Clinical and molecular epidemiological features of tuberculosis after the 2011 Japan earthquake and tsunami

To investigate clinical characteristics and prognosis in tuberculosis (TB) patients and the transmission dynamics of TB after the 2011 Japan earthquake and tsunami.

This was a retrospective observational cohort study. Data were analyzed among 93 pulmonary TB patients (tsunami-affected areas 25, non-tsunami areas 68) hospitalized during March 2011-March 2012 with 1-year follow-up since treatment commencement. Variable number of tandem repeats (VNTR) typing was conducted for 38 TB strains (tsunami-affected areas 21, non-tsunami areas 17).

Patients from tsunami-affected areas were significantly more likely to be refugees (OR 12.8, 95%CI 2.45-67.20), receive oxygenation (OR 5.0, 95%CI 1.68-14.85), and have a unique VNTR (OR 4.6, 95%CI 1.14-18.41). Patients who died within 1 year were significantly more likely to be older (OR 9.8, 95%CI 1.85-180.26), partially dependent or dependent (OR 11.9, 95%CI 4.28-37.62), and to require oxygenation (OR 4.3, 95%CI 1.47-12.89), and had lower serum albumin levels (OR 11.1, 95%CI 2.97-72.32).

Risk factors for prognosis of TB after the earthquake were associated with advanced age, low serum albumin level, functional status at admission, and oxygen requirement. The VNTR results suggest that most of the cases with pulmonary TB experienced reactivation of latent tuberculous infection, likely due to the impact of the earthquake and tsunami.