The Republic of Ireland’s failure to deal with untreated sewage is being blamed for the discovery of an antibiotic-resistant superbug on beaches close to Spiddal, Co Galway.
The discovery, by a team led by Prof Martin Cormican of NUI Galway, is the first time that the NDM enzyme has been found in bathing seawater in Europe. It has so far been found in less developed countries, particularly in Asia.
The enzyme, whose full name is New Delhi metallo-beta-lactamase, makes bacteria highly resistant to some of the last-line antibiotics available to hospitals.
Prof Cormacin said that the presence of the superbug enzyme in Co Galway was the result of the pumping of raw sewage into the sea and that NDM could have been discovered at any of 43 sites in the Republic where raw sewage from urban areas is dumped in lakes, rivers and the sea.
He said that it showed the need for people to be prepared “to pay to clean up after ourselves”, whether through water charges or general taxation. “For more than 150 years we have known that the key to preventing contamination by diseases such as typhoid and cholera was to prevent faecal matter that comes out of the bottom of one person entering the mouth of another. But in Ireland we have an 18th-century problem in the 21st century,” he said. “We are still allowing sewage to flow into the sea and rivers because we have not organised ourselves to build the treatment systems we need.”
The 43 sites where raw sewage is pumped into the sea include large towns such as Arklow, in Co Wicklow, and Rush, in north Co Dublin, as well as Spiddal and, in Co Cork, Cobh and Ringaskiddy.
People infected with NDM-containing bacteria can be slow to show symptoms if the enzyme remains in the gut, Prof Cormican said. But if somebody “becomes very sick, for example, or had major surgery, or had a transplant or intensive treatment, and their immune system isn’t working, then these kinds of bugs can get from their gut to their bloodstream. If they get into the bloodstream of vulnerable people then they are very dangerous and difficult to treat.”
The enzyme works by causing bacteria to produce carbapenemases. This makes them resistant to antibiotics of the carbapenem family, which are used in hard-to-treat cases. In February the World Health Organisation declared these “carbapenemase-producing Enterobacteriaceae”, or CPEs, a critical priority that new antibiotics were urgently needed for. High levels of such superbugs are found in many parts of Asia, the Middle East, Latin America and southern Europe.
Irish Water said it was increasing its investment in waste-water infrastructure to an average of €326 million a year under its business plan for 2016-21. New treatment plants are scheduled to be in place by 2019.