Tuberculosis: Still a real threat
Just a few decades ago, we thought TB would be a thing of the past, to be studied in textbooks as a triumph of medical breakthrough and powerful drugs. We were wrong.
Since the introduction of antibiotics to treat tuberculosis (commonly known as TB) in 1940, everyone thought the disease would soon be eliminated.
However, in 2015, the World Health Organization (WHO) found there was a mere 1.5% annual reduction in the number of new TB patients since 2000, and it was still one of the top 10 causes of death globally. The young were not spared and approximately 170,000 children died because of the disease.
More than 95% of new TB cases and deaths from TB are contributed by developing countries. To make matters worse, 61% of the new TB cases reported in 2015 came from Asia.
Why is TB NOT going away?
1. The increasing frequency of cross-border migration.
Sometimes, people undergoing treatment for TB have to move to another state or country. They may stop taking their medications prematurely due to reasons such as lack of access to treatment in the new location. This will cause TB to spread across different communities.
2. The rise of co-infection with HIV
Individuals with human immunodeficiency virus (HIV) infections is at a higher risk of contracting active TB due to their weakened immune system. Thus, as the incidence of HIV infections continues to rise, so will TB.
3. The growing incidence of multiple drug resistant (MDR)-TB
MDR-TB occurs when the bacteria mutates. This can happen because of incorrect or incomplete TB treatment.
What to watch out for
TB is a bacterial infection that usually affects the lungs. However, it can also infect other parts of the body like the kidney, backbone and brain.
There are two types of TB infection:
• Latent TB
Worldwide, an estimated 3-out-of-10 people have latent TB. Individuals with latent TB do not fall sick when they are infected and do not spread the bacteria. Unfortunately, they have a 10% risk of the infection developing into active TB.
• Active TB or TB disease
People with active TB have symptoms of the disease and can pass the bacteria to those in close contact.
Individuals with active TB usually have a productive cough, and sometimes their phlegm may be red due to the presence of blood. They may also experience chest pains, weakness, night sweats, fever and weight loss.
How does TB spread?
When a person with active TB coughs, sneezes or speaks, the germs are released into the air and if you are near enough to breathe the bacteria in, you may catch the infection.
If somebody you regularly spend time with has active TB, chances are the germs may have entered your body. Also, if you have a condition that weakens your immune system such as an HIV infection, you are at higher risk of catching TB compared to a healthy person. Another thing that puts you at higher risk of getting infected is if you live in a country where TB is very common such as Asia and Africa.
I think I might have TB
You should go to a clinic or hospital and see a doctor for a check-up if you have symptoms of TB or think you fulfil the criteria above. If necessary, the doctor will perform a TB skin test or a TB blood test to try and detect if you are carrying the bacteria in your body.
• TB skin test (also known as Tuberculin test and Mantoux test)
This is the more commonly used test. The doctor will inject a small amount of a chemical called tuberculin under your skin and draw a circle around the injection area. After 2 to 3 days, you have to return to the clinic or hospital for the doctor to see if there is any reaction to the tuberculin.
• TB blood test
The blood test is used to measure an individual’s reaction to Mycobacterium tuberculosis, the germ that causes TB.
I had BCG vaccination when I was younger; will that affect my test results?
Usually, every Malaysian is given the Bacillus Calmette-Guérin (BCG) vaccine when they are born. If you have been vaccinated before, you can still have a positive reaction to a TB skin test if you are infected. Nevertheless, it is also possible for you to have a positive reaction to a TB skin test even if you are not infected with the TB bacteria. Your doctor will be able to advise you on this.
As for the TB blood test, the result is not affected by prior BCG vaccination and may be a more accurate screening test for those who have been vaccinated.
What if my screening test results came back positive for TB?
If your TB skin or blood test came back positive, there are additional tests that the doctor will conduct, such as chest X-ray and microscopic examination of the phlegm. It is also possible that the doctor will perform more advanced tests to detect MDR-TB and HIV-associated TB, if necessary.
I have been diagnosed with TB; what happens now?
The good news is that TB is a treatable and curable disease. Generally, the management plan depends on whether you have latent or active TB.
• Latent TB
The majority of people with latent TB will not develop active TB, thus no medications will be given. However, if you have a high risk for developing active TB (i.e. have existing HIV-infection, were infected with TB in the last 2 years), you will be given medication to prevent that from happening. Depending on the type of medication and other factors, you may have to take medication for 3 to 9 months.
• Active TB
Your doctor will give you medications to take for 6 months or longer. The medications that are usually given are isoniazid, rifampicin, ethambutol and pyrazinamide. Remember, just because you feel better does not mean the bacteria is gone from your body, so make sure you finish taking your medications as advised by your doctor! If you do not do so, you may risk developing MDR-TB as the germs mutate and become immune to the medications you were taking. MDR-TB is more difficult plus expensive to treat. Moreover, you will risk spreading the disease to your loved ones.
Despite being a curable disease, TB is still a public health problem in low- and middle-income countries. We need to redouble our efforts to ensure the disease goes the way of the dinosaurs, and this means everyone everywhere needs to do their part. If you think you have TB, go for a check-up pronto. If you do have the disease, make sure you complete your treatment!