MANILA — The Philippines expanded the area of a declared measles outbreak on Thursday from the highly populated capital to nearby regions, after a steady rise in infections and deaths attributed to the disease in recent weeks.

The government’s Epidemiology Bureau raised the “red flag” after an increase in infections in the capital, Manila, as well as the northern and southern ends of Luzon, the island that includes the capital.

The Department of Health said that measles had killed 55 children age 4 or younger at San Lazaro Hospital in Manila since the start of the year.

According to the Epidemiology Bureau, there were 196 cases of measles in metropolitan Manila from Jan. 1 to 19, compared with 20 in the same period last year. The region had 10 times more measles cases in 2018 than the year before.