Evaluation of recorded video-observed therapy for anti-tuberculosis treatment

BACKGROUND: Asynchronous video directly observed therapy (VDOT) may reduce tuberculosis (TB) program costs and the burden on patients. We compared VDOT performance across three cities in the United States, each of which have TB incidence rates above the national average.METHODS: Patients aged ≥18 years who are currently receiving directly observed anti-TB treatment were invited to use VDOT for monitoring treatment. Pre- and post-treatment interviews and medical records were used to assess site differences in treatment adherence and patient characteristics and perceptions.RESULTS: Participants were enrolled in New York City, NY (n = 48), San Diego, CA (n = 52) and San Francisco, CA, USA (n = 49). Overall, the mean age was 41 years (range 18-87); 59% were male; most were Asian (45%) or Hispanic/Latino (30%); and 77% were foreign-born. The median fraction of expected doses observed (FEDO) was 88% (IQR 76-96). At follow-up, 97% thought VDOT was "very or somewhat easy to use" and 95% would recommend VDOT to other TB patients. Age, race/ethnicity, annual income, and country of birth differed by city (P < 0.05), but FEDO and VDOT perceptions did not.CONCLUSIONS: TB programs in three large US cities observed a high FEDO using VDOT while minimizing staff time and travel. Similar findings across sites support VDOT adoption by other large, urban TB programs.

Prevalence and Correlates of Injecting with Visitors from the United States Among People Who Inject Drugs in Tijuana, Mexico

Cross-border infectious disease transmission is a concern related to drug tourism from the U.S. to Mexico. We assessed this risk among people who inject drugs (PWID) in Tijuana, Mexico. We measured the prevalence and identified correlates of injecting with PWID visiting from the U.S. among PWID in Tijuana using univariable and multivariable logistic regression. Of 727 participants, 18.5% injected during the past 6 months in Mexico with U.S. PWID described mostly as friends (63%) or acquaintances (26%). Injecting with U.S. PWID was independently associated with higher education [adjusted odds ratio (aOR) = 1.13/year], deportation from the U.S. (aOR = 1.70), younger age at first injection (aOR = 0.96/year), more lifetime overdoses (aOR = 1.08), and, in the past 6 months, backloading (aOR = 4.00), syringe confiscation by the police (aOR = 3.02) and paying for sex (aOR = 2.98; all p-values < 0.05). Nearly one-fifth of PWID in Tijuana recently injected with U.S. PWID, and their reported risk behaviors could facilitate cross-border disease transmission.

Mycobacterium tuberculosis infection among persons who inject drugs in San Diego, California

BACKGROUND

Persons who inject drugs (PWID) might be at increased risk for Mycobacterium tuberculosis infection and reactivation of latent tuberculous infection (LTBI) due to their injection drug use.

OBJECTIVES

To determine prevalence and correlates of M. tuberculosis infection among PWID in San Diego, California, USA.

METHODS

PWID aged 18 years underwent standardized interviews and serologic testing using an interferon-gamma release assay (IGRA) for LTBI and rapid point-of-care assays for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections. Independent correlates of M. tuberculosis infection were identified using multivariable log-binomial regression.

RESULTS

A total of 500 participants met the eligibility criteria. The mean age was 43.2 years (standard deviation 11.6); most subjects were White (52%) or Hispanic (30.8%), and male (75%). Overall, 86.7% reported having ever traveled to Mexico. Prevalence of M. tuberculosis infection was 23.6%; 0.8% were co-infected with HIV and 81.7% were co-infected with HCV. Almost all participants (95%) had been previously tested for M. tuberculosis; 7.6% had been previously told they were infected. M. tuberculosis infection was independently associated with being Hispanic, having longer injection histories, testing HCV-positive, and correctly reporting that people with 'sleeping' TB cannot infect others.

CONCLUSIONS

Strategies are needed to increase awareness about and treatment for M. tuberculosis infection among PWID in the US/Mexico border region.

A performance evaluation of MTBDRplus version 2 for the diagnosis of multidrug-resistant tuberculosis

OBJECTIVE

To evaluate the performance of a recently updated rapid molecular diagnostic test, GenoType® MTBDRplus version 2, designed to detect drug resistance in both acid-fast bacilli (AFB) smear-negative and -positive specimens.

