H3n2 Virus: Health Ministry monitoring cases on real-time basis, says seasonal influenza expected to decline by march end

Real-time surveillance through a countrywide network of labs

Near real-time surveillance of cases of Influenza-like Illness (ILI) and Severe Acute Respiratory Infections (SARI) presenting in OPDs and IPDs of health facilities is undertaken by Integrated Disease Surveillance Programme (IDSP), National Centre for Disease Control (NCDC).

1. According to the latest data available on IDSP-IHIP (integrated health Information Platform), a total of 3038 laboratory-confirmed cases of various subtypes of Influenza including H3N2 have been reported till 9th March 2023 by the States. This includes 1245 cases in January 1307 in February and 486 cases in March (till 9th March).

2. Further, the IDSP-IHIP data from health facilities indicate that during the month of January 2023, a total of 397,814 cases of Acute Respiratory Illness/Influenza Like Illness (ARI/ILI) were reported from the country that increased slightly to 436,523 during February, 2023. In the first 9 days of March 2023, this number stands at 133,412 cases.

3. The corresponding data for admitted cases of severe acute respiratory illness (SARI) is 7041 cases in January 2023, 6919 during February 2023 and 1866 during the first 9 days of March 2023.

In 2023 (till 28th February), a total of 955 H1N1 cases have been reported. Majority of the H1N1 cases are reported from Tamil Nadu (545), Maharashtra (170), Gujarat (74), Kerala (42) and Punjab (28).

Influenza data from ICMR network of laboratories

In India, an integrated surveillance of Influenza like Illness (ILI) and Severe Acute Respiratory Illness (SARI) for the detection of human influenza virus and SARS-COV-2 virus is ongoing through structured ILI/SARI surveillance network of 28 sites. The surveillance network is comprised of 27 DHR-ICMR’s Virus Research & Diagnostic Laboratories and country’s National Influenza Centre (WHO-NIC) housed at ICMR-National Institute of Virology Pune, also a WHO Collaborating Centre for Global Influenza Surveillance & Response System (GISRS).

During the period of the first 9 weeks (January 2nd to March 5th) of 2023, the surveillance network has monitored the human influenza virus and SARS-CoV-2 infection in SARI and ILI cases. The influenza typing results are summarized below:

It can be seen that Influenza H3N2 is the predominant sub-type among the samples testing positive for influenza, since the beginning of this year.

Public Health Measures

Guidelines on seasonal Influenza: MOHFW has provided guidelines on categorization of patients, treatment protocol, and guidelines on Ventilatory management to the States/UTs which are also available on the website of the Ministry (www.mohfw.nic.in) and NCDC (ncdc.gov.in). MOHFW has also advised the State Governments for vaccination of health care workers dealing with H1N1 cases.

ICMR has also issued an advisory regarding this.