H3N2 Flu Grips Delhi-NCR: Symptoms, Treatment and Prevention Explained

The Delhi-NCR region is witnessing a noticeable surge in flu-like illnesses, largely attributed to the H3N2 strain of Influenza A. According to a recent LocalCircles survey, nearly 70 per cent of households across Delhi, Gurugram, Noida, Faridabad, and Ghaziabad report at least one family member experiencing symptoms consistent with viral fever, influenza, or Covid-like infection, signalling a widespread seasonal spike. The H3N2 virus, a subtype of Influenza A, is known to cause more severe symptoms compared to common viral fevers and can particularly affect children, elderly individuals, and those with underlying health conditions. Understanding the symptoms, treatment options, and prevention strategies is essential to staying protected during

this flu surge.

What is H3N2 influenza?

According to the World Health Organisation, H3N2 is a subtype of the Influenza A virus that causes contagious, often severe seasonal respiratory infections. It leads to symptoms like high fever, cough, fatigue, and body aches for 5 to 7 days, but sometimes leads to complications like pneumonia, especially in children and the elderly. H3N2 is characterized by a higher mutation rate and spreads via respiratory droplets. Doctors say H3N2 symptoms often appear suddenly and may include:

• High fever (often above 101°F)
• Persistent dry cough
• Severe body aches and muscle pain
• Headache
• Sore throat
• Runny or blocked nose
• Extreme fatigue
• Chills and sweating

Some patients, especially children, may also experience nausea, vomiting, or diarrhoea. The cough associated with H3N2 can linger for two to three weeks even after the fever subsides.

Why does weather change lead to infections and allergies?

According to experts, as winters have started to disappear, and daytime temperatures are rising, so do levels of dust, pollen, and airborne pollutants, all of which can irritate the nose and lungs. In many Indian cities, dry winds combined with worsening air pollution further aggravate the problem. People already dealing with asthma, sinusitis, or seasonal allergies often experience sudden breathing difficulty, wheezing, or chest tightness. These flare-ups can escalate quickly, sometimes resulting in emergency visits. “Those already burdened with asthma, sinus trouble, or allergies suddenly begin to experience breathing difficulties or tightness of the chest. These flare-ups can come on quickly and often lead to emergency visits,” said Dr Sarika Chandra, CCMO/DYMS, Emergency Physician, Kailash Hospital. At the same time, the body’s immunity may dip during seasonal transitions. While winter colds recede, viral fevers, throat infections, and gastrointestinal illnesses become more common. “While these problems may start off as minor fevers or stomach upsets, they can quickly take a severe turn and require immediate attention, especially among children and the elderly,” Dr Chandra added.

Who is at higher risk?

Doctors say that while most healthy adults recover within 5 to 7 days, certain groups are more vulnerable to complications, which include:

• Senior citizens
• Children under five years of age
• Pregnant women and breastfeeding
• Those battling asthma, diabetes, heart disease, or weakened immunity

In high-risk individuals, H3N2 can progress to bronchitis, pneumonia, or worsening of existing respiratory conditions. According to Dr Chandra, many people who do not drink enough water also get dehydrated. “Lack of water intake is another common challenge faced at this time. During the winter season, one might be accustomed to not feeling thirsty. However, during the beginning of summer, as the weather gets warmer, the body tends to lose more water through sweat. If one does not take more water, they might feel dizzy, weak, or unusually tired. In some cases, this turns into heat exhaustion or heat stroke, which needs immediate medical care,” she added.Also read: Surgery After 80: Why Age Shouldn’t Stop You from Life-Saving Treatment

Is there a treatment for H3N2?

While there is no “instant cure” for influenza, early treatment can reduce severity and duration. Doctors recommend taking adequate rest, drinking plenty of fluids to prevent dehydration, taking paracetamol for fever and body aches, and getting antiviral medications like oseltamivir - if prescribed within 48 hours of symptom onset. Also, it is important to note that antibiotics are not effective against viral infections unless there is a secondary bacterial infection. Patients experiencing breathlessness, chest pain, persistent high fever, or worsening symptoms should seek immediate medical care. (Expert inputs by: Dr Sarika Chandra, CCMO/DYMS, Emergency Physician, Kailash Hospital, Noida)