Comparison of the incidence between tuberculosis and nontuberculous mycobacterial disease after gastrectomy

Gastrectomy is a well-known risk factor for tuberculosis (TB). However, little data are available regarding the relationship between gastrectomy and the risk of nontuberculous mycobacterial (NTM) disease. Here, we investigated the incidence of TB and NTM lung disease in gastrectomized patients.

New cases of TB and NTM lung infection or disease were examined among patients who had undergone gastrectomy due to gastric cancer from 2003 to 2009 at a tertiary referral hospital in South Korea. Annualized incidence rates for cases were compared with those of the general population.

This study included a total of 2,684 patients. New mycobacterial cases were found in 41 patients. Cases of TB and NTM lung infection were 35 (85 %) and 6 (15 %) including 2 NTM lung disease cases, respectively. Annualized crude incidence rates for TB, NTM lung infection, and NTM lung disease were 327/100,000, 56/100,000, and 19/100,000, respectively. The age-standardized incidence rate of TB was significantly higher in gastrectomized patients than in the general population. However, the standardized incidences of NTM lung infection and disease were not significantly different from those of non-gastrectomized patients. Patients with NTM lung infection frequently exhibited comorbid chronic lung disease, while those with TB were more frequently found to have fibronodular lesions on preoperative chest radiography.

Gastrectomy does not appear to increase the risk of NTM lung disease. However, NTM lung infection or disease should be considered as a differential diagnosis of pulmonary TB in gastrectomized patients accompanying chronic lung disease.