The spatial analysis of extrapulmonary tuberculosis spreading and its interactions with pulmonary tuberculosis in Samarinda, East Kalimantan, Indonesia.

Background: Extrapulmonary Tubercolosis (EPTB) is an infectious disease that affects tissue outside the lungs. EPTB patients cannot be source of infection, therefore the findings in the community indicate that there are still active pulmonary TB patients acting as a source of infection. Understanding distributions of EPTB can be used as indicator to individuate the unmonitored source of TB transmission in the community.

Objectives: The aim of this study is to analyze EPTB using spatial modeling based on patients' location.

Methods: This study is an observational research with spatial analysis approach using SatScanv.9.4.4 and ArcGis v.10.4. Involving 46 samples of EPTB patients in Anatomy Pathology Laboratory of RSUD Abdul Wahab Sjahranie in 2017 and 7 pulmonary TB patients who were contacts of EPTB patients. The distribution of EPTB patients is mostly located in areas with high population density.

Results: The results showed that the distribution pattern of EPTB patients was mostly in areas with high population densities. Space-time permutation model shows there are 3 clusters of EPTB with a 2.91, 0.97, 1.13 km radius centered on -0.504177 S/117.092132 E, -0.476895 S /117.141700 E, -0.517031 S/117.092132 E.

Conclusion: The distribution of patients with EPTB and pulmonary TB indicates there is an interaction between EPTB and pulmonary TB in the cluster area. Bernoulli model shows that there is 1 cluster of EPTB and pulmonary TB with relative risk 5.29, radius of 3.19 km, and centered on - 0.458159 S / 117.149945 E.