Remember when public bathrooms didn’t have hot air hand dryers? Installed to eliminate waste and improve hygiene, research suggests that they are actually great at spreading germs, right back onto your freshly washed hands. A 2018 study brought this information to people’s attention. Researchers exposed petri dishes to bathroom air for two minutes and hand dryers for 30 seconds then compared what grew. On average, one colony of bacteria grew in the bathroom air petri dishes while 18 to 60 colonies grew from the hand dryer exposed petri dishes. Even if the hand dryers were retrofitted with HEPA filters, there were significantly more colonies of bacteria grown in the petri dishes exposed to the hand dryers.
A letter to the editor described another study (a pilot study) done in the hospital setting. Researchers found that poorly washed hands that are air dried by hand dryers may actually be dispersing microbes in droplets from those hands.
Though one mechanism of dispersal, scientists need to do more research on what is happening. Are the hot-air hand dryers are reservoirs of bacteria or simply concentrating the germs that are already present in the air? Are they dispersing the microbes from poorly washed hands in air droplets? These studies do suggest that you ruin the effects of hand washing by drying your hands with hand dryers.
In hospitals, faucets, sink surfaces, bathtubs, sinks, showers, and toilets are all known places where bacteria can thrive. But who would have guessed what researchers in Germany found? In a case study they describe tracking down the source of Klebsiella oxytoca, a species of bacteria found in the gut but which, when outside the gut, causes bronchopneumonia, urinary tract infection and septicaemia. This antibiotic resistant bacteria had been found on newborns in the German hospital’s NICU. After searching for the source of the contamination, washing machines were discovered as the reservoir. The bacteria were found in the soap dispensers, on the door seals and in the washing drum of the washing machines.
Another study looked at both washing machines and dishwashers in people’s homes. The researchers contaminated cotton swatches with resistant strains of bacteria: Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus. The swatches went through laundering/washing at 68 to 122 degrees fahrenheit. Researchers found after washing, 79 percent of the washing machines and in 96 percent of the dishwashers contained the antibiotic resistant bacteria.
A reason for the lack of sanitizing could stem from using high efficiency washers that clean clothes at lower temperatures than before. To truly disinfect clothes, disinfecting solutions like hydrogen peroxide, bleach, or Borax should be used and the temperature of the water should be at least 160°F. Experts also recommend drying clothing outside on a clothesline: sunshine is a natural disinfectant. Using a sanitizing setting for dishwashers should get dishes clean and sanitized.
Penicillin, the first of many antibiotics that have been developed, was discovered in 1928, manufactured and made available for general use in 1943. Antibiotics have treated and controlled terrible infections for over 75 years.The CDC states that
the threat of infections is especially severe with the ever growing number of antibiotic resistant microbes. Those who are at most risk are the elderly, newborns and infants and those who are immune compromised. Almost three million infections with antibiotic resistant germs occur every year and 35,000 people in the US die each year from them. Knowing how to counteract germs, where they grow and how they spread, can keep people safe.