The Current influenza spike

• Recently, Centre reviewed the rise in cases of influenza, and states have been readying hospitals for a possible spike in infections.
• The Union Health Ministry has confirmed a death each in Haryana and Karnataka due to the H3N2 subtype of the flu virus this month.
• Data from the Integrated Disease Surveillance Programme suggest at least nine people died of the flu in January.

Why is there an increase in flu cases?

• This is the flu season. India usually sees two flu peaks every year between January and March and, post-monsoon, between August and October.
• Fewer flu infections during the pandemic has resulted in a large reservoir of people with lower immunity.
• The flu virus is prone to changing its structure. “This means that we see an increase in flu cases usually every other year,
• India’s burden of conditions like diabetes and heart disease is huge even among the young.
• The yearly flu shot is not readily available in government set-ups, and its uptake is not high.

Is it unusual for people to die of the flu?

• While it causes mild symptoms like fever, cough, and runny nose in most people, like Covid.
• It can lead to complications like pneumonia and acute respiratory distress syndrome (ARDS) that can lead to death.
• Very young children, old people, people with comorbidities such as heart disease, diabetes, and kidney disease, pregnant women, and those with a weakened immune system are at higher risk of getting severe disease.

Is H3N2 a new sub-type of influenza?

• No, H3N2 is not a new sub-type of influenza.
• It is one of the sub-types of the influenza virus that has been known to cause seasonal infections.
• In fact, H3N2 caused a flu pandemic back in 1968.
• The sub-type was detected in India in 1996 and has since caused outbreaks too.
• The only difference this year is that the disease seems to be a little more severe than what is usually seen with H3N2.

Why is the flu shot updated every year?

• The list of subtypes to be included in the yearly flu shot is updated by the World Health Organisation twice a year depending on the types in circulation.
• The ICMR network of viral laboratories test respiratory samples throughout the year from sentinel sites to keep an eye on the ups and downs in the numbers of flu cases, but more importantly to track the sub-types in circulation.
• There is a need to continuously update the vaccine because of the constantly evolving nature of influenza viruses.

Conclusion: What should be done to prevent infections?

• Influenza spreads when people inhale infected droplets released by patients when they cough or sneeze.
• These droplets can survive on surfaces, and can spread if a person touches the surface and then touches their eyes, nose, or mouth.
• Chances of transmission can be reduced by ensuring that the mouth and nose are covered when you sneeze or cough, and by washing hands frequently.
• It is best to remain at home when sick, and to drink plenty of fluids.