Swine flu (H1N1) cases are projected to cross 10,000 this week, with 2,666 new cases in just one week ending February 10, taking India’s H1N1 count to 9,367 in the first 40 days of 2019. There have been 312 deaths.

While this year has registered a sharp spike in cases in February as compared to all of 2018, when there were 14,992 recorded cases and 1,103 deaths, the virus has not turned any more deadly than it was last year.

Yet, so huge is the panic that isolation and fever wards in all Delhi hospitals, both public and private, are overflowing, with everyone testing positive for H1N1 insisting on being admitted and treated.

Isolation wards and treating everyone with H1N1 with anti-virals like Tamiflu are not needed, say leading pulmonary medicine experts and virologists who recommend India must shift from a pandemic response to a programme approach to contain annual seasonal flu infections that hit 5-10% of the adult population each year.

The H1N1 virus has transitioned from a pandemic strain to a seasonal flu strain that poses no additional risk of complications and death than the other three circulating flu viruses. “We don’t need isolation wards, everyone with H1N1 doesn’t need to be tested and treated. It is no longer a novel pandemic virus that people had no immunity against in 2009-10. Most of us by now have been infected with H1N1, developed mild fever and recovered without being tested or treated,” said Dr Randeep Guleria, director, All India Institute of Medical Sciences.

“I just had a patient with H1N1 insisting on getting admitted to hospital, even after I told he didn’t need treatment and should just go home,” he said.

“What we need is infection control measures used to contain any other infections, such as tuberculosis,” said Dr Guleria, who is a professor of pulmonology at AIIMS and a member of the World Health Organization’s.

(WHO) Scientific Advisory Group of Experts on influenza vaccination for emerging markets.

“Instead of focusing on testing and treating one seasonal viral strain, India now needs to focus on classifying the severity of illness, as the treatment for severe illness from all four viruses infections remains the same – vaccinating people within 48 hours of infection, using anti-virals and giving ICU and ECMO support, when needed,” Dr Guleria added.

ECMO, or extracorporeal membrane oxygenation, provides heart-lung bypass support by pumping oxygenated blood into the body to people undergoing bypass surgery or for those in acute respiratory distress.

According to WHO, 98.3% flu infections are caused by influenza A, of which H1N1 accounts for 77.7% infections, and H3N2 for 22.3%. In India, people with flu are tested only for H1N1, with H3N2 testing done for only research purposes.

“H1N1 is no more deadly than the other three influenza viruses — H3N2, B Victoria lineage, and B Yamagata lineage — causing seasonal flu in 2019; it’s just more feared because it’s the only flu virus people hospitalised with flu-related complications are tested for,” said Dr Anil K Prasad, former professor of virology at Patel Chest Institute and chairman of the Influenza Foundation of India.

With dominant strains changing almost every year, WHO tracks global flu outbreaks and recommends a new vaccine each year against the most dominant strains. For 2018-19, WHO has recommended the quadrivalent vaccine, which protects against A/Michigan H1N1, A/Singapore H3N2; B/Colorado (B/Victoria lineage), and B/Phuket (B/Yamagata lineage).

While several developed countries recommend everyone get vaccinated against the dominant flu strains, Dr Guleria recommends prioritising vaccination to protect people most at risk. These include pregnant women, where vaccination protects the mother, the foetus and the newborn up to six months after birth; people with who are immune-compromised because of chronic medical conditions such as respiratory diseases, heart disease, diabetes, cancer, renal failure, liver cirrhosis and neurological conditions; and health professionals in transplantation and oncology wards.

“All health workers must get vaccinated as they risk infecting immuno-compromised patients. I ensure everyone in my department gets vaccinated every year, I got my flu shot while I was treating patients in OPD,” said Dr Guleria, who is a professor of pulmonology at AIIMS and a member of the World Health Organization’s Scientific Advisory Group of Experts on immunization and influenza vaccination for emerging markets.

Seasonal flu outbreaks have two peaks in India, once post winter from January to March, and the second from July to September.

“Most people have no complications, but the ones at risk must be protected with vaccination,” said Dr Prasad, who advocated a single vaccine for the world, instead of two different ones approved by the WHO for the northern and southern hemisphere.

“With growing population, rapid urbanisation and mass transport, viruses travel across hemispheres within a few hours. Infection is no longer seasonal and people are at risk 365 days a year. I recommend annual flu vaccination for people at risk all through the year,” said Dr Prasad.

First Published: Feb 16, 2019 07:33 IST