DESIGN

Sputum samples from 1128 patients at risk for multidrug-resistant tuberculosis (MDR-TB) were tested using MTBDRplus v2 and compared with reference standard MGIT™ 960™ drug susceptibility testing. The relationship of participant human immunodeficiency virus (HIV) status, diabetic status, previous treatment, and smear gradation to the likelihood of obtaining an interpretable result was assessed using logistic regression.

RESULTS

The sensitivity and specificity of MTBDRplus v2 for detecting MDR-TB, when compared to a reference standard, were respectively 96.0% (95%CI 93.5-97.6) and 99.2% (95%CI 97.0-99.9) in AFB smear-positive specimens and 82.8% (95%CI 63.5-93.5) and 98.3% (95%CI 89.9-99.9) in AFB smear-negative specimens. A dose-response relationship was observed between the proportion of interpretable test results and AFB smear bacterial load after adjusting for age, sex, body mass index, HIV status, previous treatment and diabetic status.

CONCLUSION

While MTBDRplus v2 performs well among both AFB smear-positive and -negative specimens, smear gradation appears to influence both the probability of obtaining an interpretable result and test sensitivity, indicating a significant association between bacillary load and test performance.

Mobility patterns of persons at risk for drug-resistant tuberculosis in Mumbai, India

SETTING

Tuberculosis (TB) hospital in Mumbai, India.

OBJECTIVE

To describe the mobility patterns of persons with suspected drug-resistant tuberculosis (DR-TB) and to assess whether there were significant differences in demographic or risk characteristics based on mobility.

DESIGN

Observational cohort study of TB clinic patients at risk for DR-TB.

RESULTS

Among 602 participants, 37% had ever moved from their place of birth; 14% were local movers (within state), and 23% were distant movers, between states or countries. Univariate multinomial logistic regression models showed that distant movers were more likely than non-movers to have lower income, less education, a greater number of previous TB episodes, and to have ever smoked. Compared to non-movers, local movers were more likely to have lower income and were more likely to have seen a doctor in the past 2 years. Clinical outcomes, including DR-TB, diabetes, and human immunodeficiency virus (HIV), did not differ between the three mobility groups.

CONCLUSION

Mobility was common among patients at risk for DR-TB in Mumbai. TB programs should consider the implications of mobility on the protracted treatment for DR-TB in India.

Feasibility of tuberculosis treatment monitoring by video directly observed therapy: a binational pilot study

BACKGROUND

Although directly observed therapy (DOT) is recommended worldwide for monitoring anti-tuberculosis treatment, transportation and personnel requirements limit its use.

OBJECTIVE

To evaluate the feasibility and acceptability of 'video DOT' (VDOT), which allows patients to record and transmit medication ingestion via videos watched remotely by health care providers to document adherence.

METHODS

We conducted a single-arm trial among tuberculosis (TB) patients in San Diego, California, USA, (n = 43) and Tijuana, Mexico (n = 9) to represent high- and low-resource settings. Pre-/post-treatment interviews assessed participant characteristics and experiences. Adherence was defined as the proportion of observed doses to expected doses.

RESULTS

The mean age was 37 years (range 18-86), 50% were male, and 88% were non-Caucasian. The mean duration of VDOT use was 5.5 months (range 1-11). Adherence was similar in San Diego (93%) and Tijuana (96%). Compared to time on in-person DOT, 92% preferred VDOT, 81% thought VDOT was more confidential, 89% never/rarely had problems recording videos, and 100% would recommend VDOT to others. Seven (13%) participants were returned to in-person DOT and six (12%) additional participants had their phones lost, broken or stolen.

CONCLUSIONS

VDOT was feasible and acceptable, with high adherence in both high- and low-resource settings. Efficacy and cost-effectiveness studies are needed.

Phenotypic and genotypic diversity in a multinational sample of drug-resistant Mycobacterium tuberculosis isolates

OBJECTIVE

To develop and evaluate rapid, molecular-based drug susceptibility testing (DST) for extensively drug-resistant tuberculosis (XDR-TB), we assembled a phenotypically and genotypically diverse collection of Mycobacterium tuberculosis isolates from patients evaluated for drug resistance in four high-burden countries.

