Tuberculosis – Symptoms, Diagnosis, Treatment And Prevention
Tuberculosis (TB) is a bacterial infection most often localized in the lungs (pulmonary tuberculosis) but can spread to other parts of the body (extra pulmonary tuberculosis). Tuberculosis is still a serious disease and a major cause of death in certain parts of the world. The “Koch bacillus” usually affects the lungs but may produce lesions in any organ or tissue of the human body. From the lungs, tuberculosis is easily spread to other people through coughing or sneezing. Although the treatment is a long term one, it is often completed successfully. The average duration of treatment is between 6 and 9 months. Tuberculosis can be found in latent form (on hold) or in active status.
- Latent tuberculosis means that the tuberculosis-causing bacteria can exist in the body, but it cannot be spread to others, but this person may have active tuberculosis;
- Active tuberculosis means the infection is present in the body and if the lungs are affected, the infection can be spread to others.
Human tubercle bacilli are ordinarily trasmitted by inhalation of infective droplets couched or sneezed into the air by a patient with open lesions (active tuberculosis). Bacilli remain active in wet sputum for months and even in dried sputum particles for weeks.
The routes of infection of tuberculosis are:
- Direct infection of the lung by inhalation of bacilli contained in droplets or dust particles is the most important way of infection.
- Alimentary infection, occurs through bovine bacillus, by the ingestion of contaminated milk. the organisms enter through the mucosa and the lymphoid tissues of the tonsils or pharynx to involve cervical lymph nodes, or through the intestine to reach the mesenteric lymph nodes. There may be no lesion at the entry point.
- Infection through skin (very rare) may occur in surgeons and pathologists who handle infected tissues.
As with any other infection, the development and course of tuberculosis are dependant upon virulence, dosage, and portal of entry of the bacteria. Also very important are the variable factors of the host: native and acquired resistance and hypersensitivity. Significant environmental factors tend to decrease the native resistance (malnutrition, physical and psychological stress, fatigue, certain diseases – diabetes melitus). Age appears to influence susceptibility – while infants, young adults and elderly persons are susceptible to the disease, children in the age group of 5 to 14 years are most resistant.
Tuberculosis is caused by Mycobacterium tuberculosis, a bacterium that grows slowly in body environments that are rich in blood and oxygen, such as the lungs.
If the latent form of tuberculosis is present, there are no symptoms and it cannot be spread to others. If active form is present, then symptoms are present and the infection can be spread to others. Symptoms are related to the type of tuberculosis present, be it pulmonary (the most common) or extrapulmonary. Other affections such as pneumonia and lung cancer can have similar symptoms as tuberculosis.
Active TB symptoms
Active tuberculosis symptoms emerge gradually and cover a period of several weeks to months. There may be some mild symptoms as well. Common symptoms include:
- Cough accompanied by thick mucus, sometimes with blood (sputum) for a period of approximately two weeks;
- Tachycardia (rapid heartbeat);
- Increased neck volume (affected lymph nodes in the region).
Other symptoms may include:
- Fever, chills and sweating during sleep;
- Fatigue and weakness of physical force;
- Loss of appetite and weight loss with no explicable reason;
- Decreases in the breath amplitude, chest pain.
Symptoms of extrapulmonary active TB
Symptoms of infection in other areas (excepting the lungs) vary depending on location. The infection usually remains in the lungs but bacteria can migrate thorugh the blood flow in different parts of the body.
The onset of the infection can be so light that it can easily be ignored by the patient. In a person with a healthy immune system (unaffected by other diseases/infections) the body fights bacteria by encapsulating it (wrapping it) in formations named tubers. The bacteria remain alive but cannot multiply or spread elsewhere in the body or to other persons. This stage corresponds to latent tuberculosis and many people do not overcome it.
A positive tuberculin test is how many people discover that they have latent form of TB. It takes 48 hours after the test for the reaction to take place, which is indicated by a red swelling where the needle pierced the skin. Or it can be tested with QuantiFERON-TB Gold, a blood test, which gives results in about 24 hours.
If a person’s immune system becomes unable to prevent multiplication of the bacteria, tuberculosis becomes active. In patients with latent tuberculosis, 5% (one in twenty people) will develop active tuberculosis within a year of the initial infection.
