The Department of Homeland Security's (DHS) Office of the Inspector General has released a new report that documents Customs and Border Protection (CBP) being overwhelmed by the influx of migrants at the country's southern border last year.

The DHS watchdog found that more than 850,000 migrants were stopped at the U.S.-Mexico border in 2019, which led to myriad problems at nearly all of the 14 Border Patrol stations the office inspected along the border.

Inspections took place between April and June 2019, during which CBP set a record for the number of migrants apprehended. In May 2019 alone, CBP processed more than 132,000 migrants, the most in a single month since 2005.

Record numbers led to a serious overcrowding problem at Border Patrol facilities, which only led to more serious health issues, the report said.

"Although Border Patrol established temporary holding facilities to alleviate overcrowding, it struggled to limit detention to the 72 hours generally permitted, as options for transferring detainees out of CBP custody to long-term facilities were limited," the DHS inspector general's office said, USA Today first reported.

It added: "Also, even after deploying medical professionals to more efficiently provide access to medical care, overcrowding made it difficult for the Border Patrol to manage contagious illnesses" such as the flu or gastrointestinal viruses.

Under federal law, CBP can only hold migrants for 72 hours before transferring them to ICE or the Department of Health and Human Services. However, inspections found that almost 40 percent of migrants "had been held longer than 72 hours."

Ten of the 14 sites inspected had medical teams on-site, while the other stations were staffed with agents that had paramedic training to screen migrants for illnesses or health conditions, the report said.

However, the report noted that the overcrowding at the sites made it difficult for medical teams to do their jobs effectively.

"On-site medical staff we interviewed said they were overwhelmed and the crowded conditions at the facilities were not conducive to treating contagious illnesses," the report said. "For instance, Border Patrol’s short term detention infrastructure generally did not provide sufficient space for quarantining or specialized ventilation systems."

The report also points out that CBP struggled to provide adequate care for migrant children, often not "offering children access to telephones, giving children hot meals and a change of clothing, providing access to showers, and safeguarding detainee property."