BCG World Atlas — a website that offers TB information from 180 countries

Tuberculosis is a major health threat worldwide. Every second, someone in the world is newly infected with TB bacteria.

Now, ahead of World TB Day on Thursday, Canadian researchers have launched an easy-to-use, searchable website that provides free information on current and past TB vaccination policies and practices for more than 180 countries.

BCG World Atlas, the brainchild of McGill University researchers, is being touted as a first-of-its-kind resource for clinicians, policymakers and researchers.

“The Atlas has important implications on diagnosing and treating TB and on the research that's being done on developing a new TB vaccine,” said co-author Madhukar Pai, assistant professor at McGill's Dept. of Epidemiology, Biostatistics & Occupational Health.

The Bacille Calmette-Guérin (BCG) vaccine was introduced in 1921 and is the only vaccine used to prevent TB.

The vaccine, however, remains controversial, with known variations in efficacy, strains, policies and practices across the world.

BCG Atlas project leader Alice Zwerling said that BCG vaccination could cause false positives in the skin test that is routinely used to screen for latent TB.

"As a clinician, if you're trying to interpret the skin test in a foreign-born person, you're going to want to know when the BCG vaccination was given back home and how many times it has been given," she said.

"The Atlas provides this information and can help doctors decide on when to use the newly available blood tests for TB that are not affected by BCG vaccination," she added.

More details of the website have been published in the March edition of the journal PLoS Medicine.