Notably, two antivirals FTC and 3TC were monitored in influent wastewater of both sites, however prescriptions of these were not found in the catchment region. It could be that these antivirals were prescribed outside the catchment region or could be from an unknown source. A similar observation was observed for several tuberculosis (TB) drugs, including metabolites hPZA and INa. The usual course of treatment is two antibiotics (isoniazid and rifampicin) for six months, along with additional two antibiotics (pyrazinamide and ethambutol) for the first two months of the six-month period . These are often prescribed in combination due to challenges of multi-drug resistance with many TB infections. Of note is that there are no drugs licensed in the UK for treating animals, and so presence in community wastewater will originate from human sources (Animal and Plant Health Agency, 2017).