Most countries where TB is widespread are poor; its prevalence is highest in countries with the lowest per-capita GDP. It is, therefore, not surprising that one of the main reasons TB incidences have not significantly decreased is the lack of simple, effective and inexpensive ways to detect new TB cases at an early stage. While the only way to diagnose TB is with a test like GeneXpert, these tests are expensive.
The World Health Organization
The World Health Organization (WHO) has recommended digital chest X-rays for systematic TB screening, which can show abnormalities in the lungs that suggest a patient may have TB. Although X-rays require local expertise for accurate reading, they have low operational costs and quick results.