Epidemiology and risk factors for extrapulmonary tuberculosis in Lebanon

SETTING: Lebanon is a relatively low TB-burden country, but has a high proportion of extrapulmonary tuberculosis (EPTB). Concern has been expressed that Syrian-born refugees could add to the TB burden and rates of EPTB: since 2011, >1 000 000 Syrian refugees have entered Lebanon. OBJECTIVE: The Lebanese National Tuberculosis Programme (NTP) sought to identify factors for the high proportion of EPTB and to assess the potential impact of Syrian refugees. DESIGN: NTP line-listed data from 2014-2015 were analyzed with logistic regression identified risk factors for EPTB. A trend analysis for 2011-2015 assessed TB burden by nationality and site of TB. RESULTS: Of 1347 reported TB cases from 2014 to 2015, 507 (38%) were EPTB and 46% were Lebanese. In analysis limited to Lebanese-born, the proportion of EPTB cases was relatively stable, 47% in 2011 and 52% in 2015. Modeling identified risk factors for EPTB as being female (aOR 1.79, 95%CI 1.39-2.32) and 5-15 years old (aOR 3.31, 95% CI 1.47-7.45) compared with children aged <5 years. Between 2011 and 2015, the proportion of TB cases among Syrian-born increased from 3% in 2011 to 21% in 2015 (P < 0.001); however, the proportion of EPTB versus PTB cases among Syrians remained stable (P= 0.264). CONCLUSION: Syrian TB cases increased almost 10-fold in five years (2011-2015) but their contribution to EPTB did not change. The high proportion of EPTB in Lebanon and those aged 5-15 years merits further investigation.