Mumbai News: Rising pollution, climate change to blame for attack of viruses | Mumbai News

The latest Covid-causing JN.1 subvariant hasn’t yet officially ‘arrived’ in Mumbai, but it has been detected in samples picked up from Thane, which is an insignificant 40km away for a virus that caused a pandemic almost four years back.
JN.1 is reportedly mild – though highly transmissible – and civic health officials claim most of the daily 10- to 20-odd detections are accidental findings or among persons who undergo a pre-surgery Covid test.”There is no cause for worry at the moment,” said BMC additional municipal commissioner Dr Sudhakar Shinde, emphasising on ‘BMC’s Covid preparedness”.
However, JN.1’s appearance in November-December only underlines how viruses have dominated the city’s healthscape for most of 2023. While the Covid-causing SARS-CoV-2 virus overshadowed most other viruses between 2019 and 2022, this year saw multiple outbreaks of multiple viruses responsible for measles, mumps, influenza and dengue to name a few.
Bad start to 2023
For Mumbaikars, the year began with children getting measles in higher numbers than before. The culprit of the world’s worst global outbreak of measles in 2022 was a break in measles vaccination coverage due to the Covid pandemic in 2020 and 2021, but thousands of slum children got infected and many died. “As of January 4, 2023, at least 24 children have lost their lives to the deadly outbreak, including 15 in Mumbai, four in Bhiwandi, three in Thane, and two in Vasai-Virar,” stated an article published in September in the medical journal, International Journal of Surgery: Global Health.
The city also saw a huge outbreak of influenza with H1N1, H3N2 and influenza B viruses causing cough and respiratory illnesses that lasted for 10 days to a fortnight for many of those affected. Dengue cases doubled within a year to 17,000-plus this year in Maharashtra, with Mumbai accounting for the highest chunk of 5,261 cases.
Experts have blamed rising levels of air pollution as well as climate change for the growing attack of viruses on the population.
Worse viruses or better awareness?
Senior medical consultant Dr Pratit Samdani, however, doesn’t believe the viruses have become more virulent. “It’s better awareness among people about viruses after the pandemic. Now, people rush to the doctor when they get a very high fever with respiratory problems,” he said.
Infectious diseases specialist Dr Vasant Nagvekar said the only change is in the diagnostics. “Ten years back, people accepted their doctor’s word about having a respiratory viral attack, but now we have a slew of tests that can diagnose viruses. For the first time, people are getting a diagnosis with a virus’s name,” he said.
Apart from quick and sharp detection and better awareness, there also is better surveillance. The BMC has, for one, increased reporting and surveillance centres from 22 to 880 this year.
No long-term sustainable plan
The problem exposed by the emergence of JN.1 is a slackening of the Covid watch. As cases and testing dropped significantly in the last three months, there were too few positive samples to be sent for the next step – genomic testing – that establishes the variant in circulation. The pan-India INSACOG network, which was set up in 2021 to monitor genomic variations in the Covid-causing SARS-CoV-2 virus, last posted an online update in October. Data on JN.1 has only just started trickling in: India reportedly has 63 confirmed cases, including 10 in Maharashtra.
Mumbai has not been able to run genomic tests at its own Kasturba genomic sequencing centre because the machine needs over 300 positive Covid samples per operating cycle. “But we haven’t had so many positive cases in recent times, so we couldn’t run the machine,” said civic officials. Mumbai’s samples are now being sent to the central facility at NIV, Pune.
Genomic surveillance helps identify if there is a sharp change in the virus that could lead to severe disease and deaths. “Genomic and molecular surveillance of ILI/SARI (Influenza-like illness and severe acute respiratory infections) is the cornerstone to our ability to identify emerging variants which could have public health impact,” tweeted scientist Vinod Scaria when JN.1 emerged.
While JN.1 is being seen as mild as there is no corresponding rise in deaths and hospitalisations in India, World Health Organisation’s data shows Covid killed 1,311 people between December 10 and 17 across the world. The viral infection, which has claimed almost 70 lakh lives globally since it emerged in late 2019, has seen a shocking surge in European countries and Singapore.
Can’t rule out covid surge in 2024
Scientists say Covid will not disappear. Just as H1N1, formerly called swine flu, keeps reappearing every year during weather changes, they expect Covid to remerge for a bit and subside. Dr Nagvekar said the world will have to wait and watch, but the majority scientific opinion is that Covid surges are likely every few months.
A civic hospital doctor said, “We still have Omicron in circulation since 2022, so JN.1 or any other Omicron subvariant is unlikely to cause a severe disease.”