Q: 1) I wanted to improve my awareness about AIDS Will a person be contracted with AIDS by a single sexual intercourse. 2) I have read that the AIDS virus dies as soon as it is exposed to air, so will it be contracted if one is using a shaving blade which might have dried blood stains? 3) How early can a person come to know that he/she might have AIDS, and how much time will it take for the AIDS to show its effects.

A:1) Yes, if it is unprotected sexual intercourse with an unknown person. Although the sexual mode of transmission is inefficient, it is responsible for 75 - 85% of infections world wide especially in India. Sex with one's wife is the safest. One's wife ought to be the most beautiful woman in the world. 2) Though HIV is very sensitive to heat, it is very stable at room temperature(25-27C) for 15 days and at 37C for 11 days even in dried blood spots. This is because proteins in the blood form a protective layer around the virus particles and protect it from destruction. However, heating at 56C for 10 minutes or boiling at 100C for 1 min destroys the virus completely. 3) After contracting HIV infection (by any route), the progress of infection varies from person to person. It depends on several factors. It may vary from 2-3 years to more than 15 years. Nonetheless, it is estimated that 50% persons would die of AIDS within 10 years and 75% will die within 15 years after contracting HIV infection, if not treated. Once AIDS develops, the course is rapidly downhill and majority die within 24 months.