NEW YORK (Reuters Health) - A study shows that individuals can harbor the bacterium, Clostridium difficile, but may not become ill. However, these carriers frequently shed virus onto their skin and into the environment and, as a result, may contribute significantly to disease transmission.
C. difficile is a pathogen frequently acquired in a hospital or other medical facility. It typically occurs after a course of antibiotics that destroys some of the “good” bacteria in the intestinal tract, as well as the disease-causing bacteria. C. difficile often targets the most vulnerable patients, such as cancer patients, those with weakened immune systems and the elderly. The infection usually settles in the large bowel causing severe diarrhea that can lead to colitis, but it can progress to systemic infection (sepsis) and even death.
The current report describes a C. difficile infection outbreak at a long-term care facility in which clinicians found that 35 (51 percent) of 68 residents who had no symptoms of C. difficile-associated disease (CDAD) carried a C. difficile strain not involved in the epidemic, while 13 (37 percent) of these patients carried the epidemic strains of C. difficile.
“Asymptomatic carriers outnumbered patients with CDAD in the study wards, 7 to 1,” report Dr. Curtis J. Donskey and colleagues from the Louis Stokes Cleveland VA Medical Center in the current issue of Clinical Infectious Diseases.
Among asymptomatic carriers, C. difficile was frequently recovered from skin (61 percent) and environmental sites (59 percent). Eighty-seven percent of isolates found in skin samples and 58 percent of isolates found in environmental samples matched the isolates found in the patients’ stool samples.
Spores on the skin were “easily transferred to investigators’ hands,” the authors report.
Previous CDAD and previous antibiotic use were associated with asymptomatic carriage of C. difficile. The combination of these two factors predicted asymptomatic carriage, with a sensitivity of 77 percent and a specificity of 58 percent.
These findings suggest that asymptomatic carriers are a potential source for transmission of C. difficile strains among long-term care facility residents, the investigators conclude.
“Simple modifications of current infection control practices, including glove use by health care workers and use of 10 percent bleach for room disinfection, could reduce the risk of transmission from asymptomatic carriers,” Donskey said in a statement.
SOURCE: Clinical Infectious Diseases, October 15, 2007.