NEW DELHI: India has been witnessing an uptick in H3N2 influenza cases. Seasonal influenza is a respiratory tract infection caused by four distinct types of viruses (A, B, C, and D) belonging to the Orthomyxoviridae family.
H3N2 has been the dominant subtype followed by H1N1. According to doctors, there is also a spike in ICU admissions of the elderly and kids due to H3N2 influenza.
As the symptoms of this viral infection are similar to COVID-19, the doctors have advised to extreme precautions and masking up to prevent the spread of the virus.
Other than H3N2, the country is also witnessing a surge in COVID-19 and swine flu infections. According to the real-time surveillance data by the integrated disease surveillance programme (IDSP), 955 cases of H1N1 also known as swine flu have been reported by states till 28 February.
Genome sequencing data has revealed that Influenza A H3N2 and influenza B Victoria are two viral strains driving the current surge of flu cases in the country.
In the nine weeks between January 2 to March 5, laboratories connected to the surveillance network of the Indian Council of Medical Research (ICMR) found 451 positive results for influenza A H3N2, 91 positive results for influenza B Victoria and 41 for influenza A H1N1, a government statement said.
The Indian Council of Medical Research (ICMR) has issued an advisory asking people to avoid self-medication and the use of antibiotics in case of contracting the virus.
According to the US Centre for Disease Control and Prevention (CDC), the virus (H3n2) is typically found in pigs and is a non-human influenza virus that has now infected humans. Symptoms include fever for 3 to 5 days, persistent cough, chills, breathlessness, wheezing, runny nose, nausea, sore throat, body ache, and diarrhea in some cases.
According to doctors and health experts, the virus spreads through coughing, sneezing, and close contact with an infected person and is highly contagious.
New variant could be behind fresh spike
A fast spreading XBB.1 descendent – XBB.1.16 – could be behind the recent surge in Covid cases in India, international and Indian scientists tracking the SARS-CoV2 variants told TOI on Tuesday, reports Times of India.
According to an international platform tracking Covid variants, the highest number of this sublineage’s sequences have come from India (48), followed by Brunei (22), the United States (15) and Singapore (14).
According to reports, this subvariant is showing a big jump in prevalence in at least four countries, including India. Experts tracking the Covid variants around the world have found the XBB.1.16 spreading rapidly in some regions.
“In India, XBB.1.16 is showing a high prevalence in the states of Maharashtra and Gujarat, as per covSPECTRUM. XBB.1.16 has not descended from XBB.1.5, but both have descended from the recombinant ancestor XBB and more recently XBB.1. XBB is currently dominating in India, and the latest uptick in cases in the country could be a result of XBB.1.16 and perhaps XBB.1.5, but a few more sample runs would clear the picture,” a top expert from India’s genome sequencing network said.
“Most strains isolated from Indian travellers to Singapore, the US and Brunei recently have been XBB.1.16. So, this subvariant could be driving the ongoing spike in cases in India.
It is also possible that XBB.1.16 may have originated in India,” the expert said, adding that XBB.1.16 could eventually dominate all other SARS-CoV-2 circulating variants.
According to covSPECTRUM, a platform that accesses GISAID data and helps scientists identify variants of SARS-CoV-2, India currently has 48 sequenced samples of this sublineage. According to it, as many as 39 sequenced samples of the sublineage are from Maharashtra, eight are from Gujarat and one from UP.
Dr Vipin M Vashishtha, the member of WHO’s Vaccine Safety Net who has been tracking new Covid variants during the pandemic, told TOI, “The previous XBB.1 descendant, XBB.1.5, had become dominant across the globe but not in India. But there is some worry about XBB.1.16 globally because it has certain mutations in the non-spike region of the virus: two ORF9b mutations. ORF9b has been implicated in efficient immune evasion.”
Infectious diseases expert Dr Sanjay Pujari, a member of India’s national Covid-19 task force, said, “Not much information is yet available on XBB.1.16’s relative immune escape properties and ability to cause severe illness as compared to other Omicron sub-lineages.”