‘Sars-Cov-2, influenza B Victoria behind surge in respiratory illnesses’

The current surge of respiratory illnesses in the country is being caused by the two viral strains of Sars-Cov-2 and influenza B Victoria , genome sequencing data has revealed.

“While in the beginning of the year, influenza A H3N2 was the viral strain largely driving the surge of flu cases, currently people admitted in hospitals for severe flu-like symptoms report positive for Sars-Cov-2 and Influenza B Victoria,” a government official said, requesting anonymity.

These results were found from whole genome sequencing of severe acute respiratory infections (SARI) and influenza like illness (ILI) samples by the Indian Council of Medical Research (ICMR) labs that HT has accessed.

Last week, 24 samples returned positive for Sars-Cov-2 that causes Covid-19, and five for influenza B Victoria, according to whole genome sequencing results from laboratories connected to the surveillance network of ICMR. At least 2,000 samples of patients suffering from SARI and ILI, and undergoing treatment in various hospitals across the country, have been sequenced so far.

Although Covid-19 and influenza cases have seen a surge, the rate of hospitalisations and deaths, which determine disease severity, has not seen an increase so far.

“The numbers have been going up, but fortunately, hospitalisations are low. And not many admitted in hospital require oxygen support,” said Dr RK Singal, senior director and head of the department of internal medicine, BLK Super Speciality Hospital. “That said, people must be careful and follow Covid-appropriate behaviour.”

As flu cases started rising, the Union government asked states to boost genome surveillance. States need to set a target of about 25 tests per week of SARI and ILI cases to check the spread of virus subtypes for effective management, the central government directed, according to people familiar with the matter who spoke on condition of anonymity.

“There are many subtypes of viral influenza and some of those strains dominate during the flu season. Typing helps in detecting the dominant strain so that measures can be taken accordingly, which includes recommending the flu shot,” a government scientist said. “While H3N2 was circulating more in until some weeks ago, currently Sars-Cov-2 has again taken over.”

Symptoms for both Covid-19 and seasonal influenza are similar, — characterized by a sudden onset of fever, cough, headache, muscle and joint pain, severe malaise, sore throat and a runny nose—which is why doctors ask people to be cautious. Fever is the most common symptom in the hospitalized cases of severe respiratory illnesses, with at least 90% experiencing it, followed by cough in 80% of the cases and breathlessness in 25% of the cases, according to government data.

“If you have symptoms, it is advisable to isolate yourself for a few days. If you must step out, then it is best to take the Covid test,” said Dr GC Khilnani, former head of the pulmonary, critical care and sleep medicine department at the All India Institute of Medical Sciences (AIIMS) and current chairperson of the PSRI Institute of Pulmonary, Critical Care and Sleep Medicine.