When you come home after a long journey, you should first turn on the taps and let the stale water drain away. Because standing water can lead to an increased concentration of legionella.
Anyone who hasn't turned on the tap for a long time should do so as soon as they return from vacation - and not take a sip or take a shower straight away. Bacteria could have multiplied in the water pipes - this is a health hazard.
Instead, the Institute for Loss Prevention and Loss Research of Public Insurers (IFS) recommends letting the water run at all taps before using it. In an average family home, draining about ten liters is enough to replace the water that has been in the pipes while you were away.
Legionella multiply at temperatures between 25 and 55 degrees Celsius. Stagnant water in particular can lead to an increased concentration of bacteria. In polluted systems, people can become infected, for example when taking a shower or cleaning the sink, by inhaling the finest water droplets.
The risk of infection when drinking contaminated water is lower, but an infection cannot be ruled out. According to the Federal Center for Health Education (BZgA), the water would have to accidentally get into the lungs via the trachea if swallowed.
Infection manifests itself as a form of pneumonia with cough, chills, headache, severe malaise and high fever. Diarrhea or states of confusion are also possible. This is referred to as Legionnaires' disease or Legionella pneumonia. If this is not treated or treated incorrectly, the pneumonia is often severe. With correct treatment, there are good prospects of recovery, according to the BZgA.
Pontiac fever can also be caused by Legionella, with flu-like symptoms such as fever, malaise, headache and body aches, but not pneumonia. This condition usually clears up on its own within a week.
The IFS has another tip for avoiding such infections for all house sitters - i.e. for neighbors, relatives and friends who look after the house and water the plants while the residents are away. You should fill up water at a tap that is far from the main water supply. As a result, the water is repeatedly moved in a large area of the supply lines - which can prevent the growth of legionella. In a detached house, for example, this is usually the bathroom on the top floor.
(This article was first published on Monday, August 08, 2022.)