Respiratory Viruses Surveillance Bulletin: Epidemiological Week 1

Overview

• Influenza positivity decreased to 26% in week 1 of 2026, and SARS-CoV-2 positivity continues to be below 5% (Figure 1). The predominant circulating influenza subtype remains influenza A(H3N2) (Figure 2).
• Influenza activity continues to be high in northern hemisphere countries: Brunei Darussalam, Cambodia, Lao PDR, Philippines, and Singapore, but is declining in China, Japan, Malaysia, Republic of Korea, and Viet Nam.
• Decreasing trends in influenza activity have been observed in many southern hemisphere countries except New Zealand. Pacific Island countries and areas have reported high levels of ILI positivity.