Literature Update - October, 2003
Compiled by Dr Deb Friedman, VICNISS ID Physician
ESBL Outbreaks are Expensive!
Researchers from a New York neonatal ICU (Infection Control Hospital Epidemiology 2003;24:601-6) have studied the costs of controlling
an outbreak of extended-spectrum beta-lactamase (ESBL) producing Klebsiella pneumoniae.
The 4-month outbreak cost a total of $341,751, and the major costs were for healthcare worker time providing direct patient care, and
microbiological personnel costs. In addition, infected or colonised patients had increased lengths of stay.
This is yet another piece of evidence on the burden of resistant organisms in hospitals.
Victorian hospitals are now starting to recognise the emergence of ESBLs, and in time their burden will increase. The important
preventive measures that our hospitals must emphasise are:
- Judicious use of antibiotics by physicians
- Hand hygiene and additional precautions to prevent transmission
- Pharmacy input into restricting broad-spectrum antibiotics
Increasing Resistance Among Gram-negative and Gram-positive Bacteria
Recent studies have confirmed most of our anecdotal experiences with changing resistance patterns in our hospitals.
A multicentre study from the USA (Infection Control Hospital Epidemiology 2003;24:607-12) compared the resistance rates of Enterobacteriaceae
(this includes E.coli, Klebsiella spp. etc) from patients in ICU with those from patients outside ICU. They found that over
a 5-year period (1995-2000), there was a decrease in susceptibility to ciprofloxacin, especially among E.coli. As expected,
resistance rates were higher among ICU patients.
The antibiotic which retained its activity against nosocomial Enterobacteriaceae was imipenem (keep in mind that this was a drug-company sponsored study).
The over-use of carbapenems (imipenem & meropenem) in many Victorian hospitals, as in many international centres will no doubt
alter the findings of this study with time.
In a study from the UK (Journal of Hospital infection 2003;54:179-87), researchers collected Gram-positive isolates from ICU patients.
They found that 59% of S.aureus isolates were oxacillin resistant (equivalent to MRSA), and 18% of
Enterococcus faecalis isolates were vancomycin-resistant (VRE). They did not identify any vancomycin-resistant
S.aureus (VISA) in this study.
The above resistance rates are in keeping with the Australian experience, although we are already seeing the emergence of VISA in some of our hospitals.
C.difficile in Hospitals
As infection control staff are aware, Clostridium difficile infection can easily be transmitted from patient-to-patient, and
from patients to staff.
A group from Norway have published their experiences with C.difficile-associated diarrhoea (Journal of Hospital infection 2003;54:202-206). They
attempted to answer the question about whether or not the rates of C.difficile infection were related to antibiotic use
in their hospitals. They found that even in a hospital that used a large quantity of broad-spectrum antibiotics the rate of
C.difficile was steady, in contrast, when antibiotic usage was lowered in another
hospital, the infection rate increased.
These findings indicate that infection control procedures, including hand hygiene and isolation precautions are very important in making
a difference in the rates of C.difficile diarrhoea, even though this infection is related to antibiotic consumption.