At least 76 people, most of them children, have died and hundreds been hospitalized following an outbreak of measles in the northeastern Nigerian state of Adamawa, the World Health Organization (WHO) said Monday.

About 1,118 cases of the disease have been reported in 12 of Adamawa’s 21 municipal areas since February 28, a WHO official said, citing figures from the Nigerian Federal Ministry of Health’s epidemiological unit.

Similar outbreaks of measles, which causes half a million deaths in sub-Saharan Africa annually, have been reported in five other states of Africa’s most populous nation.