A New Method to Predict the Epidemiology of Fungal Keratitis by Monitoring the Sales Distribution of Antifungal Eye Drops in Brazil

Purpose: Fungi are a major cause of keratitis, although few medications are licensed for their treatment. the aim of this study is to observe the variation in commercialisation of antifungal eye drops, and to predict the seasonal distribution of fungal keratitis in Brazil.Methods: Data from a retrospective study of antifungal eye drops sales from the only pharmaceutical ophthalmologic laboratory, authorized to dispense them in Brazil (Opthalmos) were gathered. These data were correlated with geographic and seasonal distribution of fungal keratitis in Brazil between July 2002 and June 2008.Results: A total of 26,087 antifungal eye drop units were sold, with a mean of 2.3 per patient. There was significant variation in antifungal sales during the year (p < 0.01). A linear regression model displayed a significant association between reduced relative humidity and antifungal drug sales (R-2 = 0.17, p < 0.01).Conclusions: Antifungal eye drops sales suggest that there is a seasonal distribution of fungal keratitis. A possible interpretation is that the third quarter of the year (a period when the climate is drier), when agricultural activity is more intense in Brazil, suggests a correlation with a higher incidence of fungal keratitis. A similar model could be applied to other diseases, that are managed with unique, or few, and monitorable medications to predict epidemiological aspects.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundacao de Apoio ao Ensino, Pesquisa e Assistencia do Hospital das Clinicas da Faculdade de Medicina de Ribeirao Preto da Universidade de São PauloUniv São Paulo, Fac Med Ribeirao Preto, Dept Ophthalmol, Ribeirao Preto, BrazilUniversidade Federal de São Paulo, Dept Ophthalmol, São Paulo, BrazilOphthalmos Ind Farmaceut, São Paulo, BrazilUniv São Paulo, Fac Med Ribeirao Preto, Dept Obstet & Ginecol, Ribeirao Preto, BrazilEscola Ultra Sonog & Reciclagem Med Ribeirao Pret, Ribeirao Preto, BrazilInst Nacl Ciencia & Tecnol Hormonios & Saude da M, Ribeirao Preto, BrazilUniversidade Federal de São Paulo, Dept Ophthalmol, São Paulo, BrazilCNPq: 302005/2009-9Web of Scienc