The main objective of this project is to identify the epidemiological, clinical, bacteriological, virological, parasitological and immunological determinants of influenza severity including the A/H1N1pdm infection in developing countries with special emphasis on the role of co-infections.

The secondary objectives of this project are:

1. To describe the clinical presentation, atypical forms, duration of symptoms, complications and deaths due to severe influenza.
2. To estimate the prevalence of bacterial, viral and parasitological co-infections at initial study visit in mild and severe forms of influenza.
3. To set-up a biobank of samples from influenza infected patients for further studies. Immunological and virological (molecular maker of virulence, drug resistance) determinants of influenza severity will be explored.