Andrew’s study, carried out at 21 locations within the river Thames catchment, was the first to provide actual measurements of antibiotics, antivirals and decongestants in sewage effluent and receiving rivers during an influenza pandemic, an event only likely to happen every 30 years or so. The aim was to quantify the pharmaceutical response to the pandemic and compare this to drug use during the late pandemic and the inter-pandemic periods. The findings helped to quantify the risk to wastewater treatment plants, as they will be sensitive to the amount of antimicrobials in sewage and could potentially fail to meet water quality standards during high drug use events such as an influenza pandemic.
|Dr Andrew Singer at work in one of CEH's laboratories.|
The study also provides evidence that environmental concentrations of the antiviral Tamiflu would be sufficiently high to select for antiviral-resistance in influenza viruses within wildfowl inhabiting the river Thames. Future research will need to focus on the minimum concentration of antibiotics needed to ‘knock out’ a wastewater treatment plant, and whether this concentration could be achieved during a more severe pandemic. It remains an open question as to the extent to which exposure to high concentrations of Tamiflu have actually selected for antiviral resistance in wildfowl—as this has been shown to occur in laboratory studies. Lastly, it also remains unclear as to the lasting impact of an increase in antibiotic use during a severe influenza pandemic on the environmental reservoir of antibiotic resistance and its relevance to human health. Will we need to limit antibiotic use during a pandemic in order to spare our wastewater treatment plants as well as the long term efficacy of antibiotics?
Read more about the background to the study in an article on Andrew’s blog and read the freely available study in PLOS One.
Staff page of Dr Andrew Singer, CEH
Andrew led a previous study estimating how much prescribed Tamiflu went unused during the 2009-2010 pandemic. More details in a CEH news story.