Drug-Resistant Tuberculosis

Hello all! In this week’s post, I would like to talk about drug-resistant Tuberculosis. I find this topic to be very interesting since Tuberculosis is a detrimental disease that affects numerous individuals all across the globe. Without effective antibiotics, how are patients supposed to fully recover from this deadly disease? This imposes an urgent solution in the scientific community to come up with alternative ways to overcome drug-resistant Tuberculosis. 

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As a reminder, Tuberculosis is caused by the bacteria, Mycobacterium tuberculosis. A person who has contracted Tuberculosis can infect others by simply sneezing, coughing, speaking, or even singing through aerosolized particles lingering in the air (CDC).

Example of aerosol from sneezing

Spread of Tuberculosis 

In most cases, Tuberculosis typically affects the lungs, but it can also affect the brain, kidneys, and even the spine. Most of the time TB is treated with anti-TB agents such as Isoniazid, Rifampin, Ethambutol, and Pyrazinamide. Interestingly enough, drug-resistant TB can be spread the same way that drug-susceptible TB is spread, through aerosolized particulates (CDC).

Commonly prescribed Tuberculosis Drugs

Now, what causes Mycobacterium tuberculosis to become drug-resistant to common Tuberculosis antibiotics? Firstly, drug-resistant TB can occur if the drugs prescribed to treat Tuberculosis are misused. This can occur if a patient diagnosed with active Tuberculosis does not finish their full course of TB treatment. This can occur if clinicians mistakenly prescribe the wrong treatment dosage or length. Additionally, if drugs are not available for proper treatment or poor-quality drugs are given, this can also be alternative causes for drug-resistant TB. In any case, people who are more susceptible to drug-resistant TB are those that do not take their TB medications as prescribed, those that come from sectors of the world where drug-resistant TB is more prevalent, and those that surround themselves near other people with drug-resistant TB for a prolonged period of time (CDC).

     In the figure above, drug resistance surveillance data shows an estimated 240,000 people died from MDR-TB in 2016 (WHO) . MDR-TB is a type of drug resistance Tuberculosis as described below.     

Different types of drug-resistant Tuberculosis:

How to PREVENT drug-resistant Tuberculosis (CDC)?

• Patients must take their Tuberculosis medications as prescribed by their healthcare provider.
• Avoid exposure from people who are known to have drug-resistant TB in all environments such as hospitals and crowded areas. 

Fluoroquinolone antibacterial drugs are prescribed to patients who have been diagnosed with drug-resistant Tuberculosis. Fluoroquinolones are active against Mycobacterium tuberculosis and are essentially used as a replacement drug for some of the first-line drugs to treat Tuberculosis. Some of the fluoroquinolones used to treat Tuberculosis are ciprofloxacin, ofloxacin, levofloxacin and sparfloxacin. Just like the other drugs used to treat Tuberculosis, drug-resistance to fluoroquinolones could also occur by chance or may be acquired, especially when misused (Berning, 2001).  

In this video, Harvard Medical School researchers focus in on genetic markers of drug-resistant Tuberculosis.     

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