What is Tuberculosis?
Tuberculosis is an infectious disease that has existed throughout history, going by names such as white plague and phthisis.
Tuberculosis (TB) is caused by a bacteria that gets into our bodies through the lungs.
Despite commendable medical advancement in diagnosis and treatment, Tuberculosis remains one of the top 10 killer diseases in the world. In 2017, there were over 10 million recorded cases of TB, with 1.6 million people dying from the disease in the same year, according to data from the World Health Organization.
Tuberculosis affects both adults and children, with adults being the most likely affected.
One in three persons, or about 2 billion people in the world are confirmed to be infected with Tuberculosis bacteria.
Out of these 2 billion people, 5-15% have a lifetime risk of falling ill with Tuberculosis disease.
Although tuberculosis is present in every country, people from low income areas especially in the developing countries are more susceptible to the disease.
This is due to the poor living conditions, crowded housing, poor health and poverty.
The highest number of infections usually occur in the western pacific regions and south Asia, accounting for about 62% of new cases followed by Africa, which accounts for about 25% of new cases.
People living with HIV are highly vulnerable and are 20-30 times more likely to be infected with the active tuberculosis owing to their weakened immune system.
People with other conditions that impair the immune system are also at a high risk of being infected with active TB.
Medications such as corticosteroids and infliximab have also been reported to increase the risk of getting infected with TB, especially in developing countries.
As I mentioned in the beginning, there has been commendable medical advancement in diagnosis and treatment of TB, but more needs to be done to combat the disease.
The World Health Organization has set a target of reducing the TB incidence rate by 90% and the number of TB-related deaths by 95% by the year 2035, as outlined in its ‘End TB Strategy’
WHAT CAUSES TUBERCULOSIS?
TB is an airborne infectious disease caused by the bacteria Mycobacterium tuberculosis (MTB).
TB can affect any part of the body but it most commonly affects the lungs.
The bacteria that causes TB is released into the air through tiny droplets whenever an infected person coughs, spits, shouts, or sneezes.
Infection occurs when someone inhales these droplets.
The bacteria passes through the mouth or nasal cavities to the respiratory tract and finally to the alveoli of the lungs.
Once in the alveoli, they start replicating.
It takes about six weeks for a small infection to appear which rarely gives any symptoms.
This is what is referred to as the primary infection.
Afterwards, the bacteria is carried by the lymphatic system from the lungs which is the primary site of infection, lymph nodes, kidneys, epiphyses of the long bones, and other areas of the body.
If one has a healthy immune system, the infection will remain dormant up until when the immune system becomes compromised.
If one has a weak Immune system the infection will progress into an active TB disease.
There are a number of risk factors that makes people more susceptible to TB.
Number one on the list is HIV. HIV weakens the immune system, giving an opportunity for the TB bacteria to multiply in the body. About 300,000 people died as a result of HIV-associated TB in 2017.
Living in overcrowded areas also puts one at a higher risk of being infected with TB. This is due to the congestion and poor aeration.
Malnutrition is another risk factor.
People suffering from malnutrition have low immunity and are therefore susceptible to contracting tuberculosis because their immune systems cannot fight the TB bacteria.
Other factors that increase the risk of contracting TB include substance abuse, pre-existence of diseases such as chronic lung disease, cancer, severe kidney disease and diabetes mellitus.
Babies and young children are also at high risk of contracting TB as their immune systems are weak and have not fully matured.
SIGNS AND SYMPTOMS OF TUBERCULOSIS
There are two kinds of TB; Latent TB and Active TB. With Latent TB, the bacteria Mycobacterium tuberculosis remains in an inactive state in the body.
It does not cause any symptoms, and the infected person will not even know that they are infected.
However, if the person is tested for TB, the test results will show that the person is infected. TB is not transmittable in this state but can become active whenever the immune system is compromised.
Active TB, on the other hand, means that one has the disease (TB) and is able to spread it to other people.
It might occurs in the first few weeks after being infected with the bacteria or it can occur years later.
TB can affect other parts of the body as well and when it occurs outside the lungs (extra pulmonary). In this case, the signs and symptoms vary depending on the affected part.
However, TB commonly occurs in the lungs (pulmonary).
The main symptoms of pulmonary TB are;
- A persistent cough that lasts for more than three weeks or more
- Coughing up blood or sputum.
Other signs and symptoms associated with pulmonary TB include;
- Pain in the chest or pain with breathing or coughing
- Unintentional Weight loss
- Consistent Fevers
- Night sweats
- Loss of appetite
- Weakness and fatigue
- Difficulty in breathing
- Rales (abnormal lung sounds during breathing)
In 15-20% of all active TB cases, the infection occurs outside the lungs causing other kinds of TB collectively known as extra pulmonary Tuberculosis.
Extra pulmonary TB mainly occurs when those with latent TB develop a weaker immune system and the inactive TB becomes active.
Children also can develop extra pulmonary TB.
The most common forms of extra pulmonary TB include;
- Pleural TB – it affects the thin skin surrounding the lungs referred to as the pleural membrane.
