WHO prequalifies first TB diagnostic test

ISLAMABAD: The World Health Organization (WHO) has granted prequalification to Xpert MTB/RIF Ultra, a groundbreaking molecular diagnostic test for tuberculosis (TB), marking a significant milestone in the global fight against one of the deadliest infectious diseases.

This is the first diagnostic test for TB and drug-resistance testing to meet WHO’s stringent prequalification standards. Tuberculosis remains a leading cause of death worldwide, with over a million fatalities annually, and continues to impose immense health and economic burdens, especially in low- and middle-income countries like Pakistan.

The introduction of Xpert MTB/RIF Ultra is expected to enhance TB control efforts in Pakistan, which has the fifth-highest TB burden globally, experts said on Thursday. This nucleic acid amplification test (NAAT) detects the genetic material of Mycobacterium tuberculosis in sputum samples within hours. It also identifies mutations associated with rifampicin resistance, a key indicator of multidrug-resistant TB (MDR-TB). By providing rapid and accurate results, the test addresses critical challenges in the early detection of TB and its resistant forms. The WHO emphasised the importance of this diagnostic breakthrough, highlighting its potential to strengthen health systems. “This first prequalification of a TB diagnostic test marks a critical milestone in WHO’s efforts to support countries in scaling up access to high-quality TB assays,” said Dr. Yukiko Nakatani, WHO Assistant Director-General for Access to Medicines and Health Products. She added that this innovation would significantly contribute to addressing one of the world’s deadliest infectious diseases.

The test, developed by Cepheid Inc., underwent rigorous assessment by WHO, including a review by Singapore’s Health Sciences Authority. Designed for use with the GeneXpert® Instrument System, the test can diagnose TB in patients who screen positive for pulmonary TB and have not received more than three days of anti-TB treatment in the past six months. Dr Rogerio Gaspar, WHO Director for Regulation and Prequalification, described the test as a cornerstone for effective TB care and prevention, stating, “Prequalification paves the way for equitable access to cutting-edge technologies, empowering countries to address the dual burden of TB and drug-resistant TB.”

In Pakistan, where hundreds of thousands of TB cases emerge annually, this test offers a promising solution to ongoing diagnostic challenges. Traditional methods like microscopy and culture-based testing are time-consuming and less sensitive, particularly for detecting low bacterial loads and drug resistance. The Xpert MTB/RIF Ultra test is designed to overcome these limitations by providing faster and more reliable results. For Pakistan, experts say, integrating Xpert MTB/RIF Ultra into the National TB Control Programme could accelerate efforts to combat TB and MDR-TB. Early and accurate detection is crucial to reducing transmission, initiating timely treatment, and achieving the country’s goal of eliminating TB as a public health threat by 2030.

The test’s prequalification complements WHO’s broader TB strategy, which includes the endorsement of emerging diagnostic tools and addressing equity and accessibility issues. Additionally, WHO is currently assessing seven other TB diagnostic tests to further expand diagnostic options globally.