Four countries lose measles-free status amid concern over outbreaks in Ireland
Four countries in Europe have lost their measles-free status including the UK, Albania, the Czech Republic and Greece.
Endemic outbreaks of the disease mean it is the first time there have been four elimination reversals since the grading began in 2012.
Countries with very high measles vaccination coverage remain at risk of losing their elimination status, said the World Health Organisation (WHO).
This is because of small pockets or communities with coverage levels insufficient to prevent an outbreak.
Measles outbreaks can be caused by and affect not only young children but also adolescents, teens and adults with either insufficient or incomplete vaccination.
Ireland continues to have its measles-free status.
But a number of measles outbreaks in Ireland have been identified this year.
However, they were mostly linked to cases imported by people who were abroad spreading the infection rather than cases originating here.
Health authorities here are under pressure to prove to the World Health Organisation that transmission was curtailed.
There were 33 confirmed cases of measles in Ireland in 2019 up to mid August.
"We are backsliding, we are on the wrong track," said Kate O'Brien of the WHO's Immunisation Department.
Measles is a highly contagious and potentially fatal illness that causes coughing, rashes and fever.
It can be prevented through two doses of the MMR vaccine.
Coverage in Ireland is around 92pc but there are pockets of the country where it is lower.
Countries are declared measles-free when there is no endemic transmission for 12 months in a specific geographic area.
Ms O'Brien said all four European nations that have lost their eradication status have "extremely high" vaccination coverage.
"This is the alarm bell that is ringing around the world: being able to achieve high national coverage is not enough, it has to be achieved in every community, and every family for every child," she said.
All regions of the world showed an increase in measles last year bar the Americas, which saw a minor decline - although the US registered its highest number of cases in 25 years.
Close to 365,000 cases have been reported worldwide this year, the WHO said, almost three times as many as in the first half of 2018.