The number of detainees with COVID-19 at Port Isabel Detention Center rose to 8 as of Monday - the new total doubled the figure reported from the previous week.

The cases are tracked by the U.S. Immigration and Customs Enforcement website. On Monday, the total for Port Isabel Detention Center was seven active cases with eight who were positive overall since testing began in February. 

Last week, the detention center in Los Fresnos had three active cases and four people who had tested positive overall. 

Advocates for immigration detainees have worried about the effect this could have on detainees with compromised immune systems. 

There are a total of 838 detainees who have tested positive for the virus, as of Sunday. The total number "excludes detainees who previously tested positive for COVID-19 and were either returned to the general population after a discontinuation of medical monitoring/isolation or are no longer in ICE custody," as per the agency's website. 

ICE has tested a total of 5,096 detainees in custody throughout the country so far.