I hope you realize that many people who are getting infected with COVID-19 are "essential workers" who if they want an income CANNOT work from home and are on the front lines (e.g. supermarkets, restaurants offering takeout, other stores providing essential goods like Target and Walmart) during an entire workday and may come into contact w/many infected people. And, they may not be able to claim unemployment either since they
can work.
To top it off, many of those "Mexican migrants" aren't that well off financially to begin with so they likely haven't had access to good healthcare before COVID-19. Also, some of these folks may live in a multi-generational household and/or w/many other people (for financial reasons), so if one person gets infected, it's quite likely the rest of the household might get infected.
Hourly workers also may not be able to take a significant amount of time off to get tested for COVID-19 (some areas have hours long lines to get tested) or afford to be able to take time off if they feel sick.
There have been many stories about the disparity on how people of color have been more affected by COVID-19 like
What Do Coronavirus Racial Disparities Look Like State By State?.
I'm Asian and can work from home due to the nature of my work so my exposure to potentially infected people is limited and for very brief periods of time. I have health insurance due to my employer and my company pays us VERY well, so access to routine healthcare for me from a $ point of view is NOT a problem. Most of my company can work from home (and is, due to county mandate) and we don't have a large % of Hispanic/Latino nor black workers.