International patterns of tuberculosis and the prevalence of symptoms of asthma, rhinitis, and eczema
- Erika von Mutiusa,
- Neil Pearceb,
- Richard Beasleyb,
- Soo Chengb,
- Ondine von Ehrensteina,
- Bengt Björksténc,
- Stephan Weiland on behalf of the ISAAC Steering Committeed
- aUniversity Children's Hospital, Klinikum Innenstadt, Munich, Germany, bWellington School of Medicine, University of Otago, Wellington, New Zealand, cUniversity Hospital, Linköping, Sweden, dInstitute of Epidemiology and Social Medicine, University of Münster, Germany
- Dr E von Mutius, Dr von Haunersche Kinderklinik, Klinikum Innenstadt, Lindwurmstrasse 4, D-80337 München, Germany email:
- Received 20 May 1999
- Revision requested 8 July 1999
- Revised 25 August 1999
- Accepted 7 September 1999
BACKGROUND An ecological analysis was conducted of the relationship between tuberculosis notification rates and the prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and atopic eczema in 85 centres from 23 countries in which standardised data are available. These essentially comprised countries in Europe as well as the USA, Canada, Australia, and New Zealand.
METHODS Tuberculosis notification rates were obtained from the World Health Organization. Data on the prevalence of symptoms of asthma, rhinitis, and eczema in 235 477 children aged 13–14 years were based on the responses to the written and video questionnaires from the International Study of Asthma and Allergies in Childhood (ISAAC). The analysis was adjusted for gross national product (GNP) as an estimate of the level of affluence.
RESULTS Tuberculosis notification rates were significantly inversely associated with the lifetime prevalence of wheeze and asthma and the 12 month period prevalence of wheeze at rest as assessed by the video questionnaire. An increase in the tuberculosis notification rates of 25 per 100 000 was associated with an absolute decrease in the prevalence of wheeze ever of 4.7%. Symptoms of allergic rhinoconjunctivitis in the past 12 months were inversely associated with tuberculosis notification rates, but there were no other significant associations with other ISAAC questions on allergic rhinoconjunctivitis or atopic eczema.
CONCLUSIONS These findings are consistent with recent experimental evidence which suggests that exposure to Mycobacterium tuberculosis may reduce the risk of developing asthma.
Funding: the ISAAC International Data Centre including the Health Research Council of New Zealand, the Asthma and Respiratory Foundation of New Zealand, Glaxo Wellcome International, the Child Health Foundation of New Zealand, the Hawke's Bay Medical Research Foundation, the Waikato Medical Research Foundation, Glaxo Wellcome New Zealand Ltd, and Astra New Zealand. The regional coordinating centres were supported by Glaxo Wellcome International Medical Affairs. The collaboration in Europe was partially funded by the EU Biomed programme.