Chronic cough and infection

Active infection remains an important differential diagnosis for cough lasting >8 weeks. Tuberculosis and pertussis are particularly common in some regions, and epidemiology is changing. Prompt diagnosis and treatment has public health implications; respiratory pathogens benefit from the human cough reflex for their own transmission. Specific pathogen-derived factors have now been identified that directly cause cough, particularly sulpholipid-1 and phenol glycolipid in <italic>Mycobacterium tuberculosis</italic>, the latter associated with high transmissibility. <italic>In vitro</italic> data suggest a specific ATP-mediated cough pathway in tuberculosis that should respond to gefapixant and other P2X3 antagonists. The mechanisms of sulpholipid-1 and pertussis toxin await characterisation but could aid antitussive drug discovery. Measuring cough could help determine infectiousness, and in monitoring response to antimicrobial treatment. Further study of CC in infectious conditions should lead to wider insights into cough in general, and into the interaction between respiratory pathogens and the human host. <bold>Cite as:</bold> Turner RD. Chronic cough and infection. <italic>In:</italic> Song W-J, McGarvey L, Cho PSP, <italic>et al.</italic>, eds. Chronic Cough (ERS Monograph). Sheffield, European Respiratory Society, 2025; pp. 261–271 [<ext-link>https://doi.org/10.1183/2312508X.10028324</ext-link>].