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Biomedical subjects

M C Doherty

Publications and source records attributed to M C Doherty.

9 recordsLinked to original sources
PubMed1999

HIV prevalence and risk behaviors among new initiates into injection drug use over the age of 40 years old.

Injection drug users (IDUs) who have recently initiated an injecting career have high risk behaviors for HIV infection. The average age of an IDUs first injection is typically reported as 19-20 years, and some literature has reported 'maturing out' of drug use typically around 40 years old. The purpose of this study was to discriminate risk behaviors among newer injectors by age of initiation. This cross-sectional study includes volunteers enrolled using extensive community recruitment techniques in 1988 and 1989 in Baltimore, MD. Of the 722 injection drug users who had initiated injection within the prior six years, 124 were over 35 years old of whom 53 were 40 years and older. Rates of HIV were lower among those over 40 years (13.2%) than those who were 35-39 years (22.5%) or under 35 years old (20.9%). The behavioral characteristics of those aged 35-39 were similar to those under 35 years old, but those over 40 years old when compared with less than 39 years reported injecting at least daily less frequently (88.7% vs 76.5%, p = 0.042), using a needle from a sterile wrapper (19.0% vs 36.6%, p = 0.006), and injecting with their own works (52.6% vs 28.8%, p = 0.021). This study shows that people initiate injection drug use across a wide age range and that needle hygiene practices early after initiation tend to be safer in older compared to younger initiates.

Adult↗
PubMed1998

Prevalence and incidence of hepatitis C virus infection among young adult injection drug users.

Through community-based outreach, young adult injection drug users (IDUs) were enrolled in a prospective study of the prevalence, incidence, and risk factors for hepatitis C virus (HCV) infection. Demographics and information on sexual and injecting practices were collected during semiannual interviews, and HCV infection was evaluated using a second-generation antibody assay. Of the 229 participants, 86 (37.6%) were HCV-seropositive at baseline. After adjusting for injecting frequency and duration by logistic regression, HCV seroprevalence was independently associated with reusing syringes at least once in the past 6 months (odds ratio [OR]=3.81, 95% confidence interval [CI] 1.39-11.00), injecting the first time with someone > or =5 years older (OR=2.99; 95% CI, 1.43-6.23) or alone (OR=4.02; 95% CI, 1.12-14.43) versus with someone <5 years older, and injecting cocaine or speedball exclusively (OR=4.29; 95% CI, 1.53-12.01) or with other drugs (OR=5.27; 95% CI, 2.62-10.64) versus injecting no cocaine in the past 6 months. Of the 105 originally HCV-seronegative participants who returned for follow-up, 13 seroconverted (incidence rate=16.0/100 person-years). On bivariate analysis, HCV seroconversion was significantly associated with injecting for <2 years (relative risk [RR]=7.3; 95% CI, 1.6-32.8) and continuing to inject during follow-up (RR=4.4; 95% CI, 1.0-19.9). Young adult IDUs are at high risk for HCV infection. These data support the need for wider legal access to sterile syringes, as well as expanded community outreach education to this population to prevent transmission of HCV.

Adult↗
PubMed1998

Gender differences in injection-related behaviors among injection drug users in Baltimore, Maryland.

Baseline data from 640 injection drug users in the Stop AIDS for Everyone study, an HIV preventive intervention were used to examine gender differences in self-reports of injection behaviors. In both the bivariate and multivariate analyses men reported injecting alone, in semipublic areas, and at their mother's residence more often than women. In the bivariate analyses, women reported denser personal networks, and in the multivariate analyses, women reported significantly greater overlap between their drug and sex networks. These data suggest that this overlap of sex and drug networks may reduce women drug injectors' ability to adopt and maintain HIV protective behaviors. The data also suggest that interventions need to address gender differences in the social context of risk behaviors.

Adult↗
PubMed1997

Discarded needles do not increase soon after the opening of a needle exchange program.

This study examines the effect of a Needle Exchange Program (NEP) on the quantity and geographic distribution of discarded needles on the streets of Baltimore, Maryland, and presents methods to survey discarded needles in the community. A random sample of 32 city blocks located within high-drug-use census tracts, stratified by east and west sides of the city and by proximity to the NEP, was selected for survey. Three teams surveyed the number of needles and the number of drug vials and unbroken glass bottles ("trash") to control for practice effects. Surveillance was conducted prior to initiation of the NEP in August 1994 and 1 and 2 months thereafter. Over the three study periods, the absolute count of discarded needles was 106, 130, and 128, respectively; the number of vials and bottles was 3,048, 3,825, and 3,796, respectively. The initial nonstatistically significant increase in needles (mean change = 0.38, 95% confidence interval (CI) -0.18 to 0.93) was offset by accounting for background trash. Regression models fitted with the generalized estimating equation method, which accounted for within-block correlation over time, showed no significant increase in the number of needles after adjustment for trash during the first 2 months of the NEP's operation. These data suggest that the initiation of NEPs does not result in an increase in the number of discarded needles on the street.

