15th Society for Healthcare Epidemiology of America (SHEA) Scientific Meeting
Los Angeles, April 2005
Below is an update of selected interesting topics and information presented at SHEA:
VICNISS Coordinating Centre
Staff members from the VICNISS Coordinating Centre recently attended the 15th Society for Healthcare Epidemiology
of America (SHEA) Annual Scientific Meeting 2005, held in Los Angeles. The emphasis of these meetings (intended
for health care professionals such as physicians, nurses and others) is the prevention and control of nosocomial
infections. Relevant general themes discussed this year included modifiable risk factors in surgical site infections
(such as surgical antibiotic prophylaxis) and surveillance methodology.
Two VICNISS oral presentations were delivered:
- Establishment Of A Statewide Surveillance Program For Hospital-Acquired Infections In Public Hospitals, Victoria, Australia.
- A State-wide Smaller Hospital Nosocomial Infection Surveillance Program: The First Report, Victoria, Australia
And three VICNISS posters were presented:
- Performance of the NNIS Risk Index in Predicting Surgical Site Infections in an Australian Setting
- Surgical Antibiotic Prophylaxis in Victorian Public Hospitals: Early Results from VICNISS, a Statewide Surveillance Program
- The Potential for Surgical Site Infection Rate Surveillance in Smaller Public Acute Care Hospitals, Victoria, Australia
Antibiotic Prophylaxis Projects
Dale Bratzler presented information about antibiotic prophylaxis in a well-attended plenary session. He told
us that an estimated 40-60% of SSIs are preventable, and that the overuse, underuse, improper timing, and misuse
of antibiotics occurs in 25-50% of operations. For these reasons, the CDC’s National Surgical Infection
Program (SIP) has the following quality indicators:
- Correct timing. The proportion of patients in whom antibiotic prophylaxis is
administered within 1 hour of the commencement of surgery. Because of the longer required infusion times,
vancomycin or fluoroquinolones, when indicated for betalactam allergy, may be started within 2 hours before
the incision. Antibiotics should be infused before the tourniquet is inflated in orthopaedic cases.
- Correct antibiotic choice. Proportion of patients who receive prophylactic
antibiotics consistent with current recommendations. (1. Bratzler DW.
Clin Infect Dis 2004;38:1705-15,
2. Bratzler DW. Arch Surg 2005;140:174-182).
- Antibiotic duration. Antimicrobial prophylaxis should not extend beyond
24 hours after wound closure
Bratzler also discussed the issues of antibiotic redosing in surgery and weight-based dose adjustment.
Studies of patients undergoing gastrointestinal, biliary, and cardiac operations have demonstrated that
repeat dosing of short half life antibiotics is associated with lower wound infection rates. In addition,
data from the SIP program indicates that only 12.2% of patients whose surgery was ongoing > 4 hours after
incision received an additional antibiotic dose in the operating theatre. (1. Scher KS. Studies on the duration
of antibiotic administration for surgical prophylaxis. Am Surg. 1997;63:5962, 2.
Ohge H, Takesue Y, Yokoyama T, et al. An additional dose of cefazolin for intraoperative prophylaxis.
Surg Today. 1999;29:12331236, 3.
Zanetti G, Giardina R, Platt R. Intraoperative redosing of cefazolin and risk for surgical site infection in
cardiac surgery. Emerg Infect Dis. 2001;7:828831, 4.
Bratzler DW, Houck PM, et al. Clin Infect Dis. 2004;38:17061715).
In a study of obese patients undergoing gastroplasty, blood and tissues levels of cefazolin were consistently
below the MIC for gram-positive and gram-negative organisms. However, it has been shown that obese patients
receiving a two-gram dose of cefazolin had a lower incidence of SSI than those receiving a one-gram dose. (
