Welcome to HCM Hello,unprotected or doughtfull protection with a sex worker carries risk of HIV,STD,Hepatitis B,you are under the risk of contacting any of this. Touching private parts with hands that have no open wound or scratches does not cause any problem,but touching private parts to private parts there are chances of contacting the infection The tests you can under go are VDRL for STD,HIV Elisa,western blot for HIV,Hepatitis B test ,if you are married or have a regular partner than she also has to under go these test , The incubation period for HIV is 2 week to 6 month and the incubation period for Hepatitis B is 30 days to 180 days ,so you have to repeat the HIV test once in 3 months to be sure if the initial report is negative There are no medians to prevent or cure HIV ,prevention is the only way, on contact of infection opportunistic infection are treated and infection is kept under control with antirectroviral drugs You can take hepatitis B vaccination to prevent the infection ,if you have contacted the infection already than there is no cure STD can bee treated both you and your partner should be treated HIV,STD,Hepatitis B,Unwanted pregnancies all of these can be prevented by proper and consistent use of condom Thank you Dr.Krupa