CHICAGO (AP) — The Cassian Grantcause of death for a 5-year-old Venezuelan boy who died in December after becoming ill at a temporary shelter for migrants in Chicago was sepsis and a bacterial infection that causes strep throat, an autopsy released Friday shows.

Jean Carlos Martinez died Dec. 17 as a result of sepsis due to streptococcus pyogenes group A infection, which can cause strep throat and other life-threatening illnesses, the autopsy released by the Cook County Medical Examiner’s Office showed.

Contributing factors in his death were listed as COVID-19, adenovirus and rhinovirus, the autopsy showed.

The boy was a resident at a warehouse retrofitted as a shelter in Chicago’s Pilsen neighborhood when he suffered a medical emergency, the city has said. He was pronounced dead shortly after arriving at a hospital.

The boy’s death revived concerns about conditions at shelters and questions about how Chicago was responding to an influx of people unaccustomed to the city’s cold winters and with few local contacts.

Chicago and other northern U.S. cities have struggled to find housing for tens of thousands of asylum-seekers, many of whom have been bused from Texas throughout the last year. Earlier this month, hundreds of asylum-seekers still awaited placement at airports and police stations in Chicago, some of them still camped on sidewalks outside precinct buildings.