When Volunteering Doesn't Cut It: A critical examination of Carbapenem-Resistant Enterobacteriaceae Surveillance and Trends in the United States
Background. Carbapenem-resistant Enterobacteriaceae, including Escherichia coli and Klebsiella pneumoniae, are newly emerging pathogens of public health importance. Currently no nationally representative or mandatory surveillance or reporting system exists to examine trends of these important pathogens. Objective. The purpose of the current study was to estimate trends in overall microbial burden and carbapenem resistance in E. coli and K. pneumoniae and to understand the extent to which
... ent to which hospitals which report to voluntary surveillance systems represent all hospitals in the United States. Design. We conducted a descriptive study to compare the hospitals participating in voluntary reporting systems of the University HealthSystem Consortium and the National Healthcare Safety Network with the Healthcare Utilization Project's Nationwide Inpatient Sample, a nationally representative sample of hospital discharges. Methods. Descriptive analyses examined hospital characteristics (region, bed size, hospital control, teaching status, case mix index) and patient characteristics (age, sex, race/ethnicity, admission source, admission type, discharge status, primary payer) of participant hospitals versus all US hospitals. ICD-9-CM codes identified discharges coded for E. coli and K. pneumoniae diagnoses; linear regression was used to evaluate trends in overall microbial burden of E. coli and K. pneumoniae in all US Hospitals and US Academic Centers. Trends in E. coli and K. pneumoniae resistance to carbapenem were also evaluated in hospitals participating in voluntary surveillance systems (n=13). Results. Between 2002 and 2007 , slight increasing trends in burden of both E. coli and K. pneumoniae were observed (E. coli: slope = 0.0537; K. pneumoniae slope = 0.0168). Hospitals participating in voluntary surveillance systems are larger and care for fewer elderly patients than all US hospitals. Conclusions. These results suggest that hospitals that participate in voluntary surveillance systems like the National Healthcare Safety Network and the University HealthSystem Consortium may underrepresent trends in smaller hospitals, as well as those that treat elderly patients. Increasing overall burden of infection due to these isolates only reinforces the importance carbapenem resistance in E. coli and K. pneumoniae. This important public health threat may warrant the creation of a national, mandatory reporting system for these and other antimicrobial resistant organisms.