Unveiling the Mysteries of Pulmonary Tuberculosis: Research and Clinical Perspectives

Earmine Ebate^*
*Correspondence: Earmine Ebate, Department of Clinical Studies, University of Guelph, Guelph, Canada, Email:

Keywords

Genetic • Public health • Lung cancer

Introduction

Throughout history, TB was a source of great suffering and was often referred to as the "white plague" due to the severe weight loss and paleness it caused in its victims. It afflicted notable historical figures, including Edgar Allan Poe, John Keats, and Frédéric Chopin, leaving its mark on literature, art, and culture. In the early 20th century, TB sanatoriums became common, as fresh air and rest were considered essential for treatment. Despite the advances in medical science and the development of effective antibiotic treatments, tuberculosis remains a significant global health threat. In 2020, the World Health Organization (WHO) reported an estimated 10 million people falling ill with TB, and 1.5 million deaths attributed to the disease, making it one of the top infectious killers worldwide. While the incidence and mortality rates have been on the decline, especially in high-income countries, certain regions still face formidable challenges in the fight against TB.

Literature Review

TB is not evenly distributed across the globe, with the majority of cases occurring in low- and middle-income countries. High-burden countries such as India, China, Indonesia, Pakistan, and Nigeria account for the lion's share of TB cases. In these nations, factors like poverty, overcrowding, and limited access to healthcare contribute to the persistence of the disease. One of the most pressing concerns in TB management is the emergence of drug-resistant strains of Mycobacterium tuberculosis. Multidrug-Resistant TB (MDR-TB) and Extensively Drug-Resistant TB (XDR-TB) pose serious challenges due to the limited treatment options available. These drug-resistant strains can develop when patients do not adhere to their prescribed medication regimens or when they receive inadequate treatment. Tuberculosis and HIV have a deadly synergy. People with weakened immune systems due to HIV infection are at a much higher risk of developing active TB. In many regions, TB is a leading cause of death among people living with HIV. This dual burden complicates treatment strategies and calls for integrated care [1].

Understanding the pathophysiology of pulmonary tuberculosis is crucial for effective management and treatment. TB primarily affects the lungs but can also affect other organs. The disease progresses through several stages, each with distinct clinical and radiological features. TB infection typically begins when an individual inhales droplets containing Mycobacterium tuberculosis

The bacteria enter the lungs and are ingested by alveolar macrophages, a type of white blood cell. In most cases, the immune system successfully contains the infection, and the individual remains asymptomatic. This condition is known as Latent Tuberculosis Infection (LTBI). If the immune response fails to contain the infection, the bacteria can replicate and cause primary TB disease. At this stage, patients often present with symptoms like persistent cough, fever, night sweats, and weight loss. Chest X-rays may reveal pulmonary infiltrates, and sputum smears or cultures can confirm the presence of Mycobacterium tuberculosis [2].

Discussion

Post-primary TB, also known as reactivation TB, typically occurs when latent infections become active due to a weakened immune system. It often presents with cavitary lesions in the upper lobes of the lungs and is associated with chronic cough and hemoptysis (coughing up blood). While pulmonary TB is the most common form, Mycobacterium tuberculosis can also affect other parts of the body, causing extra pulmonary tuberculosis. Sites commonly involved include the lymph nodes, bones, joints, and the central nervous system. Extra pulmonary TB can present with a variety of symptoms, depending on the affected organ. Microbiological tests are considered the gold standard for diagnosing TB. These include sputum smear microscopy, culture, and Nucleic Acid Amplification Tests (NAATs). Sputum smear microscopy is a simple and widely available test, but it has limitations in sensitivity. Culturing Mycobacterium tuberculosis from a patient's sputum allows for drug susceptibility testing but is slower. NAATs, such as the Xpert MTB/RIF assay, offer rapid and highly sensitive detection of TB and rifampicin resistance [3].

Chest X-rays and Computed Tomography (CT) scans are invaluable tools in diagnosing and monitoring pulmonary TB. Radiological findings can provide insights into the extent and location of disease, helping clinicians make treatment decisions. TST, also known as the Mantoux test, and IGRAs like the QuantiFERON-TB Gold test are used to detect latent TB infection. These tests measure the immune response to TB-specific antigens, and a positive result indicates previous exposure to the bacterium. Clinical assessment involves evaluating a patient's symptoms, medical history, and physical examination. A combination of clinical findings, radiological evidence, and microbiological tests is often necessary for a definitive diagnosis.

The treatment of pulmonary tuberculosis primarily relies on a combination of antibiotics known as anti-tuberculosis drugs. The choice of drugs and the duration of treatment depend on several factors, including the patient's age, the severity of the disease, and the presence of drug-resistant strains. The cornerstone of TB treatment involves first-line drugs, which are highly effective and less toxic. The standard regimen for drug-susceptible TB includes a combination of isoniazid, rifampicin, pyrazinamide, and ethambutol, taken for two months, followed by isoniazid and rifampicin for an additional four months. This six-month regimen is highly effective at curing most cases of TB. In cases of drug-resistant TB, treatment becomes more complex and challenging. MDR-TB and XDR-TB require treatment with second-line drugs, which are less effective, more toxic, and often require longer treatment durations. The management of drug-resistant TB also necessitates close monitoring for adverse effects and the need for individual

A critical aspect of TB treatment is patient adherence to the prescribed medication regimen. Patients are required to take their medications consistently for the entire duration of the treatment course, which can extend from six months for drug-susceptible TB to 20 months or more for drug-resistant forms. Non-adherence can lead to treatment failure, the development of drug resistance, and ongoing transmission of the disease. To enhance patient adherence, Directly Observed Therapy (DOT) programs are implemented in many settings. In these programs, a healthcare worker or community health volunteer observes the patient taking their medication, ensuring compliance with the treatment plan. DOT has been successful in improving adherence and treatment outcomes. In high-burden TB regions or among individuals at increased risk, preventive therapy may be recommended. This involves the administration of isoniazid to individuals with latent TB infection to prevent the development of active TB. Preventive therapy is crucial for reducing the reservoir of TB in communities [4-6].

Conclusion

The emergence of drug-resistant TB strains is a major challenge. MDR-TB and XDR-TB are more challenging and costly to treat, and the availability of effective second-line drugs is limited. Preventing the development of drug resistance through improved adherence and appropriate drug regimens is crucial. In many parts of the world, access to TB care and treatment remains limited, especially in remote or impoverished areas. Efforts to improve access to healthcare services, particularly for vulnerable populations, are essential in reducing the burden of TB. In many parts of the world, access to TB care and treatment remains limited, especially in remote or impoverished areas. Efforts to improve access to healthcare services, particularly for vulnerable populations, are essential in reducing the burden of TB. Pulmonary tuberculosis, once known as the "white plague," continues to affect millions of people worldwide. While great strides have been made in understanding and treating the disease, challenges persist, including drug resistance, limited access to care, and stigma. Research and innovation have provided hope for better prevention, diagnosis, and treatment of TB and a coordinated global effort is essential to control and ultimately eliminate this ancient and formidable disease. The mysteries of pulmonary tuberculosis are gradually being unveiled, but the journey towards its eradication is far from complete.

Acknowledgement

None.

Conflict of Interest

The authors declare that there is no conflict of interest associated with this manuscript.

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