Greetings Dr. Bob,
I know the window period question is one that never dies, but hopefully this touches on something that hasn't been addressed.
I know that there are certain things that could delay the HIV window period even past the conservative CDC guidelines of 6 months for absolute certainty. If a person has a potential exposure to HIV and also Hepatitis through blood, but HCV tests aren't readily available, how long must they wait to be tested for HIV to be certain they are negative. Assuming the worst case scenario, and HCV infection does occur from this potential exposure, would 12 months be enough time for a conclusive and definitive HIV test?
I can't imagine anywhere on the planet where you could get HIV testing but hepatitis screening was not available. (All you would need is a hepatitis C antibody test!) But to answer your question, yes, 12 months would certainly be conclusive.