The number of reported measles cases in Pennsylvania has topped 900.

The Pennsylvania Department of Health reported in its latest update Monday that 903 measles cases have been confirmed across 39 counties.

Berks County remains at five reported cases, according to the department’s dashboard, pa.gov/measles.

The department’s update noted the following:

New positive cases since Sept. 25: 13

• Total counties: 39

• Total cumulative cases: 903

• Total hospitalizations: 176

• Total confirmed measles-associated deaths: 4

• Measles cases among vaccinated individuals: 4 (less than 1% of cases)

According to the dashboard, Lancaster County remains the leader in cases with 363.

Cases in the region: Chester County, 83; Lebanon County, 21; Montgomery County, 3; Lehigh County, 2; and Schuylkill County, 1.

State health officials said they have administered more than 5,300 measles, mumps and rubella (MMR) vaccinations at 173 pop-up vaccination clinics in affected communities since late April when the outbreak began.

Overall, state health center staff have administered more than 7,900 MMR vaccine doses this year.

In a typical month, state health care providers administer about 25,000 doses of the MMR vaccine. In August, more than 49,000 MMR vaccines were given statewide and more than 38,000 doses have been administered over the first three weeks of September, officials said.

The department continues to advise that the best protection against measles is to get fully vaccinated. The two-dose MMR vaccine boosts a person’s immune system and provides 97% lifetime protection.

Those who have two documented doses of MMR do not need another, the department said. Adults who have only one dose or cannot find their vaccination records should talk with a health care provider or pharmacist about getting vaccinated.

Measles is spread when someone who is infected breathes, coughs or sneezes. The virus remains infectious in the air and on surfaces for up to two hours after the infected person leaves the area, the department said.

Symptoms begin with fever, cough, runny nose, and red, watery eyes (conjunctivitis), followed by a rash that starts on the head and spreads downward.

Without proper protection or supportive care, measles can be deadly, officials said. Symptoms can start seven  to 21 days after exposure.

If you believe you were exposed to measles and are experiencing symptoms, you are advised to contact your health care provider or call the health department’s hotline at 877-PA-HEALTH (877-724-3258).