Virus WAtch Week Ending 24 May 2015

Influenza and Influenza-like Illnesses (ILI)

Summary: Some indicators of influenza activity increased slightly this week, but the influenza season has not clearly commenced. Influenza B virus continues to be predominant, and RSV activity is increasing.

• ILI presentations to sentinel general practitioners (GPs) increased this week but ILI presentations to sentinel Emergency Departments (EDs) remained steady.
• Influenza B constituted the majority of influenza viruses subtyped this week; influenza A/H3N2 and, to a lesser extent, influenza A/H1N1, continue to co-circulate.
• Respiratory syncytial virus activity doubled this week.

Gastroenteritis

• Gastroenteritis presentations to sentinel GPs and EDs continue to fluctuate within expected levels.
• Rotavirus detections increased this week.

Varicella and Viral Rashes

• Shingles presentations to sentinel GPs remain above baseline level.
• Chickenpox presentations are within expected limits.
• No cases of measles or rubella were confirmed this week.

Several additional cases of mumps have been confirmed, part of an outbreak in highly vaccinated Aboriginal children in the Kimberley region, with spread to boarding schools in Perth and Esperance.

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