The number of cases of TB that can be assumed to be highly infectious increased by one third in England and Wales between 1999 and 2003, according to data presented by the Health Protection Agency at the 36th Union World Conference on Lung Health in Paris.
The proportion of cases of pulmonary TB that were smear positive increased from 31% to 41% whilst the total number of reported cases increased by 19%, to 6,780 cases in 2003. This indicates that the pool of people with TB who were highly infectious rose susbtantially.
In 2003 a total of 30% of all TB cases were diagnosed in people who had been living in the UK for less than four years, up from just under 20% in 1999.
Increases in resistance were also noted. Isoniazid resistant TB cases rose from 5.8% to 7.2% of all notifications and multi-drug resistant cases rose from 0.6% to 1.3% of all notifications, but multivariate analysis did not find these increases to be significant.
Further UK information
References
Crofts J et al. Enhanced tuberculosis surveillance in England & Wales, 1999-2003. Int J Tubreculosis Lung Dis 9 (11 sup 1): S154, 2005.