Respiratory Viruses Surveillance Bulletin: Epidemiological Week 3, 2026

Overview

• Influenza positivity increased from 17% in week 2 to 20% in week 3 of 2026, and SARS-CoV-2 positivity remains below 5% (Figure 1). The predominant circulating influenza subtype remains influenza A(H3), however increases in influenza B(Victoria) are noted (Figure 2).
• Influenza activity is increasing in some northern hemisphere countries: Cambodia and Republic of Korea, but is declining in Brunei Darussalam, China, Indonesia, Japan, Malaysia, Mongolia, the Philippines, and Viet Nam.
• Among southern hemisphere countries, only Australia and New Zealand have updated information, and influenza activity in both countries remains low.