In the previous essays I have explained why the population structure of the wizarding world is much more similar to a pre-industrial country than modern muggle Britain.
High death rates in pre-industrialised countries reflect a large disease burden. Mostly this disease burden is due to infectious diseases that are endemic and also circulated as frequent, regular epidemics. With modern medical care, developed nations like Britain have managed to cut both the disease burden and death rate from infectious diseases but clearly the wizarding world is still being plagued with….plagues.
There is a possibility that purely magical maladies exist which can only affect wizards/witches, which will explain the discrepancies between modern muggle Britain and wizarding Britain. However given that wizards and muggles are all one species with the same immune system, it stands to reason that all diseases experienced by wizards must also be able to infect muggles, whether this is literally the case is a whole different question.
A Different Way of Thinking
The healthcare systems and medical knowledge of the wizarding and muggle worlds diverged over 300 years ago, long before modern medicine came into existence. There is no reason to believe that wizards have even heard of germ theory or have any understanding of pathology. They do not need to because they have unique magical methods of curing disease and as, evidence by the ancient use of willow bark to cure malaria, you do not need to know how cures work, or even what you are curing in order to have a functioning medicine that produces good results.
Seen as wizards entered total seclusion from mundane society before the current standard nomenculture of medicine was invented, it stands to reason that they would have their own unique names for common diseases that affect all humans.
In HBP, Horace Slughorn states that Draco Malfoy’s grandfather passed away due to Dragonpox.
Dragonpox may not a purely magical malady, it may be the wizarding term for disseminated shingles, or meningococcal septicaemia (considering the wizarding world doesn’t have anything resembling a vaccination program), or even secondary syphilis.
Just because these diseases are easily treated/preventable in the modern muggle world does not mean that the same is true for the wizarding world. Just because missing bones can be regrown and there is a cure for the common cold, does not mean that wizarding medicine can cure everything. One of the biggest recurring themes in the fantasy genre is that magic has limits. On the surface the wizarding world looks more developed than the muggle world because magic can solve problems that muggles face on a daily basis such as transportation and communication, but it is wrong to assume that magic is ultimately superior to everything we have in the muggle world.
Magic may bring huge improvements in our quality of life, but the reverse may also be true.
It may be that muggle medicine only has the upperhand on wizarding medicine in the area of infectious diseases, because of the invention of vaccinations/antibiotics/anitvirals. Many of the most common and most deadly diseases that used to scourge Victorian Britain are almost unheard of today because of these two amazing muggle inventions.
The diseases that muggles have most success in preventing and treating are all infectious diseases. Whereas the ease for cure/prevention of diseases using magical means must follow a completely different logic.
For example one major branch of muggle medicine that the wizarding world does not have at all is surgery, as evidences by Ron’s impression of a doctor as muggle who cuts people up. This stands to reason as unwanted bits of tissue can easily be removed by a variety of different magical means without having to actually open the body. Bony injuries, we have seen, are amongst the easiest injuries to cure using magic whereas in muggle medicine it is often a long labourious process. It may also be that the use of magic dramatically cuts rates of certain non-infectious diseases like cancer, making tissue removals a very small part of a healer’s work load.
Wizarding medicine has much more in common with traditional folk medicine than modern medicine. Wizards most likely never discovered or were exposed to the scientific breakthroughs that underpin modern medicine, thus their medical advances comprise of entirely of guided trial and error without ever using knowledge of the underlying principles of pathology. Trial and error, especially with hundreds of years of a cumulated knowledge, can be very effective in producing treatments that work.
However, unlike the muggle world, wizarding society is also plague with much less mundane diseases. It is equally possible that Dragonpox actually comes from dragons.
Continued in Part 3 - Fantastic Beasts and Gruesome Disease