Tuberculosis (TB) also called Koch’s disease is an infectious disease that usually affects the lungs. Compared with other diseases caused by a single infectious agent, tuberculosis is the second biggest killer, globally.
In 2015, 1.8 million people died from the disease, with 10.4 million falling ill. In the 18th and 19th centuries, a tuberculosis epidemic rampaged throughout Europe and North America, before the German microbiologist Robert Koch discovered the microbial causes of tuberculosis in 1882.
Following Koch’s discovery, the development of vaccines and effective drug treatment led to the belief that the disease was almost defeated. Indeed, at one point, the United Nations, predicted that tuberculosis (TB) would be eliminated worldwide by 2025.
However, in the mid-80s, TB cases began to rise worldwide, so much so, that in 1993, the World Health Organization (WHO) declared that TB was a global emergency; the first time that a disease had been labeled as such.
According to the 2016 Global TB report, Nigeria has the highest TB burden in Africa and ranked 4th in the world. It is among the six countries that accounted for 60 per cent of the global burden of TB.
“Other countries are India, Indonesia, China, Pakistan and South Africa. Equally, Nigeria and India accounted for 48 per cent of global TB deaths among HIV-negative people and for 43 per cent of the combined total TB deaths in HIV-negative and HIV-positive people.
“The same report also revealed that Nigeria is among the ten countries that accounted for 77 per cent of the global gap in TB case finding. In 2016, Nigeria notified less than 20 per cent of the total TB cases estimated for that year. Therefore, more than 80 per cent TB cases in the country are undetected, implying that, there are lots of undiagnosed TB cases in the community which serve as a reservoir for continue transmission of TB.”
Fortunately, with proper treatment, the vast majority of cases of tuberculosis are curable. Without proper treatment, up to two-thirds of people ill with tuberculosis will die.
Here are some key points about tuberculosis:
• The World Health Organization estimates that 9 million people a year get sick with TB, with 3 million of these “missed” by health systems
• TB is among the top 3 causes of death for women aged 15 to 44
• TB symptoms (cough, fever, night sweats, weight loss, etc.) may be mild for many months, and people ill with TB can infect up to 10-15 other people through close contact over the course of a year.
• TB is an airborne pathogen, meaning that the bacteria that cause TB can spread through the air from person to person.
• TB usually affects the lungs, although it can spread to other organs around the body.
There are three kinds of tuberculosis infection: latent, active and reactivated.
Latent TB – the bacteria remain in the body in an inactive state. They cause no symptoms and are not contagious, but they can become active.
Active TB – the bacteria do cause symptoms and can be transmitted to others.
Secondary (reactivated) infection causing active disease – Some people develop active TB months or years after a minor TB infection had been halted. The body’s immune system at first stops the bacteria from multiplying (as above). However, not all the bacteria may be killed. Some bacteria may be ‘walled off’ in the scar tissue of the initial minor infection. They are stopped from multiplying by the immune system. They do no harm but can remain inactive for many years. The inactive TB bacteria may later start to multiply and cause active TB if the body’s immune system becomes weaker for some reason. A weak immune system and re-activated TB are more likely to occur if you:
o Are elderly or frail.
o Are malnourished.
o Have diabetes.
o Take steroids or immunosuppressant medication.
o Have kidney failure.
o Are alcohol-dependent.
o Have AIDS.
About one-third of the world’s population is believed to have latent TB. There is a 10 percent chance of latent TB becoming active, but this risk is much higher in people who have compromised immune systems i.e., people living with HIV or malnutrition, or people who smoke or the diabetic.
TB affects all age groups and all parts of the world. However, the disease mostly affects young adults and people living in developing countries.
What causes tuberculosis?
The Mycobacterium tuberculosis bacterium causes TB. It is spread through the air when a person with TB (whose lungs are affected) coughs, sneezes, spits, laughs, or talks.
TB is contagious, but it is not easy to get. The chances of getting TB from someone you live or work with are much higher than from a stranger. Most people with active TB who have received appropriate treatment for at least 2 weeks are no longer contagious.
Since antibiotics began to be used to fight TB, some strains have become resistant to drugs. Multidrug-resistant TB (MDR-TB) arises when an antibiotic fails to kill all of the bacteria, with the surviving bacteria developing resistance to that antibiotic and often others at the same time.
MDR-TB is treatable and curable only with the use of very specific anti-TB drugs, which are often limited or not readily available.
Who gets tuberculosis?
Anyone can get TB. The risk is increased where one or more of the following apply:
• Close contacts of a person who has active TB in the lungs (living in the same household, or spending a lot of time with that person).
• If you or your family come from a country where TB is common.
• Environment and poverty: rates of TB are higher among homeless people, prisoners, in large cities and in more deprived areas.
• A poor immune system: for example, due to HIV infection, immune-suppressing treatment, or alcohol or drug dependency.
• Malnutrition: poor nutrition and lack of vitamin D are linked to TB.
• Age: babies, young children and the elderly are more susceptible to TB.
