Experts: C. diff surveillance needed for hospitals, LTC
Experts: C. diff surveillance needed for hospitals, LTC
Lack of data on an increasingly severe disease
A group of experts recently convened in San Francisco for a special discussion on the changing epidemiology of Clostridium difficile. Leading clinicians and investigators from the Centers for Disease Control and Prevention participated in the discussion, which resulted in a summary report that was obtained by Hospital Infection Control.1 Key points of concern include:
It is well documented that C. diff. infection can occur outside the hospital setting and there is some evidence that community rates may be increasing, that disease severity may have increased in the community, and that the disease may be occurring in people who have not previously been treated with antibiotics. Infection involving new strains of C. diff, especially in hospitals but also within nonhospital settings, could represent a significant threat to public health in the years ahead.
Researchers have identified an epidemic C. diff bacterium known as NAP1/BI, or ribotype 027, which produces up to 20 times as much toxin as other strains, contains binary toxin, and is resistant to fluoroquinolone antibiotics. Some clinicians report that patients infected with 027 may have a higher risk of developing more severe symptoms. At this point, however, it is not possible to conclude definitively that higher toxin production correlates with more severe disease. Given that some researchers have not observed outbreaks of severe disease despite documentation of the epidemic strain of C. diff in their hospital, host factors, antibiotic use patterns, and infection control factors also may determine individual outcomes and propensity for epidemics.
Clinicians agree that poor infection control in hospitals contributes to higher risk of disease transmission. While strategies to control C. diff transmission in a hospital setting vary, they are generally based on fundamental principles of hygiene and transmission of bacterial agents. This includes the use of proper sanitation (i.e., hand washing) and barriers (gloves, gowns). Regular and proper cleaning of hospital rooms also is considered important to remove C. diff spores from a patient's environment. The first step in a successful infection control program is universal and standardized CDAD surveillance in all hospitals and long-term care facilities.
Efforts to identify and report the incidence of C. diff are expanding, but remain inadequate for many reasons. Hospitals have not placed a high priority on C. diff surveillance, there are no national reporting requirements in the United States, and only a few states have initiated reporting proactively. In addition, doctors may treat presumptively and may not test for C. diff, even among symptomatic patients. Broader standardized reporting of C. diff incidence and severity will significantly expand our understanding of this disease.
Several issues associated with infection continue to pose challenges in both diagnosis and treatment. It is unclear why most infected patients remain asymptomatic while some go on to develop symptomatic disease. It also is unclear why some patients experience recurrent disease while others recover fully and remain disease-free. In some cases, symptomatic patients recover without intervention, while most require medical treatment.
Because C. diff reflects a spectrum of signs and symptoms including but not limited to diarrhea, the preferred definition of CDAD is: "C. difficile associated disease." One of the primary goals in any effort to build awareness of C. diff infection should therefore be to identify the unique features of CDAD that differentiate it from other types of diarrhea. CDAD differs from other types of diarrhea in the following ways:
- Infection usually is associated with prior antibiotic exposure.
- A disturbance of the normal intestinal microbiology appears to be a major factor in disease development or induction.
- Many patients experience a recurrence of disease.
- Nosocomial spread of disease is notable.
Reference
- Gerding DN. (moderator) Understanding C. difficile infection and CDAD: New insights on prevention, diagnosis, and treatment: Key opinion leader roundtable discussion. San Francisco; Sept. 26, 2006.