Test agreement between GeneXpert and urine lipoarabinomannan test for tuberculosis diagnosis among children in Ethiopia.

Abstract

Background: Tuberculosis (TB) is one of the leading public health problems in children mainly due to difficulties in the diagnosis of disease in children. It has been reported that the commercial urine lipoarabinomannan (LAM) assays used in patients with confirmed pulmonary TB have low sensitivity. This raises the need for alternative tests to screen for M. tuberculosis infection using easily collectable samples, such as urine, in host samples. This study aimed to detect the diagnostic agreement between GeneXpert MTB/RIF and WHO-recommended LAM antigen test for the detection of TB in children using urine samples.

Methods: An institutional-based cross-sectional study was conducted on 337 children in Wolaita Sodo University comprehensive Hospital. LAM antigen and GeneXpert methods were used to detect TB from urine samples. The agreement between the two tests was assessed using Kappa statistics with the standard error (SE), concordance, and disagreements statistics. Logistic regression was used to determine factors associated with TB and P-values less than 0.05 were considered as having a statistically significant association.

Results: M. tuberculosis was detected in 26 using TB LAM giving an overall prevalence of 7.7% (5.0-10.7%) and 8.6%; CI 5.6-11.6) using GeneXpert. The two tests had an almost perfect agreement (Concordance of 99.1% and kappa value of 0.94 with a standard error of 0.034) for the detection of TB in urine samples. Co-infections with other diseases [AOR = 4.00: 95% CI, 1.428, 11.203], cough for the previous two 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] had significant associations with pulmonary TB among children in the study area.

Conclusion: Tuberculosis was still a public health concern among children under five years old in the study area. The GeneXpert had almost perfect test agreement with WHO recommended TB LAM antigen test for the diagnosis of TB among under-five children, however, it needs further confirmation study with a large sample size to use as a diagnostic test.