Commonground
Senior Moderator
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WEEKLY REPORT ON COVID-19, INFLUENZA, AND OTHER RESPIRATORY VIRUSES, 2025
Excerpt
SEASONAL INFLUENZA AND OTHER RESPIRATORY VIRUSES 2025-2026, WEEK 41-2025 The 2025-2026 seasonal influenza season runs from epidemiological week 41 of 2025 to 20 of 2026. In the cumulative seasonal influenza season (EW 41 of 2025), as of the reporting cutoff, 125 laboratory-confirmed positive influenza cases have been confirmed. 96.8% are due to influenza A (H1N1) and 3.2% to influenza B. So far in the 2025-2026 season, a total of 5,235 suspected cases of viral respiratory illness (ILI/SARI) have been reported in the USMER, of which 125 cases of influenza (2.4%) have been confirmed, with no deaths.
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EXPLANATORY NOTES
• The COVID-19 cases were laboratory-confirmed using the RT-PCR technique and correspond to each year.
• The influenza and RVO cases were laboratory-confirmed using the RT-PCR technique and correspond to the 2025-2026 seasonal influenza season.
• Surveillance for COVID-19, influenza, and RVO is conducted under a sentinel strategy with information from 461 Viral Respiratory Disease Monitoring Health Units (VRIMS), using the criteria for influenza-like illness and severe acute respiratory infection (ILI/SARI) and laboratory confirmation using RT-PCR to determine the positivity of cases and their subtyping in influenza cases.
• Deaths confirmed to respiratory viruses (COVID-19, influenza, and RVO) outside the sentinel strategy (non-USMER units), as well as cases associated with outbreaks, must be recorded in the SISVER (National System of Emergency Management System) and are included in the weekly epidemiological surveillance reports of the General Directorate of Epidemiology.
• Viruses presented as Influenza A correspond to strains that were identified as A by real-time PCR and that have not reached the subtyping centers or arrived with insufficient samples, which could be modified by the InDRE for subtyping.
• The regions of the country illustrated on the map correspond to the northern region (Baja California, Baja California Sur, Sonora, Coahuila, Chihuahua, Tamaulipas, Nuevo León, Sinaloa, and Durango), the central region (Aguascalientes, Colima, Mexico City, Guanajuato, Hidalgo, Jalisco, State of Mexico, Michoacán, Morelos, Nayarit, Querétaro, San Luis Potosí, Tlaxcala, and Zacatecas), the peninsular region (Campeche, Quintana Roo, and Yucatán), and the southeastern region (Chiapas, Guerrero, Oaxaca, Puebla, Tabasco, and Veracruz).
• The epidemiological genomic surveillance data comes from the online platform of the Global Initiative on Sharing All Influenza Data (GISAID).
• To date, the Institute for Epidemiological Diagnosis and Reference (InDRE) has not identified any mutations related to antigenic shifts, nor changes in the virulence or pathogenicity of the influenza virus. No viral resistance to oseltamivir has been identified. • The 2025 interseasonal influenza season began in epidemiological week 21 of 2025 and concluded in epidemiological week 39 of 2025.
• The 2025-2026 seasonal season began in week 40 of 2025 and will conclude in week 20 of 2026.
Source:
1) 2) SINAVE/DGE/SSA/Single Information System for Epidemiological Surveillance, as of October 8, 2025.
SINAVE/DGE/SSA/Epidemiological Surveillance of Viral Respiratory Diseases, platform accessed on October 13, 2025.
https://www.gob.mx/cms/uploads/attachment/file/1029812/Informe_semanal_ERV_SE41.pdf
WEEKLY REPORT ON COVID-19, INFLUENZA, AND OTHER RESPIRATORY VIRUSES, 2025
Excerpt
SEASONAL INFLUENZA AND OTHER RESPIRATORY VIRUSES 2025-2026, WEEK 41-2025 The 2025-2026 seasonal influenza season runs from epidemiological week 41 of 2025 to 20 of 2026. In the cumulative seasonal influenza season (EW 41 of 2025), as of the reporting cutoff, 125 laboratory-confirmed positive influenza cases have been confirmed. 96.8% are due to influenza A (H1N1) and 3.2% to influenza B. So far in the 2025-2026 season, a total of 5,235 suspected cases of viral respiratory illness (ILI/SARI) have been reported in the USMER, of which 125 cases of influenza (2.4%) have been confirmed, with no deaths.
-snip-
EXPLANATORY NOTES
• The COVID-19 cases were laboratory-confirmed using the RT-PCR technique and correspond to each year.
• The influenza and RVO cases were laboratory-confirmed using the RT-PCR technique and correspond to the 2025-2026 seasonal influenza season.
• Surveillance for COVID-19, influenza, and RVO is conducted under a sentinel strategy with information from 461 Viral Respiratory Disease Monitoring Health Units (VRIMS), using the criteria for influenza-like illness and severe acute respiratory infection (ILI/SARI) and laboratory confirmation using RT-PCR to determine the positivity of cases and their subtyping in influenza cases.
• Deaths confirmed to respiratory viruses (COVID-19, influenza, and RVO) outside the sentinel strategy (non-USMER units), as well as cases associated with outbreaks, must be recorded in the SISVER (National System of Emergency Management System) and are included in the weekly epidemiological surveillance reports of the General Directorate of Epidemiology.
• Viruses presented as Influenza A correspond to strains that were identified as A by real-time PCR and that have not reached the subtyping centers or arrived with insufficient samples, which could be modified by the InDRE for subtyping.
• The regions of the country illustrated on the map correspond to the northern region (Baja California, Baja California Sur, Sonora, Coahuila, Chihuahua, Tamaulipas, Nuevo León, Sinaloa, and Durango), the central region (Aguascalientes, Colima, Mexico City, Guanajuato, Hidalgo, Jalisco, State of Mexico, Michoacán, Morelos, Nayarit, Querétaro, San Luis Potosí, Tlaxcala, and Zacatecas), the peninsular region (Campeche, Quintana Roo, and Yucatán), and the southeastern region (Chiapas, Guerrero, Oaxaca, Puebla, Tabasco, and Veracruz).
• The epidemiological genomic surveillance data comes from the online platform of the Global Initiative on Sharing All Influenza Data (GISAID).
• To date, the Institute for Epidemiological Diagnosis and Reference (InDRE) has not identified any mutations related to antigenic shifts, nor changes in the virulence or pathogenicity of the influenza virus. No viral resistance to oseltamivir has been identified. • The 2025 interseasonal influenza season began in epidemiological week 21 of 2025 and concluded in epidemiological week 39 of 2025.
• The 2025-2026 seasonal season began in week 40 of 2025 and will conclude in week 20 of 2026.
Source:
1) 2) SINAVE/DGE/SSA/Single Information System for Epidemiological Surveillance, as of October 8, 2025.
SINAVE/DGE/SSA/Epidemiological Surveillance of Viral Respiratory Diseases, platform accessed on October 13, 2025.
https://www.gob.mx/cms/uploads/attachment/file/1029812/Informe_semanal_ERV_SE41.pdf