METHODS

M. tuberculosis isolates from India (n = 111), Moldova (n = 90), the Philippines (n = 96), and South Africa (n = 103) were selected from existing regional and national repositories to maximize phenotypic diversity for resistance to isoniazid, rifampin (RMP), moxifloxacin, ofloxacin, amikacin, kanamycin, and capreomycin. MGIT™ 960 was performed on viable isolates in one laboratory using standardized procedures and drug concentrations. Genetic diversity within drug resistance phenotypes was assessed.

RESULTS

Nineteen distinct phenotypes were observed among 400 isolates with complete DST results. Diversity was greatest in the Philippines (14 phenotypes), and least in South Africa (9 phenotypes). Nearly all phenotypes included multiple genotypes. All sites provided isolates resistant to injectables but susceptible to fluoroquinolones. Many patients were taking drugs to which their disease was resistant.

DISCUSSION

Diverse phenotypes for XDR-TB-defining drugs, including resistance to fluoroquinolones and/or injectable drugs in RMP-susceptible isolates, indicate that RMP susceptibility does not ensure effectiveness of a standard four-drug regimen. Rapid, low-cost DST assays for first- and second-line drugs are thus needed.

Second-line drug susceptibility breakpoints for Mycobacterium tuberculosis using the MODS assay

OBJECTIVE

To establish breakpoint concentrations for the fluoroquinolones (moxifloxacin [MFX] and ofloxacin [OFX]) and injectable second-line drugs (amikacin [AMK], kanamycin [KM] and capreomycin [CPM]) using the microscopic observation drug susceptibility (MODS) assay.

SETTING

A multinational study conducted between February 2011 and August 2012 in Peru, India, Moldova and South Africa.

DESIGN

In the first phase, breakpoints for the fluoroquinolones and injectable second-line drugs (n = 58) were determined. In the second phase, MODS second-line drug susceptibility testing (DST) as an indirect test was compared to MGIT™ DST (n = 89). In the third (n = 30) and fourth (n = 156) phases, we determined the reproducibility and concordance of MODS second-line DST directly from sputum.

RESULTS

Breakpoints for MFX (0.5 μg/ml), OFX (1 μg/ml), AMK (2 μg/ml), KM (5 μg/ml) and CPM (2.5 μg/ml) were determined. In all phases, MODS results were highly concordant with MGIT DST. The few discrepancies suggest that the MODS breakpoint concentrations for some drugs may be too low.

CONCLUSION

MODS second-line DST yielded comparable results to MGIT second-line DST, and is thus a promising alternative. Further studies are needed to confirm the accuracy of the drug breakpoints and the reliability of MODS second-line DST as a direct test.

Dose-response association between salivary cotinine levels and Mycobacterium tuberculosis infection

SETTING

Tijuana, Mexico.

OBJECTIVE

To describe the association between salivary cotinine levels and interferon-gamma (IFN-γ) release assay results.

DESIGN

We conducted a cross-sectional study among injection drug users. Salivary cotinine levels were measured using NicAlert, a semi-quantitative dipstick assay. QuantiFERON©-TB Gold In-Tube (QFT-GIT) was used to determine Mycobacterium tuberculosis infection.

RESULTS

Among 234 participants, the prevalence of QFT-GIT positivity for NicAlert cotinine categories 0 (non-smoking), 1 (second-hand smoke exposure or low-level smoking) and 26 (regular smoking) were respectively 42.1%, 46.4% and 65.2% (Ptrend 0.012). We found increasing trends in QFT-GIT positivity (Ptrend 0.003) and IFN-γ concentrations (Spearman's r 0.200, P 0.002) across cotinine levels 0 to 6. In multivariable log-binomial regression models adjusted for education, cotinine levels were not associated with QFT-GIT positivity when included as smoking categories (1 and 26 vs. 0), but were independently associated with QFT-GIT positivity when included as an ordinal variable (prevalence ratio 1.09 per 1 cotinine level, 95%CI 1.021.16).

CONCLUSION

Our findings suggest that a dose-response relationship exists between tobacco smoke exposure and M. tuberculosis infection. Longitudinal studies that use biochemical measures for smoking status are needed to confirm our findings.

