H3N2 flu surge in India: What Indian families need to know; Symptoms, home remedies and when to see a doctor

Every flu season brings its share of coughs and colds, but 2025 has already seen a sharper rise in H3N2 flu cases in India — especially across Delhi-NCR and adjacent areas.

H3N2 is a kind of influenza A virus that frequently modifies its genetic makeup, allowing it to evade immunity built up via prior vaccinations or infections. This strain tends to produce more severe or prolonged symptoms than a typical seasonal flu, requiring more caution from families.

How Does H3N2 Spread?

H3N2 Influenza A virus spreads by either contact with infected surfaces or respiratory droplets. In densely populated regions of the world, individuals have intimate contact with one another, which makes it easier for these infections to spread. Festive gatherings and inadequate winter ventilation can contribute to its spread.

While many infected people recover at home, understanding when to manage the symptoms at home and when to seek medical help can make a big difference — particularly for children, the elderly, and people with underlying conditions.

Also Read: Seasonal influenza: Everything you need to know about the viral infection

Classic Symptoms of H3N2 Influenza to Watch Out For

• Sudden high fever with chills
• Persistent cough, often lasting over a week
• Sore throat, nasal congestion or runny nose
• Body aches, muscle pain, severe fatigue
• Headache, sometimes nausea, vomiting, or diarrhoea (especially in children)
• Some patients are reporting unusually high fevers (around 104 °F) and more aggressive coughs this year.

According to reports, many families in Delhi-NCR are experiencing symptoms that last longer than usual and the recovery often takes more than a week.

Home Remedies vs. Doctor Visits

Home Care You Can Try

Rest & hydration: Make sure to drink plenty of fluids (water, warm broths, herbal teas).

Symptoms relief: Use paracetamol or acetaminophen as directed for fever and body ache (no more than prescribed).

Steam and saline gargle: Take steam and gargle with salt water can help ease nasal congestion and soothe your throat

Also Read: Flu, COVID or RSV? How to decode your symptoms this season

Nutrition: Soft, warm, easily digestible food helps keeps your strength up

Isolation: Separate yourself from others to avoid spreading the illness

Most people will recover in 5-7 days, but the cough and fatigue may last longer.

When to go to a doctor:

• When high fever lasts for more than 3 days or not responding to medications.
• Shortness of breath, chest tightness or wheezing.
• Coughing up blood or is accompanied with green phlegm
• Confusion or dizziness with blurred vision or fainting
• Children and the elderly especially if they have severe dehydration
• Chronic conditions (heart, asthma, diabetes, etc…) with worsening suffering or complications

To diagnose H3N2, the doctor may order RTPCR or nasal/throat swab tests. If the infection is identified early, antivirals (like oseltamivir) may be prescribed.

Also Read: 9 common vaccine myths in urban India busted: What you should know

Prevention 

Since H3N2 is transmitted quickly through respiratory droplets and surfaces as well as through coughs, sneezes, and conversation, taking preventive actions is the best approach.

The most effective preventive actions include:

• Flu vaccinations (seasonal shots typically cover H3N2)
• Frequent handwashing and refraining from face touching
• Wearing masks in crowded or enclosed areas
• Keeping indoor spaces exhausted
• Staying at home when sick to prevent the spread of illness

According to a recent survey in the Delhi-NCR area revealed that 69% of the families said at least one member of their home had flu-like symptoms. Although the majority of cases may be treated at home with rest, hydration, and basic care, being aware of the warning signs, such as prolonged fever, breathlessness or persistent cough and seeking timely medical care can prevent the spread of this rapidly spreading virus.

FAQs on H3N2 Influenza Outbreak

Q: What is H3N2 influenza?
A: H3N2 is a type of influenza A virus known for its frequent genetic changes, making it difficult for immunity to build up through prior vaccinations or infections.

Q: How does H3N2 spread?
A: It spreads through contact with infected surfaces or respiratory droplets, particularly in densely populated areas.

Q: What are the symptoms of H3N2?
A: Symptoms include sudden high fever, persistent cough, sore throat, nasal congestion, body aches, muscle pain, severe fatigue, headaches, and sometimes nausea, vomiting, or diarrhoea.

Q: When should I see a doctor for H3N2?
A: Seek medical help if you experience high fever lasting more than 3 days, shortness of breath, chest tightness, coughing up blood, confusion, or severe dehydration in children and the elderly.

Q: How can I prevent H3N2?
A: Preventive measures include getting flu vaccinations, frequent handwashing, wearing masks in crowded areas, keeping indoor spaces ventilated, and staying home when sick.