de Abreu LV, et al. - Researchers sought to analyze the cases of new daily persistent headache (NDPH), a relatively rare headache entity, among 450 individuals who had dengue fever via assessing the data of an epidemiologic study performed in a medium-sized town in southeastern Brazil (Franca, population 370,000). Among 600 cases of dengue fever reported to the Franca Health Authority during the year 2015, they located and interviewed 450 patients. NDPH was possibly present in three of these 450 patients indicating NDPH prevalence of 1:150 cases of dengue fever that is attributable to dengue fever (0.67%).