Rosemary Ancelle-Park

Knowledge of HIV serostatus and preventive behaviour among European injecting drug users

OBJECTIVE To study the effect of knowledge of HIV serostatus on behaviour for preventing the acquisition or transmission of HIV among European injecting drug users (IDU). METHODS Data on behaviour and prior knowledge of HIV status were gathered during a multicentre cross-sectional survey of 200 European IDU recruited in 12 European countries in 1990. The respective proportions of IDU who (1) used condoms, (2) did not give their used injecting equipment to other IDU and (3) injected drugs safely (ether did not re-use other IDUs equipment or re-used it only after disinfection with bleach, alcohol or boiling water during the 6 months preceding interview were compared according to whether they knew their HIV serostatus for at least 6 months prior to interview. RESULTS In comparison with IDU who had never been tested, IDU who knew that they were HIV-seropositive were more likely to always use condoms [rate ratio (RR) = 3.1; 95% confidence interval (CI), 2.3-4.2] and never gave their used equipment to other IDU (RR = 1.3; 95% CI, 1.2-1.5), but did not differ with regard to safe injecting practices (RR = 1.0; 95% CI, 0.9-1.1). Compared with IDU who had never been tested, IDU with a negative test tended to inject drugs safely more often (RR = 1.1; 95% CI, 1.02-1.2). There was no significant difference in condom use (RR = 0.7; 95% CI, 0.5-1.1). CONCLUSION These results indicate that the knowledge of HIV serostatus may help to reduce HIV transmission from HIV-positive IDU to others through safer injecting and sexual behaviour. However, for HIV-negative IDU safer injecting behaviour appears to be better accepted than safer sexual behaviour.

Knowledge of HIV serostatus and preventive behaviour among European injecting drug users: Second study

The objective of the study was to analyse the effect of knowledge of HIV serostatus on behaviours preventing the acquisition or transmission of HIV among European IDU, and to compare results with a previous similar study conducted 3 years before. Data were gathered in 1992–1993 during a retrospective multicentre cross-sectional study of IDU recruited in 11 European countries, in specialized centers and on the street. We compared, between groups with different HIV serological status (IDU who knew well before their HIV-positive serological status, IDU who knew their HIV-negative serostatus and IDU who did not know before their serological status), the respective proportions of IDU who reported that, during the six months prior to interview, (1) always used condoms, (2) never gave their used injecting equipment to other IDU, (3) always injected drugs safely. We only included IDU who had known their serological status for at least six months prior to interview. Results were compared to the similar survey conducted in 1990. From 2171 IDU recruited, data of 1334 IDU were included in the analysis. Compared with IDU who did not know their HIV serostatus, only IDU knowing their HIV-positive serostatus used condoms significantly more often (37% compared to 15%, rate ratio (RR): 2.4; 95% confidence interval (CI): 1.8–2.3) and never gave their used injecting equipment to other IDU (69% compared to 53%, RR: 1.3; 95% CI: 1.2–1.4). In comparison with the 1990 study, only condom use significantly improved and only for IDU who knew their HIV-negative serostatus (13% compared to 9%, RR: 1.6; 95% CI: 1.1–2.3). This study confirms among European IDU the relation between knowing own HIV serological status to preventive behaviours. However, there were only minor improvements between 1990 and 1992–1993, indicating that prevention of HIV transmission among IDU must be reinforced.

Factors associated with HIV seropositivity in European injecting drug users

OBJECTIVE To study factors associated with HIV seropositivity among European injecting drug users (IDU). METHODS Data on behavioural and other factors potentially associated with HIV status were collected retrospectively by personal interview with IDU (n = 2330) in a multicentre cross-sectional survey conducted in 12 European countries from 1989 to 1990. HIV status tested at the time of the survey was examined in relation to demographic data, history of imprisonment, travel to foreign countries, high-risk drug-using practices in the previous 6 months (re-using other IDUs injecting equipment without effective disinfection) and high-risk sexual behaviour in the last 6 months (multiple partners, unless none was IDU and condoms were always used). Analysis excluded IDU who claimed to be seropositive from previous testing. RESULTS Imprisonment was significantly associated with current HIV status [odds ratio (OR), 1.70; 95% confidence interval (CI), 1.2-2.87]. High-risk drug-use practices were significantly associated with current HIV status in respondents not previously tested (OR, 2.86; 95% CI, 1.09-7.35) but not in respondents claiming to be seronegative. No significant association was found for high-risk sexual behaviour. CONCLUSIONS Our experience supports the validity of retrospective investigation of behaviour in a population that is notoriously difficult to study. However, any interpretation of the apparently different associations of HIV status with high-risk sexual behaviour and high-risk drug-use practices must consider that factors tending to attenuate the correlations may operate differently in these two areas.

Surveillance of AIDS in the European Community: recent trends and predictions to 1991.

Statistical modelling is applied to routine AIDS surveillance data to assess recent trends and to provide a range of short-term predictions. Several alternative functions have been fitted to half-yearly incidence data reported by the countries of the European Community by 31 December 1989 and adjusted for reporting delays. Among homosexual/bisexual men, recent trends in AIDS incidence are more nearly linear than exponential. Higher though less than exponential rates of growth are observed among intravenous drug users and among those presumed infected by heterosexual contact. Extrapolations to the end of 1991 using each of five functions provide a range of forecasts. Projections of total cumulated cases to the end of 1991 lie in the range 60,000-78,000, with 24,000-30,000 projected cases among homosexual/bisexual men, 23,000-33,000 among intravenous drug users, and 6000-8000 in the heterosexual transmission group. With the possible exception of the latter group, the lower parts of these ranges appear more probable.

Incubation Period of Vertically Acquired Aids in Europe Before Widespread Use of Prophylactic Therapies

European surveillance data on vertically acquired (VA) AIDS cases were used to investigate the incubation period of AIDS in the absence of widespread prophylactic treatment and to assess the uncertainty associated with parametric estimates based on retrospective data. Nonparametric and parametric analyses, taking into account the effects of data truncation, were based on a total of 792 children diagnosed with AIDS between July, 1982, and June, 1990, inclusive. Among HIV-infected children who develop AIDS within 8 years, the nonparametric estimate of the median age at diagnosis was 34 months. If 20% of children are assumed to develop AIDS by the age of 1 year (a plausible estimate on the basis of published cohort data), the estimated median among all maternally HIV-infected children is 4.4 years, with 26% of children expected to remain AIDS free by 8 years of age. Results from the parametric (double Weibull) model support the hypothesis of a bimodal distribution, with a subgroup of children progressing rapidly to AIDS at a median age of approximately 5 months. However, neither the relative size of this group nor the median age at which AIDS develops in the remaining children can yet be estimated with any reasonable precision.