Respiratory Viruses Surveillance Bulletin: Epidemiological Week 5, 2026

Overview

• Regional influenza positivity is 14% in week 5 of 2026, and SARS-CoV-2 positivity remains below 5% (Figure 1). The predominant circulating influenza subtype remains influenza A(H3/N2), however increases in influenza B(Victoria) in some countries have been observed (Figure 2).
• Among northern hemisphere countries, influenza activity is decreasing in China and Mongolia, but has increased in Cambodia, Japan, Republic of Korea, and Viet Nam.
• All southern hemisphere countries have decreased influenza activity except in Papua New Guinea, where media outlets reported increase in cases of influenza A(H3/N2), including deaths [1][2][3]. However, official data for Papua New Guinea is available only until week 51 of 2025.