Mycobacterium massiliense outbreak after intramuscular injection, South Korea

Abstract

We conducted an epidemic investigation to discover the route of transmission and the host factors of an outbreak of post-injection abscesses. Of the 2984 patients who visited a single clinic, 77 cases were identified and 208 age- and sex-matched controls were selected for analysis. Injected medications per se were not found to be responsible, and a deviation from safe injection practice suggested the likelihood of diluent contamination. Therefore the injected medications were classified according to whether there was a need for a diluent, and two medications showed a statistically significant association, i.e. injection with pheniramine [adjusted odds ratios (aOR) 5.93, 95% confidence interval (CI) 2.97-11.87] and ribostamycin (aOR 47.95, 95% CI 11.08-207.53). However, when considered concurrently, pheniramine lost statistical significance (aOR 8.71, 95% CI 0.44-171.61) suggesting that normal saline was the causative agent of this outbreak. Epidemiological evidence strongly suggested that this post-injection outbreak was caused by saline contaminated with Mycobacterium massiliense without direct microbiological evidence. © 2012 Cambridge University Press.