SAN FRANCISCO -- Samples from cell phones of students studying to be healthcare professionals revealed evidence of antibiotic resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), a researcher said
Overall, 40% of examined cell phones from students in the nursing, biomedicine, pharmacy, dentistry and nutrition programs at a Brazilian university were contaminated with S. aureus, including several with evidence of resistant strains of the bacteria on their phones, reported Lizziane Kretli Winkelstroter Eller, MD, of the University of Western Sao Paulo in Brazil.
Nursing students were the worst offenders, with two-thirds of nursing students having contaminated phones, Eller and colleagues reported in a poster at ASM Microbe.
"The widespread use of cell devices in hospitals and healthcare settings has raised major concerns about nosocomial infections, especially in areas requiring the highest standards of hygiene, such as the operating room," Eller said in a statement. "In this context, cell phones may thus serve as a reservoir of bacteria known to cause nosocomial infections and could play a role in their transmission to patients through the hands of health professionals."
Eller told MedPage Today that her nursing students actually came up with the idea for the study themselves. "My students raised this doubt -- they were interested to see what they had on their phones," she said.
Eller's group collected 100 cell phones -- 20 from five different healthcare programs at the university, and tested them for both S. aureus and Escherichia coli.
In total, 65% of nursing students' cell phones were contaminated, followed by dentistry (50%) and biomedicine (40%). While the researchers found the presence of S. aureus, they noted they did not find evidence of E. coli in any of the phones.
Eller offered a hypothesis for why nursing students had the highest portion of contaminated phones, saying that in Brazil, nursing students "enter the hospital early" because they begin to practice in the hospital in their second year.
Researchers then examined the isolates they found for susceptibility to antimicrobials, including calculating the multi-resistant antibiotic resistance (MAR) index. One isolate was resistant to five different antibiotics, for a MAR index of 0.83. Of the 39 isolates tested, the authors found only three had no antibiotic resistance. They also looked at resistance by type of antibiotic, and found that 85% of isolates were resistant to penicillin.
These isolates were also evaluated for their ability to form a biofilm, or adhere to a surface. Half of isolates had "moderate adherence," with about a third with weak adherence and 7.5% with "strong adherence." Only 10% were non-adherent, the authors said.
"This bacteria is common," Eller said. She added that these results mean the healthcare professional "can carry [the bacteria] home or inside the hospital. It's a problematic thing everywhere," she noted, particularly if the healthcare professional is exposing immunocompromised patients.
The authors concluded that further research is needed to provide evidence that improving cell phone hygiene is linked with a reduction in healthcare associated infections, but for now, Eller said some practical steps are being implemented.
"We are trying to get some chemicals to clean up, [to figure out] how to get rid of these bacteria in the phone to be safe and not carry all these pathogens," she said.
The study was supported by the Sao Paulo Research Foundation.
Eller disclosed no relevant relationships with industry.