Swine flu outbreak in India raises concern

March 11, 2015, Massachusetts Institute of Technology
H1N1 virus. Credit: C. S. Goldsmith and A. Balish, CDC

Since December, an outbreak of swine flu in India has killed more than 1,200 people, and a new MIT study suggests that the strain has acquired mutations that make it more dangerous than previously circulating strains of H1N1 influenza.

The findings, which appear in the March 11 issue of Cell Host & Microbe, contradict previous reports from Indian health officials that the strain has not changed from the version of H1N1 that emerged in 2009 and has been circulating around the world ever since.

With very little scientific data available about the new strain, the MIT researchers stress the need for better surveillance to track the outbreak and to help scientists to determine how to respond to this influenza variant.

"We're really caught between a rock and a hard place, with little information and a lot of misinformation," says Ram Sasisekharan, the Alfred H. Caspary Professor of Biological Engineering at MIT and the paper's senior author. "When you do real-time surveillance, get organized, and deposit these sequences, then you can come up with a better strategy to respond to the virus."

In the past two years, genetic sequence information of the flu-virus protein hemagglutinin from only two influenza from India has been deposited into publicly available influenza databases, making it difficult to determine exactly which strain is causing the new outbreak, and how it differs from previous strains. However, those two strains yielded enough information to warrant concern, says Sasisekharan, who is also a member of MIT's Koch Institute for Integrative Cancer Research.

He and Kannan Tharakaraman, a research scientist in MIT's Department of Biological Engineering, compared the genetic sequences of those two strains to the strain of H1N1 that emerged in 2009 and killed more than 18,000 people worldwide between 2009 and 2012.

The researchers found that the recent Indian strains carry new mutations in the hemagglutinin protein that are known to make the virus more virulent. Hemagglutinin binds to glycan receptors found on the surface of respiratory cells, and the strength of that binding determines how effectively the virus can infect those cells.

One of the new mutations is in an amino acid position called D225, which has been linked with increased disease severity. Another mutation, in the T200A position, allows hemagglutinin to bind more strongly to glycan receptors, making the virus more infectious.

"Aggressive surveillance"

Sasisekharan points out that more surveillance is needed to determine whether these are present in the strain that is causing the current , which is most prevalent in the Indian states of Gujarat and Rajasthan and has infected more than 20,000 people so far.

"The point we're trying to make is that there is a real need for aggressive surveillance to ensure that the anxiety and hysteria are brought down and people are able to focus on what they really need to worry about," Sasisekharan says. "We need to understand the pathology and the severity, rather than simply relying on anecdotal information."

Learning more about the new strains could help public health officials to determine which drugs might be effective and to design new vaccines for the next flu season, which will likely include strains that are now circulating.

"The goal is to get a clearer picture of the strains that are circulating and therefore anticipate the right kind of a vaccine strategy for 2016," Sasisekharan says.

Explore further: Study identifies influenza viruses circulating in pigs and birds that could pose a risk to humans

More information: Cell Host & Microbe, Tharakaraman, K. and Sasisekharan, R.: "Influenza Surveillance: 2014-2015 H1N1 'Swine'-Derived Influenza Viruses from India" (2015)

Related Stories

Study identifies influenza viruses circulating in pigs and birds that could pose a risk to humans

May 10, 2013
In the summer of 1968, a new strain of influenza appeared in Hong Kong. This strain, known as H3N2, spread around the globe and eventually killed an estimated 1 million people.

Studies showing how bird flu viruses could adapt to humans offer surveillance and vaccine strategies

June 6, 2013
Bird flu viruses are potentially highly lethal and pose a global threat, but relatively little is known about why certain strains spread more easily to humans than others. Two studies published today in the journal Cell identify ...

Stopping influenza evolution before it starts

December 20, 2011
If you get vaccinated against the flu and then become infected with the virus, your body mounts an immune response that prevents you from getting sick. However, that pressure from the immune system can provoke the virus to ...

Immunologist explains why the flu shot might not be as effective this year

December 15, 2014
You may have heard that this year's flu shot is less effective than normal. That's a scary prospect heading into the heart of flu season. But what exactly does that mean? Why would vaccines vary in effectiveness from year ...

Recommended for you

Ambitious global virome project could mark end of pandemic era

February 23, 2018
Rather than wait for viruses like Ebola, SARS and Zika to become outbreaks that force the world to react, a new global initiative seeks to proactively identify, prepare for and stop viral threats before they become pandemics.

Forecasting antibiotic resistance with a 'weather map' of local data

February 23, 2018
The resistance that infectious microbes have to antibiotics makes it difficult for physicians to confidently select the right drug to treat an infection. And that resistance is dynamic: It changes from year to year and varies ...

Study reveals how kidney disease happens

February 22, 2018
Monash researchers have solved a mystery, revealing how certain immune cells work together to instigate autoimmune kidney disease.

Scientists gain new insight on how antibodies interact with widespread respiratory virus

February 22, 2018
Scientists have found and characterized the activity of four antibodies produced by the human immune system that target an important protein found in respiratory syncytial virus (RSV), according to new research published ...

Past encounters with the flu shape vaccine response

February 20, 2018
New research on why the influenza vaccine was only modestly effective in recent years shows that immune history with the flu influences a person's response to the vaccine.

Building better tiny kidneys to test drugs and help people avoid dialysis

February 16, 2018
A free online kidney atlas built by USC researchers empowers stem cell scientists everywhere to generate more human-like tiny kidneys for testing new drugs and creating renal replacement therapies.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Mike_Massen
1 / 5 (2) Mar 11, 2015
Hmm, looks like a portent of something like Ebola but with many more distributed vectors amassing exponentially, which also offers the competitive chance of acquired immunity but, at the expense of many... Sad that infections progress often it seems as if people are mere marbles in the grand scheme of things and also often act as if they have no interest in their own destiny or steps along that path...

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.