Excess mortality and tuberculosis among individuals with prolonged cough: a population-based study from Vietnam

• Published in: The international journal of tuberculosis and lung disease Vol. 10; no. 8; pp. 851 - 856
• Main Authors: HOA, N. P, THORSON, A. E. K
• Format: Journal Article
• Language: English
• Published: Paris, France IUATLD 01.08.2006; Union internationale contre la tuberculose et les maladies respiratoires
• Subjects: Adolescent; Adult; Age Distribution; Aged; Aged, 80 and over; Bacterial diseases; Biological and medical sciences; Cohort; Cough; Cough - epidemiology; Cough - microbiology; Cough - mortality; Female; Follow-Up Studies; Human bacterial diseases; Humans; Infectious diseases; Longitudinal Studies; Male; Medical sciences; Medicin och hälsovetenskap; Middle Aged; Miscellaneous; Mortality; Pneumology; Population Surveillance; Prevention and actions; Public health. Hygiene; Public health. Hygiene-occupational medicine; Respiratory system : syndromes and miscellaneous diseases; Risk Factors; Rural Population - statistics & numerical data; Sex Distribution; Socioeconomic Factors; Sputum - microbiology; Tuberculosis; Tuberculosis and atypical mycobacterial infections; Tuberculosis, Pulmonary - complications; Tuberculosis, Pulmonary - epidemiology; Tuberculosis, Pulmonary - mortality; Vietnam; Vietnam - epidemiology; Asia; Vietnam; Human; Mortality; cohort; Mycobacterial infection; Epidemiology; Cough; Infection; Vietnam; Tuberculosis; Cohort study; Bacteriosis; Population; Public health; Pneumology; Prolonged
• ISSN: 1027-3719; 1815-7920

SETTING: A demographic surveillance site in north-west Vietnam.OBJECTIVES: To compare notification rates of sputum smear-positive tuberculosis (TB) and mortality rates between the general population and individuals with prolonged cough.DESIGN: A cohort study of 559 prolonged cough cases in a total population of 35832, observed over 2.5 years. Outcome measures were sputum smear-positive TB and death.RESULTS: The age-standardised smear-positive TB notification rate among cough cases (553/100000 person-years [py], 95%CI 268-1143) was significantly higher than in the general population (50/100000 py, 95%CI 43-57), with a relative risk of 11.06 (95%CI 8.28-14.77). Among those who had a chest X-ray suggestive of TB but negative sputum smears prior to the study start, the rate was 6542/100000 py (95%CI 2906-12 511). The cough cohort had a 2.61 (95%CI 2.38-2.87) times higher risk of dying than the general population.CONCLUSIONS: Individuals with prolonged cough in this study run a significantly increased risk of developing infectious TB and of dying. We recommend further evaluations of improved follow-up systems aimed at identifying and treating sputum smear-negative TB cases before they convert to an infectious stage.