It doesn't matter. Syphilis is never transmitted by contact with a contaminated environment. However long the cause of syphilis (Treponema pallidum) survives in the environment, it doesn't infect people without sexual contact. Anyway, there has never been serious research to study this. Probably it's dead as soon as it dries out, which could be only a minute or two or maybe sometimes a few hours. Either way, don't worry about it. Without sex with an infected person, you are not at risk for syphilis.---
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