Epidemiological impact of mass tuberculosis screening: a 2-year follow-up after a national prevalence survey

• Published in: The international journal of tuberculosis and lung disease Vol. 16; no. 12; pp. 1619 - 1624
• Main Authors: Okada, K., Onozaki, I., Yamada, N., Yoshiyama, T., Miura, T., Saint, S., Peou, S., Mao, T. E.
• Format: Journal Article
• Language: English
• Published: Paris, France International Union Against Tuberculosis and Lung Disease 01.12.2012; International Union against Tuberculosis and Lung Disease
• Subjects: Active Case Finding; Adolescent; Adult; Aged; Antitubercular Agents - therapeutic use; Bacterial diseases; Biological and medical sciences; Cambodia - epidemiology; Chest Radiography; Child; Disease Notification; Epidemiology; Female; Follow-Up Studies; Health Surveys; Human bacterial diseases; Humans; Incidence; Infectious diseases; Male; Mass Screening - methods; Medical sciences; Middle Aged; Mycobacterium; Mycobacterium tuberculosis - isolation & purification; Pneumology; Predictive Value of Tests; Prevalence; Prognosis; Radiography; Reactivation; Registries; Sputum - microbiology; Time Factors; Tuberculosis; Tuberculosis and atypical mycobacterial infections; Tuberculosis, Pulmonary - diagnosis; Tuberculosis, Pulmonary - diagnostic imaging; Tuberculosis, Pulmonary - drug therapy; Tuberculosis, Pulmonary - epidemiology; Tuberculosis, Pulmonary - microbiology; Tuberculosis, Pulmonary - transmission; Young Adult; Cambodia; Human; chest radiography; Reactivation; Prevalence; Radiodiagnosis; Exploration; Thorax; Mycobacterial infection; Medical screening; Epidemiology; Infection; Case study; Mass; Radiography; Survey; Tuberculosis; Follow up study; Bacteriosis; Tumor; active case finding; Pneumology
• ISSN: 1027-3719; 1815-7920; 1815-7920
• DOI: 10.5588/ijtld.12.0201

OBJECTIVE: To assess the epidemiological impact of mass tuberculosis (TB) screening in the community and the prognosis of bacteriologically negative individuals with abnormal findings on chest radiography (CXR).METHODS: A follow-up study consisting of two parts-a register match of notified TB cases with 22 160 participants in a national TB prevalence survey, and a repeat medical examination for the subjects of a prevalence survey with abnormal findings on CXR-was conducted 2 years after the prevalence survey in Cambodia.RESULTS: Thirty-four cases with new smear-positive TB were detected by register match, giving a standardised notification ratio of 0.38 (95%CI 0.27-0.52). An additional seven new smear-positive TB cases and 93 new smear-negative, culture-positive TB cases were detected by medical examination. The incidence rates of bacteriologically positive TB were 8.5% per year (95%CI 6.3-11.2) in cases with a CXR suggestive of active TB and 2.9% per year (95%CI 2.2-3.7) in those with a CXR with other abnormalities.CONCLUSIONS: Detection and treatment of smear-negative, culture-positive TB cases as well as smear-positive TB cases was associated with a rapid reduction in subsequent incidence of new smear-positive TB. Sputum culture-negative individuals with abnormal CXR findings are at a high risk of disease progression, and require follow-up and potentially preventive treatment.