The one thing that comes to note on this story is the assumption that these young women were "otherwise healthy". This does not take in account that the stresses that healthcare workers experience taking care of a large population of sick people. Both women probably did not eat well because they simply wouldn't stop taking care of patients to take a break. They likely didn't get to sleep for a full night but rather only took naps when their bodies wouldn't let them go on anymore. And even knowing how important self-protective devices such as masks, gloves, and isolation gowns are, if the patient started to vomit suddenly or suddenly couldn't breathe...they likely risked their safety to provide emergent care instead of standing at the door saying "I'll get to you in a minute" watching their patient suffer. This means they were exposed, tired, and not well nourished and highly stressed with no down time.
This is a recipe that makes for immune deficiency in an otherwise medically healthy person. I know I see this kind of situation on a regular basis in American hospitals. Most nurse never get to take all their breaks. Most nurses have a lot of days where they don't even get to eat on a 12 hour shift. We are required to break and eat by law but we are not going to eat if we have a patient that is unstable or just too many patients assigned to us and we need the time to provide care. Nurses often go for hours not going to the bathroom...simply because they don't have time to stop...this is not healthy for the kidneys and can lead to bladder infections. Many nurses I know deal with gastric ulcers from the stress of their jobs. The list goes on. Young doctors often have worse expectations on them and more patients they are trying to care for. I suspect that the reason this young doctor died was because she was so run down from providing care that her body simply ran out of the energy it needed to heal.
I feel for her husband. I know exactly how he feels.