ASSESSING THE EXTENT OF THE HIV EPIDEMIC IN SWEDEN, USING INFORMATION ON THE EXTENT TO WHICH PEOPLE WHO DEVELOP AIDS ARE ALREADY KNOWN TO BE HIV INFECTED

In Sweden, cases of both HIV infection and AIDS are registered. By looking at the extent to which people who develop AIDS are already known to be HIV-infected, we can assess the coverage of the HIV registration. It was found that virtually all those who were infected by injecting themselves with drugs, blood transfusions, blood products or congenitally were already known to be infected when AIDS developed. However, when homosexual or heterosexual transmission had occurred, 20.5% and 33.3% respectively of these cases were not previously known. Working with different assumptions regarding the development of the epidemic, we find that the true number of sexually infected people is roughly twice the number of registered HIV-infected people in these groups. Our estimate is that between 3300 and 6300 people were infected with HIV in Sweden up till the end of 1990.