Field-based performance of three pre-market rapid hepatitis C virus antibody assays in STAHR (Study to Assess Hepatitis C Risk) among young adults who inject drugs in San Diego, CA

BACKGROUND

Approximately 4.1 million Americans are estimated to have been infected with hepatitis C virus (HCV), 45-85% of whom are unaware of their infection. Persons who inject drugs (PWID) account for 55.8% of all persons with HCV antibody (anti-HCV) in the U.S. PWID have limited access to healthcare and are infrequently tested for anti-HCV using conventional laboratory assays.

OBJECTIVE

To evaluate performance characteristics (sensitivity and specificity) of three, pre-market rapid point-of-care tests (one oral fluid and two finger-stick assays) from two manufacturers (Chembio and MedMira) in settings providing services to young adult PWID in San Diego, CA.

STUDY DESIGN

Behavioral risk assessment surveys and testing for HCV were conducted among persons who reported injection drug use (IDU) within the past 6 months as part of the Study to Assess Hepatitis C Risk (STAHR) among PWID aged 18-40 years in 2009-2010. Sensitivity and specificity of the rapid anti-HCV assays were evaluated among STAHR participants, using two commonly used testing algorithms.

RESULTS

Variability in sensitivity (76.6-97.1%) and specificity (99.0-100.0%) was found across assays. The highest sensitivity achieved for the Chembio finger-stick blood, Chembio oral fluid and MedMira finger-stick blood tests was 97.1%, 85.4% and 80.0% respectively; the highest specificity was 99.0%, 100.0% and 100.0%, respectively. In multivariate analysis false negative anti-HCV results were associated with female sex for the MedMira blood assay.

CONCLUSIONS

Sensitive anti-HCV rapid assays are appropriate and feasible for high-prevalence, high-risk populations such as young PWID.

DOT associated with reduced all-cause mortality among tuberculosis patients in Taipei, Taiwan, 2006-2008

OBJECTIVE

To determine whether patients receiving directly observed treatment (DOT) had lower all-cause mortality than those treated with self-administered treatment (SAT) and to identify factors associated with mortality among tuberculosis (TB) patients.

DESIGN

All TB patients in Taipei, Taiwan, diagnosed between 2006 and 2008 were included in a retrospective cohort study.

RESULTS

Among 3624 TB patients, 45.5% received DOT, which was disproportionately offered to older patients and those with more underlying illness and severe TB disease. After controlling for patients' sociodemographic factors, clinical findings and underlying comorbidities, the odds of death were 40% lower (aOR 0.60, 95%CI 0.5-0.8) among patients treated with DOT than those on SAT. After adjusting for DOT, independent predictors of death included non-Taiwan birth, increasing age, male, unemployment, end-stage renal disease requiring dialysis, malignancy, acid-fast bacilli smear positivity and pleural effusion.

CONCLUSION

DOT was associated with lower all-cause mortality after controlling for confounding factors. DOT should be expanded in Taiwan to improve critical treatment outcomes among TB patients.

Longitudinal determinants of consistent condom use by partner type among young injection drug users: the role of personal and partner characteristics

We investigated the longitudinal influence of individual-, relationship- and social-level factors on condom use by partner type among young injections drug users (IDUs) enrolled in the Collaborative Injection Drug Users Study-III/Drug Users Intervention Trial (CIDUS-III/DUIT) from 2002 to 2004. Based on longitudinal analysis using generalized estimating equations (GEE), consistent condom use with main partners was more commonly reported among males and those with greater self-efficacy for condom use; main partner’s desire for pregnancy and needle sharing were negatively associated with consistent condom use. Among those with casual partners, having fewer sex partners was associated with consistent condom use. Positive attitudes toward condom use and partner norms supporting condom use were associated with greater consistent condom use with both partner types. These findings suggest that intervention strategies targeting individual- and partner-level factors may provide avenues for intervening upon sexual risks among young IDUs.

Targeted screening and treatment for latent tuberculosis infection using QuantiFERON-TB Gold is cost-effective in Mexico

OBJECTIVE

To assess the cost-effectiveness of screening for latent tuberculosis infection (LTBI) using a commercially available detection test and treating individuals at high risk for human immunodeficiency virus (HIV) infection in a middle-income country.

