Tuberculosis: Complete Discussion

Tuberculosis (TB) is an infection caused by bacteria in the mycobacteria family; mainly Mycobacterium tuberculosis (although there are other mycobacteria that can produce the disease: Mycobacterium africanum, M. Bovis, M. Canetti, and M. microti). It usually causes a cough, fever, expectoration, sometimes with blood, tiredness and even weight loss.

Tuberculosis is also known as Koch's bacillus, in reference to its elongated form and its discoverer, Robert Koch, who succeeded in isolating the bacterium from phlegm expelled by patients with similar symptoms in 1882. In this way, he could demonstrate that it was contagious and, separating these patients from the healthy people (the well-known quarantine) prevented the dissemination of the bacteria.

Speaking of tuberculosis nowadays takes us back to times past, but, although it is a preventable infection, it is still the second most important infectious disease worldwide (after AIDS) and one of the most deadly infectious diseases, despite the advances in diagnosis and the effectiveness of treatments. According to data from the World Health Organization (WHO), it is estimated that in 2013, more than 8 million people were infected with tuberculosis - at least 500,000 were children - of which 1.2 million people died as a result of the disease. Most of these figures correspond to poorly developed and poor countries.

However, it is estimated that about 95% of tuberculosis deaths occur in developing countries, being one of the leading causes of death among women aged 15-44. 22 countries account for 80% of new cases each year (mainly in sub-Saharan Africa and south-east Asia), according to WHO, and no country in the world has managed to completely eradicate the disease.

In Spain, it is unlikely to contract the bacteria - an average of 13.1 new cases per 100,000 inhabitants per year, according to the report of the study group of mycobacteria of SEIMC (GEIM) - but, even so, anyone is susceptible to be infected. In fact, the latest data published by the GEIM, reflect that in 2011 were reported 6,046 cases of respiratory tuberculosis, although taking into account the non-notified the figure may exceed 12,000. In this way, tuberculosis ranks as the third compulsory disease in incidence only surpassed by influenza and chickenpox.

Types of tuberculosis

Although pulmonary localization is the most frequent, tuberculosis bacteria can grow in many other places in the body. It is what is known as localized tuberculosis since it only affects one organ. Some of these are, in addition to the lung: skin, gastrointestinal tract (stomach, intestine, and other associated organs), kidney and brain. The bacteria can reach the brain producing tuberculous meningitis, which is very dangerous and very difficult to treat.

Tuberculosis can spread (military or disseminated tuberculosis) by the blood reaching many organs at the same time. This form is very serious and usually appears in people in whom the immune system is debilitated or is almost nonexistent.

Causes of tuberculosis

Causes of tuberculosis

Tuberculosis occurs when the healthy person inhales microscopic drops of saliva from the patient (called aerosols), which are generated when the patient coughs or sneezes. These droplets with bacteria have a very small size and reach deep areas of the lung of the healthy person, where they could proliferate giving rise to the disease. Although the lung is the main organ in which the damage develops, other locations of the organism may be affected (see section on tuberculosis).

In spacious, well ventilated or outdoor places, contagion is complicated. This is because, although tiny droplets can be suspended for some time in the air, they end up spreading and losing their infective capacity. But in closed, poorly ventilated places, these drops can accumulate in the environment, reaching a great concentration and facilitating the inhalation of the same ones. It is for this reason that in regions or areas where poverty or overcrowding is present, the spread of tuberculosis is more plausible.

Although there are factors that determine the likelihood of infection, such as the hours shared with the patient indoors, the virulence of the bacterium (Mycobacterium tuberculosis), or the susceptibility of the healthy person, it is accepted that contracting the disease is not easy, and that a prolonged contact is necessary so that there is a real risk of contagion (in a guideline, usually determined about six hours).

Not everyone who contracts the bacteria will develop the disease. It is estimated that 90% of patients will remain undeveloped, as their immune system will either destroy the bacteria or keep them under control (latent infection). However, these people will test positive for contact with the bacteria.

