There was an outbreak during World War II and the germ sort of quieted down since then, but we still see small outbreaks of invasive strep/septicemia/flesh eating bacteria etc. Luckily, penicillin works: but people can die if they don't get diagnosed. In Henson's case, he thought it was the flu (a virus) and so didn't seek treatment.
as for the son's death: yes, people die of heart attacks in their 40's. It's not as common as in the past but it still happens. High cholesterol is the main cause, by my husband's family has some sort of "sudden death" gene so we lose one or two men each generation. It's never been diagnosed, even though half the family are docs...maybe because we live in the rural Philippines where autopsies are rare.
opps: I should have said Jim Henson delayed going to a doctor because he thought it was the flu, and when he presented to the ER after one or two days, he was already very sick. This is a really fast spreading infection that can kill quickly.