After dangerous antibiotic-resistant bacteria were repeatedly found on the clothing of newborn infants in the NICU of a hospital in Germany, investigators there went in search of their source. They eventually traced the transmissions to a single household-type washing machine used in the hospital. When that machine was removed, the transmissions stopped.
This unique case shows that washing machines in the home can harbor dangerous pathogens, according to research recently published in Applied and Environmental Microbiology.
To meet energy-saving guidelines, water temperatures used in home washers have been declining, to well below 60°C [140°F]. That cooler water makes them less lethal to pathogens, according to the report.
Hospital investigators also determined that the design of the washer itself was also partially to blame. Their report noted that bacteria “were disseminated to the [infants’] clothing after the washing process, via residual water on the rubber mantle [of the washer] and/or via the final rinsing process, which ran unheated and detergent-free water through the detergent compartment.”
Their findings could have important implications, especially for families providing in-home care for loved ones whose health makes them particularly susceptible to bacterial infections, said Dr. Martin Exner, director of the Institute for Hygiene and Public Health at the University Hospital in Bonn.
“If elderly people requiring nursing care with open wounds or bladder catheters, or younger people with [ulcerating] injuries or infections live in the household, laundry should be washed at higher temperatures, or with efficient disinfectants, to avoid transmission of dangerous pathogens,” Exner said. “This is a growing challenge, as the number of people receiving nursing care from family members is constantly increasing.”
Their findings imply that changes in washing machine design for the home should be considered to prevent the accumulation of residual water, where dangerous microbial growth can occur, he added.