1. Forse RA, Karam B, MacLean LD, Christou NV. Antibiotic prophylaxis for surgery in morbidly obese patients.
Surgery. 1989;106:750756,
2. Bratzler DW, Houck PM, et al. Clin Infect Dis. 2004;38:17061715).
Other measures which are being instituted to prevent SSI include:
- Glucose control in cardiac surgery patients
- Proper hair removal
- Normothermia in colorectal surgery patients
- Glucose control in diabetics undergoing non-cardiac surgery (test)
Catheter-Related Bloodstream Infection (CR-BSI) Prevention
Some of the strategies which can prevent CR-BSI include:
- Hand hygiene
- Aseptic technique
- Dressing changes as needed
- Chlorhexidine skin antisepsis
- Chlorhexidine impregnated sponges
MMWR 2002;51 (RR10)
One group of researchers ( R Duncan et al, Burlington, MA) presented data about the interventions that put into
place in their hospital to reduce CR-BSI:
- Routine maximal aseptic technique
- Dressing changes every 4 days
- 61% ethanol hand antiseptic (Avagard™ )
- CHG/70% isopropanol IV site antiseptic (ChloraPrep™ )
- CHG impregnated sponges (BioPatch™ )
These interventions resulted in a nearly 2/3 reduction of CR-BSI. The materials used in their study (hand rub,
prep, patch) did however cost $114,000.
Another presentation focussed on the key Behavioural / Process-based recommendations to prevent CR-BSI. These
recommendations include:
- Use a subclavian site, if possible, to minimise infection risk
- Strict aseptic technique during CVC insertion ( Raad I et. al. Infect Control Hosp
Epidemiol 1994;15:231238)
- Hand hygiene w/ manipulation of CVC & insertion site
- Replace the catheter dressing when it becomes damp, loosened, or soiled
- Do not combine the leftover content of single-use vials for later use
- Do not use guidewire exchanges routinely for non-tunnelled CVCs to prevent infection
- Remove CVC as soon as no longer needed
There is also evidence that educational interventions are effective (Sheretz, RJ et al.
Ann Intern Med 2000;132:641648). Such educational interventions have already been
used successfully in the non-ICU setting to prevent BSI. In an outpatient h aemodialysis center which had the
problem of an o utbreak of BSIs, education of staff & patients on CVC care as part of a multifaceted
intervention (i.e., new skin prep, gauze dressings) resulted in a BSI rate decrease to 1 case /100 patient
days. Other non-ICU settings which have used educational interventions, include units caring for patients on
TPN. H andbooks & self-study material about line care were given to RNs, and they were taught about the
importance of hand hygiene prior to accessing the CVC & keeping dedicated port for TPN. Such education
reduced the hub colonization rate from 68% previously to 25% (p<0.05). (1.
Price CS et al. Infect Control Hosp Epidemiol 2002;23:72529,
2. Dinç L et al. Int J Nurs Stud 2000; 37:37179).
Identifying Patients at High Risk for MRSA or
VRE Colonisation
The CDC and SHEA both recommend culturing patients at high-risk for MRSA or VRE colonisation. However,
outside of the ICU, there is no simple, cost-effective method to identify such patients.
During a 9-month study at the University of Maryland, Furuno et al, enrolled patients within 48 hours
of admission. They excluded patients previously known to be colonised with MRSA or VRE. Enrolled patients
were administered a brief questionnaire, and had nasal and rectal swabs collected. Information was also
collected from their medical records.
In total, 699 patients were cultured from the nose or groin or both:
- Prevalence of MRSA 7%
- Prevalence of VRE 5%
- Prevalence of MRSA or VRE 11%
An analysis of the results revealed that a “yes” response by patients to both receiving
antibiotics & being hospitalised in the previous 12 months identified 100% of VRE patients. They also
found that a “yes” response by patients to being hospitalised in the previous 12 months identified
most of the patients colonised with MRSA.
This study is very interesting for hospitals where routine screening for multi-resistant- organisms (MROs)
is either not necessary or feasible. It indicates that a few simple questions on admission could assist in
identifying patients at high-risk for colonisation with MROs.
Hepatitis B Vaccine Non-responders
The CDC recommends that healthcare workers (HCW) who do not respond to the primary vaccine series should complete
a 2nd three-dose vaccine series or be evaluated to determine if they are HbsAg positive. HCW who are primary
non-responders should be considered susceptible to HBV infection and be counselled regarding precautions to
prevent HBV Infection. (Reference: MMWR Vol 45/No RR18, 1997).
Ramsey et al from the University of South Alabama decided on an approach to the Hepatitis B vaccine non-responders
who pose a problem when they work as HCW.
Using the Dialysis version of Recombivax (40mcg/dose), they studied 42 HCW who did not respond to >4 doses
of vaccine previously. They vaccinated these staff at 0,1, and 6 months.