DESIGN

We developed a Markov model to evaluate the cost per LTBI case detected, TB case averted and quality-adjusted life year (QALY) gained for a cohort of 1000 individuals at high risk for HIV infection over 20 years. Baseline model inputs for LTBI prevalence were obtained from published literature and cross-sectional data from tuberculosis (TB) screening using QuantiFERON-TB Gold In-Tube (QFT-GIT) testing among sex workers and illicit drug users at high risk for HIV recruited through street outreach in Tijuana, Mexico. Costs are reported in 2007 US dollars. Future costs and QALYs were discounted at 3% per year. Sensitivity analyses were performed to evaluate model robustness.

RESULTS

Over 20 years, we estimate the program would prevent 78 cases of active TB and 55 TB-related deaths. The incremental cost per case of LTBI detected was US$730, cost per active TB averted was US$529 and cost per QALY gained was US$108.

CONCLUSIONS

In settings of endemic TB and escalating HIV incidence, targeting LTBI screening and treatment among high-risk groups may be highly cost-effective.

High prevalence of latent tuberculosis infection among injection drug users in Tijuana, Mexico

BACKGROUND

We studied prevalence and correlates of latent tuberculosis infection (LTBI) among injection drug users (IDUs) in Tijuana, Mexico, where tuberculosis (TB) is endemic.

METHODS

IDUs aged > or =18 years were recruited via respondent-driven sampling (RDS) and underwent standardized interviews, human immunodeficiency virus (HIV) antibody testing and LTBI screening using Quanti-FERON((R))-TB Gold In-Tube, a whole-blood interferon-gamma release assay (IGRA). LTBI prevalence was estimated and correlates were identified using RDS-weighted logistic regression.

RESULTS

Of 1020 IDUs, 681 (67%) tested IGRA-positive and 44 (4%) tested HIV-positive. Mean age was 37 years, 88% were male and 98% were Mexican-born. IGRA positivity was associated with recruitment nearest the US border (aOR 1.64, 95%CI 1.09-2.48), increasing years of injection (aOR 1.20/5 years, 95%CI 1.07-1.34), and years lived in Tijuana (aOR 1.10/5 years, 95%CI 1.03-1.18). Speaking some English (aOR 0.38, 95%CI 0.25-0.57) and injecting most often at home in the past 6 months (aOR 0.68, 95%CI 0.45-0.99) were inversely associated with IGRA positivity.

DISCUSSION

Increased LTBI prevalence among IDUs in Tijuana appears to be associated with greater drug involvement. Given the high risk for HIV infection among Tijuana's IDUs, interventions are urgently needed to prevent HIV infection and treat LTBI among IDUs before these epidemics collide.

Correlates of consistent condom use with main partners by partnership patterns among young adult male injection drug users from five US cities

This paper examined correlates of consistent condom use with a main partner among heterosexual male injection drug users (IDUs). Using data from a multi-site sample of young IDUs, we identified 1770 sexually active men of whom 24% (429/1770) reported an exclusive main female sex partner and 49% (862/1770) reported both main and casual female sex partners. Consistent condom use with a main partner was low among men with an exclusive main partner and those with multiple partners (12% and 17%, respectively). In multivariate analysis, consistent condom use with a main partner across partnership patterns was directly associated with anticipating a positive response to requests for condom use and by partner support of condom use; consistent condom use was inversely associated with a main partner's pregnancy desires. Among men with an exclusive main partner, consistent condom use was also inversely associated with needle sharing with a main partner. Among men with multiple partners, consistent condom use with a main partner was inversely associated with injecting with a used needle and intimate partner violence. The low prevalence of consistent condom use with main female partners among heterosexually active male IDUs indicates an increased risk for HIV transmission between men and their primary sex partners. Interventions for heterosexual males that are geared toward increasing condom use in primary relationships are warranted.

Factors associated with interest in initiating treatment for hepatitis C Virus (HCV) infection among young HCV-infected injection drug users

OBJECTIVE

We sought to identify factors associated with interest in receiving therapy for hepatitis C virus (HCV) infection among HCV-infected injection drug users (IDUs) in 3 United States cities.

