Q: My five years old son was bitten by an HIV infected kid on his hand. What are the chances of his getting the infection? The infected kid had a cavity in his teeth though there was no visible blood. Initially, there was no wound or cut or abrasion but after two days I noticed that the area where my son was bitten was covered with a small red line. It was not deep but still I am scared. Should I get my son tested?

A:While additional information would be useful in answering your question (like how many days since the episode, is the other child on any specific treatment for his HIV status, was the affected area washed immediately, etc), you have given enough information for me to give an opinion. Please understand that I am sharing my opinion based on probabilities.

I feel that it is very probable that your son is not at risk of HIV infection after this unfortunate and worrying episode. My reasons for saying this are based on the following:

The skin was not really punctured as far as you could tell and there was no bleeding at the site. I am aware that there may have been some superficial scratch or damage.
• Saliva is not a potent source of HIV even though some virus may be found in saliva.
• There was no evident bleeding in the mouth of the child who bit your son.
Prophylactic treatment with anti-retrovirals is generally given within a short while after risk exposure, and current information suggests that it must be started not later than 72 hours after exposure. You may decide to get a HIV test to reassure yourself. If so consult your doctor / HIV specialist. We now have some tests that can give results even soon after infection and it is no longer necessary to wait for 12 weeks and then get the conventional ELISA type test. While I cannot, unfortunately, totally rule out the possibility of infection, the chances of infection are very, very low.