Editorial

The cold facts: on tracking influenza outbreak

It’s vital that India scales up surveillance to track various influenza viruses

Ever since the influenza virus known as H1N1 landed on Indian shores during the 2009 pandemic, outbreaks have been an annual occurrence. The worst was in 2015, when 2,990 people succumbed to it. This year the virus has been particularly active; mortality, at 1,873 by the last week of September, is quickly catching up with the 2015 toll. In comparison, official figures show 2016 to be a relatively benign year, with an H1N1 death toll of 265. The problem with these official figures, however, is that they only capture H1N1 numbers, a practice that has been adopted in response to the severity of the 2009 pandemic. But influenza was present in India even before 2009 in the form of H3N2 and Influenza B virus types. Out of these, H3N2 is capable of causing outbreaks as big as H1N1, and yet India does not track H3N2 cases as extensively as it does H1N1. This means that seemingly benign years such as 2016 may probably not be benign at all. Data from outside government surveillance systems are making this fact apparent. For example, a surveillance project for acute febrile illnesses, anchored at the Manipal Centre for Virus Research in Karnataka, has found that influenza accounts for nearly 20% of fevers across rural areas in 10 Indian States — fevers that are often undiagnosed and classified as “mystery fevers”. During the years when the H1N1 burden is low in these regions, H3N2 and Influenza B circulation tends to spike.

All this indicates that India’s surveillance systems are still poor and underestimate the influenza burden substantially. If numbers are unsatisfactorily tracked, so are changes in the viral genome. As a 2015 commentary by a pair of researchers from the Massachusetts Institute of Technology pointed out, India submits a woefully small number of H1N1 genetic sequences to global open-access databases for a country of its size and population. Sequencing is important because it can detect mutations in genetic material that help the virus evade human immune systems, making it more deadly. Because India does not sequence a large enough sample of viral genomes, it would be missing mutations that could explain changes in the lethality of the virus. Put together, the numbers data and sequence data will enable sensible vaccination decisions. Vaccination is the best weapon that India has against this menace, because Oseltamivir, the antiviral commonly deployed against flu, is of doubtful efficacy unless administered early enough. Yet, India has thus far stayed away from vaccinating even high-risk groups such as pregnant women and diabetics, because influenza is thought to be a more manageable public health challenge compared to mammoths such as tuberculosis. Better surveillance of influenza will possibly change this perception by revealing the true scale of this public health issue.

A letter from the Editor


Dear reader,

We have been keeping you up-to-date with information on the developments in India and the world that have a bearing on our health and wellbeing, our lives and livelihoods, during these difficult times. To enable wide dissemination of news that is in public interest, we have increased the number of articles that can be read free, and extended free trial periods. However, we have a request for those who can afford to subscribe: please do. As we fight disinformation and misinformation, and keep apace with the happenings, we need to commit greater resources to news gathering operations. We promise to deliver quality journalism that stays away from vested interest and political propaganda.

Support Quality Journalism
Related Topics
Recommended for you
This article is closed for comments.
Please Email the Editor

Printable version | May 31, 2020 7:46:20 PM | https://www.thehindu.com/opinion/editorial/the-cold-facts/article19791906.ece

Next Story