A measles outbreak in Pennsylvania has topped 1,000 cases, with neighboring New York declaring a disaster emergency and mobilizing measures to fight the spread.[8104562][8070885] The outbreak, which began in 2023, has seen over 3,800 measles cases recorded across the country, with neighboring states reporting hundreds of cases.[8104562][8070885] Pennsylvania's health department said Monday that 1,004 cases of measles had been confirmed, with five residents dying after contracting the disease and 198 hospitalizations.[8104562][8070885] The largest state outbreak in more than three decades has prompted neighboring New York to declare a state of emergency about measles rates there.[8104562][8070885] The outbreak is a stark reminder of the ongoing threat of measles in the US, with vaccination rates falling in recent years.[8104562][8070885]