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Q&A: A message to clinicians on World TB Day
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Tuberculosis represents one of the top 10 causes of death globally. It is the No. 1 infectious disease killer in the world, accounting for more deaths than malaria and HIV, according to WHO.
Although the number of TB–related deaths declined 22% between 2000 and 2015, the disease still accounted for 1.8 million deaths worldwide. WHO estimated that 10.4 million people were diagnosed with TB in 2015, including 1 million children. In addition, there were approximately 480,000 new cases of multidrug-resistant TB.
In May 2014, the World Health Assembly adopted WHO’s End TB Strategy, which aims to reduce TB deaths by 90% and new cases by 80%, and to eliminate overwhelming medical costs due to TB. Despite recent progress, WHO said that current investments in TB research are not enough to fully respond to the global TB epidemic. Last year, $6.6 billion was available for TB prevention, diagnosis and treatment, but an additional $1 billion is needed for research and development. WHO’s goal is to end the TB epidemic by 2030.
World TB day is observed annually on March 24 to raise public awareness of the disease. The day commemorates the date in 1882, when German physician and scientist Robert Koch, MD, announced his discovery of the TB–causing bacillus Mycobacterium tuberculosis.
Infectious Disease News spoke with Sarojini Sonia Qasba, MD, MPH, an infectious disease specialist at Suburban Hospital/Johns Hopkins Medicine in Bethesda, Maryland, about how clinicians can contribute to the fight against TB and end the global epidemic by 2030. – by John Schoen and Stephanie Viguers
What is the most important message for clinicians to hear on World TB Day?
It is critical for all of us clinicians to become better educated, with a deeper understanding of TB diagnostics and treatment. Oftentimes, many physicians don’t think of TB as part of the differential diagnosis when they see a patient with a cough, a fever or an abnormal chest X-ray. It’s vital that we as health care professionals read as much literature as possible, and regularly tap into the knowledge and experience of our colleagues regarding the diagnosis and treatment of both latent and active TB. I believe we have an opportunity to work together to help eradicate this global epidemic by accurately diagnosing and treating patients not only with active TB disease, but also those who have latent TB infection, before it progresses to active TB.
According to WHO, six countries — India, Indonesia, China, Nigeria, Pakistan and South Africa — account for 60% of new TB cases. How can we improve prevention and care in countries with a high burden of disease?
In these countries that hold such a high burden of the disease, the biggest challenges are providing patients access to necessary educational materials, knowledgeable health care providers, diagnostic tools, and proper treatments.
Although patients in large cities likely have access to clinics, health care providers and treatments, patients in rural settings and small villages often face difficulties and lack proper education about their risks for contracting TB, and how to get tested. The key to prevention in these areas is to generate additional funding to further increase education about the disease and improve access to quality care from diagnosis to treatment. Routine screening for latent TB in these areas can also help ensure patients are treated before the disease progresses to its active phase.
What are the most significant challenges to addressing the global TB/HIV co-epidemic?
Some health care providers may not be aware of the strong link between TB and HIV. Without an in-depth understanding of the proper signs, modes of diagnosis and available treatments for both diseases independently, the co-epidemic will continue to exist. It’s important to recognize that HIV and TB very often go hand in hand. Because HIV infection weakens the immune system, a person living with HIV is 26 to 31 times more likely to develop active TB than someone who is HIV negative. Being able to diagnose people with HIV earlier is vital to getting them treated with antiviral medications to strengthen their immune system, which, in turn, will lower their risk for contracting TB.
Can you discuss new innovations in diagnostics and what they mean in the fight against TB?
There have been some significant advances in diagnostic tools during the last several years — for both latent TB infection and active TB disease.
For latent TB infection, clinicians are aware of the older Mantoux tuberculin skin test (TST), but interferon-gamma release assays (IGRAs), particularly QuantiFERON (Qiagen), are what I prefer to use for my patients. IGRAs measure the cell-mediated response to specific TB antigens in whole blood and offer several benefits over TST, including a higher accuracy level resulting in fewer false-positive results and is appropriate to use in Bacillus Calmette-Guérin (BCG)–vaccinated patients. My patients also seem to prefer the IGRA test because it requires only one doctor visit.
For an active TB diagnosis, I often use the GeneXpert (Cepheid) kit. GeneXpert is a cartridge-based, fully automated nucleic acid amplification test, or NAAT, for active TB detection and rifampicin resistance testing. It purifies, concentrates, amplifies and identifies targeted nucleic acid sequences in the TB genome and provides results from unprocessed sputum samples in less than 2 hours.
The key for all clinicians is learning how and when to properly use these diagnostic tests for at-risk patients and patients showing signs or symptoms of TB.
TB is the leading infectious disease killer worldwide, claiming 1.8 million lives in 2015. How realistic is the goal to end the TB epidemic by 2030?
I am confident we can dramatically decrease the overall rate of TB worldwide by 2030, and I believe this goal should remain one our top priorities. However, we do have several obstacles to overcome.
BCG vaccination and current strategies are not working to accelerate the decline of active TB in the countries with the highest burden. Many experts agree the only way to do this is to address latent TB infection and prevent progression to active TB. For example, in many countries, there is no routine screening of children but rather a more reactive screening process when they are exposed to active TB, usually within their household. With the high rate of infection, we need to get ahead of it, and routine screening could save a lot of lives and even lead to discovery of active TB among adults in their household.
On a more granular level, many people often travel to and from countries with higher rates of TB infection (India, Indonesia, China, Nigeria, Pakistan and South Africa), without knowledge of their risk. I believe we can collaboratively and successfully contribute to lowering these high rates of active TB disease by better educating patients (and ourselves) to identify the disease earlier and ensuring everyone in every country knows where to turn for testing, treatment or advice.
Re ference :
WHO. Tuberculosis. http://www.who.int/mediacentre/factsheets/fs104/en/. Accessed March 21, 2017.
Disclosure: Qasba is on the speakers bureau for Qiagen.