Abstract

Background: Tuberculosis (TB) is one of the leading public health problems. The childhood TB has been relatively neglected for several years, mainly due to difficulties in TB diagnosis in children. As children are considered in the majority of cases as non-contagious, asymptomatic disease is frequently ignored.

Objective: This study is aimed to detect the prevalence of pulmonary TB among under five children and evaluate the diagnostic agreement of GeneXpert MTB/RIF against Lipoarabinomannan (LAM) antigen for the detection of TB in children using urine samples

Methods: Institutional based cross-sectional study was conducted in Wolaita Sodo University Comprehensive Specialized Hospital.  LAM antigen and GeneXpert methods were used to detect TB from urine sample. Descriptive analysis was used to characterize the study population. Kappa statistics with the standard error (SE) was used to determine inter-reader agreement between LAM test results and GeneXpert. Accuracy measures (sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV) and likelihood ratio (LR)) were calculated with 95 % Confidence Interval (CI). In addition, statistical models such as logistic regression were used to determine factors associated with TB detection. Finally, P-values less than 0.05 were considered as having a statistically significant association.

Results: Out of 337 study participants included in this study, M. tuberculosis was detected in 29 in GeneXpert giving an overall prevalence of 8.6% and 26 (7.71%)  in TB LAM.  The two tests had almost perfect agreement (K=0.94, SE= 0.034) for the detection of TB in urine sample. Presence of other co-infection [AOR =4.00: 95% CI, 1.428, 11.203)], cough for previous 2 weeks [AOR = 3.700:  95% CI, 1.039, 13.183], night sweat [AOR = 4.255: 95% CI, 1.453, 12.463] and loss of appetite [AOR = 3.994: 95% CI, 1.444, 11.045] showed significant association with pulmonary TB in children.

Conclusion: TB was still the public health concern among children of under five years old. The GeneXpert for TB diagnosis showed almost perfect test agreement with TB LAM antigen method with kappa= 0.941.  Co-infection, coughs for previous 2 weeks, night sweat and loss of appetite were independent factors of pulmonary TB among children.

Keywords: Tuberculosis, GeneXpert, LAM, Wolaita Sodo, Ethiopia