After repeated visits to the doctor and months of being sick in 2004, the London barrister was finally diagnosed with drug-resistant tuberculosis. She isn't sure where she caught it -- either travelling in India years before or living in northwest London, a tuberculosis hotspot -- but experts say patients like Watterson are increasingly common across Europe.
"Nobody in Europe is 100 per cent protected from drug-resistant tuberculosis," said Ogtay Gozalov, a medical officer at the World Health Organization. He described the disease's spread in Europe as "alarming" and said previous measures to contain the outbreak were inadequate.
On Tuesday, WHO released a new plan to fight the disease across Europe that aims to diagnose 85 per cent of all patients and to treat at least 75 per cent of them by the end of 2015. Only about 32 per cent of patients with drug-resistant tuberculosis in Western Europe are properly treated; many stop taking their medicines before the treatment course is up, allowing the bug to develop resistance.
According to WHO, the nine countries with the world's highest rates of drug resistance in new tuberculosis patients are in Europe, including Azerbaijan, Moldova, Russia and Ukraine.
The agency's plan will cost $5 billion and is intended to save about 120,000 lives and $12 billion worth of diagnosis and treatment expenses by 2015.
Watterson said low awareness of the disease among health workers also allows it to spread.
"There was a delay in my diagnosis because I was a white, middle-class person and doctors didn't think to test for it," she said. Most patients with the disease are immigrants from poor countries or people who abuse drugs and alcohol.
Once diagnosed, Watterson was put into isolation for four months in the hospital and any visitors had to wear masks. She took a cocktail of drugs for nearly two years, some of which made her nauseous and so sensitive to sunlight she had to wear gloves to protect her hands in the summer.
Some experts said officials must address the stigmatization that often accompanies tuberculosis and work harder to identify patients before they spread the disease.
Ruth McNerney, a tuberculosis expert at the London School of Hygiene and Tropical Medicine, described WHO's plan as "overambitious." But she warned there could be a much bigger crisis in the future.
"If we don't solve this soon, we could end up with so much drug-resistant tuberculosis that it will be like being back in the Victorian age when there were no good treatments," she said.