Virus WAtch Week Ending 17 August 2014

Influenza and Influenza-like Illnesses (ILI)

Summary: Most indicators of influenza activity decreased this week. Overall non-influenza respiratory virus activity is also declining.

• Most indicators of influenza activity, including notifications, proportion of positive laboratory tests for influenza, Emergency Department ILI attendances and influenza-associated hospitalisations decreased this week, although ILI presentations to sentinel general practitioners (GPs) increased.
• The majority of influenza viruses subtyped were influenza A/H1N1, but there were also a significant number of A/H3N2 detections, particularly associated with epidemic activity in the West Kimberley region. Influenza B continues to circulate at a low level.
• Overall detections of non-influenza respiratory viruses decreased this week.

 Gastroenteritis

• Gastroenteritis presentations to sentinel GPs decreased while ED presentations remain steady and below baseline.

 Varicella and Viral Rashes

• Shingles and chickenpox presentations to sentinel GPs and EDs remain around expected levels.
• One case of measles was reported this week – the fifth secondary infection associated with an index case infected in the Philippines. No cases of rubella were reported this week but two cases of mumps were confirmed in adult travellers recently returned from Sri Lanka.