全球呼吸道病毒活动：每周更新N°562

GLOBAL INFLUENZA SURVEILLANCE AND RESPONSE SYSTEM (GISRS) Co-circulationInfluenzaSARS-CoV-2RSVSeverity assessment SUMMARY Globally, influenza activity decreased but remained elevated with positivity around 15% in week 3 2026. SARS-CoV-2 activity remained stable and lowoverall. Influenza predominated and positivity was around 15% in the northern hemisphere temperate and subtropical areas, and around 20% in the tropicalareas. In the southern hemisphere temperate and subtropical areas, influenza and SARS-CoV-2 positivity were both low. [Figures 1a, 1b, 1c and 1d] . qInfluenza Globally, influenza detections continued to decline. Influenza A viruses were predominant among influenza detections in week 3. [Figure 2] In the northern hemisphere, influenza percent positivity was elevated (>10%) in countries in North America and Western and Middle Africa, Southernand South-East Asia. Percent positivity was over 30% in countries in Central America and the Caribbean, Tropical South America, Northern Africa,Europe, and Western and Eastern Asia. Increases in activity were observed in countries in Central America and the Caribbean, South West andEastern Europe, and Western Asia. [Figures 3 and 4] In the southern hemisphere, influenza activity remained low overall although elevated positivity (>10%) was reported in single countries in Tropicaland Temperate South America, South-East Asia and Oceania; percent positivity was over 30% in one country in Eastern Africa. Small increases inactivity were observed in two countries in Temperate South America and one country in Oceania. [Figures 3 and 4] In the zones with elevated positivity, influenza A(H3N2) was predominant in all zones except Tropical South America where there was codominance ofinfluenza A(H1N1)pdm09 and A(H3N2). [Figures 5 and 6] qSARS-CoV-2Globally, SARS-CoV-2 positivity remained stable and low, with single countries reporting elevated positivity (>10%) in South West and Temperate South America. A small increase in activity was reported in a single country in South West Europe. [Figures 7 and 8] qRespiratory Syncytial Virus (RSV)Globally, SARS-CoV-2 positivity remained stable and low, with single countries reporting elevated positivity (>10%) in South West Europe and Temperate South America. A small increase in activity was reported in a single country in South West Europe. [Figures 9 and 10] RSV and influenzaactivity were both elevated in single countries in Central America and the Caribbean, Northern and South West Europe, and Western Asia. qSeverity assessmentThe severity assessments here are reported from countries, areas and territories. Assessments for transmissibility can be reported based on syndromic parameters and/or influenza-specific parameters. In northern hemisphere temperate and subtropical areas, influenza-specific transmissibility wasreported as moderate (2); transmissibility using syndromic data was reported as below seasonal threshold (8), low (14) and moderate (9). In tropicalareas, influenza-specific transmissibility was reported as below seasonal threshold in a single country. [Figures 11 and 12] Co-circulation of influenza and SARS-CoV-2 1c) Weekly numbers of influenza andSARS-CoV-2 virus specimens tested andpercent positivity in tropical areas 1d) Weekly numbers of influenza andSARS-CoV-2 virus specimens tested andpercent positivity in southern hemispheretemperate and subtropical areas 1b) Weekly numbers of influenza andSARS-CoV-2 virus specimens tested andpercent positivity in northern hemispheretemperate and subtropical areas Influenza 3) Proportions of specimens that tested positive forinfluenza (year-week:2026-03) 4) Change in proportions of specimens that testedpositive for influenza (year-week:2026-03) 6) Weekly distribution of influenza virus types andsubtypes by geographic zone (last 12 months) 5) Proportions of influenza virus types and subtypes byinfluenza transmission zones (year-week:2026-03) SARS-CoV-2 7) Proportions of specimens that tested positive forSARS-CoV-2 (year-week:2026-03) 8) Change in proportions of specimens that testedpositive for SARS-CoV-2 (year-week:2026-03) Respiratory syncytial virus 9) Proportions of specimens that tested positive for RSV(year-week:2026-03) 10) Change in proportions of specimens that testedpositive for RSV (year-week:2026-03) Severity assessment 12) Syndromic transmissibility (year-week:2026-03) 11) Influenza specific transmissibility (year-week:2026-03) 13) Number of countries, areas or territories reporting to FluNet (from year-week2025-51to year-week2026-03) Additional information Data and methodsThe data presented in this report originates from virologic surveillance conducted by countries, areas, and territories (CATs) and submitted to WHO FluNet through participation or collaboration with the Global Influenza Surveillance and Response System (GISRS). These CATs employ diverse methodologies to monitor respiratory virus activity, which may resultin var