Before WWII diagnosis for disease that spread easily like TB could be seen under a microscope. Many people with good immunity had TB which were walled off as granulomas and lived to old age. My mother-in-law had them from 1916 and died in 2001. The law required mandatory institutionalization. There was a crematorium there to stop the spread of disease. If you ceased to have the little critters under the microscope for a defined period of time you got out. It was a pitiful thing from just a sneeze. It became against the law to spit on the sidewalk. And spittoons were banished. Even today TB is not easy to get rid of.
Since it is like any germ, it doesn't care what part of you it feeds off of. But microscopes definitely could ID it. Microscopes go back to the 1700s. The fact that one has it, may leave them with barnacle like nodules especially in the lungs, staying in them all their life. I use to wonder why my mother-in-law try to prove she was good at sports when I didn't see evidence of her being athletic. Her lungs became compromised from TB in childhood. It was a hidden handicap for her. But it also gave her use a sense of witty fun to get through tough times.