Virus WAtch Week Ending 31 May 2015

Influenza and Influenza-like Illnesses (ILI)

Summary: Indicators of influenza-like activity increased this week, but influenza virus detections remain steady, and increases in non-influenza virus activity, particularly RSV, appear to be responsible. Influenza B virus dominates influenza activity at present.

• ILI presentations to sentinel general practitioners (GPs) and sentinel emergency departments (EDs) increased this week.
• Influenza virus detections and hospitalisations for influenza remain relatively 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 continues to increase.

Gastroenteritis

• Gastroenteritis presentations to sentinel GPs and EDs continue to fluctuate within expected levels.
• Norovirus detections are fluctuating from week-to-week.

Varicella and Viral Rashes

• Shingles presentations to sentinel GPs and EDs are above baseline level.
• Chickenpox presentations are low.
• No cases of measles or rubella were confirmed this week.
• Several additional cases of mumps have been confirmed as 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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