Comparison of Xpert MTB/RIF Assay and the Conventional Sputum Microscopy in Detecting Mycobacterium tuberculosis in Northern Thailand oleh Kanokwan Pinyopornpanish, Romanee Chaiwarith, Chansom Pantip, Rassamee Keawvichit, Kanlaya Wongworapat, Phadungkiat Khamnoi, Khuanchai Supparatpinyo, Thira Sirisanthana