At least the women from Geylang are tested. The problem is that
Singaporeans go to Batam, Bintan, Bangkok, China and God knows what
other places....where the prostitutes are NEVER tested for
gonorrhoea, much less HIV.
One way to discourage it is to name and shame. Send reporters on
these overseas sex trips and photograph the men who go and visit
the prostitutes there. Publish their photos in the newspaper...that
will stop a lot of them and scare many more not to follow their
example.