Abstract

Measurements carried out in sewage water from six residential neighbourhoods in Utrecht revealed the presence of particularly resistant CPE bacteria (carbapenemase-producing Enterobacteriaceae). This means that CPE are present in the general population, and not restricted to people in health care facilities. The analysis of sewage water has proven to be an efficient method for determining whether these bacteria are present in the general population. Also, this method is non-invasive, as people do not have to be individually examined. RIVM therefore recommends measurements in sewage water, as this makes it clear at a national level whether and where people are present who are carriers of CPE or other particularly resistant microorganisms (multi-drug-resistant organisms).

In the Netherlands, CPE are found to be present in human beings only infrequently. They are more common in other parts of the world, such as South East Asia, Southern Europe, and North Africa. People who have travelled to such countries, particularly if they have stayed in a local hospital, are more likely to be carrying CPE.

Although healthy people do not generally fall ill as a result of CPE, vulnerable persons such as the elderly and hospital patients can become sick. Diseases caused by CPE are difficult to treat because they are resistant to antibiotics that are used as last resort treatments. As a result, these resistant bacteria pose a threat to public health and it is therefore important that they do not spread any further among people, animals and in the environment.

There are various types of CPE. Different types of CPE were found in sewage from residential neighbourhoods compared to health care institutions . By comparing the CPE types found at different places in the sewer system, it is possible to determine how CPE spread within the population and how this can be prevented.

For the purposes of this study, sewage water from nine different locations in the city of Utrecht was analysed: in six residential neighbourhoods, a hospital, a nursing home, and an asylum seekers centre. The sewage treatment facility in Utrecht treats the wastewater from these neighbourhoods and institutions on a daily basis. In addition to the nine measuring points in the sewer system, RIVM also analysed the sewage water collected from the entire city centre of Utrecht that flows into the sewage treatment facility. This was done to check whether the measuring points chosen were representative for the entire city.