This is a Geographic Information System (GIS)-based retrospective study. Data will be extracted from the NTUH medical records database, including the date of notification, sex, birth date, residence address, etc of each tuberculosis case. Each case will be geocoded to generate spatial coordinates for mapping purpose based on the street address and postal code. To protect the privacy of these patients, the personal identification data of TB patients, including name and ID numbers, will not be encoded. The encoded data file will also be strictly kept confidential.