A clinical and lung function study of chronic lung disease and asthma in coastal Papua New Guinea.

A prevalence survey on the island of Karkar had previously shown that chronic lung disease was common in both sexes after the age of 35 years and that, in part, this was related to the smoking of home-grown air-cured tobacco. To investigate the nature of this chronic lung disease, 37 nontuberculous subjects with reduced ventilatory capacity (forced expiratory volume in one second less than 75% predicted) underwent clinical and lung function investigations. Ninety-two per cent had adventitiae, 62% had chronic productive cough and 54% had dyspnoea on exertion. Lung function tests showed an irreversible obstructive defect with a variable, but on average, only moderately reduced transfer factor. The chest radiography showed evidence of hyperinflation in 38% of cases but non had narrowing or loss of pulmonary vessels suggestive of emphysema. "Inflammatory changes" occurred in 35% and were associated with a mild but significant element of restriction. The results suggest that chronic bronchitis and chronic bronchiolitis were the main underlying abnormalities and that emphysema was comparatively unimportant. Asthma appeared to be relatively uncommon, especially in children. The clinical and lung function findings in 16 asthmatics were essentially similar to those observed in asthmatics elsewhere and the atopic status of asthmatics and controls was similar to that observed in developed societies. In common with Highland asthmatics however, the age at onset was in early adult life rather than in childhood.