N.ews began to circulate at the end of the week that high-performance washing machines can be a haven for dangerous bacteria, but before you throw away your appliances, you should probably know that these fears are exaggerated.
The news comes from a study published on Friday in the journal Applied and environmental microbiology, which describes how one washing machine in a German hospital spreads drug-resistant bacteria to infants in the neonatal ward using freshly washed hats and socks. After the washing machine was discovered as a source of bacteria, the machine was removed from the hospital. Children – who were colonized but not infected – he returned to normal.
At first glance, the results sound scary and raise new concerns about the safety of washing machines – especially those with high efficiency that use colder water to save energy.
But for several different reasons, this fear is largely unfounded.
It was not a high-performance machine
First of all, it seems that the washing machine was not energy-efficient: the study authors write that " [149 °F] a washing program was used for each washing cycle that is several degrees warmer than "well below 60 ° C (140 ° F)", which the accompanying press release describes as low energy washing.
While the paper still says that the clothes were "probably" rinsed later in cold water without detergents, they also say that it is humidity – caused by warm air condensing on cooler rubber – "[provided] optimal moist environment ”for microorganisms to hang in a rubber seal around the machine door.
And when it comes to the dispute about whether rinsing was too cold or the laundry wasn't hot enough, the US Center for Disease Control does not seem too worried about the difference of a few degrees, instead saying that by following the directions on your clothes labels or detergents should be enough.
"Hot water cleaning is not necessary for all home laundries," writes CDC. "Read and follow the instructions for clothing and soap or detergent. Wash and dry clothes at the warmest temperatures listed on the clothing label. "
Later, washing clothes in the hot-drying cycle should be enough to kill the residual unpleasantness, according to medical doctor Alexandra Sowa
"To get rid of side effects from the washing cycle, you had to tumble dry for 30 minutes or iron," said Sowa The New York Times in 2017, "Heat from a low drying cycle or iron was enough to free clothes from [any previously] studied bacteria. "
What happened to the German machine?
Bending the rules
In the German case, the machine in question was described in the study as a "domestic washing machine with integrated dryer" – which is extremely high no type of pad recommended for the hospital environment, write the authors.
"It should be emphasized that the use of ordinary household washing machines for washing patients' clothing in clinical settings is not allowed in accordance with applicable hygiene regulations in Germany," write the authors.
However, they still claim that this machine was technically is located outside the main laundry room of the hospital and was intended only for mothers' clothes and the hats and socks mentioned above.
Regardless of location, a home machine in a hospital setting – which is inevitably infected with germs – is not enough to work compared to industrial machines that can work much warmer, and in some cases with forces G to 387 to remove excess water.
Take-out point: exercise common sense
Like this study, previous studies reported finding bacteria in household appliances such as washing machines (and even dishwashers), but other studies have shown that temperature has no effect on reducing this type of bacteria.
Therefore, to be safe, you should clean your washing machine from time to time, especially in easy to ignore crevices. And if your clothes are especially germs after a cold or flu, maybe run them through hot water as well as a hot drying cycle.
And if you work in a hospital, make sure you actually use industrial-grade machines.
But will your washing machine make you sick? Probably not.
In the period from April 2012. To May 2013, 13 newborns (1 to 4 weeks old) and one child in a children's hospital ward in Germany were colonized with the help of extended spectrum beta-lactamase (ESBL) Klebsiella oxytoca (CTX-M-15).
A microbiological source tracking analysis, including human and environmental samples, was performed to identify sources and transmission paths K. oxytoca clone. In addition, various hygiene intervention methods were assessed.
isolates K. oxytoca stresses were detected in the detergent drawer and on the rubber door seal of the home washer / winch used in the same ward for washing the underwear of newborns, as well as in two sinks. These strains were typed using PFGE and multi-location sequence typing (MLST). The environmental results were compared with the discoveries of human strains and isolates found on clothing. The results showed that the strains were identical using both techniques (ST201 and pulsed-field gel electrophoresis) [PFGE] type-00531, a hospital-specific clone previously not isolated in Germany), highlighting the washing machine as a reservoir and fomit for carrying these multi-resistant bacteria (MDR). After switching off the washing machine, no further colonization was detected over the next 4 years.