Active pulmonary tuberculosis is highly contagious. Tuberculosis is spread when a person who has the infection expires bacteria and another person inhales it from the air. The tuberculosis bacteria can remain in the air for several hours. Coughing, sneezing, laughing and singing may release more bacteria than breathing itself.
Tuberculosis is more likely to spread under the following conditions:
- For people living in crowded environments. Tuberculosis can spread easily in homes, hospitals, shelters for homeless people, schools, barracks and prisons
- For people who live with people that are already suffering from tuberculosis. This is a factor that increases the possibility of contracting the disease. Tuberculosis is not spread by handling objects touched by an infected person.
In general, after two weeks of treatment with antiobiotics the infection is contained and cannot be spread to others. Discontinuation of medication may cause delayed healing and also recurrence. In these cases it is necessary to restart the therapy. Reappearance may occur 6 to 12 months after stopping the treatment. Also, omitting to finish the treatment (stopping it at some point), can influence the bacteria’s ability to develop resistance to the administered drug, making the treatment more difficult.
Without treatment, the active form of tuberculosis can cause serious complications, such as:
- Cavities or pockets in the lung parenchyma. These diseased areas of the lungs can cause bleeding and may lead to overgrowth of other bacteria and the formation of abscesses (pus-filled cavities);
- Holes that form between the airways (broncho-pleural fistula);
- Difficulty in breathing due to blocked airways.
Infants, children and individuals infected with HIV, which also show the active form of tuberculosis, need special treatment.
Individuals have an increased risk of becoming infected with tuberculosis when:
- Come into contact with persons with active tuberculosis (at home, at work, at school). Active tuberculosis is highly contagious;
- Care for people who have active untreated tuberculosis (medical staff)
- Live in crowded conditions where they can come into contact with people who have tuberculosis, such as those working in prisons, hospitals, nursing homes, military barracks, shelters for homeless people
- Poor access to medical care, such as homeless people, farm workers (farmers) or people who use drugs or alcohol
- Traveling from, or in regions where tuberculosis is common, such as Latin America, Africa, Asia, Eastern Europe and Russia.
People with latent form of tuberculosis (which can not be spread to other people) are at risk of developing active tuberculosis if they:
- Suffer from a disease and undergo a treatment that weakens the immune system, such as HIV, some cancers or diabetes;
- Have poor access to medical care, such as beggars, workers in different areas or alcohol and drug users;
- Follow a long-term treatment with corticosteroids.
- Show a weakened immune system such as the elderly, newborns, women who recently gave birth, people who have had organ transplants and take medications for preventing organ rejection;
- Suffer from a chronic lung disease caused by inhalation of various dusts (silicosis);
- Are 10% below normal weight.
The doctor should be contacted immediately if a person:
- Has symptoms (continuous cough accompanied by fever, fatigue and weight loss) that could be caused by tuberculosis;
- Was in intimate contact with someone who has active tuberculosis (which can be transmitted to others) or someone who might be suspected of having tuberculosis;
- Yellowing of skin, or if the accused shows pain after taking Isoniazid or other anti tuberculosis drugs.
The doctor should be contacted as well if, after the tuberculosis test a red swelling at the location of the neeedle puncture. The test reaction should be inspected by a specialist after 2-3 days, to decide if the patient needs other tests or treatment.
One of the following specialists should be consulted if tuberculosis is suspected:
- Nearest public health center
- Doctors (general practitioners, family medicine doctors, internists, pediatricians)
- Pneumology doctors specializing in treating lung problems
- Infection disease specialists in treating infectious diseases.
If a patient has tuberculosis resistant to several types of medication, he should go to a specialized hospital in such tuberculosis treatment.
The watchful waiting period refers to a prudent approach (seeing and doing). If the patient feels better on his own, medication is no longer needed. If the condition worsens, the doctor, together with the patient will decide the next step. If the patient shows continuous symptoms of tuberculosis (combined with symptoms like fever, cough, fatigue and weight loss) treatment is necessary. The doctor or other health professionals should be contacted as soon as possible. Also, if someone came into contact with a person who has active tuberculosis, he or she shouldn’t wait for the first symptoms to appear, a doctor should be contacted as soon as possible.
