As a total novice, what are the basics of good health care that have been alluded to a few times? Got hospitals, court doctors (but they are only useful for the ruler?), closing the gates, possibly living in a colder climate and ? ? ? ?
You have essentially sides 2 of the health problem: Characters and Poplation.
Population
Almost no one worries about population outside of black death scenario because while prosperity is a nice bonus (that you lose if you are being ravaged by an epidemic, or gets raided, or gets besieged), depopulation (the one that gives you province penalties) requires prolonged exposure to severe epidemic. Hospitals and events are only ways to deal with this side of the problem. When constructing hospitals think about the likely origin of the epidemics, for example if denmark is covered in hospitals sweden and norway are far more resistant to them because the only way to spread is over water and that is less likely. Also poor provinces and provinces where there are no trade posts seem to be more resistant to epidemics, so if you really care, embargo republics and burn down all the trade posts. I wouldn't.
Characters.
This is what everyone I've seen arguing about disease one way or the other seems to have a probllem with. I'll list the tools you can use to protect yourself and what they are good for.
1. Court physicians. They are bread and butter of your court decease defences. You want the highest possible learning guy you can get your mittens on, 10/15/20/25 are your steps, each makes your guy better. Traits give variety of alternative treatments and bonuses to skill with renown phys being equal to extra 5 points of learning, others are weaker. There also is a small boost if he likes you so right religion/culture guys are better, but Learning is Key, because a high learning physician will eventually get the trait of being renown anyway.
2. Foci. Foci that give you a flat boost to health make you less likely to die, simple as that. Getting a dog from hunting, cat from intrigue (I think it's from intrigue, but it may just be a random event) and a rat from spending time in a dungeon for full collection is ideal but usually you are lucky if you have any one of them. Special mention goes to carousing foci that helps you get rid of depressed and stressed quite quickly, since they are health penalties we don't want them around.
3. Hospitals. Here we use them to prevent the need to go into seclusion, since if your capital is in a middle of an epidemic you are that more likely to get sick. So yeah build one in your capital, but don't go into debt doing so, remember they are only helpful if they are well upgraded.
4. Seclusion. Aside from game mechanic of locking yourself in, reducing number of people in your court seems to make non epidemic deceases less likely to occur. So yeah, kick all those courtiers out and when the epidemic comes close the gates and listen to the cries of the peasants from outside.
5 Armies. Warning, this has not been tested by me. Aka, run away. Commander in charge of an army is not in his court, as such cannot be affected by w/e horrible desease is happening there. On the flip side sending your imbecile heir into every decease ridden area on the map is a great alternative to kinslayer.
Also, it has been mentioned that the more recent patches have toned things down some without Paradox mentioning it. Any agreement on this?
The "problem" arose with 1.6, there was only 1.6.1 since then and nothing like this was mentioned IIRC.