My brother is worried about getting hiv infection, he had sex last night with a commercial sex worker (CSW) in kula lampur. He seem to have partial intercourse. Once without condom. Although he rinsed with water after ejection. And he hadn't erected in vagina. Our family is totally worried about this incident. And he is also very sad. Although the CSW said she doesn't have any HIV or STD. Is there a way to prevent hiv or to know if he was infected with it or not.