Imagine you鈥檙e a paramedic assigned to an ambulance, working face-to-face with sick people, some carrying an infectious disease. Would you be worried about falling ill yourself? Just as important, how do first responders stay healthy in otherwise unhealthy places?
That鈥檚 the concern of researchers at the 草莓视频 (COPH), who just published a study on reducing airborne pathogens in emergency vehicles. The paper 鈥�,鈥� appeared in the Journal of Emergencies, Trauma, and Shock.
Shawn Jones, lead author of the study and a 2024 USF graduate, said COVID made the issue paramount to the personal safety of emergency workers.
鈥淥ccupational transmitted infections are always a major concern to the EMS and health care industry, and COVID only placed a greater emphasis on them,鈥欌�� said Jones, now a scientist with Tampa Bay Water.
鈥淭he pandemic created a market for interventions that treated contaminated air, but the products can be expensive, time consuming and overly complex to execute. We wanted to find a cheaper, simpler and faster method that can be deployed even in remote, resource-limited environments.鈥欌��
Jones wrote the journal paper along with fellow alumnus , associate professor, ; and , professor, in the same department. The challenge was creating a faster, but still reliable and affordable method of disinfecting contaminated ambulances. During the pandemic, many EMS services relied solely on manual cleaning or the use of foggers and gas generators. This equipment requires training, a power supply, costly reagent refills and adequate time to perform, often taking several hours.
Ambulance disinfection protocols being performed.
鈥淲hat is most important to the public is its safety in an emergency situation,鈥� Bourgeois said.
鈥淗ealthcare-associated infections and multidrug-resistant organisms have been found on stretchers, blood pressure cuffs and monitoring devices,鈥欌�� she said. 鈥淒isinfecting these surfaces with UVC (ultraviolet light), alcohol or hydrogen peroxide wipes and sprays may fall short for various reasons, including risk of recontamination 鈥� and significant downtime.鈥欌��
The team focused on the use of chlorine dioxide (ClO2) gas to rapidly treat contaminated air in the ambulance. This allows EMS personnel to reenter the vehicle and manually clean surfaces without the risk of exposure to airborne pathogens and surface recontamination, protecting themselves and future patients from infections.
They tested two different applications of ClO2 to determine an ideal dose; contact and ventilation times needed to reliably reduce residual airborne virus in the vehicle; and to prevent risk of over-exposure to the gas. The team used a framework called the 鈥渉ierarchy of susceptibility of viruses to environmental surface disinfectants" to refine their study.
Chlorine dioxide gas is a strong oxidant and proven to be effective at killing microbes even when used in small quantities. It's cheap to produce, can be stored for long periods as stable reagents and doesn't require electricity or specialized equipment to activate. However, disadvantages include risk of injury from improper use. To limit these dangers, the team created a list of standard operating procedures.
Just as important is time, which is critical in communities with a limited ambulance fleet and overworked paramedics.
Shawn Jones (Photo courtesy of Jones).
鈥淥ur method can be completed in as short as 15 minutes,鈥欌�� Jones said. 鈥淚n high demand scenarios, first responders can initiate the process when they vacate the vehicle during the patient hand-off phase of transport. After 15 minutes, the vehicle can be ventilated for safe re-entry to manually clean surfaces and the teams can begin to respond to the next call.鈥欌��
Although COVID created a need to revisit the issue of decontaminating ambulances, other pathogens continue to pose a problem such as RSV, influenza and bacterial pneumonias, all of which spread via air or droplets.
鈥淥ur decontamination method is capable of treating these pathogens and plays a vital role in breaking the infection chain between sick respiratory patients and first responders and patients who occupy the vehicle next,鈥欌�� Jones said.
The new study follows on the heels of similar COPH research from 2024, 鈥�Needs Assessment of Infection Prevention and Control Training for Emergency Responders,鈥� presented at the 2024 Interprofessional Education Collaborative fair.