Symptoms of tuberculosis
While latent TB is symptomless, the symptoms of active TB include the following:
• Cough lasting more than three weeks is often a first symptom of active tuberculosis (TB). It can start as a dry irritating cough. It tends to continue for months and get worse. In time the cough produces a lot of phlegm (sputum), which may be bloodstained.
• High temperature (fever),
• Night sweats
• Feeling unwell
• Weight loss
• Chest pain
• Poor appetite.
• You may become breathless if the infection progresses and damages the lungs. If left untreated, complications often develop, such as fluid collecting between the lung and the chest wall (pleural effusion). This can make you very breathless. If the TB gets close to a blood vessel in the lung then you may cough up blood.
TB infection sometimes spreads from the lungs to cause infection in other parts of the body. Depending on which part of the body is affected, various symptoms may then occur:
• Lymph glands – you may have a swollen gland or glands anywhere in the body. If the swollen glands are in the neck, armpit or groin then you may see or feel them.
• Gut and tummy (abdomen) – the TB may cause tummy pain or swelling, or poor digestion of food with diarrhoea and weight loss.
• Bones and joints – TB can get into a bone or joint, causing bone pain (for example, in the spine) or pain and swelling in a joint.
• Heart – TB sometimes causes inflammation around the heart, with chest pain or shortness of breath.
• Kidneys and bladder – if these are infected, you may have pain in the side (loin), or pain when passing urine or blood in urine.
• Brain – TB can cause meningitis, with symptoms such as:
Headache, Feeling sick (nausea), Being sick (vomiting), Fits (convulsions), Drowsiness, A change in behaviour.
• Skin – TB can cause certain rashes, including erythema nodosum – a red, lumpy rash on the legs – or lupus vulgaris which gives lumps or ulcers.
• Spread to many parts of the body – this is called miliary TB, and can affect many organs, including lungs, bones, liver, eyes and skin.
Diagnosis of tuberculosis
TB is most commonly diagnosed via a skin test involving an injection in the forearm.
To check for TB, a doctor will use a stethoscope to listen to the lungs and check for swelling in the lymph nodes. They will also ask about symptoms and medical history as well as assessing the individual’s risk of exposure to TB.
The most common diagnostic test for TB is a skin test where a small injection of PPD tuberculin, an extract of the TB bacterium, is made just below the inside forearm.The injection site should be 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.
Unfortunately, the skin test is not 100 percent accurate and has been known to give incorrect positive and negative readings.
However, there are other tests that are available to diagnose TB. Blood tests, chest X-rays, and sputum tests can all be used to test for the presence of TB bacteria and may be used alongside a skin test.
MDR-TB is more difficult to diagnose than regular TB. It is also difficult to diagnose regular TB in children.
Treatments for tuberculosis
The majority of TB cases can be cured when the right medication is available and administered correctly. The precise type and length of antibiotic treatment depends on a person’s age, overall health, potential resistance to drugs, whether the TB is latent or active, and the location of infection (i.e. the lungs, brain, kidneys).
People with latent TB may need just one kind of TB antibiotics, whereas people with active TB (particularly MDR-TB) will often require a prescription of multiple drugs.
Antibiotics are usually required to be taken for a relatively long time. The standard length of time for a course of TB antibiotics is about 6 months.
TB medication can be toxic to the liver, and although side effects are uncommon, when they do occur, they can be quite serious. Potential side effects should be reported to a doctor and include:
o Dark urine
o Loss of appetite
o Nausea and vomiting
It is important for any course of treatment to be completed fully, even if the TB symptoms have gone away. Any bacteria that have survived the treatment could become resistant to the medication that has been prescribed and could lead to developing MDR-TB in the future.
Directly observed therapy (DOT) may be recommended. This involves a healthcare worker administering the TB medication to ensure that the course of treatment is completed.
Prevention of tuberculosis
• Face mask
If you have active TB, a face mask can help lower the risk of the disease spreading to other people.
• A few general measures can be taken to prevent the spread of active TB.
Avoiding other people by not going to school or work, or sleeping in the same room as someone, will help to minimize the risk of germs from reaching anyone else. Wearing a mask, covering the mouth, and ventilating rooms can also limit the spread of bacteria.
• TB vaccination
In some countries, BCG injections are given to children in order to vaccinate them against tuberculosis.
TB is both preventable and treatable. It is a tragedy that it remains one of the biggest killers worldwide. Relieving poverty, better nutrition and prompt treatment of TB are the most important ways of reducing TB worldwide. Immunisation also helps.
How do I get tests and treatment for tuberculosis?
Tests and treatment for TB are free in government hospitals. Your doctor will refer you for tests if he or she suspects that you have TB. Treatment is normally from a TB clinic. Most people with TB can have treatment at home. Hospital admission is not usually necessary unless: You are quite ill, The treatment is complicated for some reason,You have difficult circumstances such as homelessness.
Some people find it hard to remember to take their medication regularly. If so, you may be offered ‘observed treatment’, where a health worker sees you for each dose.
If you have symptoms suggestive of TB or know someone who does, kindly go to the nearest government health centre/hospital and get tested.