'Spitting on the street spreads disease'

Experts have warned that a re-emergence of spitting on the street, which was discouraged during the 1880s, could be contributing to the spread of TB.

Dr John Moore-Gillon, a TB expert from the London Chest Hospital, said: "The chances of contracting TB by casual contact is very low, but if lots of people are spitting in the street or in enclosed places, and if the incidence of TB in the population is high, then it will increase, albeit slightly."

He added: "Spitting, like smoking, is essentially a social habit which can affect the health of others. People spit for many reasons, not just because they need to, but because it makes a statement.

"In some social groups spitting is regarded as a mark of 'cool'. Young boys spit to emulate football and athletic stars who spit after intense aerobic exercise when it is difficult to swallow.

"But in countries like India and China, which have high rates of TB, spitting is not a social statement - it's simply the accepted way of clearing the throat and getting rid of excess saliva. Both countries have initiated major anti-spitting drives and hope public education or onthespot fines will deter culprits."

A spokesperson from the Public Health Laboratory Service said: "TB can be spread when a person with infected lungs coughs, spits and hawks up phlegm from the throat creating droplet suspension in the air which can be breathed in.

"Although not a major driver in spreading infection in Britain, historically and globally there was a risk of spreading TB with the processes associated with clearing the throat."