Delhi sees rising seasonal influenza activity as H1N1 cases cross 1,700

The virus was responsible for the 2009 influenza pandemic but has since continued to circulate globally as part of seasonal flu patterns

Delhi is witnessing increased seasonal influenza activity, with 1,777 H1N1 cases reported through August 20, 2026, while Agilus Diagnostics has observed a H1N1 positivity rate of nearly 30% among individuals tested at its reference laboratory over the past week.

Health experts, however, have advised against unnecessary panic, noting that A(H1N1)pdm09 is now an established seasonal influenza virus. The virus was responsible for the 2009 influenza pandemic but has since continued to circulate globally as part of seasonal flu patterns.

Seasonal influenza activity can fluctuate depending on factors including weather conditions, population immunity and patterns of transmission. The increase in cases in Delhi is therefore prompting greater attention to timely diagnosis and appropriate medical care rather than alarm.

Dr. Yoginder Pal Singh, Head – HLA and Molecular Biology, Agilus Diagnostics, said the rise in H1N1 cases highlights how quickly seasonal respiratory infections can spread, particularly in crowded or poorly ventilated settings.

He noted that influenza symptoms can overlap considerably with those of COVID-19 and other respiratory infections, making it difficult to identify the cause based on symptoms alone. Common symptoms include fever, cough, sore throat, body aches, headache, fatigue, chills and a runny or blocked nose.

“Prompt testing and medical evaluation are particularly important for high-risk individuals,” Dr. Singh said, adding that physicians may consider RT-PCR testing or comprehensive respiratory panels depending on a patient's symptoms and medical history. A Complete Blood Count (CBC) or C-Reactive Protein (CRP) test may also be recommended where clinically appropriate.

The timing of treatment can also be important. Antiviral medicines are generally most effective when started within 48 hours of symptom onset, making early medical consultation particularly relevant for people at higher risk of complications. Antivirals should be taken only under medical supervision.

Groups considered more vulnerable to severe influenza complications include young children, older adults, pregnant women, people with diabetes, heart or lung disease, asthma and individuals with weakened immunity.

Doctors also recommend prompt medical attention when warning signs such as difficulty breathing, persistent or high fever, chest discomfort, confusion, severe weakness, dehydration or falling oxygen saturation develop.