In 2008, the Medical Officer of Health at Alberta Health Services (Edmonton, Canada) was notified that, in some practice settings, a syringe was used to administer medication through the side port of an intravenous circuit and then the syringe, with residual drug, was used to administer medication to other patients in the same manner. This practice has been implicated in several outbreaks of bloodborne infection in hospital and clinic settings.

A risk assessment model was developed to predict the risk of a patient contracting a bloodborne viral infection from the practice. The risk of transmission was defined as the product of 5 factors: (1) the population prevalence of a specific bloodborne pathogen, (2) the probability of finding a viral bloodborne pathogen in an intravenous circuit, (3) the rate of syringe reuse, (4) the probability of causing disease given a bloodborne pathogen exposure, and (5) the susceptibility of the exposed person.

The risk was modeled first with consistent use of the proximal port of the intravenous circuit. The risk of transmission of hepatitis B virus was approximately 12–53 transmission events per 1,000,000 exposure events for a range of practice probabilities (ie, frequency of the risk practice) from 20% to 80%, respectively. The risk of transmission of hepatitis C virus was approximately 1.0–4.3 transmission events per 1,000,000 exposure events for the same practice probability range, and the risk of transmission of human immunodeficiency virus was approximately 0.03–0.15 transmission events per 1,000,000 exposure events for the same practice probability range. The use of the distal port was associated with a 10-fold decrease in the risk.

Practitioners must practice safe, aseptic injection techniques. The model presented here can be used to estimate the risk of disease transmission in situations where reuse has occurred and can serve as a framework for informing public health action.

In patients with smear-positive pulmonary tuberculosis who are hospitalized or reside in congregate settings, guidelines recommend airborne infection isolation until sputum smear results are negative. Studies have identified factors associated with delayed sputum smear and culture conversion in patients with tuberculosis. Because these studies did not use methods of survival analysis, estimates of time to sputum smear conversion that are based on initial patient characteristics are not available. The ability to predict time to sputum smear conversion could be useful for programmatic planning and patient counseling.

We performed a cohort study using survival analysis to identify factors associated with time to sputum smear and culture conversion. We defined the time to sputum smear conversion as the time elapsed from the start of treatment to the first date of sustained conversion.

Ninety-eight patients had sputum smear samples positive for acid-fast bacilli. Lower initial smear grade (on 1+ to 4+ scale) and absence of cavitation on chest radiograph were associated with earlier sputum smear conversion in bivariate analysis. In multiple regression analysis, initial smear grade (hazard ratio, 0.45; 95% confidence interval, 0.35-0.57) and drug resistance (hazard ratio, 2.30; 95% confidence interval, 1.08-4.89) remained statistically significant; a model comprising only initial smear grade performed almost as well. Predictors of sputum culture conversion were similar.

Initial smear grade was the strongest predictor of time to sputum smear and culture conversion in patients with pulmonary tuberculosis and may be a useful predictor for programmatic planning and patient counseling.

To evaluate the incidence of needlestick injuries (NSIs) among different models of safety-engineered devices (SEDs) (automatic, semiautomatic, and manually activated safety) in healthcare settings.

This multicenter survey, conducted from January 2005 through December 2006, examined all prospectively documented SED-related NSIs reported by healthcare workers to their occupational medicine departments. Participating hospitals were asked retrospectively to report the types, brands, and number of SEDs purchased, in order to estimate SED-specific rates of NSI.

Sixty-one hospitals in France.

More than 22 million SEDs were purchased during the study period, and a total of 453 SED-related NSIs were documented. The mean overall frequency of NSIs was 2.05 injuries per 100,000 SEDs purchased. Device-specific NSI rates were compared using Poisson approximation. The 95% confidence interval was used to define statistical significance. Passive (fully automatic) devices were associated with the lowest NSI incidence rate. Among active devices, those with a semiautomatic safety feature were significantly more effective than those with a manually activated toppling shield, which in turn were significantly more effective than those with a manually activated sliding shield (P < .001, x2 test). The same gradient of SED efficacy was observed when the type of healthcare procedure was taken into account.

Passive SEDs are most effective for NSI prevention. Further studies are needed to determine whether their higher cost may be offset by savings related to fewer NSIs and to a reduced need for user training.