INTERVIEW WITH PROF GEMMELL WHO CONDUCTED THE HOSPITAL TESTS

In an interview with Alison Patterson of Byotrol, Prof Curtis Gemmell gives further explanation on the results of the trial as presented in his poster at the Health Infection Society Conference 2006.

Why was the study carried out?
The study was carried out because there is no information currently available on the presence of environmental MRSA (Methicillin Resistant Staphylococcus aureus) in a typical busy hospital ward. The ward maps as seen in the poster were used to provide a baseline on which to compare the effect of different cleaning regimens. It is a good starting point for some very important and valuable research.

Do we need to worry about Staphylococcus aureus ?
Staphylococcus aureus is important because it causes life threatening infection and secondly the bug is carried by 30% of normal individuals in their noses. It is can easily be transferred to hands and therefore easily transmitted from visitor to patient, patient to patient, patient to nurse, patient to doctor, patient to environment and by cross infection to other patients.

We keep hearing about HAI’s.
What is HAI ? HAI is a Hospital Acquired Infection and is an infection which develops during a patient’s stay in hospital. This can include a wide variety of different bacteria, including Staphylococcus aureus, enterococci, Clostridium difficile, Acinetobacter species, to name a few. An added dimension to the problems caused by these organisms is their ability to acquire resistance to commonly used anti-biotics in hospitals as is the case with MRSA. This makes it more difficult to choose the right antibiotic to treat infection.

How was the study designed?
The study was designed to monitor the possible association between environmental MRSA and potential transfer of MRSA infection between patients in a vascular surgery ward over a six month period. Six months was chosen in order to understand the long-term effects of the use of a novel disinfectant technology (Byotrol) as compared to standard cleaning processes.

How many people were involved?
A ward was chosen in a busy university teaching hospital which had a history of ongoing MRSA infections causing problems in patients undergoing vascular surgery. Such patients are particularly prone to infection problems during convalescence and are therefore an appropriate group on which to study the effect of environmental cleaning on the incidence of infection. Patients usually remain in the ward for periods ranging from 5 to 14 days, depending on their underlying medical condition, and includes patients with diabetes who are particularly prone to infection.

In the course of the six months a total of 250 patients spent time in the ward.

A typical hospital ward comprises a small number of single rooms where patients with MRSA are treated and larger rooms containing 6 beds which accommodate those patients without infection on admission. In this study we chose a mixture of both types of room in order to compare the effect of using the new Byotrol technology on the incidence of environmental MRSA, MRSA colonisation MRSA infection.

Where was the product used?
Byotrol wipes were used on high contact sites close to the patients such as bed rails, TV remote control, nurse call system, lockers, sink taps and door handles. On these sites it was used once per day on the assumption that Byotrol would retain activity until the next application. These sites were swabbed once per week and tested in the microbiology laboratory for the presence of MRSA.

The Byotrol was applied to only 5% of the normal areas cleaned in the ward and was an add-on to the normal cleaning process. The Byotrol technology was present in disposable wipes which were easily used by the cleaning staff. Based on the information obtained from the weekly MRSA ward maps, comparison between the Byotrol treated areas and the control (non-Byotrol) areas, in terms of MRSA contamination, was possible. The study was conducted for 4 months in the first instance and then the two areas were switched over.

Why were the areas switched over?
This was to ascertain whether (1) the Byotrol technology allowed residual anti-bacterial activity on high contact sites and (2) whether its introduction to the control area would reduce MRSA levels.

What were the results?
The results of the first stage showed that the Byotrol reduced environmental MRSA levels by 50% * The incidence of MRSA in the control area was 12.7% compared to 6.7% in the Byotrol treated area i.e. 50% reduction.
* The level of contamination i.e. numbers of MRSA was higher in the control area than in the Byotrol treated area. Following the switchover there was evidence that the Byotrol treated area continued to suppress environmental MRSA and secondly its introduction into the previous control area reduced MRSA contamination.

Does reducing MRSA reduce HAI?
Perhaps. The reason we say perhaps is that over the 4 month period there were 10 cases of HAI due to MRSA of which 6 were in the control area (there were 7 bed spaces in this area) and 4 were in the Byotrol treated area (there were 8 beds in this area). This information is of course interesting but does not reach the levels or the sample size for ust to say it has scientific significance, but if the trial were to continue for a longer period of time then there is every likelihood that more reliable and significant results would have been achieved.
Improved cleaning procedures are only part of the bundle of processes that need to be fully implemented and rigorously maintained in hospitals to reduce HAI’s and such bundles should not be viewed as short term solutions, but should be used in the long term to achieve success.

What do you mean by level of contamination?
Levels of contamination were measured by counting the number of colonies (cols) which grew on a selective culture medium after swabbing individual sites.
Numbers of colonies exceeding 20 represents a high level of contamination; less than 10 indicates a low level of contamination.

Are there different types of MRSA?
Yes there are but in the UK there are two predominant epidemic types:
EMRSA15
EMRSA16
(EMRSA = epidemic MRSA)

During this period of study there was only one type present in the ward – EMRSA15. However using molecular techniques a number of different varieties of EMRSA15 were found and this information allowed us to follow the transfer of MRSA from patient to patient and patient to environmental site.

Are any further studies planned?
This present study has been really an exploratory one of limited duration and of limited size. A future study should last for a longer period and involve comparison of Byotrol technology as the only cleaning regimen in one part of a ward compared to a similar ward using conventional cleaning procedures. Such studies are planned in local hospitals. Prof Curtis Gemmell will be responsible for their design and implementation based on his previous experience.

This is the first published study and this evidence will be transmitted to the NHS as appropriate.

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