Pregnant women, older people, children under 5 years of age are at greater risk of developing serious or complicated diseases.
The National Institute of Health issued a notice on the prevention and control of seasonal influenza (H3N2) after 340,856 suspected cases were reported nationwide between epidemiological weeks 44 and 49.
The objective of this advisory is to alert and facilitate health authorities and other stakeholders to ensure timely preventive and control measures, covering preparation to address the increased workload expected in outpatient and inpatient departments over the coming months.
According to the advisory, influenza is an acute viral respiratory disease caused by influenza A and B viruses, which causes annual epidemics. Influenza A is associated with increased transmissibility and severe illness among older adults, young children, pregnant women, and people with chronic illnesses.
During the 2025-2026 season, a new genetic subclade of influenza A (H3N2), subclade K, emerged globally. Recently, there has been a rapid increase in the detection of H3N2 cases since August 2025 in different WHO regions.
The Southeast Asian region has shown increased positivity of influenza cases, with H3N2 predominating (66% of all influenza A cases) from May 2025 to the end of November. Similarly, Australia and New Zealand have also reported an increase in influenza cases, with a significant proportion of the H3N2 subclade.
Pakistan is also seeing an increase in cases of influenza-like illness (ILI) and severe acute respiratory infections (SARI). The country has reported a total of 340,856 suspected cases of ILI between epidemiological weeks 44 to 49 from all provinces and regions through the Integrated Disease Surveillance and Response System, with 12% positivity of H3N2 cases among the samples analyzed.
According to the advisory, seasonal influenza viruses can present with mild symptoms but can progress to severe illness, particularly in high-risk people, including patients with chronic illnesses (such as asthma, diabetes, heart and lung disease), pregnant women, older people, and children under five years of age, who are at higher risk of developing severe or complicated illness.
Vaccination is the most effective way to prevent infection and serious outcomes caused by influenza viruses, especially in high-risk groups. Influenza (seasonal flu) can be spread from person to person by coughing or sneezing or through contaminated hands or other surfaces.
The advisory emphasized that if someone is sick or has been in close contact with people who have a flu-like illness, the following preventative measures are recommended to limit the transmission of influenza:
• Frequent and thorough handwashing with soap and water, and use of hand sanitizer when away from handwashing facilities.
• Cover your mouth and nose when sneezing or coughing
• Sick patients should rest and avoid crowds.
• Take social distancing measures
It is noted that the CDC-NIH Public Health Emergency Operations Center (PHEOC) is periodically monitoring the flu situation.
Considering the recent surge of influenza in several regions, notable increase in H3N2 cases, limited access to healthcare services, unsatisfactory infection prevention and control practices in different settings, and limited health awareness in the community, the flu season in Pakistan may be severe.
Therefore, it is essential that people, especially those who belong to high-risk groups, take preventative measures, such as getting vaccinated, practicing good hygiene, and seeking medical attention immediately if symptoms persist.
The objective of this advisory is to alert and facilitate health authorities and other stakeholders to ensure timely preventive and control measures, including preparation to address the increased workload expected in outpatient and inpatient departments over the coming months.
