Parabasalids in respiratory secretions and lung diseases.

I read with great interest in a recent issue of CHEST (April 2014) the article by Khemasuwan et al, 1 who provided a comprehensive review of helminthic and protozoal infestations of the respiratory system. Regarding the protozoal infestations, however, I think the authors have omitted a group of fl agellated protists, the parabasalids, some of which are well-known protozoa and others of which are considered as uncommon emerging pathogens. 2