Prevalence of bronchiectasis
The prevalence of bronchiectasis is not accurately know and data varies considerably throughout the world with a very high incidence in the Indigenous populations of New Zealand and Australia (Chang et al 2010). Females and the elderly are also more frequently affected (Seitz at al 2012, Quint et al 2016).
This condition can affect anyone at any age but occurs more frequently in less affluent communities and in Indigenous communities (Chang et al. 2003, Twiss et al. 2005). Although increasingly recognised, there is a lack of data in Australia. The only available Australasian data on chronic suppurative lung disease and bronchiectasis is in children aged under 15 years. The Australian Bronchiectasis Registry will facilitate more accurate estimates of Australian disease burden in the future. A study of Central Australian Aboriginal children found a prevalence of 1,470/100,000.
In New Zealand, the reported prevalence is 3.7 per 100,000 population, but this varies according to ethnicity. Pacific children aged under 15 years have an estimated incidence rate of bronchiectasis of 17.8 per 100,000. This compares to 4.8 and 1.5 per 100,000 for Māori and New Zealand European children respectively, of the same age (Twiss 2005).
In 2003, the incidence of bronchiectasis in Auckland children was 24/100,000 for Māori compared to 4/100,000 for European groups. (Edwards et al, 2003) Another New Zealand study reported the incidence as 4.8 per 100,000 children compared with 1.5 per 100,000 for the European population. The rate of hospitalisations for bronchiectasis in 2003-2005 were 3.6 times the rate for non-Māori, with the rate rising to 6-fold at ages 45-64 years. (Crengle et al, 2006). In 2000, 27% of adults in South Auckland hospitalised with bronchiectasis were Māori (Roberts et al, 2012). A recent study has shown hospital admission rates to be 5-fold higher for Māori than Non-Māori (Bibby et al, 2015).
In the United States, a 2005 study estimated a range from 4.2/100,000 in the 18-34 years age group to 272/100,000 in those over 75 years of age. More recent information has shown 1106 cases per 100,000 population over an eight-year period (Seitz et al 2012, Weycker 2005).
A study in the UK, investigating changes in the incidence, prevalence and mortality of bronchiectasis in the UK from 2004 to 2013, found the prevalence in men was 486/100,000, and 566/100,000 in women, with prevalence highest in patients over 60 years of age (Quint et al 2016).
Groups at risk include those with established lung disease such as chronic obstructive pulmonary disease (COPD). Bronchiectasis has been identified in up to 50% of these patients. It is likely that many people with chronic respiratory symptoms due to bronchiectasis remain undiagnosed.
A family history of cystic fibrosis, Kartagener’s Syndrome and primary ciliary dyskinesia (PCD) is important as these conditions share an autosomal recessive inheritance pattern and therefore may increase the risk of bronchiectasis.
The prevalence of severe cystic bronchiectasis has decreased because of the introduction of vaccination against childhood infections, improved socioeconomic conditions and the availability of antibiotics, but in parts of the world where social conditions are poor and health care less available bronchiectasis remains a much more common cause of morbidity and mortality.