Tuberculosis continues to be one of the world's deadliest infectious diseases, claiming some 2,70,000 lives each year in India alone, according to the WHO's Global Tuberculosis Report 2015. An estimated one-third of the world's population has latent TB, meaning that they are infected by the TB bacterium but they show no symptoms and are not infectious. Most people with latent TB will never progress to active TB disease, as long as a strong immune system continues to keep their TB infection inactive. It is only after the TB bacterium multiplies and causes active disease that symptoms develop.
For TB, early and accurate diagnosis is critical for prompt and effective treatment to start and the cycle of transmission to be broken. It is also important to determine whether the disease is resistant to first-line drugs. If it is, a different and lengthier second-line treatment regimen is required.
Many of the current tests have low sensitivity, meaning that they miss too many people with TB.
TB presents a tough challenge for diagnosis. Children are particularly difficult to diagnose because they have trouble producing sputum samples. Traditionally, TB has been diagnosed by looking for evidence of TB bacteria in sputum and taking chest x-rays. The time-consuming nature of these traditional methods is a real concern because it can take anywhere between a week to six weeks to get the lab results. Many of the current tests have low sensitivity, meaning that they miss too many people with TB. Moreover, TB diagnostics require trained personnel and expensive laboratory equipment, both of which present challenges in a country such as India. Finally, it is difficult and even more time-consuming to detect drug-resistant TB using traditional lab methods, taking up to 120 days to get a result.
In 2007, FIND started its operations in India and signed a memorandum of understanding with the Central TB Division and the Ministry of Health and Family Welfare to introduce new, rapid and quality-assured tests for TB at an affordable price for the public health sector. Since then, FIND has supported the development of a number of new rapid diagnostic tests and tools. These tests reduce diagnosis time from several weeks--or even months for drug-resistant TB--to just 2-5 hours. Cepheid's GeneXpert MTB/RIF molecular test is one of these more rapid tests. It can detect the DNA of the TB bacterium from sputum samples in less than two hours. It can also provide a rapid indication of drug resistance, as it can detect genetic mutations indicative of resistance to the drug Rifampicin.
FIND has supported the development of new rapid diagnostic tests and tools that reduce diagnosis time from several weeks--or even months--to just 2-5 hours.
In 2009, the EXPAND-TB (Expanding Access to New Diagnostics for TB) project was launched to accelerate access to new, rapid diagnostics for patients at risk of multidrug-resistant TB (MDR-TB) in 27 countries. Funded by UNITAID, this initiative was collaboration between World Health Organization, the Stop TB Partnership's Global Laboratory Initiative, Global Drug Facility and FIND, working closely with the Government of India. Over the course of the project, more than 80,000 people were diagnosed with MDR-TB in India in project-supported labs. This project ended in December but will be continued by the Central TB Division with additional financing from The Global Fund.
TB is curable, but it must be diagnosed first. Early and accurate TB detection is needed to ensure that the right course of treatment is quickly prescribed, thereby halting the spread of TB, including its drug-resistant forms. Diagnostic solutions need to be integrated into our strategy to combat TB in India and around the world.
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