Structure, Personnel, and Responsibility
The responsibilities of the hospital IPP include surveillance and prevention of HAIs, continuing education of medical
TABLE 2 Distribution of the five most common nosocomial pathogens isolated from major infection sites reported to the NHSN from 2009 to 2010a
% of total at each
NHSN,NationalHealthcareSafetyNetwork;CoNS,coagulase-negative staphylococci. Data are from reference7.
staff, control of infectious disease outbreaks, protection of em-ployees and visitors from infection, and advice on new prod-ucts and procedures. The program is generally directed by a physician/epidemiologist and enforced by the infection pre-vention committee. Every hospital must also have a working infection prevention staff, comprising one or more infection preventionists (IPs). The IPs coordinate surveillance and pre-vention of HAIs, among many other related activities, and provide their data to the infection prevention committee.
Infection Prevention Committee
The infection prevention committee is responsible for re-porting and evaluating HAI data and for drafting and imple-menting policies, procedures, and guidelines pertinent to
TABLE 3 Attributable mortality of nosocomial bloodstream infection due to selected pathogens
Mortality
Enterococcus 43 12 31 18
spp.
VRE 67 30 37 17
Candida 57–61 12–19 38–49 19,20
spp.
a
CoNS, coagulase-negative Staphylococcus spp.; VRE, vancomycin-resistant Enterococcus spp.
the practice of infection prevention. The committee should be multidisciplinary, with representatives from all depart-ments, including clinical microbiology, and should meet every 1 to 3 months to review hospital-specific HAI data and to formulate policy. The members bring the needs and perspectives of their departments to the committee and, in turn, take back important information about infection prevention initiatives and policies. Other responsibilities of the committee include reviewing technical information about new products, devices, or procedures pertinent to infection prevention and instituting allnecessary control measures in the event of an outbreak or other infection-related emergency.
The clinical microbiologist, or the microbiology supervi-sor in an institution that does not have a doctoral-level microbiologist, isan integral component of the infection prevention team and thus must be an active member of the infection prevention committee. Because the infection prevention committee frequently bases its decisions on the results of microbiological tests, the clinical microbiologist must instruct members of the committee how to integrate culture results and which microbiological approaches can be used to solve specific infection prevention problems.
The microbiology laboratorycan benefit if the infection prevention staff understands the routine processes in micro-biology, e.g., timelines for the processing of blood, wound, or urine cultures and related techniques (29). Specimen processing timelines enable infection prevention staff to u n d e r s t a n d v a r i o u s e x p e c t a t i o n s o f t u r n a r o u n d t i m e s (TATs) for specific results and time constraints of microbi-ology test services and can educate them as to when they can expect follow-up information for routine cultures, thus minimizing premature phone calls to the laboratory request-ing culture information. Conversely, while servrequest-ing on the committee, the microbiologist will learn about the problems confronting infection prevention personnel and thus will be better able to organize the laboratory’s response to such problems.
In addition, the microbiologist should inform the com-mittee about changes in methods, reagents, or instrumenta-tion that may substantially affect the laboratory’s ability to detect and characterize HAI pathogens. These include changes in thesensitivities and specificities of diagnostic methods and changes in antimicrobial susceptibility testing (AST) interpretive criteria, as well as taxonomic changes that may create confusion. An example of changes in testing and reporting criteria that directly affect infection preven-tion efforts is the recent change in the interpretive break-points for cephalosporins and carbapenems against the En-terobacteriaceae enacted by both the Clinical and Laboratory Standards Institute (CLSI) (30) and the European Commit-tee on Antimicrobial Susceptibility Testing (EUCAST) (31). The new (lower) breakpoints are intended to obviate the need for extended-spectrumβ-lactamase (ESBL) con-firmatory testing or modified Hodge testing (confirmation of carbapenemase) for clinical use. The result of this change in testing and interpretive criteria has been the loss of considerable epidemiologic data available from routine test-ing, as isolates with ESBL production may no longer be confirmed or flagged as such (32), and in some instances, this has led to an increase in the number of isolates charac-terized as resistant to these agents and therefore potentially MDR, with major implications for infection prevention (33–
36). One institution recently reported that this change re-sulted in a 35% increase in the number of MDR-GNRs identified and a concomitant increase in the hospital’s use of contact precautions (33).
