Literature Update - November, 2003
Compiled by Dr Deb Friedman, VICNISS ID Physician
Risk Factors for Surgical Site Infection
An infection control unit from Thailand has published their experiences with surveillance for SSI in a university hospital (Am J Infect
Control 2003;31:274-9). They utilised NNIS definitions for operative procedures and SSI, and categorised patients according to the NNIS
risk index. They conducted postdischarge surveillance on patients who attended outpatients and on patients who were readmitted to hospital.
They collected data on over 4000 major operations over a 19-month period, and detected 192 SSIs (rate=4.3/100 operations). Multivariate analysis
revealed that independent risk factors for SSI included duration of operation, ASA class, and degree of wound contamination.
These risk factors have been identified previously, and the above results validate the use of the NNIS risk index in major operations.
Evaluation of Blood Cultures
A study from a Turkish hospital looked at blood cultures drawn (Clinical Microbiology & Infection, 2003;9(10):1038). They found
that 10.7% of cultures were contaminated, and that of the 567 episodes of bloodstream infection, 73.4% were hospital-acquired. The most
commonly isolated microorganisms were staphylococci (44%, methicillin resistant 69.4%), enterococci (15%) and Escherichia coli (12.5%)
in hospital acquired episodes. Death attributable to bloodstream infections was 16.6% in hospital acquired episodes. The highest
mortality occurred in patients with bacteremia due to Pseudomonas aeruginosa (37.5%) in hospital-acquired episodes. Underlying
diseases, severity of illness, presence of bladder catheter, previous use of antibiotics, tracheal intubation and adequacy of treatment
were found to be significantly associated with death.
This study confirms what most of us know to be true. Hospital-acquired bloodstream infections are mostly caused by staphylococci, and they
contribute to mortality, especially in patients who have underlying diseases.
In addition, the rate of blood culture contamination (approximately 10%) is similar to the rate that many of our hospitals would experience. Infection
control departments can address this by educating staff about the aseptic technique required for collecting blood cultures, and the optimal timing and number
of blood cultures that should be drawn.
No fires from Alcohol-Based Hand Rub Dispensers
Alcohol-based hand rubs reduce nosocomial infections, and are increasingly being used in hospitals to improve compliance with hand hygiene. They do however
carry a small risk of starting fires. A group from the USA administered a questionnaire to infection control professionals about the use of alcohol-based hand
rubs, and whether or not any fires attributable to the dispensers had occurred (Infection Control Hospital Epidemiology 2003;24:618-9). Eight hundred and
forty responses were received from most states of the USA, and none of them reported a fire attributed to alcohol-based hand rub dispensers.
The benefits of providing these hand rubs to health care workers outweigh the concerns that they represent a fire hazard. Keep rubbing!