METHODS

IDUs aged 18-35 years who were HCV-infected and seronegative for human immunodeficiency virus underwent surveys on behaviors, experience, and interest in treatment for HCV infection and readiness to quit drug use.

RESULTS

Among treatment-naive IDUs (n=216), 81.5% were interested in treatment for HCV infection, but only 27.3% had seen a health-care provider since receiving a diagnosis of HCV infection. Interest in treatment for HCV infection was greater among IDUs with a high perceived threat of progressive liver disease, those with a usual source of care, those without evidence of alcohol dependence, and those with higher readiness scores for quitting drug use. Interest in treatment for HCV infection was 7-fold higher among IDUs who were told by their health-care provider that they were at risk for cirrhosis or liver cancer.

CONCLUSIONS

Improving provider-patient communication and integrating treatments for substance abuse and HCV may increase the proportion of IDUs who initiate treatment for HCV infection.

Prevalence, incidence, and correlates of chlamydia and gonorrhea among young adult injection drug users

PURPOSE

To measure prevalence, incidence, and correlates of chlamydia and gonorrhea among injection drug users (IDUs).

METHODS

Participants (n = 2129; 63% male, 52% white, ages 18-30 years) in five US cities were tested for chlamydia and gonorrhea by urine LCR assay and completed a standardized questionnaire about demographics and recent sexual behavior. Logistic regression identified correlates of prevalent infection; incidence rates were calculated from 6-month follow-up data.

RESULTS

Chlamydia prevalence was 5.2% and did not differ by gender. Gonorrhea prevalence was 0.2% among men and 2.0% among women, P < .001. Among men, younger age [OR (95% CI): 0.89 (0.83-0.96)], age at sexual debut [0.91 (0.83-0.99)], and African American race [2.92 (1.53-5.59)] were associated with chlamydia. Among women, age at sexual debut [1.16 (1.02-1.31)] and commercial sex [1.96 (1.03-3.74)] were associated with chlamydia, and with gonorrhea [1.27 (1.04-1.56)] and [5.17 (1.66-16.11)], respectively. At 6 months, the cumulative incidence of chlamydia was 1.7% among men and 4.4% among women, P = .03; no men and 1.3% of women tested positive for gonorrhea, P = .01.

IMPLICATIONS

Prevalence and correlates of chlamydia and gonorrhea were similar to other samples, suggesting that screening criteria need not be modified for IDU populations. The number of behavioral correlates identified was limited; perhaps unmeasured sexual-network-level factors play a role in determining sexually transmitted disease (STD) prevalence.

The effect of a needle exchange program on numbers of discarded needles: a 2-year follow-up

OBJECTIVES

This study estimates the quantity and geographic distribution of discarded needles on the streets of Baltimore, Md, during the 2 years after a needle exchange program opened.

METHODS

Thirty-two city blocks were randomly sampled. Counts were taken of the number of syringes, drug vials, and bottles before the needle exchange program opened and then at 6 periodic intervals for 2 years after the program opened. Nonparametric and generalized estimating equation models were used to examine change over time.

RESULTS

Two years after the needle exchange program opened, there was a significant decline in the overall quantity of discarded needles relative to that of drug vials and bottles (background trash). The block mean of number of needles per 100 trash items was 2.42 before the program opened and 1.30 2 years later (mean within-block change = -0.028, P < .05). There was no difference in the number of discarded needles by distance from the program site.

CONCLUSIONS

These data suggest that this needle exchange program did not increase the number of distribution of discarded needles.

Correlates of HIV infection among young adult short-term injection drug users

OBJECTIVES

To identify risks associated with HIV infection among young adult short-term injection drug users.

METHODS

Current injection drug users, between 18 and 29 years of age, were recruited through street outreach to participate in a cross-sectional survey of HIV prevalence by circumstances of drug injection initiation, HIV-related risk behaviors, and a follow-up to estimate HIV incidence.

