Human immunodeficiency virus (HIV) infection in parenteral drug users: evolution of the epidemic over 10 years. Valencian Epidemiology and Prevention of HIV Disease Study Group.

BACKGROUND: Evaluation of acquired immunodeficiency syndrome (AIDS) prevention strategies requires an on-going follow up of the frequency of human immunodeficiency virus (HIV-1) infection. The aim of this study was to examine the trends in prevalence and incidence of HIV-1 infection among injecting drug users (IDU) during the period 1987-1996. METHODS: Transversal and cohort studies were designed which included a consecutive sample of 7132 IDU who attended three AIDS Prevention and Information Centres in the Region of Valencia (Spain) and voluntarily asked to be tested for HIV antibodies. The prevalence was estimated for each year based on the serological status of HIV-1 when the patient first visited the centre. The annual incidence rates were calculated based on the seronegative patients in which a new determination of HIV-1 was done. In order to control the possible effects on the estimations of age, sex and duration of addiction of the people studied, Poisson and logistic regression models were adjusted. RESULTS: Prevalence and incidence rates of HIV-1 infection showed parallel trends over time. The overall prevalence found was 43.6% (95% confidence intervals [CI]: 42.4-44.7%). Of the 4023 seronegative individuals, 1746 were followed up over the whole of the study period. The incidence rate observed was 6.85 x 100 persons/year (95% CI : 6.04-7.66). The prevalence figures show a decrease, which is most marked from 1990 onwards and then they tend to stabilize over the past few years. The incidence rates increase slightly up to 1991 (9.8 x 100 persons/year), and then begin to decrease. CONCLUSION: Trends of prevalence of HIV-1 infection approximate trends of subjacent incidence rate. Despite decrease in HIV-1 infection frequency observed over 10 years, both the prevalence and incidence figures continue to be high in absolute terms. It is necessary to intensify and adapt preventive measures to each subgroup at risk of infection and in the case of heterosexual transmission ensure that the failure observed in the case of IDU is not repeated.

Variations in cotinine levels in smokers during and after pregnancy.

OBJECTIVE: To compare the antenatal and postnatal cotinine levels in smoking women after controlling for the differences in smoking practices. STUDY DESIGN: A paired comparison of two measurements of cotinine concentration was conducted in 40 smoking women voluntarily recruited in a prenatal education program held in La Fe Hospital, Valencia, Spain, during 1990 and 1991. Cotinine concentration was assayed by gas chromatography in samples of saliva obtained during and after pregnancy. The Wilcoxon matched-pairs test and multiple linear regression analysis were used. RESULTS: The cotinine per cigarette ratio during pregnancy (median 3.53 ng/ml per cigarette) was significantly lower than the ratio in the postnatal testing (median 9.87 ng/ml per cigarette). This difference persisted after allowing for differences in reported cigarette consumption. CONCLUSION: These findings suggest that the available equivalencies between cotinine level and nicotine intake obtained from adult nonpregnant populations cannot be directly applied during pregnancy.

Prevalence of antibiotics to hepatitis C in a population of intravenous drug users in Valencia, Spain, 1990-1992.

BACKGROUND: Hepatitis C has been related to other viral diseases such as the human immunodeficiency virus infection (HIV) or hepatitis B (HBV). The objective of this study was to estimate the prevalence and determinants of antibodies to hepatitis C virus (HCV) in intravenous drug users (IVDU) in Valencia (Spain) and to compare the seroprevalence between the HCV, HIV and HBV in this high risk group. METHODS: A cross-sectional study was conducted in a sample of 1056 current IVDU from the Valencia area who attended the city's AIDS Information Centre between January 1990 and December 1992. Information on sociodemographic, sexual behaviour, and drug use variables was collected by means of a structured questionnaire. Antibodies to HCV, HIV and HBV were assayed by ELISA test. RESULTS: The seroprevalence of HCV for the whole period was 85.5% (95% confidence interval [CI]: 83.2-87.5%), ranging from 76.5% in 1990 (95% CI: 71.9-81.1%) to 87.8% in 1992 (95% CI: 82.5-93.1%). Year of testing and prevalence of HBV markers showed an independent association with HCV seroprevalence. When only IVDU aged < 25 years were analysed, sharing of needles also appeared as an independent dominant. Of those IVDU with less than one year of addiction, 69% were HCV seropositive compared with 41% for HBV and 14% for HIV. CONCLUSIONS: Intravenous drug users in Valencia showed one of the highest reported hepatitis C seroprevalences (85.5%). A more efficient parenteral transmission of hepatitis C virus than HBV or HIV is suggested.

Trends in incidence and prevalence of HIV-1 infection in intravenous drug users in Valencia, Spain.

