A less consistent inter-city trend was observed for CLR. Interestingly whilst over the winter months, monthly averages of PNDls of CLR were significantly higher in Bath when compared to Keynsham (p≤0.05). Between December 2018-February 2019, CLR averaged 273 ± 72 mg 1000inh -1 day -1 in Bath vs 176 ±51 mg 1000inh -1 day -1 in Keynsham (77% difference). In contrast, in summer, PNDLs were much lower, and comparable between the two sites; with CLR averaging 121 ± 35 and 102 mg 1000inh - 1 day -1 in Bath and Keynsham, respectively (19% difference). Whilst it is known that macrolide prescriptions often peak in winter, more macrolide AAs were prescribed per person in winter in Bath than Keynsham. Respiratory infections do tend to follow predictable fluctuations, with colder months leading to rapid spreading of infections, due to individuals spending increased time in enclosed spaces indoors . Furthermore, the spread of infections occurs much quicker in urbanised areas, such as cities, due to higher population densities and an increased amount of shared air space . Potentially, the reason why Bath had more CLR prescribed per person in winter could be due to more rapid spreading of viral infections in a city versus a town.