RESULTS

At enrollment, 33 (14.4%) of 229 participants were HIV-seropositive. Significant bivariate associations with HIV at the time injection drug use was initiated included age less than or equal to 18 years, having receptive anal sex with the person who assisted with initiation, and having two or more 'trainers' before being able to self-inject. Injecting risks positively associated with HIV included cocaine or speedball (heroin and cocaine together) injection versus heroin or amphetamine injection, injecting five or more times per day, daily crack smoking, backloading, sharing needles at peak drug use, and not using a new needle for every injection. Sexual practices associated with HIV included reporting > 100 lifetime sex partners, a history of sexual assault, being gay or bisexual, and trading sex for money or drugs after starting to inject. In a multivariate model, trading anal sex for money or drugs after initiating injection drug use [odds ratio (OR), 14.2; 95% confidence interval (CI) 3.2-62.3], cocaine/speedball injection (OR, 10.3; 95% CI, 2.2-47.9), daily crack smoking (OR, 4.2; 95% CI, 1.7-10.5), and having two or more trainers (OR, 2.6; 95% CI, 1.1 - 5.9) were independently associated with HIV. During 12 months of follow-up, four persons seroconverted for HIV (annual incidence: 2.6%; 95% CI, 1.1 -5.9%)

CONCLUSIONS

Among short-term injectors, both sexual and injecting practices were important predictors of HIV infection, indicating that a proportion of HIV infections among young injection drug users can be attributed to sexual transmission. The incidence rate for HIV infection suggests that immediate steps should be taken to prevent new infections among young injection drug users.

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.

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.

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.

Physician satisfaction with human immunodeficiency virus type 1 and hepatitis B virus testing in San Diego County

Physician satisfaction with the laboratory testing process is one indicator of the physician's perception of the quality of laboratory testing and the effectiveness of the communication of the laboratory results. This study compares the level of satisfaction of physicians reporting their experience with human immunodeficiency virus type 1 (HIV-1) testing with the satisfaction levels of those physicians reporting their experience with hepatitis B virus (HBV) testing. By mail, 6,570 licensed San Diego County physicians were surveyed. Among those who tested for HIV-1 or HBV, their satisfaction with four different HIV-1 or HBV testing parameters was assessed: 1) specimen submission process, 2) test accuracy, 3) clarity of test report, and 4) turnaround time. Overall, physician satisfaction with both HIV-1 and HBV testing was high, particularly for test accuracy (means of 2.79 and 2.84, respectively on a 3-point scale), although slightly lower for turnaround time (means of 2.40 and 2.43, respectively). Mean satisfaction with the specimen submission process and test accuracy were higher for physicians who ordered HBV tests than for those who ordered HIV-1 tests. Satisfaction with the four HIV-1 testing process parameters varied significantly by physician specialty, practice type, and type of laboratory used. For HBV testing, significant differences were observed only for turnaround time. For both HIV-1 and HBV testing, those who received a final interpretation of laboratory results were more satisfied with test report clarity than those who did not. Although physician satisfaction with HIV-1 and HBV testing is high, this study identifies the least satisfied groups and specific areas in the testing process than may need improvement.

Variability of reporting and lack of adherence to consensus guidelines in human T-lymphocyte immunophenotyping reports: results of a case series

Percentages and absolute counts of CD4+ lymphocytes, as determined by T-lymphocyte immunophenotyping (TLI), are prognostic, as well as diagnostic, of the course of human immunodeficiency virus type 1 infections and are important indicators for initiating Pneumocystis carinii pneumonia prophylaxis and antiretroviral therapy. In December 1990, we requested that a nonrandom sample of 17 laboratories provide us with typical reports of their TLI results from an immunodeficient patient and from a patient whose TLI results were within the laboratory's normal reference ranges. We also searched published literature and documents proposed by professional organizations for recommendations regarding T-lymphocyte testing and reporting. This article compares guidelines for reporting TLI results, as proposed by the National Committee for Clinical Laboratory Standards in Document H42-P, with samples of reports obtained in our case series. Most reports follow some, but not all, of the proposed guidelines. A majority of the laboratories provided interpretations of the results in their reports. We found considerable variation in normal reference ranges. We describe this variation in detail for the CD4+ T-lymphocyte counts and CD4+ T-lymphocyte percentages. This article describes some of the TLI result report forms currently being used and identifies important quality issues in this rapidly expanding area of clinical laboratory testing.

