LONDON -- In the shadows of some of London's tallest skyscrapers and richest banks lurks a disease borne of the poverty and squalor usually associated with the Victorian era rather than a 21st-century financial capital.
Tuberculosis is staging a comeback in London, where some neighborhoods suffer infection rates found in African countries in which the disease is endemic. The number of cases surged 50 percent in the 10 years to 2009, according to a National Health Service agency.
The airborne bacteria has taken root in a population of recent immigrants, addicts and homeless who live close to affluent business districts and may pose a risk for those they rub elbows with.
"You wouldn't expect to see that," says Brian McCloskey, the Health Protection Agency's regional director for London. "TB is one of the biggest public health problems we have."
One hot spot is Tower Hamlets, a borough that draws together Canary Wharf, the home of some of Europe's largest banks, and pockets of poverty that stretch along the Thames' old docks east of the Tower of London and north past Whitechapel, where Jack the Ripper preyed on prostitutes in 1888.
Tuberculosis, transmitted by coughs and sneezes, doesn't just strike the needy.
After a worker at a Canary Wharf bank fell ill in 2010, Julian Surey, a nurse at Tower Hamlets Tuberculosis Service in East London, says he was sent with colleagues to her office to screen 14 of her co-workers, a challenge in an open-space environment where employees share keyboards and telephones.
"They were hot-desking and it was a nightmare," Mr. Surey says. "People did get concerned." Some workers demanded to see private doctors rather than be tested and treated by the state-run National Health Service, the 37-year-old nurse recalled. One person who sat next to the original patient contracted TB, according to Mr. Surey. He declined to identify the bank, as did other nurses.
One sneeze can release up to 40,000 droplets and each one can potentially cause infection. An untreated patient can infect up to 15 others a year, the World Health Organization estimates.
The condition, which can remain dormant in the body for decades but spread through the air and require extended courses of antibiotics once it has been roused, is difficult to diagnose, treat and contain.
"Can you get it on the Tube? In theory, yes," Mr. Surey says, referring to London's rapid transit system. "It can go to everyone," he says of the disease, which once active can kill half of those it infects if they aren't treated.
Transmission is more common among members of the same household, according to Mr. McCloskey. Treatment usually requires taking one or two antibiotics for three to six months, costing about 2,000 pounds ($3,155) for an uncomplicated case.
But drugs are only part of the solution. Tuberculosis is a sensitive subject with social and political ramifications, says Graham Cooke, a senior lecturer in the department of medicine at the Faculty of Medicine at Imperial College London.