Only 10% of people who are infected will become ill. The manifestation of the disease usually happens in the two years after the infection (the bacteria grows very slowly). If no symptoms of tuberculosis occur at that time, the risk decreases, but never disappears; increasing again in advanced ages, or to the appearance of diseases that compromise the patient's immune system.

Indeed, people who suffer from a disease that has weakened their immune system (HIV positive, diabetic, etc.), those affected by malnutrition, the elderly and children are the population groups most at risk of contracting active tuberculosis.

Symptoms of tuberculosis

The symptoms of tuberculosis treated in this section correspond to pulmonary tuberculosis, the most common. However, it should not be forgotten that there are other types of tuberculosis, as it can affect other areas of the body.

The name 'tuberculosis' comes from the tendency of the bacteria to form granulomas or tubers in the lungs. In many cases, the early stages of the disease develop without symptoms. In these cases, the diagnosis is established when the patient is analyzed for the presence of other pathologies and the bacterium is discovered by chance. In more advanced stages, the symptoms of tuberculosis are quite non-specific, that is, they may be common to many diseases. These are usually:
  • A cough: is the most important. Not only because it is a pulmonary pathology, but because it is the most frequent mechanism of contagion. Being so common to many diseases, in many cases, it may not be given importance. Therefore, it is important that you consult your doctor when a cough lasts longer than two weeks.
  • Expectoration: phlegm is expelled, sometimes accompanied by blood.
  • February: it is a fever of only a few tenths, which usually appears at the end of the day.
  • Loss of appetite and weight loss: also quite common in many pathologies.
  • Sweating at night.
  • Pain in the chest: due to the pressure produced by the infection in the lungs.
  • Fatigue and excessive tiredness in relation to the effort made: lung function can be compromised, and therefore it is difficult to get oxygen to the lungs and, from there, to the rest of the body.
When the bacteria begin to multiply in the lung, it colonizes the tissue. In later stages of the disease, small holes in the lungs are very characteristic, making it easier for the bacteria to spread.

Diagnosis tuberculosis

Diagnosis tuberculosis

When the patient visits the clinic with symptoms that may indicate tuberculosis, the doctor will ask a series of questions aimed at knowing the duration of the problem, whether or not the patient has been in contact with tuberculosis patients and for how long. In addition, will commission several tests to corroborate the diagnosis of tuberculosis, none too complex, such as sputum analysis (phlegm) and chest X-ray.

The analysis of phlegm in the laboratory is especially important (phlegm is the mechanism of the expulsion of bacteria and therefore appear in it). The X-ray will show the patient's condition. If the gaps in the lung mentioned in Symptoms have already appeared, the disease is considered to be at an advanced stage requiring immediate treatment and may mean that the patient is potentially contagious.

Another very common test to detect the spread of tuberculosis is the tuberculin test, which involves injecting under the skin a derivative of a bacterium protein, which is harmless, and then study the skin reaction. The interpretation of the result must be done by a professional since both the positive and the negative can have different interpretations. After the test, you do not have to scratch your arm even though it bites; In that case, a cold gauze can be applied to relieve the itching, but without touching the puncture since it could alter the result of the test.

If the patient has been vaccinated against the bacterium (BCG vaccine) or has been in contact with another mycobacterium of the non-tuberculous environment, it may give positive reaction (False Positive, because it does not actually present the infection). On the other hand, despite having contracted the tuberculosis bacteria, the result may appear negative (False Negative) if the contact has been recent. It usually takes two to eight weeks for the body to react to the test; therefore, it is often repeated at two months, to corroborate the result.

If the doctor concludes that the patient has tuberculosis and that the bacterium has remained in his / her organism an important time, it will be necessary to know the people with whom it has been related, to institute a preventive treatment and to try to prevent the disease from developing in the.