Diagnosis of active pulmonary tuberculosis
Doctors diagnose active pulmonary tuberculosis using anamnesis (history of the disease), physical examination of the patient and examining the patient and observing the symptoms (cough, fatigue, fever and sweating while sleeping). Doctors will also take into account the results of sputum cultures. Mucus examination from the lungs is the best method to diagnose active tuberculosis. If the bacteria grows on culture mediums, susceptibility testing will show the types of drugs capable of destroying the bacteria. Susceptibility testing results appear after 1-6 weeks because Mycobacterium tuberculosis grows very slowly.
Researchers are working on new tests that can provide faster results. Chest radiography does not give a clear indication of tuberculosis. Radiography is indicated if the tuberculin test result is positive, if tuberculosis symptoms such as cough, fatigue, fever or sweating appear during sleep or if there is an uncertain reaction to the tuberculin test due to a weakened immune system.
Diagnosis of latent pulmonary tuberculosis
Tuberculin skin test will show if latent tuberculosis is present. The test will also show if another infection with tuberculosis was present at any given time before the patient underwent the test. QuantiFERON-TB Gold is a blood test which was approved by the FDA (U.S. Food and Drug Administration) to detect latent tuberculosis. It’s faster and more accurate than the skin test, but is still less accessible.
Diagnosis of extrapulmonary tuberculosis
The diagnosis of extrapulmonary tuberculosis includes varied tests:
- Taking a sample from the affected location (biopsy). The sample is sent to a laboratory for analysis;
- Urine culture for the detection of renal tuberculosis;
- Sample from the fluid surrounding the spinal cord (CSF – cerebrospinal fluid) to detect cerebral infection with tuberculosis;
- Tomography to detect if tuberculosis has spread in the body; can also diagnose lung cavities caused by tuberculosis;
- MRI (Magnetic Resonance Imaging) to detect brain tuberculosis and spinal cord tuberculosis;
- HIV testing is usually done along TB testing. Patients can also get tested for hepatitis.
Tests during TB treatment
During treatment, sputum testing is done once a month or sometimes more often, to make sure that antibiotics are effective. At the end of treatment, a chest radiography for future reference. Patients may undergo another series of tests in order to check if the medication affects other organs: the liver function, eye tests (if ethambutol was adminstred) and acoustic tests (if streptomycin was administred)
All patients with tuberculosis who present themselves at the local or state hospitals can spread the infection to other people and cause an outbreak. Most medical authorities try to prevent tuberculosis outbreaks and encourage early testing for people with a high risk of contracting and developing the disease.
Centers for Disease Control and Prevention recommend TB testing for people who:
- Are infected with HIV (Human Immuno-Deficiency Virus) or other conditions that put them at risk of contacting the tuberculosis infection;
- Are living with a person who has active tuberculosis;
- Use drugs;
- Born in areas of the world where tuberculosis is common: Latin America, Africa, Asia, Eastern Europe or Russia;
- Live or work in hospices, shelters for homeless people, prisons, etc.;
Physicians treat tuberculosis with antibiotics to kill the bacteria. These drugs are administered to all persons who have tuberculosis, including infants, children, pregnant women and people with deficient or weakened immune systems. People who have latent tuberculosis also receive treatment to prevent the transformation of the bacteria into the active form.
In treating latent or active TB, it is recommended:
- Using combinations of drugs to treat tuberculosis. Standard initial treatment combines four drugs to prevent TB from becoming multiresistant to treatment;
- Following treatment for a minimum of six months or more if necessary;
- Strictly following the indications for treatment. That could mean daily presence of specialized medical staff daily when the drugs are administered. Treatment includes full administration of all doses of antibiotic. These consultations ensure correct treatment, which is necessary due to its long duration;
- Trying different combinations of drugs, if the treatment doesn’t show any results, due to bacterial resistance (when tests show that the bacteria causing TB is still active).
Extrapulmonary tuberculosis treatment
Extrapulmonary tuberculosis treatment, is usually the same as for pulmonary tuberculosis. You may need other types of drugs, corresponding to the place where the infection is localized or if other complications exist.
