April 17, 2013
Half Of 2009 UK Swine Flu Pandemic Drug Flushed Down The Toilet
Brett Smith for redOrbit.com — Your Universe Online
By analyzing sewage, a group of European researchers was able to determine that about half of the Tamiflu prescribed during the 2009-2010 influenza pandemic went unused in England.
The team´s findings, which were published in the open access journal PLOS ONE, could be used to inform the next pandemic reaction by health officials and served as validation for the novel method used to measure widespread prescription drug compliance.
“Influenza pandemics are rare, making a study such as this a unique and important window into how people behave during a public health emergency such as a pandemic,” said study co-author Andrew Singer, from the UK´s Centre for Ecology & Hydrology. “This study sheds new light on people´s willingness to follow medical advice on antiviral usage. Importantly, this method could be used to monitor how many people take certain kinds of medicine in real time and alert national health authorities to the need for stronger public information campaigns during pandemic emergencies.”
During the height of the UK H1N1 pandemic in the fall of 2009, scientists collected sewage samples from two waste water treatment plants: one in a rural setting and one in an urban setting. These samples were tested using mass spectrometry techniques for Oseltamivir carboxylate, the active ingredient in Tamiflu. This allowed the scientists to test for drugs that were dumped down the toilet and not count those that were simply excreted after being ingested.
The analysis indicated a compliance rate between 45 and 60 percent, meaning 45 to 60 people out of every 100 people completed their Tamiflu course, as prescribed.
“Our study was the first compliance study to utilize waste water as an evidence base for whether a population consumed Tamiflu or not,” Singer said. He added that the study´s design allowed the researchers to check compliance rates on a scale larger than previous studies.
“One population was just over 6,000 people and the second population was 208,000,” Singer added. “Tamiflu gets transformed into the active antiviral only after being consumed, and is released into the sewage with every visit to the toilet. This waste water epidemiology approach is particularly robust for drugs such as Tamiflu and potentially more reliable than some survey based methods of assessing compliance.”
Compliance rates are important to health officials, as poor rates waste limited antiviral stocks and misused drug can lead to antiviral resistance. The Singer-led study differs from previous research on antiviral compliance that only focused on small populations of 200 or less. Previous methods also used self-reporting as a way of measuring compliance — which can often be an unreliable metric.
“With approximately half the collected antivirals going unused, there is a clear need to improve public health messages so that less antiviral is wasted and that the duration and severity of infection is reduced,” Singer said. “Furthermore, we feel the waste water epidemiology approach undertaken can potentially help shape future public health messages, making them more timely, targeted, and population sensitive, while potentially leading to less mis- and un-used antiviral, less wastage and ultimately a more robust and efficacious pandemic preparedness strategy.”