The global emergence of multidrugresistant (MDR) tuberculosis (TB) and extensively drug-resistant (XDR)-TB threatens to derail the efforts of TB control programmes worldwide. From 2000 to 2010, 161 pulmonary MDR-TB cases (including six XDR-TB cases) were reported in Singapore, and of these, 80% occurred among the foreign-born, with an increasing trend seen after 2004. Among new pulmonary TB cases, the highest incidence of MDR-TB occurred among patients from Myanmar (8%), followed by Vietnam (4.4%) and China (2.3%), while among those previously treated, the highest incidence was found in patients from Vietnam (50%), followed by Indonesia (33%) and Bangladesh (33%). Although the proportion of Singapore-born pulmonary TB cases with MDR-TB has remained comparatively low (0.2% and 1.3% in new and previously treated cases, respectively), there is no room for complacency. Top priority must be accorded toward the proper treatment of drug-susceptible TB cases under strict programme conditions so as to prevent the development of MDR-TB in the first place.
Antitubercular Agents ; therapeutic use ; Emigrants and Immigrants ; Extensively Drug-Resistant Tuberculosis ; epidemiology ; Humans ; Mycobacterium tuberculosis ; Singapore ; epidemiology ; Tuberculosis, Multidrug-Resistant ; drug therapy ; epidemiology ; transmission

INTRODUCTION: It is vital to diagnose and treat pulmonary tuberculosis (PTB) early, in the interests of the patient and public health. At the Singapore Tuberculosis Control Unit (TBCU), it was not uncommon to discover abnormal chest radiographs (CXRs) predating their PTB diagnosis by months to years in the electronic medical records (EMRs) of sputum acid-fast bacilli smear-positive patients. Our study explored this observation. METHODS: The EMRs of sputum smear-positive PTB patients treated at the TBCU from January to July 2014 were viewed for abnormal CXRs preceding their PTB diagnosis. Information in the EMRs pertaining to the indication for the CXRs, radiological reports (including whether the possibility of PTB was stated) and action taken was captured. RESULTS: Of the 254 sputum smear-positive patients, 108 had previous CXRs in their EMRs, of whom 39 (36.1%) had previous CXRs compatible with PTB. Most of these were performed in tertiary institutions and for reasons unrelated to PTB. No action was taken in response to these CXRs in 24 (61.5%) patients. 27 (69.2%) patients had abnormal CXRs dating back more than six months, with 12 (30.8%) dating back more than 30 months before the PTB diagnosis. Patients aged ≥ 55 years were significantly more likely to have previous CXRs that were compatible with PTB. CONCLUSION PTB patients may be asymptomatic or have chronic indolent disease and remain undiagnosed for years. There is a need for vigilance within our healthcare system to seize opportunities for early diagnosis and treatment to prevent the spread of this infectious disease in Singapore.