Introduction: Cough is a key symptom of tuberculosis (TB) as well as the main cause of transmission. However, a recent literature review found that cough frequency (number of coughs per hour) in patients with TB has only been studied once, in 1969. The main aim of this study is to describe cough frequency patterns before and after the start of TB treatment and to determine baseline factors that affect cough frequency in these patients. Secondarily, we will evaluate the correlation between cough frequency and TB microbiological resolution. Methods: This study will select participants with culture confirmed TB from 2 tertiary hospitals in Lima, Peru. We estimated that a sample size of 107 patients was sufficient to detect clinically significant changes in cough frequency. Participants will initially be evaluated through questionnaires, radiology, microscopic observation drug susceptibility broth TB-culture, auramine smear microscopy and cough recordings. This cohort will be followed for the initial 60 days of anti-TB treatment, and throughout the study several microbiological samples as well as 24 h recordings will be collected. We will describe the variability of cough episodes and determine its association with baseline laboratory parameters of pulmonary TB. In addition, we will analyse the reduction of cough frequency in predicting TB cure, adjusted for potential confounders. Ethics and dissemination: Ethical approval has been obtained from the ethics committees at each participating hospital in Lima, Peru, Asociación Benéfica PRISMA in Lima, Peru, the Universidad Peruana Cayetano Heredia in Lima, Peru and Johns Hopkins University in Baltimore, USA. We aim to publish and disseminate our findings in peer-reviewed journals. We also expect to create and maintain an online repository for TB cough sounds as well as the statistical analysis employed.
Bibliographical noteFunding Information:
This work was funded in part by the National Institutes of Health award 5D43TW006581 'Infectious Diseases Training Program in Peru', award 5D43TW009349-03 'Inter-American Training for Innovations in Emerging Infectious Diseases', Grand Challenges Canada Contract No. 0539-01-10 'Smartphone app for cough monitoring of tuberculosis patients', and award 5R21AI094143-02 'Cough-a rapid indicator of response to therapy in pulmonary TB'. CAE and JSF thank the Imperial College Biomedical Research Centre for financial support. The contributions of CAE to this research were funded by: The Joint Global Health Trials consortium of the Wellcome Trust, UK-MRC and DFID (award MR/K007467/1); The Wellcome Trust (awards 078340/Z/05/Z, 105788/Z/14/Z and 201251/Z/16/Z); The Bill and Melinda Gates Foundation award OPP1118545; and IFHAD: Innovation For Health And Development.