Seroprevalence and correlates of HIV and HCV among injecting drug users in Edmonton, Alberta.

BACKGROUND: Injection drug users (IDUs) are at risk for acquiring human immunodefiency virus (HIV) and hepatitis C virus (HCV) via parenteral and sexual transmission. We determined the seroprevalence and correlates of HIV and HCV for IDUs recruited in Edmonton, Alberta. METHODS: Edmonton was one site of a multi-site, national survey (I-Track Study). From April to June 2005, IDUs were recruited and administered a questionnaire collecting information on demographics, drug use, sexual behaviours, and HIV/HCV testing behaviours. Finger-prick blood samples were collected for serology testing. Seroprevalence of HIV and HCV was determined and correlates of infection were assessed using logistic regression. RESULTS: Of 275 IDUs, 68% were male, the median age was 38 years and 70.6% were Aboriginal. HIV prevalence was 23.9%, HCV prevalence was 66.1% and HIV/HCV co-infection was 22.8%. Cocaine (36.9%) was reported to be the drug injected most often in the previous six months. Correlates for HIV were sex trade (OR 2.9, 95% CI 1.0-8.3) for women, and older age (OR 1.1, 95% CI 1.0-1.2) and needle exchange program (NEP) use (OR 5.7, 95% CI 1.3-23.7) for men. For women, having a casual sex partner was protective for HCV (OR 0.28, 95% CI 0.10-0.78). Independent correlates for HCV among males included age (AOR 1.2, 95% CI 1.1-1.3) and younger age of first injection (AOR 0.92, 95% CI 0.87-0.96). CONCLUSION: The high HIV and HCV prevalence found in this study among IDUs in Edmonton highlights the complex needs of the IDU community and the continued need for targeted programming.

Reducing Salmonella on cantaloupes and honeydew melons using wash practices applicable to postharvest handling, foodservice, and consumer preparation.

Washing conditions that included a soak or brush scrub were evaluated for removal of Salmonella from the surface of smooth (honeydew) or complex (cantaloupe) melon rinds. Melon rinds were spot-inoculated onto a 2.5 cm2 area of rind (squares) with approximately 6.0 log(10) CFU/square of an avirulent nalidixic acid-resistant strain of Salmonella typhimurium. Melons were washed by immersion in 1500 ml of water or 200 ppm total chlorine and allowed to soak or were scrubbed over the entire melon surface with a sterile vegetable brush for 60 s. Inoculated sites, uninoculated sites ("next to" sites) that were adjacent to inoculated sites, and sites on the side of the melon opposite (remote sites) the inoculated site were excised and pummeled in a stomacher for 2 min prior to plating onto tryptic soy or bismuth sulfite agar supplemented with 50 microg/ml nalidixic acid. S. typhimurium was reduced on the rind of cantaloupe by 1.8 log CFU/melon after soaking for 60 s in 200 ppm total chlorine, which was significantly better than the 0.7 log CFU/melon achieved with soaking in water. For both water and 200 ppm total chlorine, scrubbing with a vegetable brush was shown to be significantly (0.9 log CFU/cantaloupe) more effective than soaking alone. When honeydew melons were soaked or scrubbed in water, reductions of 2.8 log CFU/melon or >4.6 log CFU/melon (four of five samples), respectively, were observed. However, when water treatments were used, the presence of Salmonella-positive "next to" and remote sites indicated that bacteria were spread from inoculated site on the rind to uninoculated sites either through the rinse water (40-70 CFU/ml of Salmonella) or scrub brush (400-500 CFU/brush). Transfer to other sites occurred more often with cantaloupe than honeydew melons. This transfer was eliminated when 200 ppm total chlorine was used. When 200 ppm total chlorine was used, Salmonella could not be detected in the water or on the scrub brush. For optimal microbial removal in food service and home settings, melons should be scrubbed with a clean brush under running water. However, to ensure the benefits of brushing, instructions for cleaning and sanitizing brushes must also be emphasized. For food service settings where concentration and pH can be adequately measured, the use of chlorinated water may provide additional benefit.

Reducing Salmonella on apples with wash practices commonly used by consumers.

The efficacy levels of practices used by consumers to wash smooth-surface fruits and vegetables were compared. Golden Delicious apples were spot inoculated near the blossom end with 50 microl of a cocktail of six serotypes of Salmonella enterica (with a total inoculum level of approximately 10(9) CFU per apple). The inoculum was dried for 1.5 h, and apples were either treated immediately or held for 24 h prior to treatment. Treatments included wetting with approximately 5 ml of water, vinegar (5% acidity), or a 200-ppm chlorine solution, rubbing for 5 or 30 s, rinsing with 200 to 600 ml of 24 or 43 degrees C water, and drying with a sterile paper towel. Residual populations of Salmonella were determined by rubbing the treated apple for 30 s in 20 ml of Dey-Engley neutralizing broth and plating on tryptic soy agar and bismuth sulfite agar. Rubbing treatments carried out for 5 and 30 s both resulted in a significant reduction in Salmonella populations (1 log10 CFU per apple) relative to populations on samples held for 30 s. A 5-s rub followed by a 200-ml flowing-water rinse reduced populations by 3 log10 CFU per apple. No further decrease in population was obtained by rinsing with 400 or 600 ml of water. Increasing the rinse water temperature to 43 degrees C did not significantly improve microbial removal. Drying the apple with a sterile paper towel resulted in an additional decrease of approximately 0.4 log10 CFU per apple. A reduction of 3.2 log10 CFU was achieved with a combination of wetting with water, rubbing for 5 s, rinsing with 200 ml of water, and drying with a paper towel for apples inoculated just prior to or 24 h before treatment. Reductions obtained for apples treated with 5% vinegar and with a 200-ppm chlorine solution were significantly larger (2.1 to 3.2 log10 CFU per apple, respectively) than those achieved with water.