After that, once a year in a good year, twice in a bad one, and I get the flu every other year or so, even with the vaccine. If I get the flu it also gives me a sinus infection more often than not. Nose slightly stuffy 100% of the time, now. Almost all my strep and sinus infections trend toward landing me in the ER, on saline, if I don't get antibiotics—rarely do they just go away. Haven't made it quite that far yet but I've been damn close.
All I can figure is HGH is a hell of a drug. I was also super-fit (looking, plus solidly healthy-range BP) until about the end of that age range, despite eating ~2x my on-paper "maintenance" calories of pure garbage food every day. Go figure. I eat much less and much better now, am fatter, and get sick sometimes rather than never getting sick. Getting old sucks.
I'm 37 now and went for years in my 20's without needing to visit a doctor more than a couple of times in total. I can see some of the changes that come with age but for me they're mostly related to slower physical recovery after exercise and some general wear on knees etc. Common colds might also make me feel somewhat worse than they would have 10 or 15 years ago, but I almost never develop any complications that would require anything else than time, and the change has been gradual enough to make it difficult to judge.
I think I've needed a course of antibiotics perhaps twice in the past ten or fifteen years (can't remember exactly; not often anyway), and one of them was in an exceptional situation.
That leads me to somewhat doubt most (generally healthy) people would manage to get infections requiring antibiotics so often that it would lead to the large (now temporarily reduced) total number of doctor's visits that the article brings up. Or if they do, then people are getting infections that require medical treatment way more often than I imagine. (That's also possible, since I live in a northern climate that doesn't really promote infections most of the time.)