In our samples DENV genotypes and Procaterol hydrochloride clades were not associated with severity of the disease and neither to any region of the city. However, the dataset is small and need to be further characterized to confirm this observation. In fact the co-circulation of different clades and/or clade replacement is related to high genetic diversity of that isolates and can lead to new distinct biological proprieties that may induce more severe disease. Recently, two complete distinct strains of DENV-1 were observed in Brazil. DENV-2 serotypes from Manaus were grouped with the Asian/ American genotype that is more virulent than the indigenous American genotype and is also the predominant genotype in Brazil. DENV-3 belonged to genotype III introduced from the Caribbean Islands and present in Brazil since the last 15 years. All DENV-4 analyzed in this study belonged to genotype II. DENV-4 was first described in Manaus in 2008. It was found that this DENV-4 belonged to the genotype I, which is of Asian origin and was never described in the American Continent. Presently, probably, 2 genotypes of DENV-4 are circulating in Manaus. Our study is the first for Belgium to give an extensive overview of the disease characteristics, costs, QoL score and QALY��s lost related to both ILI and clinically diagnosed flu, for ambulatory patients and for patients not CP 524515 seeking professional medical care. As expected, patients seeking medical care report a higher cost and a lower quality of life than community patients. Having an underlying illness strongly increases the average cost and decreases the average quality of life for all ILI patients. Although previous vaccination in the same season is associated with lower cost and better quality of life for community patients, this is not the case for ambulatory care patients. Possibly, this group includes people who did not mount a sufficient immune response after vaccination and/or patients who were vaccinated only very shortly before the onset of disease. Cost and quality-oflife is very similar for ILI patients whether or not they were clinically diagnosed with flu, except when they have an underlying illness. The decreasing trend in costs by age for ILI patients categorized as ��unlikely flu��, could be explained by the relatively higher proportion of children with pneumonia.