- TB of the central nervous system – it affects the brain and the spinal cord. When the TB bacteria affects both the brain and the spinal cord, it causes TB meningitis. Patients experience drowsiness, have deferred reactions, have difficulty moving their limbs, speaking or focusing their eyes.
- TB of the bones and joints – it affects the bones and joints. It causes pain and swelling in the affected area. Most people suffering from this kind of TB usually relate it to accident or injury and never to TB.
- TB in the lymph nodes– it affects the mostly the lymph nodes in the neck and clavicles, which then swell and infect the surrounding skin.
- Abdominal TB– it affects the abdominal cavity which contains organs like the liver, spleen and the bowels.
- Genitourinary TB– it affects the kidneys, bladder and the urinary tract.
Normally when a person develops active TB, the common symptoms (cough, fever, night sweats, weight loss etc.) may be mild for many months.
This can cause the infected person to delay in seeking medical care which in turn results in the transmission of the bacteria to others.
People suffering from TB can infect up to 10-15 other people through close contact over the course of a year. Without proper treatment up to two thirds of people suffering from TB will die.
It is therefore important to seek medical advice if you notice any of the symptoms mentioned above.
DIAGNOSIS OF TUBERCULOSIS
If a patient shows any of the symptoms associated with TB, doctors will carry out some tests to confirm whether the person is infected. The most common diagnosis of TB is through a skin test.
While this test is used to find out whether TB is present in one’s body or not, it should not be used as the only means of diagnosis as interpreting a positive or negative skin test can be difficult.
The test is usually done to diagnose latent TB. A small extract of the TB bacterium known as PPD tuberculin is injected into the skin just below the inside forearm.
The injection site is then checked after 2-3 days, and, if a hard, red bump has swollen up to a specific size, then it is likely that TB is present.
Skin testing for TB among infants is done during regular checkups. Infants are usually screened at one year, while children are screened at the age of five.
Diagnosis Through Chest X-Ray
A chest x-ray may be conducted to view the status of a patient’s lungs.
If the person has active TB, the x-ray results will show damaged lungs.
The x-ray results together with pulmonary symptoms presented by the patient can be used to make a diagnosis.
Unfortunately, other medical conditions such as lung cancer mimic symptoms similar to TB and the x-ray result may also show damaged lungs.
Other tests might therefore be required to ensure a correct diagnosis of TB. X-rays together with CT Scans can also be used to diagnose TB affecting the bones and the joints
Diagnosis Through Sputum Tests
In this test, a sputum sample is examined under a microscope for bacteria that causes TB.
In some instances, the sputum may also be cultured to see if there are TB bacteria present.
However, this it may take up to six to eight weeks for a sputum culture to yield definite results.
In areas experiencing an outbreak of the disease, diagnosis can be done on the basis of a positive sputum smear alone.
Any patient with symptoms indicating TB who has a positive sputum smear should be started on anti-TB therapy, even if a culture is going to be done.
Diagnosing extra pulmonary TB can be difficult. Samples from the affected parts are drawn and tested for TB bacteria.
In the case of TB meningitis, a medical doctor must perform a lumbar puncture – this requires inserting a needle into the back in order to access the fluid surrounding the spinal cord.
This fluid is in turn used to check for TB bacteria. The same applies for Pleural TB. A sample of fluid is drawn from the space between the pleural layers using a needle.
Diagnosing Multi-Drug Resistant TB (MDR-TB) can be very difficult and expensive.
Multidrug-resistant tuberculosis occurs when the TB bacteria become resistant to both isoniazid and rifampicin, the 2 most powerful, first-line anti-TB drugs.
MDR-TB is still curable, although it requires the use of second-line drugs.
However, second-line drugs are usually expensive and toxic.
The diagnosis of TB among children can also be very difficult especially in instances where a sputum is required, since they might have trouble producing sputum.
TREATMENT OF TUBERCULOSIS
TB is a treatable and curable disease.
People suffering from TB are usually given anti-TB drugs which effectively help in fighting and killing the TB bacteria.
Treatment of drug-sensitive TB is divided into a two-month intensive phase of treatment comprised of taking daily dosages of rifampicin (RIF), isoniazid (INH), pyrazinamide (PZN) and ethambutol (EMB) followed by a four-month continuation phase consisting of rifampicin (RIF) and isoniazid (INH).
95% people who are properly treated for TB get cured.
The main reason why the remaining 5% do not get cured is because they did not take the medicines as prescribed and therefore risk the possibility of the TB becoming drug resistant.
Drugs administered to TB patients are also supposed to stop them from spreading the disease.
The patient is also usually advised to stay at home until the infection period is over.
In some cases, hospitalization may also be recommended to prevent the spread of the TB bacteria at least until the infection period is over.
This is normally two to four weeks after the commencement of treatment.
It is strongly advised to continue with the treatment even when there are no symptoms as earlier on before treatment began.
Failure to do so might result in the TB bacteria re-growing and becoming resistant to the drugs. When the treatment is over, after six months, the TB bacteria is said to be eliminated.
Sometimes, treatment for TB may come with side effects and complications.
Although anti-TB drugs are relatively safe, some may be toxic to some people.
