How to differentiate between H3N2 virus and H1N1 (swine flu) infection

H3N2 is a strain of seasonal flu—it has been the dominant strain in this year's influenza season. This strain of flu is being considered highly infectious and has been causing long term sickness in people. The long existing cough and fever has left people with questions of safety.

The signs and symptoms of severe disease caused by H3N2 influenza can vary from person to person. The symptoms include high fever, severe headache, body pain, sore throat, severe and persistent cough , cold and congestion in the lungs. Other symptoms include body aches, nausea, vomiting, or diarrhea.
Dr. Vinay Bhatia, Head -Molecular Biology, National Reference Lab, Oncquest Laboratories Limited, Gurugram, says, “The illness is said to cause fever that lasts for 3-5 days and a prolonged cough and cold for up to three weeks. If one is finding it difficult to breathe, have low blood pressure, high rate of breathing, bluish lips, seizures, confusion, one must be taken to hospital immediately. An uptick in ICU admissions was seen mostly in those who have comorbidities and those older than 65 years of age.”

Children below five years of age, people who are 65 years and older, pregnant people, and people with certain long-term health conditions like asthma, diabetes, heart disease, weakened immune systems, and neurological or neurodevelopmental conditions are at a higher risk of developing complications due to the virus, as per CDC.

Also Read: H3N2 virus influenza: When does the flu get serious? THESE severe signs and symptoms could be a warning​

According to Dr. Bhatia, “Influenza A H3N2 infection is more severe than A H1N1 or B in terms of fever, leukopenia, and C-reactive protein. Myalgia and other symptoms such as fever, headache, general malaise and sore throat were equally frequent in influenza A H3N2, A H1N1, and B infections.”

H3N2 and H1N1 viruses can be diagnosed through laboratory testing. "The sample for laboratory testing of H3N2 and H1N1 viruses is similar to the sample collected for COVID-19 testing that is the nasal swab and pharyngeal swab. The method of testing for H3N2 and H1N1 viruses is also similar to COVID-19 testing, that is RT PCR test.

Health experts in India are calling for people to wear masks, practice careful hand hygiene, and get a flu shot if they haven’t already. The H3N2 strain “tends to be particularly hard on vulnerable populations.
“There is no need to panic and it’s also a good idea to keep following common sense flu prevention guidelines, like practicing good hand hygiene (knowing how to wash your hands) and doing your best to stay away from people who are coughing and sneezing,” advises Dr. Bhatia.