Influenza Strain H3N2 Mutates Over Time, Spreads Through Droplets: Ex-AIIMS Director Randeep Guleria

Dr Randeep Guleria said that every year, during this time of the year (early summer), there is an increase in cases of infection caused by H3N2, which is a subtype of Influenza A virus.

Dr Randeep Guleria said influenza spreads in the same way as SARS-CoV-2: through droplets or aerosols. The doctor stated that only those with comorbidities need to be careful. ( Image Source :Twitter/@ANI )

There is currently an increase in influenza cases with symptoms such as fever, sore throat, body aches, cough and runny nose, said Dr Randeep Guleria, Chairman, Institute of Internal Medicine & Respiratory & Sleep Medicine, and Director, Medical Education, Medanta, Gurgaon, news agency ANI reported. 

Guleria is a former director of the All India Institute of Medical Sciences, New Delhi.

He also said that every year, during this time of the year (early summer), there is an increase in cases of infection caused by H3N2, which is a subtype of Influenza A virus. H3N2 is a virus which mutates over time, through a process called antigenic drift.

According to the United States National Institutes of Health (NIH), antigenic drift is the accumulation of mutations in viral proteins selected by the immune system of host organisms as the virus circulates in a population, and reduces the duration of immunity conferred by infection and vaccination.

Guleria said influenza spreads in the same way as SARS-CoV-2: through droplets or aerosols. The doctor stated that only those with comorbidities need to be careful.

However, everyone should take precautions by wearing a mask, washing hands regularly, and maintaining social distancing, he said. A vaccine against influenza is available for the high-risk groups and the elderly.

On March 5, 2023, the Director General of Health Services Dr. Nutan Mundeja conducted a meeting with seniors of central hospitals and experts in medicine, where it was discussed that Covid-19 cases have decreased to a great extent, but many other viruses, including H3N2, a subtype of Influenza A virus, are still present, Dr Ajay Shukla, Director, Dr. Ram Manohar Lohia Hospital, New Delhi, said.

He also said that these infections can be serious for people with low immunity, and everyone continues using masks, it will be very helpful. 

Shukla said doctors are discussing commencement of vaccinations for different viruses. 

Dr Amrit Suri from Dr Ram Manohar Lohia Hospital said 20 to 25 per cent of the infections reported to the hospital daily are cases of viral infection. He also said that many patients are elderly. 

The doctor warned that people should follow all the steps and precautions which they took care of following the onset of the Covid-19 pandemic.

India's first death from H3N2 reported in Karnataka

On Friday, March 10, India’s first case of death due to the Influenza virus A subtype H3N2 was confirmed in Karnataka, Bengaluru, ABP News reports. The person who died due to H3N2 was an 85-year-old man from Hassan district. He suffered from a cough and fever for a few days, and then succumbed to H3N2 infection, the State Health Department Commissioner Dev confirmed to local news channels.

More than 50 cases of infection from H3N2 have been confirmed in Karnataka. In Hassan, six cases of infection have been confirmed.

Since the elderly are more prone to H3N2 infection, the health department has taken measures to monitor comorbidities and people aged above 60 years.

Dev has advised that an audit must be carried out on the first death from H3N2. He has asked people who did not take self-help treatment to consult a doctor.

Karnataka Health Minister K Sudhakar said Monday that there is no need to panic regarding H3N2 infections in the state, and that proper guidelines will soon be issued on precautions to be taken. 

Sudhakar also said an order would be issued making it compulsory for the healthcare workers of all hospitals to wear masks.

People who suffer from the symptoms of H3N2 must not take medicines without doctor’ advice. Also, they must not consume antibiotics unnecessarily, Sudhakar said. 

The minister has also advised people to avoid sun exposure from 11 am to 3 pm, drink at least two to three litres of water everyday, and consume buttermilk and fresh juices. These steps could help one recover from the infection within two to five days, according to the minister. 

According to experts from the Indian Council of Medical Research (ICMR), persistent cough, sometimes accompanied by fever, being reported across the country for the past two to three months, is due to H3N2.

H3N2 causes more hospitalisations than other subtypes, according to the experts.