Complications include drug resistance by certain TB strains and relapse of the disease. Minor side effects which one should not worry about and can continue taking the drugs include;
- Rifampin can make one to become more sensitive to the sun
- Rifampin can result in a brownish coloration in saliva, tears and urine. It may also result in a brownish stain on contact lenses.
- If one is taking rifampin and methadone (to treat drug addiction), the methadone dosage may need adjustment as one may experience withdrawal symptoms.
- Rifampin can also reduce the effectiveness of birth control pills and implants. It is advised to use other birth control methods while taking rifampin.
In some cases, TB treatment may have adverse side effects, in which case you should immediately notify your doctor.
Some of these symptoms include:
- Lack of appetite
- Yellowish skin or eyes
- Consistent fever for three or more days
- Tingling fingers or toes
- Skin rash
- Easy bleeding
- Abdominal pains
- Tingling or numbness around the mouth
- Aching joints
- Blurred vision
- Ringing in the ears
- Easy bruising
Patients need to be closely monitored in case of severe adverse reactions to the medication.
There are also patients who might skip their medication after initiation.
To avoid this, it is highly recommended for the patient to have a support system to ensure they do not skip the medication, since this might lead to drug resistance.
TB treatment typically lasts about six months, though longer treatment is suggested in cases of TB meningitis and TB affecting the bones and joints.
Treatment of Drug Resistant TB
Resistance can be either mono-resistance or multi-resistance.
With mono-resistance, the TB might be rifampicin-resistant or isoniazid-resistance.
Multi-resistance is resistance of both Rifampicin and Isoniazid. People with Multi-Drug Resistant TB require advanced specialized treatment which is not as effective as the usual anti-TB drugs and most times cause severe side effects.
MDR-TB is more expensive to treat and cure than Drug-sensitive TB.
The success rate of curing MDR-TB is very low. People infected with MDR-TB will most certainly infect others with the same strain of TB.
Drug resistance is most common in people who:
- Do not take their medications as prescribed by the doctor
- Do not take their medication
- Develop TB again even after previously undergoing TB treatment
- Live in areas with a high rate of Drug Resistant TB. These places include Haiti, South East Asia, Philippines and Latin America
Directly Observed Treatment (DOTS)
This is a strategy used by primary health services to detect and cure TB patients. DOTS combines five elements: microscopy services, drug supplies, monitoring systems, political commitment, and direct observation of treatment.
The biggest challenge of curing TB patients is failure of the patient to complete treatment.
With the DOTS system, the patient is closely monitored by a community worker who ensures that the patient takes the medication as prescribed.
The health system of that particular community is thus responsible for achieving a cure.
With DOTS system, resources are first directed towards identifying those who are infected through sputum tests. The sputum usually test positive for persons with active TB.
After identification, the health community workers counsel, observe and record patients taking the correct dosage for the duration stipulated in treatment of TB.
In most cases, patients usually start to feel better after a few weeks of treatment and they may be tempted to stop taking their medication. The community health worker ensures that this does not happen.
DOTS system produces success cure rates of up to 85 percent even in the poorest countries, and helps prevent new infections and the development of MDR-TB.
The World Bank rates DOTS as one of the most cost-effective health interventions.
Treatment of Tuberculosis Through Surgery
Surgery is likely to be used in cases of extra pulmonary TB.
Here the surgery is done to obtain sample tissues for biopsies and also to relieve the patient of pain and complications brought about by the disease.
PREVENTION OF TUBERCULOSIS
Owing to the high number of deaths that result from TB, preventive measures have been put in place to help eradicate this disease.
TB prevention depends primarily on the vaccination of infants and the early detection and treatment of active cases.
Many countries use Bacillus Calmette-Guérin (BCG) as part of their TB prevention program.
BCG reduces the risk of getting infected by 20% in children and reduces the risk of developing active TB by almost 60%. It is the most widely used vaccination with 90% of children in the world being vaccinated.
With knowledge comes great power. Educating people suffering from TB is a powerful instrument in combating the occurrence of TB.
They should know how to take their drugs properly to reduce risks of developing drug resistant TB and also minimize the risk of spreading it to other people.
They also need to be educated on how not to spread it to other people. This includes cough etiquettes, covering ones mouth while sneezing, or wearing a mask in public places. They need to know when to seek treatment.
The general public also needs to be educated on TB prevention to help prevent the stigmatization of TB patients.
People should also be educated on ways to maintain and boost their immune systems to prevent dormant TB infection from becoming active.
Other preventive measures include preventing people with latent TB from developing active TB, TB treatment as a preventive measure to reduce the risks of the TB bacteria from spreading, as well as avoiding living in overcrowded places without proper aeration.
While TB is a preventable and curable disease, it can easily result in death if treatment is not started enough, or if the patient fails to follow the proper treatment guidelines.
If you start experiencing any of the symptoms associated with TB, you should seek immediate medical attention to ensure that it is diagnosed early.
If diagnosed with the disease, you should follow the doctor’s guidelines to the letter.
Don’t stop taking the medication even when you start feeling better, since this might result in the bacteria becoming resistant to drugs and therefore harder to treat.
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