There are various treatments recommended for people with HIV and tuberculosis. If the treatment is stopped too soon, or the doses are not taken properly, the treatment could last longer or the patient may need to start the treatment again from the beginning. This can lead to worsening symptoms or antibiotic-resistant infections that are more difficult to treat.
Curing tuberculosis requires the administration of antibiotic treatment all the way!
Correct administration of medication is important for people with weakened immune systems. They could be at risk of infection recurrence because initial infection was never cured. Recurrences often occur 6-12 months after treatment. Treatment for recurrences is based on the severity of the disease and takes into account the medicine administered during the initial treatment. Doctors also use medication to prevent conversion of latent tuberculosis in the active form.
Treatment is very important for people who have latent tuberculosis and:
- Also HIV infected;
- Underwent a chest radiography that suggests tuberculosis infection, but did not complete the tuberculosis treatment;
- Are drug addicts;
- Have a disease or are taking medications that weakens immune system;
- Underwent a tuberculin skin test two years ago, which was negative, but now is positive.
Home treatment focuses on the correct drug use, in order to prevent the development of bacterial resistance. The patient must maintain contact with health professionals and also report any side effects, especially vision problems. If the patient plans to move during treatment it is recommended to announce health professionals in order to make arrangements for a continuous administration of medication. Home treatment includes:
- A healthy diet to ensure the necessary intake of nutrients, vitamins, , that the body needs in order to fight back the infection. It is also indicated to consult a dietitian;
- Covering the mouth when coughing or sneezing. In the first two months of treatment, when disease can spread easily to others.
Antibiotics are used simultaneously to treat tuberculosis. For people who present multidrug-resistant tuberculosis, drug treatment can continue for 24 months. Antibiotics are can be given as injections or pills.
Extrapulmonary tuberculosis is currently treated with the same drugs and for the same period of time as pulmonary tuberculosis but cerebral tuberculosis , bone tuberculosis in children can be treated in less than 12 months. Corticosteroid drugs may also be recommended in severe cases in order to reduce inflammation.
One or two antibiotics are generally used to treat latent tuberculosis infection which can not be spread to others, but can turn into active tuberculosis. Poly-drug therapy for tuberculosis treatment involves the administration of four antibiotics at the same time. This is the standard treatment for active tuberculosis.
Four of the most commonly used antibiotics:
Other drugs are used if the treatment is not effective or if the person has a known case of antibiotic resistant TB. Other drugs commonly used include:
- Streptomycin (STM)
It is very important to administer the full dose of drugs recommended by doctors. This promotes healing and removes the risk of relapse (disease recurrence) and the development of antibiotic resistant bacteria.
The treatment is rarely surgical but it can treat complications of the lungs or other body parts.
Surgery is indicated:
- To stop lung hemorrhages that can not be stopped by any other method;
- The removal of “pockets” (collections) of pus that were not reabsorbed after antibiotic treatment;
Surgery for extrapulmonary tuberculosis is often used to remove or repair damaged organs or prevent complications such as:
- Brain level tuberculosis infections. The doctor may place a surgical drain (tube) that drains excess fluid to prevent an increase in pressure that can affect the brain;
- TB pericarditis (infection at heart level). The surgeon may remove the pericardium that surrounds the heart;
- Renal tuberculosis (infection of the kidneys ). The surgeon may need to remove the affected kidney, repair it or other parts of the urinary system;
- Joint infection. Surgery may be required to cure the affected areas of the spine or joints (orthopedic surgery).
How to avoid contacting active tuberculosis.
Active tuberculosis is an infection that spreads in the body of the sick person and is highly contagious. The World Health Organization estimates that one third of the world population is infected with the bacterium that causes tuberculosis. To prevent infection people must:
- Do not spend too much time in a crowded places with known people with active tuberculosis (if the person is not under treatment for at least two weeks);
- Wear protective masks, especially they are working in care centers for those with tuberculosis.
How to avoid turning latent tuberculosis in active tuberculosis.
Generally treatment with Isoniazid for 9 months or Rifampin/Rifampicin for 6 months, prevents conversion of latent tuberculosis. This treatment is recommended for people which were discovered as carriers of bacteria after the tuberculin test