Experts have expressed concern over the drastic increase in the number of HIV positive cases in Rajasthan during the past three years. Till the end of the previous year, the State had 340 cases tested HIV positive and 58 cases of AIDS but the officials here feel that with every one case detected there ought to be 10 other cases going unnoticed. They expressed the fear that Rajasthan at present must be having at least 600-700 cases of HIV positive.