ALBUQUERQUE, N.M. (AP) — An autopsy report confirmed Wednesday that an 8-year-old Guatemalan boy who died while in custody of the U.S. Border Patrol on Christmas Eve succumbed to a flu infection — one of two deaths of Central American children in December that drew attention to the plight of migrant families at the southern border.

The New Mexico Office of the Medical Examiner released its autopsy findings for Felipe Gomez Alonzo two days after Guatemalan authorities said they had received a copy of the report disclosing the boy had a rapid, progressive infection that led to organ failure.

An...