Wednesday April 24, 2019

Three Mutations if Occurred at Same Time Could Turn Bird Flu a Potential Pandemic: Experts

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Bird Flu
Health officers cull poultry at a wholesale market, as trade in live poultry is suspended after a spot check at a local street market revealed the presence of H7N9 bird flu virus, in Hong Kong June 7, 2016. VOA
  • The flu strain, known as H7N9 has infected at least 779 people in outbreaks in and around China
  • Mutations in three amino acids made the virus more able to bind to human cells, making the virus more dangerous to people
  • Wendy Barclay, a virologist and flu specialist, said the study’s findings were important in showing why H7N9 bird flu should be kept under intense surveillance

London, June 18, 2017: Scientists have identified three mutations that, if they occurred at the same time in nature, could turn a strain of bird flu now circulating in China into a potential pandemic virus that could spread among people.

The flu strain, known as H7N9, now mostly infects birds but it has infected at least 779 people in outbreaks in and around China, mainly related to poultry markets.

The World Health Organization said earlier this year that all bird flu viruses need constant monitoring, warning that their constantly changing nature makes them “a persistent and significant threat to public health.”

At the moment, the H7N9 virus does not have the capability to spread sustainably from person to person. But scientists are worried it could at any time mutate into a form that does.

To assess this risk, researchers led by James Paulson of the Scripps Research Institute in California looked at mutations that could potentially take place in the genome of the H7N9 virus.

They focused on the H7 hemagglutanin, a protein on the flu virus surface that allows it to latch onto host cells.

The team’s findings, published in the journal PLoS Pathogens on Thursday, showed that in laboratory tests, mutations in three amino acids made the virus more able to bind to human cells — suggesting these changes are key to making the virus more dangerous to people.

Scientists not directly involved in this study said its findings were important, but should not cause immediate alarm.

“This study will help us to monitor the risk posed by bird flu in a more informed way, and increasing our knowledge of which changes in bird flu viruses could be potentially dangerous will be very useful in surveillance,” said Fiona Culley, an expert in respiratory immunology at Imperial College London.

She noted that while “some of the individual mutations have been seen naturally, … these combinations of mutations have not,” and added: “The chances of all three occurring together is relatively low.”

Wendy Barclay, a virologist and flu specialist also at Imperial, said the study’s findings were important in showing why H7N9 bird flu should be kept under intense surveillance.

“These studies keep H7N9 virus high on the list of viruses we should be concerned about,” she said. “The more people infected, the higher the chance that the lethal combination of mutations could occur.” (VOA)

Next Story

WHO Calls for Better Vaccination Coverage Against Increasing Number of Measles Cases

The United Nations agency, citing preliminary data, said that more than 112,000 cases of the preventable but highly contagious disease have been reported across the globe

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measles
Steve Sierzega receives a measles, mumps and rubella vaccine at the Rockland County Health Department in Pomona, N.Y., March 27, 2019. VOA

The number of measles cases worldwide nearly quadrupled in the first three months of the year compared to last year, the World Health Organization reported Monday.

The United Nations agency, citing preliminary data, said that more than 112,000 cases of the preventable but highly contagious disease have been reported across the globe in the January-to-March period. WHO called for better vaccination coverage against measles, which can kill or leave a child disabled for life.

Over recent months, WHO said spikes in the disease have occurred “in countries with high overall vaccination coverage, including the United States … as well as Israel, Thailand, and Tunisia, as the disease has spread fast among clusters of unvaccinated people.”

measles
Public health authorities worry about outbreaks in communities where vaccination rates are low, fueled by a growing movement of people who view the MMR vaccine, mumps and rubella as dangerous. VOA

“While this data is provisional and not yet complete, it indicates a clear trend,” WHO said. “Many countries are in the midst of sizeable measles outbreaks, with all regions of the world experiencing sustained rises in cases.”

The agency said the reported number of cases often lags behind the number of actual cases, meaning that the number of documented cases likely does not reflect the actual severity of the measles outbreaks.

For three weeks in a row, U.S. health authorities have added dozens of new reports of measles to its yearly total, now at 555, the biggest figure in five years. Twenty of the 50 U.S. states have now reported measles cases.

measles
FILE – 15-month-old August Goepferd received mumps and rubella booster shot at a clinic at Children’s Minnesota in Minneapolis. VOA

ALSO READ: New York Takes Drastic Steps to Prevent Spread of Measles Outbreak

More than half of the U.S. total — 285 cases — have been reported in New York City. Officials in the country’s largest city last week ordered mandatory measles vaccinations to halt the outbreak that has been concentrated among ultra-Orthodox Jews in the city’s Brooklyn borough.

City health department officials blamed anti-vaccine propagandists for distributing misinformation in the community. (VOA)