Virus WAtch Week Ending 16 August 2015

Influenza and Influenza-like Illnesses (ILI)

Summary: Indicators of influenza activity remain relatively steady, suggesting we are around the peak of the influenza season. Non-influenza virus activity continues to decline.

• ILI presentations to sentinel general practitioners (GPs) and emergency departments (EDs) remain relatively steady and within ranges seen in mild influenza seasons.
• Influenza virus detections, notifications and percent positivity appear to have plateaued. Influenza B virus (57% of detections) continues to predominate, but appears to be declining in absolute and relative terms; influenza A/H3N2 now comprises 41% of cases.
• Hospitalisations with confirmed influenza appear to be declining.
• Non-influenza respiratory virus activity, and particularly RSV, continues to decrease.

Gastroenteritis

• Gastroenteritis presentations to sentinel GPs and EDs are relatively steady and consistent with levels experienced previously at this time of the year.
• Norovirus detections are low and steady, and rotavirus detections increased this week.

Varicella and Viral Rashes

• Shingles and chickenpox presentations to sentinel EDs and GPs are near or below baseline levels.
• No cases of measles or rubella were confirmed.

Several further cases of mumps have been confirmed in the Kimberley and Pilbara regions, primarily among vaccinated Aboriginal children, teenagers and young adults. Most recent cases are residents of Broome or Port Hedland, or nearby communities.