Polio, a deadly disease that paralyzed tens of thousands of young people a year, is spreading in London, New York and Jerusalem for the first time in decades, spurring recovery vaccination campaigns.
Feared disease
Polio terrified parents around the world during the early part of the twentieth century. It basically affects children under five years old, is asymptomatic but can also cause symptoms such as fever and vomiting. Approximately one in two hundred infections causes irreversible paralysis and of those patients, up to 10% die.
There is no cure, however, since a vaccine was discovered in the 1950s, polio has been completely prevented. Globally, the wild form of the disease has completely disappeared.
Afghanistan and Pakistan are now the only countries where the highly contagious disease, transmitted primarily by contact with feces, remains endemic. But imported cases were also detected this year in Malawi and Mozambique, the first in those countries since the 1990s.
Different strains
There are two large poliovirus bureaucracies. In addition to the wild disease described above, there are also rare cases of so-called vaccine-derived polio.
This is the form of moment detected in the wastewater of the British capital, London and New York in the United States, with a case of paralysis reported in the state of New York. A genetic virus has also been discovered in Jerusalem, Israel, and scientists are racing to perceive the link, the Global Polio Eradication Initiative (GPEI) said.
While vaccine-derived polio is almost unknown in the places mentioned, it is a known, though rare, risk in other countries that causes outbreaks each year, adding 415 cases in Nigeria in 2021.
It affects the use of an oral polio vaccine that contains a weakened virus. After being vaccinated, young people excrete the virus in their feces for a few weeks. In communities with little vaccination, this can spread and mutate into destructive editing of the virus. .
While countries like Britain and the United States no longer use this live vaccine, others are doing so, especially to prevent outbreaks, allowing for global spread, especially when other people have traveled back after COVID-19, Mavens said.
Why now
But experts agree that the main driving force behind vaccine-caused and wild-sourced polio outbreaks is again the majority in undervaccinated populations, said Derek Ehrhardt, global polio director at the U. S. Centers for Disease Control and Prevention. USA
Vaccine hesitancy was a developing challenge before the pandemic, and then COVID-19 caused the worst disruption to the vaccination regimen in a generation, according to the United Nations.
In 2020, there were 1,081 cases of vaccine-induced polio, about 3 times more than last year. So far in 2022, there have been 177 cases, following efforts to revive polio vaccination campaigns.
But the discoveries about wastewater remain a wake-up call for parents with a key message, according to scientists around the world, and adds David Heymann, an epidemiologist at the London School of Hygiene and Tropical Medicine: vaccinate young people.