Literature Update - June, 2006
Compiled by Dr Deb Friedman, VICNISS ID Physician
Pertussis in Healthcare Facilities
Although classically recognised as a disease of infants and children, the reported incidence of Bordetella pertussis
infection (whooping cough) in adolescents and adults has increased at a remarkable rate over the past decade. Pertussis
is responsible for 7%-32% of cough illnesses that last 1 week or longer in adolescents and adults. This increase in pertussis
in adolescents and adults is likely due to waning protection from childhood vaccination and also an improved ability to
diagnose pertussis serologically. Despite high rates of routine pertussis vaccination among children, rates of pertussis
infection are also increasing in infants, and young children suffer the greatest morbidity, and even mortality from pertussis.
Healthcare-associated outbreaks of pertussis also have been increasingly recognised, and are often the result of under-recognition
of pertussis and subsequent failure to isolate patients with suspected infection. In addition, healthcare workers are at
increased risk for acquiring B. pertussis infection likely the result of regular contact with infected patients and waning
protection from childhood vaccination or natural infection. Infected HCWs can then serve as vectors of infection to other
susceptible contacts, including patients, other employees, and even their own children.
The most recent edition of Infection Control Hospital Epidemiology will do nothing to allay our anxiety about
pertussis in hospitals. Three different articles (Bryant K, et al, Bamberger E, et al, & Giugliani C, et al, Infect
Control Hosp Epidemiol 2006; 270) illustrate that both staff and visitors with undiagnosed pertussis infection are capable
of causing a large scale outbreak among high-risk patients, which can be complex and laborious to resolve, and that contacts
often experience difficulty being compliant with postexposure prophylaxis (PEP).
So what can we learn, and what is the upside?
• Although erythromycin is poorly tolerated for PEP, azithromycin and clarithromycin can also be used and are better tolerated
• Booster immunisation for adults is available and recommended
• Serology can be performed to detect infection, and guide PEP
Contamination of Healthcare Equipment
Healthcare equipment is a significant source of hospital-acquired infections (HAI). A recent study has confirmed that high
levels of contamination are present on a wide range of healthcare equipment from stethoscopes to ultrasound machines (J Hosp
Infect 2006;63:239-245) The good news is that the majority of contamination and hence any risk of acquiring a HAI can be reduced
substantially by regular cleaning of equipment with 70% alcohol. The next step is to make sure that hospitals have cleaning
protocols in place to ensure that equipment is cleaned after use.
Procedure Duration as a Risk Factor for SSI
A recent study has compared the US NNIS T times with data collected in England (J Hosp Infect 2006;63:255-262). For those who
are not aware, the Surgical Site Infection Surveillance Service in England holds data collected by 168 hospitals from 1997-2002.
The results show that English and US T times were the same for all surgical categories except coronary artery bypass graft
and vascular surgery, where the English T time was 4 h. Operations lasting for longer than the T time were associated with
a higher risk of SSI in abdominal hysterectomy, CABG, gastric surgery, knee prosthesis, large bowel surgery and vascular surgery.
Orthopaedic Surgeons Beware of Conjunctival Contamination
A recent study (J Hosp Infect 2006;63: 275-280) of 110 sets of personal face and eye protective equipment (Sterishields) has
addressed whether or not these protective shields used in orthopaedic procedures on the hip joint are prone to contamination.
They found that all Sterishields demonstrated macroscopic contamination with an average of 203 blood and fat spots. The number
of these was significantly higher in the lower half of the Sterishields. In addition, nearly half of surgeons admitted to not
using adequate eye protection routinely. This study demonstrates that there is a high risk of conjunctival contamination with
fat and blood in major total joint arthroplasty, and infection control programs would be well served to discuss this matter
with their surgical colleagues!
Surgical Antiseptics and the Risk of Operating Room Fires
In a recent letter to the Australian New Zealand Journal of Surgery (2006 May;76(5):422-3) responding to an article suggesting
a complete ban on alcohol based skin antiseptics in theatre because of the risk of fire, the authors strongly suggest that the
benefits from using the alcohol based skin antiseptics far outweigh the controllable risk such as fire. Appropriate precautions
should be taken to prevent fire in theatre, and adequate contact time for microbial killing and for drying the antiseptic will
provide better post surgical outcomes.
Well, goodbye to all of you for now, as this is my last literature review. Keep well and keep up the great work!
Deb Friedman