If you are raped by someone who is HIV-positive and you then go on emergency ARVs in order to prevent you getting the disease, how do they stop you from getting HIV? I’ve heard that with normal ARVs you can only take them after your CD4 count has dropped below 200, so how are the emergency ARVs different? How do they stop you from actually getting the disease if you take them right away, but don’t stop you from getting the disease if you wait before you take them?

You ask a very interesting and complex question. I hope that my answer will satisfy you.
Firstly, there is no difference between the treatment you get after a rape (post-exposure prophylaxis) and the treatment you get when you are HIV-positive and your CD4 count is 200 or below. These drugs are the same but given for different reasons.

In the first few weeks of getting HIV, your body fights hard to protect itself. If you are HIV-negative and you get raped, the ARV’s will ensure that the virus does not duplicate in your blood and your immune system is able to kill off the entire virus in your blood. \

However, the doctors must make sure that you are HIV negative at the time of getting raped and you can only get ARVs within the first 72 hours of the rape for them to be effective. If you are already HIV-positive, you will not be given ARVs, but instead be referred to an AIDS clinic for further treatment.

It is also important to note that even if one has taken the drugs for the prescribed period after a rape, you should be retested after six month. The ARVs do not cure the HIV. They are given to you to help your body fight the virus.