Respiratory viral infections in hospitalised paediatric patients in the tropics

Respiratory viruses are a huge disease burden globally. An understanding of the seasonal trends and the ability to predict peak periods of respiratory virus disease incidence is useful for clinical care.

This is a retrospective analysis of paediatric hospitalizations of laboratory-confirmed viral respiratory tract infections in KK Women's and Children's Hospital, Singapore, from 1 January 2011 to 31 December 2016. Standard direct immunofluorescence was used to detect respiratory syncytial virus (RSV), influenza A and B viruses, parainfluenza 1, 2 and 3 viruses, metapneumovirus and adenovirus.

A total of 97 840 specimens were analysed with a positive detection rate of 23.8%. RSV made up the largest proportion (42% of the total positive results), predominating between May to September. Influenza A had two peaks, June to July and December to January. Type 3 was the most common parainfluenza virus and showed annually recurring peaks. In contrast, parainfluenza 1 and 2, metapneumovirus and adenovirus had a biennial pattern. The test of seasonality detected identifiable seasonality for RSV and parainfluenza 3 virus.

In conclusion, respiratory viruses have different and overlapping seasonality in tropical Singapore. Respiratory virus testing for patients admitted for acute respiratory infection is useful to target antiviral therapies and appropriate infection control practices.