If a person has been exposed to HIV infected body fluids (for example, through being raped) then he or she should start with ART within 72 hours of possible post exposure through rape or unprotected sex. This is called Post-exposure prophylaxis (PEP). PEP is a short-term anti-retroviral treatment that reduces the likelihood of HIV infection after exposure to HIV-infected blood or sexual contact with an HIV-positive person. The drug regimen for PEP consists of a combination of ARV medications that are taken for a period of four weeks.