Patients can easily spread bacteria that's difficult to control to their nurses' clothing, according to a new study funded by the U.S. Centers for Disease Control and Prevention (CDC).

Researchers say the sleeves and pockets of nurses' scrubs and the railing on hospital beds were the most likely areas to be contaminated.

The study tracked the transmission of bacteria that included methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa — all of which have shown resistance to many antibiotics.

The researchers looked at 167 patients who received care from 40 nurses during three separate 12-hour intensive care shifts.

Intensive care units were of interest because almost half of hospital-acquired infections in the U.S. occur in ICUs, according to the CDC. 

Hand wash

The lead author of the CDC study recommends hand-washing after all patient encounters, the use of disposable gloves and gowns when treating patients with specific infections, and meticulous and regular cleaning of patients' rooms. (Mariana Bazo/Reuters)

Staphylococcus aureus is one of the three bacteria commonly found in Canadian hospitals, the Canadian Patient Safety Institute says.

About 220,000 Canadians get hospital-acquired infections each year, and 8,000 die from them, the institute says.

All nurses involved in the U.S. study cared for two or more patients per shift and used new scrubs for each shift. Researchers took cultures twice a day from the nurses' scrubs, patients and the patients' rooms and found 22 (18 per cent) transmissions of the same strain of bacteria.

Same number for bugs spread to nurses, rooms

Of those transmissions, six (27 per cent) were from patient to nurse, six were from the room to the nurse and 10 (roughly 45 per cent) were from patient to the room.

Researchers tested the sleeves, pockets and midriffs of nurses' scrubs and found the pockets and sleeves were the most likely to be contaminated. They also took samples from supply carts, beds and bed rails and found the latter most likely to be contaminated.

The types of bacteria in the 22 transmissions were:

  • Seven methicillin-susceptible Staphylococcus aureus.
  • ​Five methicillin-resistant Staphylococcus aureus.
  • ​Three Stenotrophomonas maltophilia.
  • Three Acinetobacter baumanii complex.
  • Two Klebsiella pneumoniae.
  • ​Two Pseudomonas aeruginosa.

The researchers did not identify any bugs that had spread from nurses to patients, but they noted this kind of transmission likely occurs in hospitals.

"We think it's more common than not that these bugs spread to patients in hospitals because of temporary contamination of healthcare workers," Dr. Deverick Anderson, lead author of the study and associate professor of medicine at Duke University Medical Center, Durham, N.C., said in a release.

The study was presented in New Orleans on Thursday at ID Week, the annual meeting of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association and the Pediatric Infectious Diseases Society.

Data and conclusions presented at meetings are usually considered to be preliminary until published in a peer-reviewed medical journal.