Case count and toll

The state health department said on Monday that 1,004 measles cases had been confirmed, a total that state health officials calculate makes this the largest state outbreak in more than three decades. Five residents have died after contracting measles, and 198 have been hospitalized.

• •Officials have said the outbreak began in April west of Philadelphia and have attributed it to low vaccination rates.
• •Infections have climbed over the past three months, with the highest number in the 24-49 age range.
• •Lancaster county, which has sizeable Amish and Mennonite populations, remains the hardest hit, with 391 cases according to official figures.

A dispute keeps the state out of the CDC count

Pennsylvania's figures are not included in a CDC count because of an ongoing dispute between Governor Josh Shapiro and US health secretary Robert F Kennedy Jr over how to classify measles-related mortality. Shapiro has called Kennedy "incompetent", while Kennedy has publicly questioned whether the state's recorded fatalities were directly caused by measles. The CDC, which Kennedy oversees, currently lists two measles deaths in the US this year.

Vaccine access expanded

Governor Shapiro has expanded access to the measles, mumps and rubella (MMR) vaccine in affected communities. In an August statement, he said that measles does not care about a person's county, faith or social circle, and he urged everyone to take the disease seriously and to discuss any concerns with a trusted health care provider.

Outbreaks beyond Pennsylvania

• •In New York, Governor Kathy Hochul declared a state of emergency on Monday, citing 108 cases in the state as of 3 October.
• •Ohio, which shares a border with Pennsylvania and also has a significant Amish population, has reported more than 200 cases this year.
• •Outbreaks have also been reported in Texas, Utah and South Carolina; South Carolina's is the largest, with 997 cases.

Nationally, the CDC reported 3,887 confirmed measles cases as of 1 October, along with the highest number of measles-associated deaths in decades - the worst US year for the disease since 1991. According to the Associated Press, the most recent outbreak to surpass 1,000 cases struck New York City in the early 1990s and infected more than 4,500 people. Domestic spread of measles was eliminated in 2000 by high vaccination rates, but those rates have since fallen below the 95% coverage needed to prevent outbreaks.

In November, international health officials will meet to determine whether the US and Mexico have lost their measles-free status.