New Delhi, Sep 17 : Changing weather conditions are driving influenza A strain H3N2 cases in Delhi-NCR, said health experts on Wednesday.

City doctors have reported a sharp increase in viral illness in Delhi-NCR.

H3N2 is a seasonal flu that circulates in humans and mutates over time.

Children, older adults, and pregnant women are most vulnerable to the disease. It also causes more severe symptoms in high-risk populations such as those with weakened immune systems and patients with asthma, COPD, cardiovascular disease, or diabetes.

'Cases of influenza due to H3N2 are rising. Major symptoms include fever, cough, sore throat, myalgia (muscle pain), Animesh Ray, Additional Professor, Department of Internal Medicine, AIIMS, told IANS.

The expert noted that the condition is usually mild but can turn severe in people with other conditions.

'Though most cases are mild, yet those with comorbidities like kidney problems, diabetes, heart diseases, lung diseases may have complications in the form of pneumonia, lung failure, etc,' Ray said.

According to a survey of over 11,000 households by social community platform LocalCircles, 69 per cent reported at least one member displaying symptoms such as fever, cough, sore throat, and respiratory distress.

'The cases are rising because of changing weather conditions and lack of vaccination,' Dr. Atul Gogia, senior consultant medicine at the leading city-based hospital, told IANS.

'The symptoms are similar to seasonal flu in the form of cough, cold, running nose, and can involve the lungs, leading to pneumonia,' he added.

In children, the symptoms may include nausea, vomiting, or diarrhoea. Many patients have also reported fever lasting over 5-7 days, with cough persisting even after other signs subside.

The experts advised proper hand washing, the use of masks, and vaccination to prevent H3N2. They also suggested getting annual vaccinations, avoiding close contact with sick people, and isolating those who are ill.

/IANS