Use of a modified nominal group process for improving laboratory performance in human immunodeficiency virus type 1 antibody testing. Reaching consensus on three questions concerning HIV-1 testing

Using expert panels of medical technologists and public health microbiologists, a modified nominal group process was used to reach a consensus on three questions concerning current human immunodeficiency virus type 1 (HIV-1) testing methods. The questions related to important sources of error, improving the testing process, and improving proficiency testing. The modified nominal group process proved to be effective in developing lists of errors in laboratory testing; it provided a fast, economic means of identifying possible areas for improving laboratory quality assurance and training programs. For the HIV testing model, the focus group panelists indicated laboratory pipetting errors, labeling, and specimen identification as the most important sources of error. To improve the quality of this testing, the panel recommended standardizing test interpretation and restricting testing to laboratories licensed to perform HIV-1 testing. To improve proficiency testing, the use of blind specimens and establishing minimum standards of performance were suggested.

Content and design of laboratory report forms for human immunodeficiency virus type 1 antibody testing

In a pilot study involving proficiency testing for human immunodeficiency virus, markedly diverse and potentially confusing test report forms were encountered among participating laboratories. Therefore, a comprehensive study of human immunodeficiency virus type 1 report forms was conducted from state-licensed testing laboratories in California. Participants analyzed three serum samples of known human immunodeficiency virus type 1 antibody reactivity and reported their results on forms that they would normally submit to clinicians. Report forms from 84 laboratories were evaluated for content, design, and clarity. Differences were found among commercial, hospital, and public health laboratories. The significance of these findings is discussed. This technique also may be applied to evaluate laboratory report form design and content for other diagnostic test results.

Analytic results of HIV-1 testing using blind proficiency testing

The use of blind proficiency testing (PT) to examine analytic performance of human immunodeficiency virus type 1 (HIV-1) antibody testing. A total of 32 hospital, blood bank, public health, and commercial laboratories were included in this study. Test sera were introduced as clinical specimens for HIV-1 testing from private practitioners, group practices, clinics, and hospitals in Southern California. A total of 26 laboratories were located throughout California, with six laboratories located in six other states. Results from 306 enzyme immunoassay screening tests and 192 supplemental tests for HIV-1 were reported. Although one positive specimen was reported as indeterminate in almost 30% of results, screening and supplemental testing performances were excellent, with accuracy levels comparable to performance reported on open PT and performance evaluation surveys in the United States. The indeterminate results were attributed to the interpretive criteria used rather than to laboratory errors. Blind PT can be an important tool in improving the quality of total laboratory testing, the usefulness of laboratory results in patient care, and ultimately the health of the public.

Methods for a model blind proficiency testing system

The method developed for establishing a blind proficiency testing (PT) system is presented. The Laboratory Assurance Program of the Graduate School of Public Health at San Diego State University is developing and pilot testing innovative strategies that will evaluate and improve the performance of clinical laboratories. To date, a total of 32 laboratories have been incorporated into this program along with 12 counseling and testing sites. From June 1988 to December 1989, five blind PT surveys for human immunodeficiency virus type 1 antibody testing were conducted, representing 306 proficiency specimens entered into the testing system as simulated patient specimens. Despite the difficulties and expense involved, we found the system to be acceptable and to have certain advantages over conventional methods of external testing.

Identification of nonanalytic issues in HIV-1 antibody testing using blind proficiency testing

Blind proficiency testing was used to examine nonanalytic performance indicators for human immunodeficiency virus type 1 (HIV-1) antibody testing. Physician offices, clinics, and hospitals located throughout Southern California submitted simulated patient specimens to laboratories as routine test requests. A total of 32 laboratories were involved during five blind proficiency testing surveys. Turnaround time for a reactive specimen ranged from three to 17 days. Laboratory charges for evaluating a reactive specimen varied depending on the volume of testing, prevalence of reactive specimens, and whether screening and confirmatory tests were billed separately or as a package price. Charges for an enzyme immunoassay screening test plus supplemental tests ranged from $11.75 to $114.50, with a median of $31.00 for 24 laboratories that participated in one of the five surveys. Evaluation of laboratory report content revealed that 37% of the 16 screening reports and 71% of the 14 supplemental reports contained information that was unrelated to the patient results. Evaluation of the testing system documents the need to monitor multiple outcomes of the total laboratory testing process, not just the analytic testing phase.