In response to reports on the surge in respiratory infections in children in China and the general alert on monitoring trends in influenza-like illnesses (ILI) and severe acute respiratory infections (SARI) by the Union Health Ministry, the Health department has directed all district medical officers to keep a tab on ILI/SARI cases in hospitals and to renew the alert against H1N1 fever across districts.
The November-December period is the usual season when flu and respiratory illnesses, such as H1N1, shows a spike in Kerala, especially among children, and hence the general alert against H1N1 has been renewed, the Director of Health Services said here.
The spike in respiratory illnesses and clusters of pneumonia reported among children in northern China since mid-October has set the alarm bells ringing in the rest of the world, even though China has clarified that the surge in respiratory infections is due to flu and other known pathogens.
Catch-up phenomenon
Experts have linked the surge in respiratory infections in China to the ‘catch-up” phenomenon or the concept of “immunity debt” in children.
After three years of stringent pandemic restrictions due to its ‘zero Covid policy”, it was only late last year – much later than rest of the world – that China suddenly lifted all restrictions. So the cohort of children who were not exposed to any of the seasonal viruses these last three years and are “immune-naive” are now falling ill due to the seasonal pathogens currently in circulation.
“Some experts have questioned the concept of “immunity debt”. However, what China is going through now is something all nations experienced at different points of time since last year, when schools reopened after Covid. In November 2021, when Kerala withdrew all mandatory non-pharmacological interventions (NPI), we also experienced this surge in seasonal infections in children. From January 2022, we have had a spate of infections in children – hand, foot and mouth disease, influenza and respiratory synctical virus (RSV), adenoviruses and also the more serious influenza-associated encephalitis in children. So the theory that China is going through the catch-up phenomenon is very much plausible,” points out R. Aravind, Head of Infectious Diseases, Govt Medical College hospital, Thiruvananthapuram.
Seasonal surge
In October last year, the State had issued an alert on the rise in respiratory infections in children because of “immunity debt”. It also had to formulate guidelines to manage influenza-associated encephalitis in children, which had claimed a few lives too.
Health officials said that H1N1 cases were being reported in the State throughout the year and with the beginning of the cooler weather and intermittent rains, seasonal surge in influenza cases should be expected.
There is no situation that warrants any concern at present, though districts have been put on alert on the China situation, they said.
