Prevalence of Mycobacterium tuberculosis infection among injection drug users in Toronto.

BACKGROUND: Injection drug users are at increased risk of Mycobacterium tuberculosis infection and active tuberculosis (TB). The primary objective of this study was to determine the prevalence of M. tuberculosis infection among injection drug users in Toronto, as indicated by a positive tuberculin skin test result. An additional objective was to identify predictors of a positive skin test result in this population. METHODS: A cross-sectional study was carried out involving self-selected injection drug users in the city of Toronto. A total of 171 participants were recruited through a downtown Toronto needle-exchange program from June 1 to Oct. 31, 1996. RESULTS: Of 167 subjects tested, 155 (92.8%) returned for interpretation of their skin test result within the designated timeframe (48 to 72 hours). Using a 5-mm cut-off, the prevalence rate of positive tuberculin skin test results was 31.0% (95% confidence interval 23.8% to 38.9%). Birth outside of Canada and increasing age were both predictive of a positive result. INTERPRETATION: There is a high burden of M. tuberculosis infection in this population of injection drug users. The compliance observed with returning for interpretation of skin test results indicates that successful TB screening is possible among injection drug users.

Partner notification for sexually transmitted diseases: an overview of the evidence.

OBJECTIVE: To compare the effectiveness of alternative partner notification strategies for gonorrhea, chlamydia, syphilis, HIV and hepatitis B. DATA SOURCES: Studies were identified using MEDLINE, EMBASE, SCISEARCH and other databases, review of reference lists and personal contact with over 80 international experts. STUDY SELECTION: Studies with at least two comparison groups exposed to different partner notification strategies were included. DATA EXTRACTION: Methodological rigor was assessed, and information regarding study populations, interventions and outcomes was extracted independently by two reviewers. MAIN RESULTS: Twelve studies met our inclusion criteria; five were methodologically strong; seven provided data on the referral process; four provided data on trained interviewers compared with routine care providers; and three provided data on the interview process. CONCLUSIONS: Only limited, broad conclusions regarding the effectiveness of various partner notification approaches could be drawn from these comparative studies. Until newer data become available, practice guidelines must be based to a large extent on other grounds.

Partner notification for sexually transmitted diseases: proposed practice guidelines.

Using the results of an analysis of available scientific evidence and a survey of current practice in Canada, as well as expert opinion, these guidelines attempt to consider current partner notification practice in Canada and recommend an approach to determining practice which is flexible enough to address local circumstances. Priority areas for future research were also identified.

A survey of public health partner notification for sexually transmitted diseases in Canada.

OBJECTIVE: To describe the range of practice for sexually transmitted disease (STD) contact tracing/partner notification (PN) by public health agencies in Canada. METHODS: A two-level mailed survey, using two different questionnaires, was conducted from Aug. 1991 to Feb. 1992, directed to: 1) provincial and territorial epidemiologists/directors of STD control, asking about program organization; and 2) 154 local health units/provincially run PN programs, asking about practice patterns of STD partner notification. CONCLUSIONS: In Canada, STD PN by public health agencies is routinely practised in most provinces. PN efforts vary by the STD; less PN effort goes to chlamydia despite a high burden of illness; HIV PN is frequently perceived to be within the responsibility of the physician. For STDs with higher PN effort, the preferred method is provider referral. Targeting is seldom utilized, and there are little available data at a local level monitoring even process measures of effectiveness.

An approach to the development of practice guidelines for community health interventions.

The Community Health Practice Guidelines (CHPG) project was initiated to develop a systematic approach to the critical evaluation of evidence on the effectiveness and efficiency of community health interventions and to the formulation of evidence-based practice recommendations. Three community health interventions--immunization delivery methods, partner notification for sexually transmitted diseases and the combination of restaurant inspection and education of food handlers--were used as prototypes to develop a standardized approach. The CHPG process consists of three components: a review of scientific evidence, a practice survey and formulation of practice guidelines. Imperatives for further development of the CHPG and define research priorities process include creating a coalition of public health organizations to sponsor the process and refining the consensus process so that the practice guidelines accurately reflect both the scientific basis of public health practice and the values of those affected.

The Ontario HIV seroprevalence study of childbearing women: results from the first year of testing.

The Ontario HIV Seroprevalence Study of Childbearing Women is an unliked anonymous seroprevalence study designed according to the well-established ethical and legal guidelines for such studies. Commencing in November, 1989, randomly selected neonatal heelprick specimens were tested for the presence of HIV antibodies after all identifying information had been permanently and irrevocably unlinked from the specimens. During the first year of the study 94,119 (approximately 60% of all submitted specimens) were tested. Twenty-six specimens which were repeatedly reactive by EIA were confirmed as positive for an overall crude seroprevalence rate of 2.8 per 10,000 women having live births (95% CI: 1.8-4.1). Twenty-five of the 26 confirmed seropositive results came from babies born in hospitals in the Metropolitan Toronto, Ottawa-Carlton, or Hamilton-Peel-Halton regions.

Needle sharing behaviour among injection drug users (IDUs) in treatment in Montreal and Toronto, 1988-1989.

Injection drug users (IDUs) entering treatment programs in Montreal and Toronto were recruited for a study of drug using behaviour and risk of HIV infection. Only those who had injected within 6 months of entering their treatment program were eligible for participation. 183 subjects were recruited in Montreal and 167 in Toronto between November, 1988 and October, 1989. Each participant completed a standardized interviewer-administered questionnaire which focussed on, among other things, drug history and needle sharing behaviour. Approximately three-quarters of respondents in both cities reported sharing needles and syringes within the 6-month period prior to their entry into treatment. Our analysis, which focussed on variables associated with needle sharing revealed that having a sexual partner who injected, trouble obtaining sterile needles and syringes and cocaine injection were significantly and independently associated with needle sharing in a logistic regression model which also controlled for city of recruitment.

Epidemiologic study of deaths and injuries due to tornadoes.

A case-control study, using both matched and unmatched controls, was carried out on individuals who were injured or killed by a series of tornadoes that passed through Ontario, Canada, on May 31, 1985. Many serious injuries (25%) and almost all (83%) deaths were the result of becoming airborne, while most minor injuries (94%) were due to being struck by objects. Head injury was the most common injury type. Few (21%) of those in buildings chose the recommended location, and most (61%) were not in the least damaged part. Most (91%) had less than one minute's warning, and only 47% had a functioning radio at the time the tornado hit. The following risk factors for injury and death were identified: poor building anchorage; location other than in a basement, especially outdoors; age over 70 years; and high wind strength. These findings support previous findings and point to measures which have potential for preventing death or serious injury in future tornadoes: adequate warning systems and public education to ensure that individuals understand the warning and respond by seeking appropriate shelter. Those in adequately anchored buildings should shelter in an interior room or basement. Those who are outdoors, in poorly anchored buildings, mobile homes, or portable classrooms require access to an adequately anchored building, preferably with a basement, during severe storm warnings. This should be arranged by local authorities.