Major decline of hepatitis C virus incidence rate over two decades in a cohort of drug users

Injecting drug users (DU) are at high risk for hepatitis C virus (HCV) and HIV infections. To examine the prevalence and incidence of these infections over a 20-year period (1985–005), the authors evaluated 1276 DU from the Amsterdam Cohort Studies who had been tested prospectively for HIV infection and retrospectively for HCV infection. To compare HCV and HIV incidences, a smooth trend was assumed for both curves over calendar time. Risk factors for HCV seroconversion were determined using Poisson regression. Among ever-injecting DU, the prevalence of HCV antibodies was 84.5% at study entry, and 30.9% were co-infected with HIV. Their yearly HCV incidence dropped from 27.5/100 person years (PY) in the 1980s to 2/100 PY in recent years. In multivariate analyses, ever-injecting DU who currently injected and borrowed needles were at increased risk of HCV seroconversion (incidence rate ratio 29.9, 95% CI 12.6, 70.9) compared to ever-injecting DU who did not currently inject. The risk of HCV seroconversion decreased over calendar time. The HCV incidence in ever-injecting DU was on average 4.4 times the HIV incidence, a pattern seen over the entire study period. The simultaneous decline of both HCV and HIV incidence probably results from reduced risk behavior at the population level

Prospective cohort study of female sex workers and the risk of HIV infection in Alicante, Spain (1986-96)

OBJECTIVE: To measure the incidence of HIV infection over a 10 year follow up in a cohort of female commercial sex workers in Alicante (Spain), and to determine factors associated with high risk of infection. METHODS: A prospective cohort study was carried in an AIDS information and prevention centre in Alicante, Spain. Of the 1388 female sex workers who initially sought the services of the centre since September 1986, 657 completed at least one additional follow up visit before December 1996. Main outcome measures were infection with HIV-1 and reported risk behaviours. RESULTS: During 1815 person years of observation among 657 female sex workers who were free of HIV infection (negative test), 16 women developed of HIV infection (incidence rate of HIV infection = 8.8 cases/1000 woman years, 95% confidence interval (CI): 5.4-14.4). Reported current use of injecting drugs at the first visit was associated with an increased risk of HIV infection (relative risk, RR = 12.87, 95% CI: 4.81-34.15) as well as having an usual partner with injecting drug addiction (RR = 20.89, 95% CI: 7.44-58.70). Infection also was associated with younger age (RR for 1 year = 0.86, 95% CI: 0.76-0.96). After multivariate adjustment using Poisson regression analysis, the factors that remained significantly associated with the risk of HIV infection were current use of injecting drugs (RR = 4.61, 95% CI: 1.37-15.46), and having a usual partner with injecting drug addiction (RR = 10.08, 95% CI: 2.94-34.57). There was also some evidence that a younger age could be related to infection. CONCLUSION: These data suggest that the risk of HIV infection among this cohort of female sex workers in Alicante is predominately associated with the use of injecting drugs, and having a regular partner with injecting drug addiction. An increasing number of clients did not play a role in the risk of infection.This project has been supported by grants of the Generalitat Valenciana (IVESP) and the Fondo de Investigación Sanitaria (FIS 89/0775, FIS 95/1688)

Methadone maintenance treatment (MMT) in general practice or in specialized centers: profile of patients in the Swiss Canton of Vaud.

We studied profile of patients (n=1782) treated in specialized centers and general practice (GP) enrolled in methadone maintenance treatment (MMT) programs during 2001 in the Swiss Canton of Vaud. We found that GPs treated the majority of patients (76%). Specialized centers treated a higher proportion of patients with uncontrolled intravenous use of cocaine and heroin, and prescribed neuroleptics as concomitant medication three times more frequently than GPs. Patients treated in specialized centers were more likely to undergo screening for HIV, HBV, HCV, and receive complete HBV immunization. In conclusion, specialized centers are more likely to treat severely addicted patients and patients with a poor global assessment (physical, psychiatric, and social)

Do Young Heroin Users in Madrid, Barcelona and Seville have Sufficient Knowledge of the Risk Factors for Unintentional Opioid Overdose?

To identify the self-perceived reasons for unintentional opioid overdose of young heroin users in three Spanish cities and their agreement with objective risk factors for overdose. Computer-Assisted Personal Interviews (CAPI) were held with 991 street-recruited current heroin users aged 18–30. The general reasons for overdose and the reasons for the last overdose suffered were explored with open-ended (OEQs) and pre-coded questions (PCQs). Limited knowledge of overdose risk factors was defined as mention of fewer than two objective risk factors for unintentional overdose in the OEQ. Univariate, bivariate, and logistic regression methods were used. 77.8% (Seville), 64.9% (Madrid) and 57.2% (Barcelona) of participants have limited knowledge of overdose risk factors. Residence in Seville and not having attended courses or meetings on overdoses were significantly associated with limited knowledge, after adjusting for other factors. The most frequently identified general reasons in OEQ or PCQ were using heroin in large amounts (66.8%), together with tranquilizers (62.0%), adulterated (60.7%), or purer than usual (57.6%). Most reasons were selected more frequently in PCQ than in OEQ, especially rapid injection of the entire dose and using heroin shortly after using tranquilizers or alcohol, by injection, or after a period of abstinence. The results were similar for overdoses suffered by participants. Most young heroin users do not have sufficient knowledge of overdose risk factors, especially the use of heroin by injection, after a period of abstinence, or together with alcohol or methadone. Specific informational or educational programs adapted to the local context are critically needed