Tuberculosis is the 7th leading cause of death worldwide
According to CDC, 9,105 cases of tuberculosis have been diagnosed in the United States in the year 2017. The prevalence of pulmonary tuberculosis being diagnosed along with asbestosis ranges from 3.8%-36%, thus establishing an association between the two lung disorders. Patients with asbestosis show poor immune response and reduced defensive capacity of the lung, which makes them prone to infections including Mycobacterium tuberculosis.
In 2002, a single-blind cohort study reported an association between asbestos exposure and pulmonary tuberculosis in a group of Iranian factory workers, which included 202 workers exposed to asbestos and 201 workers non-exposed to asbestos. The study concluded that exposure to asbestos is a predisposing factor to the development of secondary tuberculosis, which may occur due to the reactivation of dormant foci of Mycobacterium infection in the lungs. According to the American Lung Association, more than 9.6 million people suffer from an active form of tuberculosis. People with a latent form of tuberculosis are asymptomatic and carry a 15% lifetime risk of developing an active infection, the risk is higher in immunocompromised individuals.
Common signs and symptoms of tuberculosis and interstitial lung diseases
The signs and symptoms of asbestosis and other interstitial lung diseases are quite similar to the symptoms of other lung diseases including tuberculosis. The table below summarizes and compares the symptoms of tuberculosis and asbestos-related interstitial lung disease:
|
Tuberculosis
|
Interstitial Lung Diseases
(Asbestosis)
|
- Difficulty in breathing
- A persistent Cough, productive
- Weight loss
- Fever
- Fatigue
- Chest pain
|
- Shortness of breath
- Dry, non-productive cough
- Weight loss
- Increased fatigue on exertion
- Fever
- Chest pain
- Clubbing of fingers
|
Generally, the most common symptoms of a respiratory disorder such as a cough and difficulty breathing tend to get overlooked or sometimes wrongly thought to be because of habits such as smoking, aging, or infections, more commonly tuberculosis. This can lead to patients being subjected to unnecessary anti-tuberculous treatment and its side effects as well as a delay in deriving appropriate care. Therefore, early diagnoses of interstitial lung diseases including asbestosis require a higher degree of clinical suspicion.