Decreasing seroprevalence of human immunodeficiency virus type 1 in a regional blood donor population

[HIV seropositivity in blood donors from 1990 to 1992: prevalence, estimation of residual risk of transfusion-related infections and epidemiology]

In France, HIV seroprevalence in blood donations still decreased from 1990 to 1992 with an important diminution in 1992, in first time donors as well as in regular donors. During the last 1992 semester, this prevalence reached 0.051%: 0.19% and 0.026% in donations from first time and regular donors respectively. The residual risk was estimated to be 1 for 580,000 donations in 1992 (CI 95% = 1/2,000,000 to 1/330,000). Sex ratio was 3.7 and 3.4 in 1990 and 1991 and increased to 5.5 in 1992 due to a very small number of seropositive women, which seems to be an important epidemiological indicator. The major at-risk group is still represented by homo-bisexual men.

Human immunodeficiency virus antibodies in sera of Australian blood donors: 1985-1990

OBJECTIVE

To describe the results of human immunodeficiency virus type 1 (HIV-1) antibody testing of blood donations in Australia.

DESIGN

Blood transfusion services tabulated the number of HIV-1 antibody tests carried out on blood donations and the number of donations found to be positive, from 1985 to 1990.

SETTING

All blood transfusion services in Australia.

PARTICIPANTS

All donors of blood in Australia from 1 May 1985 to 31 December 1990.

OUTCOME MEASURES

The proportion of blood donations found to have HIV-1 antibody, according to State or Territory, year of donation and, when available, age, sex and donation status (repeat or first-time) of the donor.

RESULTS

To the end of December 1990, 5,367,970 donations had been tested for HIV-1 antibody, and 46 were found to have the antibody, giving an overall prevalence rate of 0.86 per 100,000 donations. The highest rate was recorded in New South Wales, followed by Western Australia, and four of eight Australian States and Territories reported no donors with HIV-1 antibody. There has been no clear trend with time, but the rate is about 20% higher for 1989-1990 than for 1985-1986. Of donors found to have HIV-1 antibody, 67% were male and 33% female, and 41% reported no known or potential exposure to HIV-1 other than heterosexual contact. Among blood donors in two major Australian cities, the overall prevalence of HIV antibody was higher in those who were male, younger, and first-time donors. There has been a recent increase in the number of blood donors with HIV-1 antibody who were women reporting heterosexual contact as their only potential exposure.

CONCLUSION

The rate of HIV-1 antibody in Australian blood donations remains very low and shows no clear temporal trend, but specific donor characteristics define higher rates of antibody prevalence.