The National Institute of Health (NIH) has issued an advisory on the prevention and control of Seasonal Influenza (H3N2) amid a rising number of cases reported globally and within Pakistan. The advisory aims to alert provincial health authorities and relevant stakeholders to implement timely preventive and control measures.
According to the NIH, the advisory also calls for enhanced preparedness to manage a potential increase in patient load at outpatient and inpatient departments during the coming months, as influenza activity intensifies across the country.
Influenza is an acute viral respiratory illness caused by Influenza A and B viruses and leads to annual epidemics worldwide. Influenza A, particularly the H3N2 subtype, is associated with higher transmissibility and more severe disease, especially among older adults, young children, pregnant women, and individuals with underlying conditions such as asthma, diabetes, and heart or lung diseases.
The NIH noted that during the 2025–2026 influenza season, a new genetic subclade of Influenza A(H3N2), referred to as Subclade K, has emerged globally. Since August 2025, a rapid increase in H3N2 cases has been observed across several World Health Organization (WHO) regions.
In the South-East Asia region, influenza positivity has risen significantly, with H3N2 accounting for 66 percent of all Influenza A cases reported between May and the end of November 2025. Similar patterns have also been reported in Australia and New Zealand, where a substantial share of influenza cases belong to the H3N2 subclade.
Pakistan is currently witnessing an increase in influenza-like illness (ILI) and severe acute respiratory infection (SARI) cases. Surveillance data from the Integrated Disease Surveillance and Response System shows that 340,856 suspected ILI cases were reported nationwide between epidemiological weeks 44 and 49, with 12 percent of tested samples confirmed positive for H3N2.
Taking into account the rising case numbers, limited access to healthcare in some regions, gaps in infection prevention and control practices, and low public awareness, the NIH has warned that the ongoing flu season in Pakistan could be severe.
The advisory stressed that seasonal influenza may begin with mild symptoms but can progress to severe or complicated illness, particularly among high-risk groups. Vaccination was emphasized as the most effective tool to prevent infection and reduce severe disease outcomes.
To curb transmission, the NIH advised frequent handwashing with soap and water or the use of alcohol-based hand sanitizers, covering the mouth and nose when coughing or sneezing, avoiding crowded places when ill, ensuring adequate rest, and observing social distancing where possible.
The NIH further stated that the Public Health Emergency Operations Center at the CDC-NIH is closely monitoring the influenza situation and coordinating response measures to reduce the impact of seasonal influenza across Pakistan.
