Bronchiectasis: a neglected cause of respiratory morbidity and mortality.

Bronchiectasis is a progressive condition characterized by irreversible destruction and dilation of airways generally associated with chronic bacterial infections. Although in Western countries, the morbidity and mortality from bronchiectasis is considered to have declined markedly in the modern era, the condition continues to cause significant morbidity and mortality in the south-west Pacific and probably also in South-East Asia. There is a high prevalence in indigenous populations in the region and factors such as poverty, substandard housing, malnutrition, barriers to medical care and inadequate education are all likely to have a major impact on prevalence and outcome of bronchiectasis. Although bronchiectasis has been viewed as a disease of medium and large airways, there is now increasing evidence of the importance of small airways disease in bronchiectasis and that it may play an integral role in pathogenesis. Chronic inflammation of the bronchial wall by mononuclear cells is common to all types of bronchiectasis. A vicious cycle of bacteria (mediated lung toxicity and bacteria) provoked, host-mediated inflammatory lung damage has been described. If progressive lung damage with its attendant morbidity and mortality is to be prevented, this vicious cycle needs to be broken. The two distinct therapeutic goals in bronchiectasis are to reduce morbidity and to prevent progression of underlying disease. It may be possible to modulate the host response directly and thus reduce tissue damage, but the precise role of immuno-modulatory therapy in bronchiectasis is still unclear. The management of this hitherto neglected disease, which reaches almost epidemic proportions in some ethnic groups and is an ongoing source of considerable morbidity and mortality, requires a comprehensive, multidisciplinary approach, which can be modelled on the successful management of chronic asthma in New Zealand.