The respiratory inflammatory response to the swine confinement building environment: the adaptation to respiratory exposures in the chronically exposed worker

Abstract

Swine confinement facility workers often develop respiratory problems secondary to their work, including the asthma-like syndrome, exacerbation of underlying asthma, chronic bronchitis, and mucous membrane irritation syndrome. Organic dust toxic syndrome is seen in these workers as well. Swine confinement barns are characterized by the presence of multiple factors that can cause respiratory tract and systemic inflammation symptoms, including dust, endotoxin, and ammonia. Investigators have found evidence of inflammation characterized by increased numbers of neutrophils, macrophages, and to a lesser degree, lymphocytes in both naïve subjects and swine confinement building workers. Interestingly, this inflammation is most pronounced in subjects with no prior exposure to this environment. This finding suggests that adaptation or tolerance to endotoxin or other substances in this environment is induced by repeated exposures. Interventions have been devised to reduce the risk of symptomatic respiratory disease from working in a swine confinement facility. The efficacy of several of these interventions was tested using objective measures of respiratory tract inflammation. Recent finding suggests that such studies should be done in swine confinement workers if they appear promising using testing of naïve subjects exposed to this environment.