High risk groups are people who due to their lifestyle or occupation, are at very high risk for acquiring HIV infection. These include sex workers (both male, female, and transgender prostitutes), intravenus drug users, men who have sex with men, and people who have sex with many different partners whose sexual history and HIV status they do not know.
Prostitutes in India are very often infected with HIV/AIDS because they have sex with many different people every night. Since they do not have proper information about HIV/AIDS and how to protect themselves by using a condom every time they have sex without protection, they get infected. Also, many times they cannot afford to buy and use condoms, their customers do not tell them of their infections even if they know they are infected, and prostitutes do not have the power to refuse customers who may look very sick, and thus suspected of carrying HIV or other sexually transmitted diseases.
Truck drivers, especially those that drive long distance from one part of the country to another, have been found to have a high incidence of HIV in all parts of the world. The reason for this is that they spend a large part of their life away from their families and to relieve their lonliness and tensions they have sex with prostitutes and even worse with many different prostitutes during their long journeys. Since many of these prostitutes are HIV+, the risk of transmission increases with the number of times they have sex and with the number of different prostitutes they have sex with. The high risk has nothing to do with being a truck driver -- it has to do with having sex with many different prostitutes (people whose sexual history you dont know) and often.
Rajan Gupta