COVID-19 transmission risks in conjunction with illegal migrants in the U.S. are alarming, according to a leaked briefing document meant to be presented to President Joe Biden this Thursday, Aug.10.

“In the last 2-3 weeks, the percent positivity rates among all demographics have increased,” the document stated, which was obtained and reported by NBC News

Although the specific dates o or how many migrants were tested, as of Wednesday, Border Patrol detained more than 15,000 of the ineligible border crossers.

According to the document, more than 18% of the families leaving Border Patrol custody were infected with the coronavirus over the past two to three weeks. Among the unaccompanied children, that rate stood at 20%. 

The Immigration and Customs Enforcement (ICE) also had to remove a handful of migrants about to be deported by plane and arrange quarantine for them because they were COVID-19 positive. According to the outlet, some flights had more than a quarter of the passengers infected. 

Retaining the COVID positive migrants for quarantine also applies to those categorized as “expedited removal,” which describes when they are shortly removed from the U.S. after crossing the border. 

The file added that the Department of Homeland Security might need to increase medical staffing at border processing centers.

In a separate DHS file meant to be viewed by the White House, the NGOs and local governments struggled with the substantial number of COVID-positive illegal migrants they were taking care of.

It noted that such high infection rates were possible because the migrants were cramped in Customs and Border Protection (CBP) facilities over a lengthy period, together with the highly transmissive Delta variant in place.

NBC News said while under Border Patrol custody, not all the migrants will be tested for the lethal virus unless they exhibit symptoms. They would be scanned for the virus as they leave their custody. 

The second file said the Biden administration required the CBP to test all the migrants they detain, but the agency said it was not equipped to conduct such a large number of tests on the many illegal border crossers being held.

Deputy Border Patrol Chief Raul Ortiz said the agency was already too strained by the number of illegal border crossers to afford COVID testing, which could put them over the edge.

“As you can see, we’re already overwhelmed,” Ortiz told the outlet.

The Biden administration had recently imposed stiffer measures with deporting the illegal migrants due to the threats of the Delta variant. But such policies will not apply to unaccompanied minors.

The rates of unaccompanied child migrants at the border had skyrocketed. On August 4, 834 children were encountered in that one day by federal agents on the southern border.

According to preliminary official figures, the United States will reach the 19,000 marks for lone children taken into custody in July, breaking the previous high set in March.

With such further perils of the Delta variant, which is known to be capable of infecting younger patients, it seems harder now for the Biden administration to reconcile between more humane border policies and handling the lethal Delta variant in the U.S.

Border Patrol agents apprehended more than 200,000 migrants in July, according to NBC reports.