Measles is no longer considered eliminated in the UK, Greece, the Czech Republic and Albania. (AFP)

Measles cases are skyrocketing in Europe and the disease is surging in four countries previously considered to have eliminated it, including the UK, the World Health Organization (WHO) warned Thursday, urging countries to step up vaccination efforts.

The WHO said there were 89,994 cases of measles in 48 European countries in the first six months of 2019, more than double the number in the same period in 2018 when there were 44,175 cases, and already more than the 84,462 cases reported for all of 2018. Based on 2018 data, the disease is no longer considered eliminated in the UK, Greece, the Czech Republic and Albania.