HOUSTON — An autopsy has found that a 7-year-old girl from Guatemala died of a bacterial infection while detained by the U.S. Border Patrol, in a case that drew worldwide attention to the plight of migrant families detained at the southern U.S. border.

The El Paso County Medical Examiner’s office released a report Friday of its findings in the death of 7-year-old Jakelin Caal Maquin. Jakelin died Dec. 8, just over a day after she was apprehended by Border Patrol agents with her father.

The report says traces of streptococcus bacteria were found in Jakelin’s lungs, adrenal gland, liver, and spleen. The autopsy says she faced a “rapidly progressive infection” that led to the failure of multiple organs.

The medical examiner did not determine which form of streptococcus bacteria Jakelin contracted.

Jakelin was one of two children to die in Border Patrol custody in December, raising questions about the agency’s medical practices as it faces a surge in migrant families crossing the southern border.

U.S. Customs and Border Protection said shortly after Jakelin’s death that she was apprehended with her father, Nery Gilberto Caal Cuz, in a group of 163 migrants on Dec. 6 in New Mexico. The father signed an English-language form stating Jakelin was in good health, but it remains unclear whether he understood what the form said.

Hours later, a bus carrying the two left the Antelope Wells port of entry for the Lordsburg station, roughly 90 minutes away. By then, according to a Customs and Border Protection statement, Jakelin’s temperature had reached 105.7 degrees Fahrenheit (40.9 degrees Celsius). Emergency medical technicians had to revive her.

She was flown to a hospital in El Paso, Texas, where she died the next day.

CBP says large groups of migrants are increasingly heading to remote areas of the border such as rural New Mexico, overwhelming its capacity to deal with them. The Border Patrol recently started releasing families immediately instead of referring them to processing, a step the agency said was necessary to relieve overcrowding in its facilities.

Advocates have long warned that immigration facilities are ill-suited to detain families. After Jakelin’s death, the U.N. special rapporteur on the human rights of migrants urged the U.S. not to detain migrants and called for “a thorough investigation” of her death.