In my Will Rees mysteries, he meets people who are ill with tuberculosis several times. The frequency of deaths from this disease in my fiction in not an accident. It was a pandemic that still has not been eradicated. In 2017, there were more than 10 million cases of active TB which resulted in 1.6 million deaths; it is therefore the number one cause of death from an infectious disease. Most of these deaths, and most of the new infections, occur in the developing world.

I was mostly familiar with TB as ‘consumption’, a disease that afflicted Victorian poets. Although TB was common in both the poets, the upper classes and the slum-dwellers, it was not a new disease during Victorian times. It has been around for millennia. Bison remains from 17,000 years ago display the effects of the disease.  (No one is sure if TB jumped to humans from the bovine like smallpox or whether it developed independently.) TB scars have been found on Neolithic skeletons and on the spines of Egyptian mummies.

So, it has been around a very long time. Despite that, it was not identified as a single disease until 1820 and the bacillus that caused it was not discovered until 1882 (by Robert Koch. He received the Nobel prize but failed to recognize that one of the transmissions of TB was via infected milk.)

Before the advent of antibiotics, and even with the best care in the sanatoriums set up for this purpose, 50% of the patients died within five years. In 1815, one in four died of the illness in England.

Antibiotics beat back the disease, but new drug resistant strains raise the possibility of a new epidemic. Even now, in modern times, about one quarter of the world’s population is infected with TB.