Treatment of tuberculosis

Treatment of tuberculosis

This infectious disease can be treated, but the treatment of tuberculosis is long and somewhat complex. It is based on taking several antibiotics for periods of time never less than six months. Two antibiotics are usually combined for six months (isoniazid and rifampicin are the most common), but one or two more antibiotics are associated during the first two months so that the action on the bacteria is more aggressive from the beginning.

Although there are standard treatments for tuberculosis, the doctor will prescribe what is considered most appropriate for each case and in the exact dose.

Tips for monitoring tuberculosis treatment

The treatment of tuberculosis is long and complicated, but it is very important to take the medication every day and during the months that the doctor indicates. There are many people who, as soon as they notice improvement, leave the treatment. Many of these people will develop the disease again; and it is possible that the new bacteria will be resistant to conventional treatments, requiring less usual treatments or complicating them. Adherence to treatment for six months is a complete cure, and greatly reduces the risk of relapse.

The medication should be taken once a day and on an empty stomach, preferably in the morning, as it increases the absorption, both in quantity and in speed, increasing the effectiveness of the treatment. Do not take anything for up to half an hour after taking the medication.

At two or three weeks, the patient is considered to be no longer infectious, ie there is a much lower risk of someone being infected by contact with the patient. Usually, at this time the patient is able to return to their daily routine.

Generally, treatment of tuberculosis does not usually require hospitalization. Only in severe cases, such as the spread of the disease or that it has been established in some important location (such as the brain), hospitalization is necessary. If there are no complications, the patient can follow the treatment at home.

During the treatment of tuberculosis, the doctor will make tests to know the evolution of the disease (repeat the analysis of sputum and x-ray); as well as blood tests. This is done to know the state of liver functioning since some of the drugs most frequently used to treat tuberculosis can be hepatotoxic (induce liver toxicity). It is one of the main adverse effects, although generally of a mild nature, and in many cases, the cause of the abandonment of the treatment ahead of time. Stomach upset, vomiting, yellowing of the skin, are symptoms of hepatic failure. It is advisable not to drink alcohol during treatment. If these symptoms appear, you should consult your doctor. If consultation is not possible, it is preferable to stop taking the medication until it is possible to contact a healthcare professional.

Other medications may cause vision changes (ethambutol). While rifampicin, one of the main antibiotics used, can dye orange-colored body fluids (urine, tears or sweat). This is absolutely normal and should not be interrupted by treatment.

It is advisable to use sunscreen during the treatment of tuberculosis, and even after some time since some of these medicines can produce photosensitivity (greater sensitivity to sunlight).

Medication may interact with certain medications: antiepileptics, anticoagulants, antidiabetics, oral contraceptives ... decreasing their effectiveness. Consult your doctor or pharmacist if the patient is taking any of these drugs. Therapy against the AIDS virus can also be affected (see section 'Tuberculosis in special situations').

Isoniazid, another frequent medication, could very rarely interact with some foods (sausages, cheeses, certain fish ...) producing facial redness, headache or vomiting. It is known as flush and, although it is not serious, it can be very annoying. This may require avoidance of these foods during the treatment of tuberculosis.

Evolution of tuberculosis

Treatment for tuberculosis is very effective. The patient may notice an improvement in a short time, but treatment should not be abandoned, as completing the cycle of antibiotics ensures a total cure of the disease. For this reason, tuberculosis is a relatively easy disease to cure and to manage, since shortly after taking the medication, the patient stops expelling bacteria.

If it is not diagnosed in time, it is possible that tuberculosis leaves some sequelae in the lung, such as small scars, which does not imply that the treatment is less effective; that is, that the infection is also eradicated. However, the lung may not work as well as before suffering from tuberculosis. For this reason, the doctor often asks for spirometry at the end of the treatment to check the functioning of the lung once tuberculosis has been cured. However, it is necessary to insist that, if the antibiotics are taken in time, tuberculosis heals completely, the risk of relapse is very low and the patient can lead a normal life.