37/42 (88%) responded with >10IU/ml of HBsAb 1 month after 3rd dose. These “responders” were
of mean age 41 years, while non-responders were of mean age 50 years. They concluded that age is a risk factor
for non-response.
Hand Hygiene Campaigns
Of course no infection control conference would be complete without some studies on hand hygiene. Elward et
al from Washington University, St Louis, educated HCW about the benefits of alcohol-based handrubs in 4 Hospitals
of 60-1400 beds.
They then evaluated the impact of the educational intervention on observed hand antisepsis, by measuring
alcohol foam consumption, nosocomial infection rates, and MROs one year pre- and post- intervention.
4,338 HCWs attended 200 educational sessions. They found a statistically significant increase in observed
hand hygiene at 1 Hospital only, although there was an increase in alcohol foam purchased in all facilities.
There was no significant changes in rates of nosocomial MRSA, VRE, ESBL-positive Klebsiella/E coli post intervention.
They did however detect a reduction in nosocomial resistant Pseudomonas spp.
(at 4 hospitals ) & Clostridium difficile (at 3 hospitals).
Meanwhile, Didier Pittet’s group from the University of Geneva presented information about their
educational interventions with feedback to HCW. Few studies have studied the efficacy of education and feedback
in improving hand hygiene (HH) in settings where alcohol-based handrubs have been introduced. Following baseline
observations, educational sessions were given on several occasions to nurses & at a conference for physicians.
Repeat observations were then conducted several weeks after educational sessions. The e ducational sessions included:
- Discussion of sources of hand contamination
- Description of standard precautions
- Indications for HH before, during, and after patient care
- Feedback to volunteers regarding their baseline compliance
They observed a total of 363 HH opportunities before education and 304 HH opportunities after education.
There was an improvement in compliance with HH among both doctors and nurses after the education sessions
and feedback of their performance. However, the improvements tended to be in HH performed before touching
intact skin, and before touching the patient’s environment. Staff did not improve their performance
with HH for care of wounds and other areas of contact with non-intact skin or bodily fluids.
Ethics of Infection Control
An interesting session on the ethics of infection control discussed the issue of the ethics of contact isolation
to prevent transmission of MRSA/VRE. As HCW, we usually expect that patients should accept interventions such as
contact islation which protect other patients. But, an ethical dilemma arises if isolation worsens their medical outcomes.
Studies on contact isolation have shown that c onsultant doctors are half as likely to examine patients in
isolation (Saint et al. Am J Infect Control 2003;31:3546), and that although there is no increase in hospital
mortality among isolated patients, there are more preventable adverse events, a greater dissatisfaction, and
less documented care (Stelfox et al. JAMA 2003;290:18991905).
Postexposure Prophylaxis (PEP) for Occupational Exposures to HIV
An excellent session about PEP for occupational exposures to HIV revealed the CDC’s updated recommendations,
and suggested a checklist for hospitals.
Updated recommendations for Occupational HIV PEP, 2005:
- Inclusion of new antiretroviral drugs
- Statements when PEP is not needed or should be discontinued
- Use of rapid testing for source patients
- Reevaluation within 72 hours after exposure
Some Situations where HIV PEP is Rarely if Ever Warranted:
- Low volume intact skin contact with HIV
- Exposure to unknown source in situations where HIV prevalence is low
- Low risk exposure to unknown source
The regimens currently recommended are usually two-drug regimens. For example:
- Zidovudine 600mg (ZDV)/ lamivudine (3TC) 300mg PLUS emtricitabine (FTC) 200mg
- Lamivudine (3TC) 300mg PLUS tenofovir (TDF) 300mg/emtricitabine (FTC) 200mg
An alternate basic regimen is:
- stavudine (d4T) + lamivudine (3TC)/emtricitabine (FTC)
- d4T + ddI should be avoided
PEP Checklist for Facilities:
- Establish a bloodborne pathogen policy
- Implement management policies
- Establish laboratory capacity for bloodborne pathogen testing
- Select and use appropriate PEP regimens
- Provide access to counselling
- Monitor adverse events
- Monitor exposure management programs (e.g.,evaluate time between exposure and evaluation, monitor completion of follow-up)
