title: A method to assess seasonality of urinary tract infections based on medication sales and google trends.
abstract: BACKGROUND
  Despite the fact that urinary tract infection (UTI) is a very frequent disease, little is known about its seasonality in the community.
  
  
  RESULTS
  To estimate seasonality of UTI using multiple time series constructed with available proxies of UTI. Eight time series based on two databases were used: sales of urinary antibacterial medications reported by a panel of pharmacy stores in France between 2000 and 2012, and search trends on the Google search engine for UTI-related terms between 2004 and 2012 in France, Germany, Italy, the USA, China, Australia and Brazil. Differences between summers and winters were statistically assessed with the Mann-Whitney test. We evaluated seasonality by applying the Harmonics Product Spectrum on Fast Fourier Transform. Seven time series out of eight displayed a significant increase in medication sales or web searches in the summer compared to the winter, ranging from 8% to 20%. The eight time series displayed a periodicity of one year. Annual increases were seen in the summer for UTI drug sales in France and Google searches in France, the USA, Germany, Italy, and China. Increases occurred in the austral summer for Google searches in Brazil and Australia.
  
  
  CONCLUSIONS
  An annual seasonality of UTIs was evidenced in seven different countries, with peaks during the summer.
authors.affiliation: Département de médecine générale, UPMC Univ Paris 06, Paris, France ; UMRS 707, UPMC Univ Paris 06, Paris, France ; U707, INSERM, Paris, France.
authors.forename: Louise
authors.initials: L
authors.lastname: Rossignol
authors.forename: Camille
authors.initials: C
authors.lastname: Pelat
authors.forename: Bruno
authors.initials: B
authors.lastname: Lambert
authors.forename: Antoine
authors.initials: A
authors.lastname: Flahault
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Chartier-Kastler
authors.forename: Thomas
authors.initials: T
authors.lastname: Hanslik
mesh_terms: D000900:Anti-Bacterial Agents / Q000191:economics*; D001315:Australia; D001938:Brazil; D002681:China; D005602:France; D005858:Germany; D006801:Humans; D020407:Internet; D007558:Italy; D057386:Search Engine; D012621:Seasons; D018571:Sentinel Surveillance; D014481:United States; D014552:Urinary Tract Infections / Q000453:epidemiology*
chemical_list: D000900:Anti-Bacterial Agents