New Delhi: After the New Delhi superbug bogey, British journal Lancet in its latest report has claimed that one in five immigrants from the Indian subcontinent are carriers of the latent disease, which often progresses to active TB within a few years of their arrival in Britain.
The results based on research by scientists, published in The Lancet Infectious Diseases journal, Friday, showed 20 percent of recent immigrants from the Indian sub-continent and almost 30 percent from sub-Saharan Africa are carriers of latent TB.
The report says that tuberculosis screening for new immigrants fails to detect most cases and hence there is a strong case for stricter screening of people arriving from India and other countries of the subcontinent.
"By changing the threshold for screening, and including immigrants from the Indian subcontinent, we could pick up 92 percent of imported latent TB," said Ajit Lalvan from Imperial College London, who led the study. "By treating people at that early stage, we can prevent them from developing a serious illness and becoming infectious."
Current British border policies require immigrants from countries with a TB incidence higher than 40 per 100,000 people to have a chest X-ray on arrival to check for active TB, but detection is just 0.01%.
TB is caused by a bacterial infection which is normally asymptomatic, but about one in 10 cases lead to active disease which attacks the lungs and kills around half of those affected.
A worldwide pandemic: Among the 15 countries with the highest estimated TB incidence rates, 13 are in Africa, while a third of all new cases are in India and China, according to the World Health Organization (WHO).
In India, the disease occurs in 185 per 100,000 people, as per the WHO`s global TB report, 2009. The WHO also says drug-resistant TB is rapidly increasing around the world and these often fatal strains of the disease are expected to affect two million people by 2050.
In UK, the national incidence of TB is said to have has risen dramatically over the last decade, increasing by almost 50 percent between 1998 and 2009. Much of this increase has been driven by a 98 percent increase in cases among immigrants, and have a 20 times higher incidence of TB than people born in Britain.