Ambulances & Vehicle Ops, Columns, Operations, Patient Care

The Truth about Ambulance Bacteria

Review of: Alves DW, Bissell RA, “Bacterial pathogens in ambulances: Results of unannounced sample collection.” Prehospital Emergency Care. 12(2):218-224, 2008.

The Science
Sterile swabs were moistened with sterile water and rubbed over the same five areas of the first four ambulances that were preparing to return to service in a large urban program. The areas were 1) Oxygen flow meter knob, 2) lower back edge of the bench seat, 3) Push-to-talk switch on the patient compartment radio, 4) driver-side door handle, and 5) sliding door track of the overhead cabinet. The swabs were then provided to a microbiologist who, using standard techniques, isolated and identified any organisms present. The crews of the ambulances had no knowledge beforehand that these samples would be taken and all had the same protocol for cleaning and disinfecting the ambulances.

Of the 20 samples, 19 showed growth. Only two swabs grew organisms considered to represent significant threats, and one swab grew an organism that could be considered an opportunistic pathogen in immunocompomised patients. The remaining swabs grew routine skin flora or environmental contaminants.

The two swabs with the higher-threat organisms came from the same area — from the lower bench seat of two separate ambulances. It was surmised by the authors that liquid wastes may pool in these areas and that routine cleaning agents don’t readily reach them.

The authors concluded this study should heighten our awareness of the need for more thorough cleaning procedures.

The Street
I reported on a similar study awhile back that looked more specifically at areas with which the patient comes into contact. (“Is MRSA Lurking in Your Ambulance?”) That study indicated significant potential for exposure to MRSA. With this study’s extremely small numbers, it examined only five areas chosen by the authors, areas not based on any scientific reasoning other than that they seemed like the most logical places for rescuers to touch. However, in the beginning of the article the authors discuss the issue of stethoscopes and other equipment.

My fear is that some will take this study as stating the risk is low when in fact we don’t know what the risk is. What’s needed is an ergonomic study to examine first what areas our patients come into contact with. What pieces of equipment do we use and don’t clean? What do we touch and not disinfect? Then we need to measure bacterial counts on those items. Once that data is collected, then we can make reasoned conclusions about the risks — not only to our patients but to our providers.