Members of the infection prevention team must commu-nicate with each other to accomplish their goals. Communi-cation canbe enhanced if the infection prevention staff members regularly make rounds in the laboratory to ask questions, review microbiological and molecular testing re-sults, and discuss current problems and views. Likewise, the microbiology staff should attend conferences at which infection prevention personnel discuss epidemiological principles and contemporary topics. Unfortunately, several ongoing trends challenge these valuable personal interven-tions between microbiology and infection prevention per-sonnel (34). Consolidation of CML services, off-site reloca-tion of microbiology laboratories, and total reliance on electronic medical records to the exclusion of first-hand observation (e.g., review of plates or Gram stains) too often keep clinicians and infection prevention personnel out of the microbiology laboratory and keep microbiologists con-fined to the laboratory.
HAI Surveillance
Active HAI surveillance programs are associated with re-duced rates of infection and their consequent morbidity and mortality (25,37); national and state accrediting agencies require hospitals to do HAI surveillance, and public report-ing of certain HAI rates is now a requirement for U.S.
hospitals that participate in the Medicare program (38).
Thus, systematic surveillance of HAIs is the IPP’s most important activity. Surveillance is also the IPP’s most costly and time-consuming activity. Surveillance allows the IPP to monitor the frequency and types of HAIs, detect outbreaks, evaluate compliance with infection prevention guidelines, provide data for policy development, and monitor the effect of infection prevention interventions on HAI rates. To accomplish the overallgoal ofdecreasing infection rates, the IPP mustprovide surveillance datato clinic units as soon as possible, accompanied by suggestions for improve-ment and reminders of existing infection prevention prac-tices. IPPs can compare their hospital rates with national benchmarks compiled and reported by the CDC NHSN system (39). Figure 1 is a sample format for comparing
FIGURE1 Rates of central venous catheter (CVC)-associated infection in a medical ICU (MICU). Sample chart format for reporting nosocomial infection rates in an ICU compared with CDC NHSN benchmarks. doi:1128/9781555817381.ch8.f1
infection rates in an ICU with national benchmark data.
The IPP should provide infection rates, recommendations for reducing rates, and assistance in implementing interven-tions to unit personnel, such as medical directors, nurse managers, and clinicians.
The IPP should design a surveillance system that is com-pliant with state and federal mandates, appropriate for the specific needs of the hospital, and feasibly based on their budget. Because surveillance consumes more resources than any other infection prevention activity (40), IPPs must design the most efficient surveillance system possible. The most complete and accurate surveillance program would require an IP to review charts of all hospitalized patients daily, but this approach obviously is not practical inany but the smallest of hospitals. IPPs should focus limited re-sources in the highest-risk areas (e.g., intensive care, hema-tology/oncology, burn, and organ transplant wards) and use various screening techniques to increase surveillance effi-ciency. IPs can use a variety of data sources (e.g., microbiol-ogy reports, nursing care plans, antibiotic orders, radiolmicrobiol-ogy reports, vital signs, and discharge diagnoses) to determine which charts should be further reviewed.
Review of microbiology data is probably the most common single method for case finding, and it compares favorably in some circumstances with more-comprehensive ward-based surveillance (41,42). For example, Yokoe and colleagues re-ported that review of microbiology data alone was both more resource efficient than and as effective as applying the CDC’s definition of health care-associated bloodstream infection (43). Such laboratory-based surveillance allows the IP to effi-ciently review a large amount of data. Moreover, medical in-formation systems can enhance laboratory-based surveillance further by linking laboratory data with data from many other sources (44,45), including pharmacy (antimicrobial use), ra-diology, billing (diagnostic codes), patient census data, and nursing notes (vital signs, care plans).
Although reviewing microbiology reports is an essential part of surveillance, these data alone may not detect all H A I s o r a l l o u t b r e a k s . T h e s e n s i t i v i t y a n d s p e c i f i c i t y of laboratory-based surveillance depend upon b ot h t he
frequency with which clinicians obtain cultures and the quality of the culture specimens received by the lab. In addition, while laboratory-based surveillance may quickly detect outbreaks due to unusual pathogens, or infections at unusual sites, outbreaks or clusters due to common patho-gens at common sites (e.g., Escherichia coli urinary tract infection) may go undetected forlonger periods of time.
An optimal surveillance program will include data from multiple sources to help IPs determine which charts deserve further review. The University of Iowa previously validated a surveillance strategy using primarily microbiology reports and nursing care plans and found the sensitivity and specific-ity to be 81% and 98%, respectively (46). More recently, we introduced and validated a computer-based screening algorithm that provides for each IP each day a list of all patients in their units that had specificabnormalities in vital signs or white blood cell counts, positive microbiology findings, or different combinations of tests ordered within a 24-h period (e.g., chest radiograph and culture of respiratory secretions or cultures from two or more body sites). After reviewing this list, the IPs review the medical records of a smaller percentage of patients, thereby reducing the amount of time required for surveillance.
The overall approach to surveillance in each health care facility should be monitored and adjusted by the infection