Difference of No Difference: Tuberculosis in Hong Kong

Globally, tuberculosis (TB) has continued to be a major public health problem despite medical advances over the past century. According to the World Health Organization (WHO), Hong Kong is classified as a region having intermediate burden of TB. Using GIS to help visualize TB cases, these two maps were created: one showing actual individual cases and the other randomly located cases. The maps resemble each other but were produced from two different datasets.

The map of individual cases was made from data provided and authorized by the Tuberculosis and Chest Service of Hong Kong Government. In order to protect the confidentiality of patients, residential addresses first were geocoded and then randomly assigned to buildings within 200 meters.

The use of available aggregated data can also contribute to the generation of meaningful maps. The other map uses district-based TB data in the public domain. District-based data was distributed randomly over the built environment in lowland and along coastal areas. Agricultural lands, wetlands, and hydrological features are deemed as uninhabitable where no TB cases should be located. The result is a distribution map with total anonymity of patients.

Courtesy of Stanley Ho Centre for Emerging Infectious Diseases.