Clostridium difficile infections on rise in United States at short-stay facilities

An analysis of data gathered from the National Hospital Discharge Survey (NHDS) shows that Clostridium difficile-associated disease (CDAD) rapidly increased among patients at US hospitals from 2000 to 2003, particularly among patients aged ≥65 years.

Researchers warn that a continued increase in CDAD cases may place added strain on the US healthcare system.

"The financial costs and patient illness caused by CDAD in US short-stay hospitals appear substantial," the authors stated. "New initiatives in the areas of surveillance, prevention, and control of CDAD are urgently needed."

During the overall study period from 1996 to 2003, researchers identified an increasing number of overall (primary and other) CDAD diagnoses, with cases nearly doubling from 98,000 (95% CI, 84,000–112,000) in 1996 to 178,000 (95% CI, 151,000–205,000) in 2003 (slope expressed as the average change in value per annum, b=28,000; 95% CI, 19,000–38,000; P<.001).

The increase in CDAD rates appears to be a more recent trend. From 1996 to 1999, the authors found no significant trend in CDAD diagnoses.

However, CDAD rates experienced an upwards trend from 2000 to 2003 in both primary-listed diagnosis (b=3.1; 95% CI, 1.70–4.48; P=.008) and any diagnosis listed on patients' discharge (b=9.48; 95% CI, 6.16–12.80; P=.01).

Among those aged ≥65 years, the rate of CDAD discharge diagnoses was much higher than those in other age groups with 228 diagnoses per 100,000 patients (95% CI, 200–256). For those aged 45–64 years, 40 diagnoses were estimated per 100,000 patients (95% CI, 34–45; P<.001). The slope of the increase also was much greater in the older age group (b=58.1; 95% CI, 36.5–79.7; P=.01) than for those aged 45–65 years (b=7.9; 95% CI, 4.0–11.7; P=.03).

Larger hospitals were found to have higher rates of CDAD diagnoses, as those with 100 to 299 beds (0.42%; 95% CI, 0.37%–0.47%; P=.004) and ≥300 beds (0.38%; 95% CI, 0.35%–0.40%; P=.03) had significantly higher rates than hospitals with <100 beds (0.30%; 95% CI, 0.23%–0.36%; P value not provided).

Possible causes of the increase in CDAD include antimicrobial drug use patterns, the use of alcohol-based hand sanitizers as cleansers in lieu of soap and water, and the possible emergence of more resilient C difficile strains.

"The overall scope and magnitude of CDAD are great and may exceed those of other important hospital pathogens," the authors stated. "Clinicians should be aware of the risk posed by CDAD in their hospitalized patients, remain cognizant of the importance of judicious antimicrobial drug use, and support infection control efforts for CDAD in the healthcare settings where they practice."

According to the authors, CDAD-related costs exceeded $600 million in 2003, while the excess illness and costs of C difficile in 2001, 2002, and 2003 exceeded the estimated annual number of methicillin-resistant Staphylococcus aureus infections for 1999–2000. CDAD also resulted in 600,000 excess hospital days in non-federal facilities, the authors stated.

Study limitations included the sensitivity of CDAD diagnostic tests, with hospitals using toxin immunoassays instead of C difficile cultures or cytotoxin assays, and the use of discharge data, which is dependent on the sensitivity of individual hospitals' coding for CDAD.

SOURCE McDonald LC, Owings M and Jernigan DB. Clostridium difficile infection in patients discharged from US short-stay hospitals, 1996–2003. Emerg Infect Dis. 2006;12:409–415.