Measles cases have reached a record high in Europe this year, with more popping up on the continent in the first six months of the year than have occurred in any 12-month period over the last decade, according to the World Health Organization.
Last year, 23,927 people were infected with measles in Europe, which at the time was considered a record high. However, so far in 2018, more than 41,000 adults and children have contracted the disease—almost double the previous year—and in half the amount of time, CNN reports.
The largest outbreak is in Ukraine, which accounts for 23,000 of the 41,000 cases. Other countries that have had more than 1,000 infected people include Italy, Greece, Georgia, Russia, Serbia and France.
The Centers for Disease Control (CDC) is currently monitoring a measles outbreak in the United States as well. That outbreak has impacted 21 states, but only 107 people have reportedly contracted the disease, the majority of which were unvaccinated.