Delhi H1N1 Influenza Surge: Symptoms, Who Is at Higher Risk and How To Prevent Infection

Delhi has reported a sharp rise in H1N1 influenza cases this season, with 1,344 infections recorded compared with 229 during the same period last year. The nearly six-fold increase comes as doctors report a rise in patients with cough, cold and fever, with hospitals seeing more influenza and other respiratory infections during the post-rainy season.

Dr Satish Koul, Principal Director and Unit Head of Internal Medicine at Fortis Memorial Research Institute, Gurugram, told ANI that hospitals have witnessed an increase in patients with respiratory symptoms over the past three to four weeks. "Over the past 3-4 weeks, hospitals have witnessed a rise in patients presenting with cough, cold and high fever. Testing has revealed a significant increase in H1N1 (swine flu) cases, with doctors reporting that they are seeing around 7-10 such patients daily in the OPD. There has also been a slight increase in COVID-19 cases," he said. Chandipura Virus in Gujarat: Symptoms, Who’s Most at Risk, Treatment and Preventive Measures.

H1N1 Symptoms To Watch Out For

Doctors said most H1N1 infections are generally mild, with fever typically subsiding within three to five days. However, some patients can develop complications, particularly those belonging to vulnerable groups.

Dr Sanjeev Sinha, Professor of Medicine, Department of Medicine, AIIMS Delhi, attributed the rise in influenza cases to seasonal changes during the monsoon. "During monsoon, there's a decrease in temperature. So, because of the temperature change, the influenza virus is more common nowadays. They have a sore throat, nasal discharge, dry cough and headache," he said. Is Andhra Pradesh Seeing a New COVID-19 Wave?

According to Sinha, upper respiratory tract infections have also increased in outpatient departments, with some patients testing positive for influenza, particularly H1N1 and influenza A.

"In our OPD, there is an increased number of patients who are suffering from upper respiratory tract infections, and we found that they are positive for influenza, especially H1N1 and influenza A," Sinha said.

Common symptoms reported by doctors include:

• High-grade fever
• Sore throat
• Dry cough
• Runny nose or nasal discharge
• Headache
• Muscle and joint pain
• Extreme weakness

Dr Atul Kakar, Chairperson, Internal Medicine, Sir Ganga Ram Hospital, told ANI that Delhi is witnessing a seasonal increase in viral respiratory infections, with many patients reporting flu-like symptoms.

"Many of them have high-grade fever, which has been running for a few days. A few of them have cold and cough; many of them complain of joint pains, muscle pain, extreme weakness, runny nose and throat pain. This is a type of trend which we are now seeing, especially during this post-rainy season. So, the number of patients is definitely much more," he said.

Who Is at Higher Risk of H1N1 Complications?

While most infections are self-limiting, doctors have warned that certain groups are more vulnerable to severe illness and complications. These include elderly people, young children and individuals with underlying health conditions such as diabetes, hypertension, heart disease and chronic kidney disease.

People with chronic obstructive pulmonary disease (COPD) and those who are immunocompromised are also considered more vulnerable. Kakar said some patients with severe symptoms require hospitalisation. "Children, elderly people and immunocompromised individuals, as well as those with underlying conditions such as chronic obstructive pulmonary disease (COPD), heart disease and kidney disease, are more likely to develop severe symptoms. A few of them require hospitalisation because of the severity of symptoms. The majority of symptoms are self-limiting and last for about five to seven days," he said.

When Should You Seek Medical Help?

Doctors have advised people not to ignore persistent or severe symptoms, particularly if they belong to a high-risk group. Pneumonia-like symptoms, persistent high fever and difficulty breathing warrant prompt medical attention.

Authorities have also advised people with flu-like symptoms to monitor their health and report to the nearest health facility if symptoms worsen. Warning signs include high fever, difficulty breathing, bluish discolouration of the skin or lips and blood in sputum.

How To Prevent H1N1 Infection

Authorities have reiterated preventive measures to reduce the spread of H1N1 and other respiratory infections. People are advised to cover their mouth and nose with a handkerchief or tissue while coughing or sneezing. Regular handwashing with soap and water or the use of an alcohol-based hand gel is also recommended.

People should avoid touching their eyes, nose or mouth and stay away from crowded places where possible. Authorities have also advised maintaining more than an arm's length distance from people who are infected. Adequate rest, sleep and nutrition are also recommended.

H1N1: Dos and Don'ts

Under the preventive guidelines, people are advised to:

• Cover the mouth and nose while coughing or sneezing.
• Wash hands frequently with soap and water or use alcohol-based hand gel.
• Avoid touching the eyes, nose and mouth.
• Avoid crowded places.
• Maintain more than an arm's length distance from infected people.
• Get adequate rest, sleep and nutrition.
• Stay home and limit contact with others when symptomatic.

People are also advised against shaking hands or hugging in greeting when illness is circulating. They should avoid taking medicines without consulting a physician and avoid meeting relatives and friends while experiencing symptoms.

Dr Sinha advised people diagnosed with H1N1 to take precautions. "If you are diagnosed with it, then isolate yourself at home for two or three days, use a face mask. If you get the infection, immediately contact the doctor about the treatment."

What the Rise in Cases Means

The increase in reported H1N1 infections comes amid a broader seasonal rise in respiratory illnesses in Delhi and the National Capital Region.

Doctors say most cases remain manageable and self-limiting, but the increase highlights the importance of recognising symptoms early and taking precautions to limit transmission.

For older adults, young children, immunocompromised people and those with chronic diseases, medical attention may be particularly important if symptoms become severe or fail to improve.

(The above story first appeared on LatestLY on Aug 11, 2026 05:35 PM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).