Chest radiographic features and factors associated with smear negative, culture positive pulmonary Tuberculosis in Uganda: a population based study.
Kabahuma, Kihika Lilian
MetadataShow full item record
Pulmonary Tuberculosis (PTB) remains a significant cause of morbidity and mortality worldwide. Early, accurate detection and treatment of active cases is vital for good clinical outcomes and disease control. Although sputum smear microscopy is commonly used for diagnosing PTB, 30-60% of all PTB cases are smear negative pulmonary tuberculosis. The objective of this study was to determine the social demographic, clinical and radiographic factors associated with SNPTB in Ugandan communities and describe the chest radiographic features of smear negative culture positive PTB. Methods: This retrospective study used data collected by the school of public health and the National Tuberculosis and Leprosy Program (NTLP) in the 2013/2015 Uganda National TB prevalence survey. Case control study design was used. Social demographic, clinical and radiographic variables of the 93 cases who had SNPTB were matched against randomly selected controls in the same age bracket and analysed by logistic regression using STATA 13, to find factors associated with SNPTB. Descriptive statistics were used to summarize the categorical characteristics of the study participants in form of percentages. Continuous variables such as age were summarized into median and inter quartile range. Median and interquartile range were used because the data was not normally distributed. Results: Factors male sex (AOR= 2.48, 95CI=458-4.213, p=0.001), being single (AOR=2.05, 95%CI=1.250-3.371, p=0.004), current smoking (AOR= 2.39, 95%CI=1.302-4.391, p=0.005) and urban setting were positively associated with SNPTB. Among the clinical features, cough ≤ 2 weeks (AOR=2.92, 95%CI=1.548-5,535, p=0.001), a positive HIV result (AOR=2.54, 95%CI=1.437-4.496, p=0.001), being on current PTB treatment (AOR=14.67, 95%CI=1.675- 128.517, p=0.015) were positively associated with SNPTB. Radiographically 87% of the cases had abnormal chest radiographs. 75.2% of the cases had features that were highly suggestive of active PTB. 63.4% of the cases had features of active post primary PTB, whereas 11.8% had features of atypical PTB. 13% of the cases had normal chest radiographs. Consolidations, nodules, and pleural effusion were positively associated with developing SNPTB, however the study had low power. Conclusion: Chest radiography is able to identify features suggestive of active pulmonary tuberculosis in more than half of the patients with negative sputum smears.