Stevie Miller had been suffering from a nagging, hacking cough for about a year when the blackouts started.

Hed stand up and suddenly crumple in a heap on the ground, then come to moments later feeling dazed, with no clue about what had just happened. He began to experience these episodes more frequently, up to several times a week.

By this point, Stevie had grown accustomed to feeling miserable most days he was cold, tired, hungry and weak. I felt run down every day, Stevie said. Since 2010, hed been living homeless on the streets of east London, sleeping on park benches and under market stalls, in squats and abandoned buildings, in shipping containers and church halls.

Getting sick was inevitable. You just cannot look after yourself in a healthy way, Stevie said. A lot of it is to do with your mental state and the insecurity of not knowing what is next. It wears you down, and you dont look after yourself properly, and end up getting ill. Thats why, when his cough first started, Stevie hardly gave it a second thought.

Mostly, he was grateful that he had a roof over his head, albeit a temporary one. In the winter months, as the weather began to turn cold, the charity North London Action for the Homeless found Stevie shelter in churches around Hackney. He spent each night huddled on a mattress in various church halls, together with dozens of other homeless people.

I would be lying inches away from the next person, and all around you would hear people coughing, snoring and talking in their sleep, Stevie said. Soon, his coughing would echo theirs.

The blackouts were something new, however. When Stevie collapsed on the street one afternoon in 2013, concerned bystanders called an ambulance, and Stevie was rushed to Homerton Hospital . It turned out the blackouts were caused by salt deficiency and hypertension, but doctors were suspicious about his persistent cough and referred him to the respiratory clinic. Tests revealed that his cough wasnt simply the byproduct of an ordinary cold. Stevie had contracted a disease that was more commonly associated with life in the 19th century: tuberculosis.

TB is a bacterial infection spread through the air when infected individuals cough or sneeze. It spreads easily in crowded areas with poor ventilation, and among individuals who have compromised immune systems that arent strong enough to fight it off.

Stevie, now 69, cant be sure exactly where he contracted TB. One of the church halls he slept in during the bleak winter months is a likely source, but he could have been exposed in some other cramped and crowded place where he sought shelter together with other homeless and vulnerable people.

It was inevitable that someone in his situation would get TB, said Sue Collinson, a specialist TB care worker at Homerton Hospital who looked after Stevie. The risk factors for homeless people catching TB are significant, compared to the normal population.

If left untreated, TB can be life-threatening, and even delays in treatment can have a devastating impact on a persons health. Globally, TB kills more than 1.6m people a year more than HIV and malaria combined. It is most prevalent in countries such as India, Pakistan, China, Indonesia, Nigeria, Bangladesh, the Philippines and South Africa.

Tuberculosis used to be widespread in the UK as well. During the Victorian era, it was a leading killer, responsible for 40% of all deaths among working-class people in cities. Literary greats such as Robert Burns, Elizabeth Barrett Browning and the Bronte sisters all died from the disease.