Nightclubs said to be cause of serious TB outbreak

Helen Barratt Clegg scholar, BMJ

Last month the Daily Mail reported that young people in crowded nightclubs were spreading tuberculosis (TB) and causing a serious "outbreak." The London Evening Standard also stated that, according to experts, "the hot, sweaty conditions of nightclubs and busy bars are ideal places for bacteria to breed. The disease can be spread by the saliva of a TB sufferer, either through kissing or sharing a drink."

A spokesperson from the Department of Health confirmed that around 60 cases of the isoniazid-resistant TB had been seen over the past six years in Greater London. However, he explained that there was no common risk factor. Professor Francis Drobniewski, head of the Public Health Laboratory Service's national TB unit, confirmed that a link with drug misuse had been identified as a large proportion of the people were known drug takers.

The increase in the number of cases of TB reported in London is believed to be mainly because of the large number of people migrating to the capital from areas with a high incidence of the disease. However, the population affected by this latest outbreak is unusual. According to Professor Drobneiwski, a large proportion of those affected are "young, UK born, white, and reasonably affluent." The Daily Mail reported that the outbreak was believed to have originated with a Nigerian student in London in 1995. Drobniewski confirmed that the student had been one of the early cases but that most were seen between 1999 and 2000.

The outbreak has been isolated to the capital and most cases of TB have been in north London. Professor Drobniewski pointed out that there is a greater risk of contracting TB in London than anywhere else in the UK anyway, principally because overall the number of cases continues to rise. The incidence of TB in London is four times greater than the national average, with almost half of the 7000 cases seen nationwide each year being found in the capital: 7.5% of the TB seen in London is isoniazid resistant.

The bacterium responsible for the outbreak is unusual in that it takes patients longer to recover from the illness. Nine months of antibiotic treatment is required to combat the infection, in contrast to the usual six months. Patients suffering from "normal" TB have a relapse rate of around 2-3%, but the rate is 10% in those with the drug resistant strain. This is complicated further by a low rate of compliance among the affected group. However, both the incubation period and mortality rates of the strain are similar to "normal" TB.

Professor Drobniewski emphasised that as the tuberculosis bacterium is spread by the respiratory route there is no danger from sharing beer glasses or even close contact. He also added that there was no reason for people visiting nightclubs to be unduly concerned.



studentBMJ 2001;09:305-356 September ISSN 0966-6494