全球呼吸道病毒活动：每周更新568号

GLOBAL INFLUENZA SURVEILLANCE AND RESPONSE SYSTEM (GISRS) Co-circulationInfluenza SUMMARY Globally, influenza activity remained stable and positivity was above 10% in week 9 2026. SARS-CoV-2 activity remained low overall. Influenza predominatedand positivity was just above 10% in the northern hemisphere temperate and subtropical areas and around 25% in tropical areas. In the southern hemispheretemperate and subtropical areas, influenza and SARS-CoV-2 positivity were both low. [Figures 1a, 1b, 1c and 1d] Globally, RSV positivity remained stable qInfluenza Globally, influenza detections continued to decline in week 9. Influenza A viruses were predominant among influenza detections, with a slight increase In the northern hemisphere, influenza percent positivity was elevated (>10%) in countries in North America, Western and Northern Africa, Western,Southern and South-East Asia. Percent positivity was over 30% in countries in Central America and the Caribbean, Europe and Eastern Asia. In the southern hemisphere, influenza activity remained low overall although elevated positivity (>10%) was reported in a few countries in TropicalSouth America and in single countries in Temperate South America and South-East Asia. No increases in activity were observed in any countries in In the zones with elevated positivity, influenza A(H3N2) was predominant in most of the zones except Central America and the Caribbean andWestern Asia where influenza A(H1N1)pdm09 was dominant, Western Africa where influenza B was dominant and in Northern Africa, South-East and qSARS-CoV-2 Globally, SARS-CoV-2 positivity remained stable and low, with single countries reporting elevated positivity (>10%) in Central America and theCaribbean and Northern Europe. Small increases in activity were reported in single countries in Central America and the Caribbean and Eastern qRespiratory Syncytial Virus (RSV) Globally, RSV positivity remained stable and low, with a few countries reporting elevated positivity (>10%) in Central America and the Caribbean,Europe and Western Asia. Percent positivity was over 30% in one country in Northern Africa. Small increases in activity were reported in singlecountries in Northern and Eastern Africa and Northern Europe and a few countries in South West and Eastern Europe. [Figures 9 and 10] RSV and The severity assessments here are reported from countries, areas and territories. Assessments for transmissibility can be reported based on syndromicparameters and/or influenza-specific parameters. In the northern hemisphere temperate and subtropical areas, influenza-specific transmissibility wasreported as below seasonal threshold (1); transmissibility using syndromic data was reported as below seasonal threshold (23), low (9) and moderate(3). Influenza-specific transmissibility was reported as low in a single country in the southern hemisphere temperate and subtropical areas. [Figures 11 Co-circulation of influenza and SARS-CoV-2 1b) Weekly numbers of influenza andSARS-CoV-2 virus specimens tested and Influenza SARS-CoV-2 Respiratory syncytial virus Severity assessment Additional information Data and methods The data presented in this report originates from virologic surveillance conducted by countries, areas, and territories (CATs) and submitted to WHO FluNet through participation orcollaboration with the Global Influenza Surveillance and Response System (GISRS). These CATs employ diverse methodologies to monitor respiratory virus activity, which may resultin variations between this report and other surveillance summaries published elsewhere. To assess trends, the proportion of specimens tested positive for influenza or SARS-CoV-2 was smoothed over a 3-weeks period. This analysis includes only countries that tested 10 ormore specimens in at least two of the three weeks. Weekly changes in the smoothed positivity rate for each virus were calculated as absolute differences from the previous week. These The influenza transmission zones map is based on data aggregated over a 3-weeks period, moving backward from the current week until a minimum threshold of 100 tested samples isreached within each influenza transmission zone. Pie charts are displayed on the map only if the total percent positivity in a influenza transmission zones map is 20% or higher. Alltrend analyses are based on ISO 8601 calendar week numbering. Severity assessments: The severity assessments here are reported from countries, areas and territories.WHO’s Pandemic influenza severity assessment (PISA): a WHO guide to assess the severityof influenza in seasonal epidemics and pandemics, 2nd ed outlines the methods for which countries, areas and territories can derive these severity assessments. Assessments for Countries, areas and territories may not provide assessments year-round. The assessments may be revised over time if there is retrospective/delayed reporting or updating of previouslyreported data. These assessments are made in the