Polio largely vanished thanks to vaccines. So why is it now back in more countries?
Infections, wastewater samples in U.K., U.S., Israel point to challenges in wiping virus out globally
Polio, a potentially disabling virus that's long been forgotten in many parts of the world, is now circulating in parts of the U.S. and U.K., on the heels of an outbreak in Israel — prompting health officials to launch vaccination campaigns to ensure the public is protected.
Even in Canada, a country free of polio for the last two decades, medical experts say it's a wake-up call that the virus still poses a threat to anyone who remains unvaccinated, given polio's ability to spread through global travel networks and wastewater systems.
On Wednesday, British health authorities announced they will offer a polio booster dose to children aged one to nine in London, after finding evidence the virus has been spreading in multiple regions of the capital. Britain's Health Security Agency said polio virus samples were found in sewage water from eight boroughs of London, but there were no confirmed infections.
Still, the agency's analysis showed transmission has likely "gone beyond a close network of a few individuals."
"We know the areas in London where the poliovirus is being transmitted have some of the lowest vaccination rates," said Dr. Vanessa Saliba, a consultant epidemiologist at the U.K. Health Security Agency. |