Our objective was to describe and compare the trends of incidence and prevalence of HIV-1 infection in intravenous drug users (IDUs) in Valencia, Spain in 1987-1992. A cohort study was carried out in AIDS Information Centers located in the Valencia Region (Spain). Point seroprevalence was calculated for in each year according to HIV status at the first contact. Incidence annual rates were calculated from those IDUs identified as seronegative in their first visit and who returned for a new testing. From a total of 4,207 IDUs who contacted these centers, 4,131 (98.2%) asked voluntarily for HIV-1 testing. The seroprevalence for the whole period was 48.4% (95% C.I., 46.88, 49.92). Follow-up information was available for 604 subjects of the total 2,130 subjects who were seronegative in their first visit. The incidence rate for the 1988-1992 period was 12.02/100 person-years (95% C.I., 9.62, 14.41). Prevalence showed an overall decreasing pattern with a minimum corresponding to the year 1992 (43.6%). Incidence rates increased mildly until 1990 (13.93 per 100 person-years), to stabilize beyond at approximately 10 per 100 person-years. Our incidence rates are very high regardless of the decline of prevalence. Effective risk reduction programs among IDUs have been almost nonexistent in Spain up to now and should become an immediate priority.

Sharing of injection equipment among 3755 intravenous drug users in Valencia, Spain, 1987-1992.

BACKGROUND: In order to identify, in a sample of heroin intravenous drug users (IVDU), those factors associated with the predominant risk behaviour related to the transmission of HIV-1 infection--sharing of injection equipment--a cross-sectional survey was carried out in Valencia, Spain from 1987 to 1992. METHODS: Informed consent and pertinent data were obtained from 3755 heroin IVDU recruited at two public AIDS Information Centres in two cities in the region of Valencia. Data were gathered on sociodemographic variables, and sexual and drug use behaviour by interview. The subjects were subsequently tested for HIV-1 antibody. A univariate analysis was carried out to identify variables that were significantly associated with sharing injection equipment. A logistic regression model was used to control for possible confounders. RESULTS: The IVDU who were teenagers, prostitutes (OR = 1.95), who had antibodies to HIV-1 (OR = 1.30) or who had an IVDU steady partner were at significantly higher risk for sharing of injection equipment. Higher levels of education, condom use (OR = 0.65) and living in the smaller city (OR = 0.75) were inversely related to sharing injection equipment. CONCLUSIONS: Our results suggest that different subgroups of IVDU have different characteristics that place them at different risk for HIV-1 infection. These characteristics should guide the design and intensity of specific preventive interventions. Teenagers and IVDU with low educational levels should be targetted for special attention by health authorities.

[Prevalence of human immunodeficiency virus infection among parenteral drug users in the community of Valencia 1987-1991)]. / Prevalencia de la infección por el virus de inmunodeficiencia humana en consumidores de drogas por vía parenteral en la Comunidad Valenciana (1987-1991).

BACKGROUND: To contribute to the knowledge of the frequency and distribution of infection by the HIV-1 in intravenous drug consumers (IVDC) the prevalence of infection in those in whom the voluntary serologic testing was practised and tendency over 5 years were studied. METHODS: The study included 2794 IVDC from centers of primary health care (70%) or those who attended directly (30%), from 1987 to 1991, to three Centers of Information and Prevention of AIDS located in the cities of Valencia, Alicante and Castellón in which the voluntary and free practice of the test of antibodies versus HIV-1 was performed. The serologic test (enzymoimmunoassay) was carried out in 2694 individuals whose positive results were confirmed by Western-blot. Risk factors of the infection in addition to sociodemographic data were collected by questionnaire. RESULTS: The estimated global prevalence was of 49.9% with confidence intervals of 95% (CI 95%) of 48.1% to 51.7%. Differences were observed according to the city with the highest being Valencia (55.3%, CI 95%: 52.8%; 57.8%) in comparison with Alicante (43.7%. CI 95%: 40.5%; 46.9%) and Castellón (41.3%, CI 95%: 35.6%, 47%). A decrease in prevalence was detected during the period studied (chi 2 of tendency = 6.37; p = 0.011), with this decrease only being produced in Alicante and Castellón. No differences were found with regard to sex in contrast to those found according to age, from 35.3% in those under 20 years of age to 59.5% in those over 29 years (chi 2 of tendency = 80.62; p < 0.0001). Only in the youngest age groups was a decreased tendency in prevalence found. The IVDC attended reported interchanging of needles at the time of consultation in 16.9% (CI 95%: 15.5%; 18.3%) with a descending temporal tendency from 27.7% in 1987 to 2.8% in 1991 (chi 2 of tendency = 14.18; p = 0.0001). Only 18.7% (CI 95%: 17.2%; 20.2%) of the IVDC used condoms in more than 66% of their sexual encounters of vaginal coitus. No differences were found with respect to sex or year of consultation. CONCLUSIONS: The prevalence of infection by the HIV-1 in intravenous drug consumers requesting the serologic test is decreasing in the Community of Valencia. This reduction in frequency should be confirmed by estimated rate of incidence of seroconversion. The frequency of the use of condoms in intravenous drug consumers is low conditioning a high risk of extension of the epidemics by sexual transmission.