Baltimore↗
PubMed1996

Viral infections in short-term injection drug users: the prevalence of the hepatitis C, hepatitis B, human immunodeficiency, and human T-lymphotropic viruses.

OBJECTIVES: The purpose of this study was to estimate the prevalence and correlates of four blood-borne viral infections among illicit drug injectors with up to 6 years of injecting experience. METHODS: We analyzed data from 716 volunteers recruited in 1988 and 1989. Test results for hepatitis C virus (HCV), hepatitis B virus (HBV), human immunodeficiency virus, type 1 (HIV), and human T-lymphotropic virus types I and II (HTLV) were examined across six sequential cohorts defined by duration of drug injection. RESULTS: Overall, seroprevalence of HCV, HBV, HIV, and HTLV was 76.9%, 65.7%, 20.5% and 1.8%, respectively, and 64.7%, 49.8%, 13.9%, and 0.5%, respectively, among those who had injected for 1 year or less. Among the newest initiates, HCV and HBV were associated with injecting variables, and HIV was associated with sexual variables. CONCLUSIONS: The high rates of HCV, HBV, and HIV infections among short-term injectors emphasizes the need to target both parenteral and sexual risk reduction interventions early. Renewed efforts at primary prevention of substance abuse are indicated.

Adolescent↗
PubMed1995

Acquisition and use of needles and syringes by injecting drug users in Baltimore, Maryland.

Our objective was to determine how injection drug users (IDUs) in Baltimore, Maryland obtain and use needles and syringes (NS) for drug injection, before the opening of a needle exchange program (NEP). The method of this study was a cross-sectional structured interview survey in 1992 of active IDUs in a longitudinal study of human immunodeficiency virus (HIV) infection. For 466 IDUs (94.6% black, 83% male), usual sources of NS were "street" dealers (49.6%), pharmacies (29.8%), diabetics (16.3%), friends/neighbors (2.2%), and "shooting galleries" (1.9%). Half (53.5%) reported pharmacy purchase of NS, and 55.6% had diabetic friends/relatives. Twenty-three percent traded drugs, and 5% traded sex for NS. Eighty-eight and two-tenths percent would use a needle exchange program; 24.6% currently own no NS (median owned = 2.2). NS reuse was common (median = three times). Concern about (55.2%) or history of (33.9%) hassle/arrest for NS possession was typical; 81% kept NS at home, and 67% do not carry NS when purchasing drugs. Pharmacy purchasers (versus "street") were less likely to have been jailed, shared NS, or used shooting galleries during the preceding 6 months. In Maryland, although IDUs can legally purchase NS at pharmacist discretion, possession remains illegal; fewer than one-third of IDUs use pharmacies, and most obtain NS from illegal sources. Most IDUs reuse NS, but discard them after several uses. Current patterns of NS acquisition and use in Baltimore are likely to increase HIV transmission. Increased availability and decriminalization of NS possession could decrease the risk of injection-related HIV transmission.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Inadequate bleach contact times during syringe cleaning among injection drug users.

Objectives were to measure syringe cleaning strategies used by injection drug users (IDUs) and to assess syringe contact with bleach during cleaning demonstrations. IDUs were interviewed about cleaning activities during their most recent injection episode; they demonstrated these activities on videotape. Coders reviewed the videotapes, categorized activities, and used stop watches to record bleach exposure. Of 161, 146 subjects reported cleaning at last injection, 85 (58%) of 146 used full strength bleach. Of bleach users, 20% had total contact time (duration of bleach inside syringe) of > or = 30 s; combining draw (time taken to fill syringe) and contact times, 54% of bleach users had total "flush" times of > or = 30 s. Median observed time per bleach flush was 16 s. Median reported cleaning times were twice as long as observed. Recent reports indicate 30 s of exposure to undiluted bleach is necessary to inactivate HIV in the laboratory; here, 80% of IDUs using bleach had contact of < 30 s. Judgment of contact time was inaccurate. On average, instructions advocating two bleach flushes may reach 30 s; here, half the subjects had insufficient time with two flushes. The majority showed inadequate techniques, therefore, alternate cleaning strategies should be developed.

Adult↗
PubMed1987

Ferroxidase II activity and serum cholesterol.

Ferroxidase II (Fox II) was developed in serum by acid incubation for 24 h. The resulting activity showed a strong positive correlation with the serum cholesterol concentration in normal subjects and patients with hyperlipidaemia. The potentiating effect of cholesterol on developed Fox II has been confirmed by the in-vitro addition of cholesterol to serum. There was no significant correlation between developed Fox II and caeruloplasmin (ferroxidase I) or between cholesterol and caeruloplasmin.

Ceruloplasmin↗