How long does the serum from a syphilitic lesion remain contagious? Suppose an infected person has serum on his hand, touches a doorknob, and then X minutes or hours later another person touches the same doorknob?
Or any other surface - toilet flush knob, table, etc.
I read that syphilis is most often transmitted by direct contact with a lesion - but I'm asking about indirect contact via transfer of the lesion's serum. I guess the same question is - how long do the spirochytes(?) live when exposed to air? Thank you.