Use of network analysis multidrug-resistant tuberculosis contact investigation in Kanchanaburi, Thailand

Objective To characterise MDR-TB outbreak and incorporate social network analysis with contact investigation to detect case-contact linkages and clusters. Methods MDR-TB cases registered in the district hospital between October 2012 and September 2015 were interviewed and their contacts were investigated. A relationship-based weighted network was constructed. Results Among 43 interviewed MDR-TB cases, 20 (47%) were male, five (12%) were asymptomatic (and discovered incidentally) and 22 (51%) had underlying diseases. From the documented 115 contacts, 61 (53%) were household contacts and 49 (43%) were close (non-household) contacts; 70 (61%) were screened for TB using various tests. In this network, we prioritised 37 contacts connected with more than one MDR-TB patient. The largest cluster was identified in the pharmacy unit of the hospital. Conclusion This investigation yielded a significant number of MDR-TB contacts, and social network analysis facilitated the prioritisation for screening. Social network analysis is useful and feasible in this program setting and complements MDR-TB contact investigation.