Wild swimmers have more multi-resistant bacteria in their intestines

Wild swimmers have more multi-resistant bacteria in their intestines

Infections in people who regularly swim in rivers, canals and streams are less treatable with antibiotics. This is due to the fact that, during swimming, one ingests water containing bacteria that are resistant to several antibiotics. The National Institute for Public Health and the Environment (RIVM), which carried out this research, therefore advises people to swim at official or other well researched swimming locations. Hence, the quality of water from official locations must comply with European regulations.

How was the research carried out? 
Before and after swimming competitions and city swims, the faeces of participants were examined for resistant ESBL-producing E. coli. These are bacteria that are resistant to multiple antibiotics. The number of swimmers carrying more of these multi-resistant bacteria before and after the event was the same, but higher than the average Dutchman. It was concluded that people who swim more often in polluted water are more likely to come into contact with the bacteria.

People do not only come into contact with resistant bacteria via polluted surface water. This can also be done via other people, via the environment, via contact with animals or by eating (animal) products.

Source: Blaak H. et al. 2019, Resistant intestinal bacteria in open water swimmers, RIVM Letter report 2019-0113. Download link