Hi,

A stranger on the train shake hand with me and after I reached home I realised that there is a long cut on my hand. Would I get aids if the man put his blood on a ring and use it to cut me? Should I go for a HIV test? How long should I wait before I go for the test? Pls advise thanks.

Based on the epidemiological knowledge of HIV and its transmission, there is no evidence that HIV has been transmitted through casual contact. It's important to remember that HIV is only known to be transmitted through the following three ways:

1)Sexual contact: anal, vaginal, and oral sex

2) Blood-to-blood contact: sharing injection needles, occupational exposures, blood transfusions (which is rare in the U.S.). This does not include coming into contact with blood when shaking hands with a stranger.

3) Mother-to-infant: either through delivery or during breast feeding

If you are not engaging in any of these activities, then the odds of transmission are theoretical only.

Also, HIV does not survive in the environment long enough to cause transmission through contact outside of the above three categories. This is why we don't see transmission through contact with inanimate objects and other forms of casual contact (like eating food, sharing drinking glasses, using public restrooms, etc.). Studies of families living with an HIV infected person have demonstrated this. See "Survival of HIV in the Environment" (http://www.thebody.com/cdc/survival.html) for more information.

RMK