Childhood Bronchiectasis around the World
Gregory J. Redding M.D.
Professor of Pediatrics, University of Washington School of Medicine
Chief, Pulmonary and Sleep Medicine Division, Seattle Children's Hospital
Seattle, Washington, USA
Key words: bronchiectasis
Mailing Address:
Pulmonary and Sleep Medicine Division, Office A-5937
Seattle Children's Hospital
4800 Sand Point Way N.E.
Seattle, Washington, USA
e-mail: gredding@u.washington.edu
Telephone: 206-987-2174
Fax: 206-987-2639
Bronchiectasis has been described as an orphan disease in developed countries around the
world, most often associated with conditions that compromise pulmonary host defenses,
such a immunodeficiencies, cystic fibrosis (CF), or disorders of ciliary motility.
However, worldwide, the most common etiology for bronchiectasis is probably lung
injury following acute respiratory infections. The prevalence of bronchiectasis should
therefore parallel the distribution of childhood mortality and hospitalization for
pneumonias in very young children worldwide.[1]
The lungs response to infection varies with the etiology but both viruses and bacteria can
lead to chronic airway injury. Certain infections, e.g. adenoviruses of certain serotypes,
produce bronchiolitis obliterans after a single infection with subsequent bronchiectasis.
Severe pneumococcal pneumonia can also produce bronchiectasis as a sequelae.[2] More
often, children with bronchiectasis have had recurrent acute lung infections or they
experience combinations of lung infections and conditions predisposing to lung injury or
airway mucus production. Chronic productive cough is more common among children
passively exposed to tobacco smoke and the frequency of bronchiectasis in some
populations is coincident with crowding, a high prevalence of lower respiratory tract
infections, and high prevalences of smoking in families.
Chronic productive cough is the most common clinical symptom associated with
bronchiectasis. In some populations, the prevalence of chronic productive cough reaches
up to 20% of middle school children.[3] Chronic productive cough can occur with or
without associated wheezing. Bronchiectasis is associated with chronic obstructive lung
disease but focal bronchiectasis does not necessarily produce air trapping or reduced
airflows. In general, the more diffuse the disease, the more likely obstructive lung
disease coexists. Also, approximately 40% of children and adults with bronchiectasis
will have a reversible component, responsive to short acting bronchodilator treatment.
Worldwide prevalences of chronic cough and bronchiectasis in children do not exist.
There is likely a similar distribution of bronchiectasis to frequency of severe LRIs in
children and smoking rates among families. Several infectious epidemics also contribute
to the frequency distribution of childhood bronchiectasis. Human Immunodeficiency
virus (HIV) and tuberculosis prevalences vary across the world, these conditions both can
result in recurrent or chronic pulmonary infections, and lead to bronchiectasis. Similarly
the prevalence of indoor pollution, such as indoor biomass combustion, is likely to
predispose to chronic airway mucus production and chronic productive cough long term.
It is unlikely that the distribution of bronchiectasis prevalences will emerge soon as the
diagnostic gold standard is a high resolution computerized tomographic (CT) scan of the
lungs.[2] The reason bornchiectasis has been described so well in certain populations is
because those populations, however rural, have access to CT scans nearby.
Actionable items to reduce bronchiecatsis worldwide will be population based.
Immunization programs both for pneumococcal and perhaps influenza infections must be
in place. New polyvalent pneumococcal vaccines covering more than 7 serotypes are in
clinical trials in young children.[4] Improved water access for hand washing will reduce
the prevalence of acute respiratory infections, as well reduced crowding. Indoor tobacco
and other smoke exposure needs to be reduced. Whether medical treatments such as
antibiotics can alter the evolution of bronchiectasis after acute lung infections remains
unclear. Safe feeding practices may reduce the risk of aspiration and these practices are
amenable to public health initiatives. A better description of the magnitude of the
problem is essential if chronic suppurative lung disease in childhood is to become a
priority.
References
1.
Redding GJ, Byrnes CA. Chronic respiratory symptoms and desieases among
indigenous children. Ped Clin N Am 2009; 56:1323-1342.
2.
Chang AB, Masel JP, Boyce NC, et al. Non-CF bronchiectasis: Clinical and
HRCT evaluation. Pediatr Pulmonol 2003; 35:477-483.
3.
Lewis TC, Stout JW, Martinez P, et al. Prevalence of asthma and chronic
respiratory symptoms among Alaska Native children. Chest 2004; 125:16651673.
4.
Singleton RJ, Hennessey T, Bulkow LR, et al. Invasive pneumococcal disease
caused by non-vaccine serotypes among Alaskan Native children with high levels
of 7-valent pneumococcal conjugate vaccine coverage. JAMA 2007; 297:17841792.