As peak travel season kicks into high gear, a troubling virus outbreak is casting a shadow over some of Europe’s most popular summer destinations. Health officials from the European Centre for Disease Prevention and Control are sounding the alarm after more than 2,000 people were sickened and nine died in a recent outbreak of hepatitis A — a highly contagious virus that’s spreading through Central Europe, with cases now reported in Slovakia, Hungary, the Czech Republic, and Austria.

While hepatitis A doesn’t typically make headlines, this surge has doctors and travel authorities urging vigilance. In the Czech Republic alone, six people have died — including multiple children. Slovakia is reporting nearly 900 confirmed cases, and Hungary has seen over 500. Even neighboring Germany has documented a few connected cases, suggesting the outbreak may be spreading beyond its initial clusters.