MRSA and vancomycin-resistant Enterococci can be present in hospital food, although patient infection with either may be uncommon, according to researchers.
The mere presence of the pathogens in hospital food warrants further study of possible infection, they suggested in Infection Control and Hospital Epidemiology.
“While this study was not designed to determine conclusively whether patients acquired MRSA or VRE from their hospital food, our results suggest that acquisition via food may be rare,” researcher Jennie H. Kwon, DO, MSCI, of the Washington University School of Medicine’s division of infectious diseases, and colleagues wrote. “Additionally, patients enrolled in this study collected their own food specimens. Thus, the patients themselves may have been the source of the contamination.”
The researchers included 149 patients in the study conducted at Barnes-Jewish Hospital in St. Louis. From their meals, the patients collected 910 total food specimens, which were tested for MRSA and VRE.
Seventeen patients (11%) submitted one or more specimens that tested positive for MRSA, and the same number of patients submitted one or more that were positive for VRE.
Altogether, MRSA was cultured from 29 specimens (3.2%), and VRE was cultured from 22 (2.4%).
The researchers noted that one patient submitted specimens with seven isolates of one MRSA type, SCCmec IV.
Both MRSA and VRE were cultured from every food category except nuts, the researchers said. They added VRE came from 5% of dairy or egg specimens, whereas MRSA was recovered from the same percentage of bread or grain specimens. All other food types yielded less than 5% positivity rates for either pathogen.
Only four patients had positive MRSA or VRE clinical cultures themselves after also having positive culture of either from food. Those patients had no previous clinical history of either pathogen. Of the four patients, two had MRSA or VRE cultured from food on more than 1 day.
“Because the overall food contamination rate was low, this pattern suggests patient contamination,” the researchers wrote. “Thus, prior clinical history or possible self-contamination may eliminate the possibility of food acquisition in all but two patients (1%).”
The low rate in their study does not eliminate the need to further understand potential food contamination in hospitals, they added.
“While MRSA and VRE have been documented in retail food previously, the comparability of results prior to our study cannot be determined,” the researchers wrote, citing other studies. “The effect of food preparation on the bacterial burden in hospital food is unknown. Despite these limitations, our study indicates that MRSA and VRE can be present in the food of hospitalized patients, and the implications of this finding warrant additional study.” – by Joe Green
Disclosures: Kwon reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.