Tuberculosis in special situations

Let us see how tuberculosis behaves in certain special situations, such as in patients with HIV, pregnant or lactating women, and children:

Tuberculosis in special situations

Tuberculosis and HIV

Tuberculosis is a very common infectious disease in AIDS patients; and is, in fact, the leading cause of death in these patients. Many of them find that they are AIDS patients when they develop this or other infections.

When a person contracts the HIV virus, they can contract it and develop the disease (AIDS). If it eventually develops, the patient's defenses decrease considerably, being more susceptible to infection. Because of this, patients with AIDS are much more likely to develop tuberculosis if they acquire the bacteria (remember that approximately 90% of healthy people do not develop the disease because their immune system is able to destroy the bacteria). If a patient with HIV comes in contact with the tuberculosis bacterium, a preventive treatment should be used to try to prevent the growth of the bacteria.

If they develop the infection, they should take the usual treatment. In these patients, the treatment of tuberculosis is basically the same, although prolonged over time (in some cases, more aggressive therapy may be needed). HIV medication (antiretrovirals) may interact with antibiotics for tuberculosis. In this case, the doctor will decide what is most convenient for the patient.

Tuberculosis in pregnancy and lactation

In principle, the therapy to be used in pregnant women affected by tuberculosis is the same. Only one of the antibiotics, pyrazinamide, is contraindicated. The rest can be used. The chest X-ray can be done with protection for the baby, and diagnostic tests to find out if a pregnant woman is infected is not contraindicated either.

During lactation, there are no problems with antibiotics either. The amount that is expelled with milk is minimal and does not pose risk to the infant.

The therapy is the same for tuberculosis in children but adjusting the doses to the small weight. Only one antibiotic, ethambutol, is contraindicated (because it is difficult to assess its ocular toxicity in children).

Generally, a child is not easily spread and, if he does, develops the disease faster than the adult. Therefore, if a child with tuberculosis, it is most likely that an adult in your environment is sick and infected. It should be investigated and treated also the adult, who may not know his condition.

Prevention of tuberculosis

Tuberculosis can be prevented, but it depends, above all, on the patient's attitude. It should always be coughed up in a tissue paper, which should be placed in the trash in a closed plastic bag.

Prevention of tuberculosis

During the first two to three weeks of treatment, the patient should be kept isolated in a room, which should be ventilated several times a day and remain with the door always closed to prevent the spread of bacteria to other rooms of the house. Personal contacts should be brief and limited, and anyone who comes in contact with the patient should wear a mask to avoid inhaling the bacteria present in the air. On the outside, there is no risk, provided that a reasonable distance is maintained. The rays of the sun kill the bacteria, so it is convenient that the patient's room is sunny. If patient isolation can not be carried out at home, you should go to the hospital

During this period, the patient will not maintain intimate contacts or sexual intercourse, as he may still be in the infective phase. Only when you have two or three weeks of treatment will you be assured that you can no longer infect anyone. It is necessary to avoid during this time the closed places, with many people, like the public transport.

After this period of two or three weeks, the patient may leave the insulation, and the contacts will not require the use of a mask.

What to do if you have been in contact with a tuberculosis patient?

If a person has been in contact for a long time with a tuberculosis patient, they should go to the doctor and discuss the case. Symptoms (or lack thereof), chest X-ray, and certain simple tests, such as tuberculin, will tell the doctor if you have contracted the bacteria and if you require preventive treatment to avoid infection.

If the contact has been mild, for a short time, or has occurred in an open environment, there is little risk of contracting the bacteria. However, you should consult a doctor if you have doubts about it.

Several studies are currently underway in search of an effective vaccine to protect against tuberculosis, in fact, twelve of them have already entered the clinical trial phase. In general, they are based on the use of antigens that replace the old BCG vaccine, or that it potential.
Previous Post
Next Post
Related Posts

0 komentar: