Frequency of tuberculosis among diabetic patients in the People’s Republic of China

Wang, Hong-Tian; Zhang, Jing; Ji, Ling-Chao; You, Shao-Hua; Bai, Yin; Dai, Wei; Wang, Zhong-Yuan

A survey was carried out by Lin et al in 2011-2012 in which five DM clinics were selected to represent the central, east, northwest, and southwest of mainland China. 26 Patients aged 14 years or older diagnosed with DM and treated in the five DM clinics were enrolled from September 2011 to the end of March 2012. The screening for active TB followed the guidelines of the China National Tuberculosis Program (NTP). The screening was based on five questions regarding symptoms: 1) cough for longer than 2 weeks, 2) night sweats for 4 weeks or longer, 3) fever for 4 weeks or longer, 4) weight loss over the previous 4 weeks, and 5) any suspicion of active TB to account for extra-pulmonary TB. Patients with positive symptoms (an affirmative answer to any of the five questions) were referred to TB clinics for further investigation. When the diagnosis of active TB was made using sputum-smear microscopy for acid-fast bacilli (AFB) and chest radiography, the patient was referred to the NTP for registration and treatment. Between 68% and 79% of patients with DM were recorded as having been screened for TB. Of the 15,342 patients screened in the study, seven were identified as having TB and were receiving anti-TB treatment, 92 had positive symptoms (0.6% of those screened), 88 were referred for TB investigation (four were not referred for personal reasons), and 48 were newly diagnosed with TB (55% of those screened). All except one of these patients were started on anti-TB treatment, with one patient being lost to follow-up after diagnosis. A total of 55 DM patients (established and new) were identified as having TB: 40 with new and 15 with recurrent TB, 28 with smear-positive PTB, 24 with smear-negative PTB, and three with extra-pulmonary TB. The frequency of TB among patients with DM in the People's Republic of China was about 958 per 100,000. Other risk factors for TB -including HIV, steroid use, and immunocompromised states that may coexist with DM -were ruled out in screening patients with DM for TB. (Tables 1 and 2 ). The total number of TB cases was 6,421 (males 3,632, females 2,789) and the total number of DM cases among these was 567 (males 406, females 161). The 8.8% prevalence of DM in patients with TB was much higher than in patients without TB. We found that the number of TB and TB + DM cases changed year by year. TB cases and TB + DM cases ranked highest in 2011 and in 2012, respectively. The lowest numbers for both were in 2003 (many SARS [severe acute respiratory syndrome] patients were treated that year). The average age of the TB + DM patients was 56.07 years (17-87 years). The average age of TB patients was 45.03 years (21-84 years) . Males were overrepresented in the TB + DM group, compared to the TB-only group. There were 216 cases (48.5%) positive for AFB among 445 cases with PTB, and the positive rate in the DM group was obviously higher than that in the TB-only group. There were 41 serious cases of DM (7.2%), which was higher than in the TB-only group (3.3%). In the DM group, 236 cases (41.6%) had concurrent infections with other bacteria, viruses, or fungi, but the TB-only group had 1,315 patients with other infections, with a rate of 22.5%, clearly lower than the DM group. However, the hospitalized death rates in the two groups were very similar, at 1.2% and 1.4% for the TB-only group and the DM-only group, and the average periods of hospitalization in these two groups were also similar at 27.48 days and 27.6 days, respective