KEY POINTS
- Respiratiry syncytial virus, parainfluenza viruses and human metapneumovirus are important and frequent causes of respiratory tract infection, especially in children.
-Seasonality of respiratory viruses is variable depending on the grographical region.
-Measlas remains a serious disease, especially in the immunocompromised in whom it may be 'spotless' and often fatal, and in less developed countries where it contributes to significant morbidity and mortality.