.
If the virus is a "normal" virus, then yes transmission rates should go down in Northern Hemisphere as we approach summer and increase in Southern as they will be approaching winter. But we don't know if this is a "normal" virus, especially if indeed China is lying and it escaped from their lab.