Screening Patients With Type 2 Diabetes for Active Tuberculosis in Communities of China

P atients with diabetes mellitus (DM) are at higher risk of tuberculosis (TB) (1), especially in China, where there is a high burden of both diseases (2). Comorbidity of DM and TB (DM 1 TB) results in higher probabilities of treatment failure, multidrug resistance, and death (3). In China, epidemiologic information for DM 1 TB is limited, and effective tools to identify cases of DM 1 TB are not available. Therefore, this cross-sectional, observational pilot study aimed to identify the prevalence, risk factors, and clinical symptoms of TB in patients with DM. A stratified-cluster random sampling method was used to enroll patients with diagnosed type 2 DM who were $25 years of age in randomly selected villages in two sampling sites/counties (Ningyang and Yishui in the Shandong Province) from May to July 2012. Diagnostic criteria of DM followed the guidelines of World Health Organization (4). TB screening guidelines were recommended by a consensus of experts. Diagnostic criteria of active TB followed the International Standards for TB Care (5). The study was approved by the ethics committee of Shandong University. After providing written informed consent, each patient was interviewed about their demographics and medical history, and then chest radiography was performed. Patients with abnormal chest radiographs provided three sputum specimens for sputum smear and culture. Patients in our study were diagnosed as having active TB if they met one of three criteria: positive smear, positive culture, or positive chest radiograph, as determined by a clinical diagnosis team. A Poisson regression model was used to evaluate the associations between TB and risk factors in patients with DM. The overall enrollment rate of patients with DM was 68.7% at both sites. TB was diagnosed in 14 of 4,085 patients with DM. Thirteen new TB cases (8 in Ningyang, 5 in Yishui) included one with a positive culture, and 12 with a positive radiograph (none of the new cases had a positive smear). One case in Yishui was retreated and had a positive smear. The prevalence of TB in patients with DM at the two sampling sites was 342.7 per 100,000 persons, compared with 42.8 per 100,000 persons in the local general population (i.e., approximately 8 times in relative risk). Table 1 presents the de-mographics and symptoms of the groups with DM 1 TB and DM only. The Poisson regression further identified the risk factors in adjusted odds ratio (OR) and 95% CI. Male …