Nigerian health authorities are struggling to contain a rapidly spreading meningitis outbreak that has so far killed 151 people across the west African nation, mostly in remote parts of the northern region with children affected the most.

While cases first recorded in October have spread to 23 of Nigeria’s 36 states, nearly half of the deaths, 74, were reported this year, the Nigeria Center for Disease Control said this week, with local partners describing the recent rise in fatalities as “alarming.”

Most deaths from the disease have been mainly due to infected people not going to health facilities or arriving there late with severe complications, NCDC spokesperson Sani Datti told The Associated Press, a common problem in past outbreaks in the country.

The current outbreak has hit Africa’s most populous country as its health sector reels from U.S. aid cuts ordered by the Trump administration in February that have affected multiple countries. Nigeria relied heavily on such aid over the years to help fight similar outbreaks and support its underfunded healthcare systems.