The H3N2, which has been in wide circulation for the past two-three months, causes more hospitalisations than other subtypes. In a Kanpur hospital, one out of four patients reported fever, cough and shortness of breath.
By Milan Sharma: There has been a rise in virus infections in the last three months in India. It takes more than two weeks for people to recover from high fever. Weakness and fatigue remain. So what's causing these Covid-like infections? We decode.
A persistent cough, sometimes accompanied by fever, runny through India for the past few months is due to Influenza A subtype H3N2.
We reached Hallet Hospital in Kanpur to take stock of the infection spread in the area. At least 50 out of 200 patients currently admitted to the hospital have complained of high fever, persistent cough and shortness of breath. The change in weather has intensified the spread of the infection.
Once the emergency department is full, patients are shifted to different wards. A patient's relative we met at one of the wards said the patient has been experiencing fever for the last 5-6 days and is having difficulty breathing. The patient was admitted to the Kanpur hospital after he complained of shortness of breath.
Another patient we met had a persistent cough and the doctor prescribed many tests.
Richa Giri, head of the medical department at Hallet Hospital, said in the last 24 hours, 23-24 patients were given oxygen support and some needed ventilator support.
Viral infections are common at this time of the year. But a surge in the number of cases is not. So what changed?
According to Dr Giri, it is difficult to differentiate this virus from Covid. Since it is a subtype of influenza A, it is difficult to conduct tests as one requires a separate kit for every subtype.
Dr Peeyush Ranjan, Prof, department of medicine at AIIMS, New Delhi told India Today that H3N2 is a viral infection, similar to Covid. The symptoms are high fever, persistent cough, runny nose, and chest congestion which leads to pneumonia in severe cases.
“We used to hear about the influenza swine flu virus or H1N1. There are two antigenic forms, H antigen and N antigen. Just like H1, H3 is also a variant and, just like N1, N2 is another variant. It spreads through droplets and is a respiratory infection. We need to take Covid precautions, and maintain hygiene," he said.
DIFFERENCE BETWEEN H3N2 and COVID
Dr Peeyush Ranjan pointed out that Covid affects the lower respiratory tract, leading to pneumonia, and H3N2 affects the upper respiratory tract, causing symptoms like fever, cough and cold.
He said, "Another major difference is, unlike regular flu, this [H3N2] is spreading fast."
We found out that some private hospitals have begun tests to identify H3N2 cases, but doctors said these tests are unnecessary and expensive. Private hospitals may charge as much as Rs 6,000 for an H3N2 test.
“In my opinion, tests for H3N2 are only for very severe and unexpected cases, or if a patient is not getting cured. The line of treatment doesn’t change irrespective of the test being done," Dr Anant Mohan of the department of Pulmonology at AIIMS New Delhi told India Today.
“Persistent dry cough is more this time. Maybe this could be one of the features of this infection. Most recover without any active or specific therapy. Most people with this influenza don’t need a chest x-ray,” he added.
Not just in Kanpur, Uttar Pradesh, Delhi is also witnessing a surge in H3N2 cases. The capital has reported a 20% surge in infections compared to UP's 30%.
Dr Dhiren Gupta, a paediatrician at Sir Gangaram Hospital in Delhi, said, “A DNA virus, especially an adenovirus, has 60 subtypes. Sub-type 14 is more serious than others. It can cause severe pneumonia in an immunocompetent host."
"Our centre is facing a crisis in the ICU. We don’t have a definite treatment for adenovirus. So, we are speculating why this is happening. Most likely due to Covid and the fact that our immunity against many of these viruses went down. There is not only a rise in viral infection, but the severity has also gone up,” he added.
He further said, "In the last year, we were expecting that influenza-like illnesses would reduce after Covid pandemic, but the opposite has happened. Viruses like meta-virus, rhinovirus, adenovirus, and influenza viruses have increased. The other unusual thing is that it affects the upper respiratory tract, like the throat, nose and eyes, and symptoms also persist for a long time. The adenovirus and the number of cases infected by this virus is generally less than 5%, which has increased now. Not just immunocompromised patients but those who have some sort of robust immunity have also been affected by this virus."
The severity of this virus has increased as compared to the past few years, Dr Gupta added, and the reasons are still being explored.
"Maybe we have not been exposed to any other virus apart from Covid19, hence our immunity to these viruses went down. Innate immunity has also fallen. Like was seen in Rubella and measles. This is one of the reasons why viruses that remained subdued in the past and were not too severe when infected, their level of severity has also increased," he stated.
(With inputs from Simar Chawla)