A new study has revealedthat washing machines can sometimes harbor drug-resistant bacteria that could pose risks to susceptible people.The study researchers describe a unique case in which a washing machine was linked to the spread of drug-resistant bacteria to newborns at a German hospital. The authors of the study noted that the occurrence appears to be the first reported case of a hospital’s washing machine spreading harmful pathogens to patients.
The study lead author, a senior physician at the Institute for Hygiene and Public Health at University Hospital Bonn in Germany, Dr. Ricarda Schmithausen said the case is “highly unusual” for a hospital because it involved a household type of washing machine, rather than the industrial machines that are typically used in health care settings. However, the authors opined the study has implications for household washers, particularlyenergy-efficient washers that use lower water temperatures, which are less likely to kill pathogens.
An infectious disease specialist and a senior scholar at The Johns Hopkins Center for Health Security in Baltimore, Dr. Amesh Adalja said while washing machines are designed to get rid of soiling and smells, “they’re not designed to make your clothes sterile. They don’t get hot enough to kill every form of life that’s on your clothing.”
In the current case, doctors at the German hospital noticed that newborns in their facility kept testing positive for a particular strain of drug-resistant bacteria known as Klebsiella oxytoca. According to Healthline, this bacterium is known for causing serious infections in health care settings, such as in nursing homes and intensive care units. The newborns didn’t actually get sick from the K. oxytoca, the bacterium was found on their skin without causing an infection. But its presence was still a cause for concern given that it can cause conditions such as pneumonia, urinary tract infections and wound infections, particularly in those with weakened immune systems.
At first, doctors thought the bacterium could be passing from health care workers or the mothers themselves to their newborns, but tests ruled out this route. Next, doctors tested some surfaces in the hospital, such as the babies’ incubators, but these also came back negative. Finally, they traced the source to a particular washing machine. Samples taken from the washer’s rubber door seal and detergent compartment tested positive for K. oxytoca.
Household washers typically are not permitted for washing patients’ clothing at hospitals. But in this case, the authors said the washing machine in question was located outside the hospital’s central laundry facility, and it was used only for washing mothers’ clothes, and caps and socks for the newborns. After the health care staff stopped using this washing machine, there were no further cases K. oxytoca transferred to newborns.
In addition, the authors said that, with household laundry machines, people may need to take some precautions when doing laundry for certain groups of susceptible people, such as elderly people who require nursing care, those with compromised immune systems and people with infected wounds that are discharging pus. In these cases, study senior author, chairman and Director of the Institute for Hygiene and Public Health at the University Hospital Bonn, Dr. Martin Exner recommends washing laundry “at higher temperatures, or with efficient disinfectants” to avoid transmission of pathogens.
Experts have however quelled the fear of washing machine users by saying they do not need to worry about their washing machines harboring bacteria as the vast majority of bacteria on our bodies and clothes are not harmful.Adalja said that the report describes “a special circumstance” that applies to a hospital setting. He further explained that outside the hospital, people usually don’t need to go beyond practicing good hygiene, such as handwashing, when they or a loved one is sick.
In conclusion, the authors suggest that washing machines should be further investigated as possible sources for contamination in health care settings.