Asthma in Latin America is a growing public health problem and seems to be most prevalent and cause most morbidity among poor urban populations. This article will review the findings of recent human studies of the associations of asthma prevalence in Latin America with factors associated with poverty and inequality including childhood infections, stress, environment, nutrition and diet.
Most asthma in childhood in Latin America is nonatopic and has been associated with exposures related to environmental dirt, diet and psychosocial distress. These factors are strongly linked to poverty and inequality. Interestingly, infections with bacterial, viral and parasitic pathogens in childhood appear to attenuate atopy in childhood but have no effect on asthma symptoms. There are biologically plausible mechanisms by which dirt exposures (e.g. endotoxin and other microbial products and nonmicrobial irritants), diet and obesity and psychosocial stress may cause airways inflammation.
Most childhood asthma in Latin America is nonatopic for which important risk factors are those of poverty including poor hygiene (i.e. dirt), poor diet and obesity and psychosocial stress. There is evidence that exposures to infections in early childhood reduce atopy but not asthma. Research is needed to identify causes of nonatopic asthma that may be suitable for primary prevention or other public health intervention strategies for asthma in Latin America.
aCentro de Investigaciones FEPIS, Quinindé, Esmeraldas Province, Ecuador
bMolecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
cColegio de Ciencias de la Salud, Universidad San Francisco de Quito, Quito, Ecuador
dInfectious Diseases Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
eInstituto de Saúde Coletiva, Universidade Federal de Bahia, Salvador, Bahia, Brazil
Correspondence to Philip J. Cooper, Casilla 17-22-20418, Quito, Ecuador. Tel: +593 62737158; fax: +593 62737158; e-mail: P.J.Cooper@liv.ac.uk