What is tuberculosis?
Tuberculosis is a serious, sometimes contagious bacterial infection, usually caused by Mycobacterium tuberculosis. This bacterium was discovered in 1882 by Robert Koch. By using several suitable antibiotics at the same time, tuberculosis is now mostly treatable.
Phenomena
TB is primarily a disease of the lungs but in principle all organs are affected by the tubercle bacteria. In the West makes approximately 60% of all cases of pulmonary tuberculosis tuberculosis from. In Asian countries is relatively more tuberculosis in other organs, such as lymph node tuberculosis. The most common symptoms of pulmonary tuberculosis are persistent cough, weight loss, night sweats, pain in the chest and coughing up blood. "Open pulmonary tuberculosis" means that in the sputum tuberculosis bacteria under the microscope after staining can be seen. This is the most infectious variant of pulmonary tuberculosis. Lymph node Tuberculosis is manifested by a swelling of the lymph nodes, for example in the neck. It is also possible that tuberculosis is located at more places at the same time out. The symptoms of tuberculosis outside the lungs depends on the place where the disease is located. In spinal tuberculosis for example, will back pain may occur. Meningitis (tuberculous meningitis) is the most deadly form of TB. Due to the swelling of lymph nodes may also be afflicted bronchi, causing bronchiectasis may arise, this happens to TB, especially in the rechtermiddenlob (syndrome Brock).
Tuberculosis infection method
By far the main mode of infection occurs by inhaling small, airborne droplets containing tuberculosis bacteria are spread by pulmonary tuberculosis patients. Especially when coughing are widely spread infectious droplets. Another way people can be infected through consumption of food containing tuberculosis bacteria. Thus, people may become infected by drinking milk from cows suffering from bovine tuberculosis. Bovine tuberculosis is caused by Mycobacterium bovis. In the Netherlands, this method of infection much earlier, but this was successfully opposed by the introduction of pasteurized milk and TB-free livestock.
Pathology
Upon infection with tuberculosis bacteria, the bacteria enter through the lungs. At the point of entry into the lungs, the bacteria multiplies and can be transported via the lymph to the regional lymfklierstation. This is often the longhilum. In the lymph nodes in the hilum or elsewhere in the mediastinum, an immune reaction occurs in which the lymph node increases. This may be visible on a chest x-ray. The following is a spread of the tuberculosis bacterium via lymphatic and blood throughout the body. After about 6 weeks, the body has developed immunity usually enough to withstand the infection. Remain throughout the body still latent (dormant) tuberculosis bacteria behind. In approximately 1% of the people will be adjacent to the tuberculosis infection occur. In about 10%, the dormant tuberculosis bacteria at a later time become active again and cause tuberculosis disease. This is called post-primary tuberculosis. Here, there is a preference for the upper lung lobes (in particular for the apico-dorsal segment) but tuberculosis can occur anywhere in the body. Tuberculosis is, therefore, a systemic disease, the removal of only the part where tuberculosis is expressed (e.g. a lung lobe) is not sufficient. Illness usually occurs within a year or two after infection, but it may take 60 years or even longer. In people with lowered immunity or young children is more likely than approximately 10% of developing tuberculosis. In HIV-infected people who are not covered against the risk of getting TB after infection about 10% per year. In countries where HIV is found therefore often much tuberculosis. In Africa south of the Sahara, most TB patients are also HIV positive. TB worsens the course of an HIV infection and vice versa accelerates HIV infection, the emergence and development of tuberculosis.
Tuberculosis test
Mantoux test
At the Mantoux test, a small amount of purified proteins of Mycobacterium tuberculosis (tuberculosis antigens) was injected into the skin. If the patient in the past, is once infected with TB, he or she has thereby developed an immune reaction (Type IV allergy), which in turn shows by a red, raised spot at the site of the injection. This does not prove that such person is suffering from tuberculosis, only that the immune system has previously been introduced to the bacteria. Which may already have been overcome by the body (cured, old TB) or are still active. The TB skin of size says nothing about the degree of resistance to the TB bacterium. The results of the Mantoux test is specified in the number of millimeters that the swelling (induration) wide. The sometimes present reddening of the skin is the result of no importance. HIV / AIDS, some immune-lowering medications and acute viral infections, the TB skin can be less reliable. The number of false-negative results than is growing.
Previously everyone at a young age already infected with the bacteria but nowadays this is a rarity in most western countries. In young people who were born in a country that has long been relatively little tuberculosis patients is a positive Mantoux test by an infection with tuberculosis bacteria so not much; the very elderly the rule rather than the exception, as they in their youth when tuberculosis occurred more are infected. This also applies to many immigrants who have lived for years in a country where tuberculosis is prevalent. In practice, these are often non-Western countries. This makes the test in countries where TB incidence little longer time screenend suitable instrument for detecting people who are infected by a contagious tuberculosis patient.
X-ray
In the fight against tuberculosis is to detect tuberculosis and extensive use of lightweight pictures to the lungs. Pulmonary tuberculosis almost always gives a visual picture deviation. In poor immune status (eg HIV / AIDS) is the picture (just as the Mantoux test) is less reliable because the defects can be reduced.
Direct microscopy (from sputum or BAL)
The best known are the Ziehl-Neelsen stain and Auramine staining. This acid-fast rods can be demonstrated. These are usually, but atypical mycobacteria tuberculosis bacteria and Nocardia, inter alia, also be positive in this test. These tests give the most important indication about the infectiousness of the TB patient. BAL stands for bronchoalveolar lavage: at a bronchoscopy a little water is introduced into the lung, which is sucked up again later, and then is examined.
Rear
If possible, an attempt is made to grow the tuberculosis bacterium. From almost all is to make a culture, sputum, urine, biopsies etc. case of a positive diagnosis of TB tuberculosis culture is fixed and it is possible to test a variety of resistance to drugs. In about one-third of the patients do not manage to culture the bacteria. The diagnosis must be made on other grounds, eg by the complaints, X-rays etc. The most famous tuberculosis culture is the culture on Lowenstein-Jensen culture medium, see Fig. Because the M. tuberculosis grow slowly takes about culture very long, up to 3 months to it. Nowadays, most laboratories do also a culture in a liquid medium, in order to find a positive culture result more quickly, 1-2 weeks belongs to the possibilities. A tuberculosis culture must always be requested separately by the physician. In children with a starting tuberculosis it is apparent, at most, in the half of the patients possible to grow the tuberculosis bacterium. Also, only about half of complaints. The diagnosis is, therefore, often in children on the basis of the chest X-ray and the presence of an infectious tuberculosis patient placed in the immediate vicinity.
DNA gene probes
Two well-known are the PCR and the Battery Probe. It is examined with the tests or the DNA-fragment with the name IS6110 is present. If this is the case, the found mycobacterium belonging to the Mycobacterium tuberculosis-complex (MBTC). Unfortunately, this segment is missing in some cases and needs to be migrated to other tests. The PCR can also be done directly on sputum. The Battery Probe ™ can not be done directly, sputum, it is carried out on a positive culture. It is important to remember that the PCR can give positive results important if the tuberculosis bacteria are dead.
Recent exist also test ("rapid test"), which without culture can be done on sputum decreased in order to demonstrate resistance to antibiotics. This is done by the detection of certain known mutations in the DNA of the tuberculosis bacterium that lead to resistance to antibiotics. When rifampicin, it is a mutation in the rpoB gene that is found in more than 95% of the rifampicin-resistant tuberculosis bacteria. When INH is more difficult because there occur various mutations that make the tuberculosis bacterium resistant to a greater or lesser extent. A well-known mutation is the kat G mutation that is responsible for a little more than 50% of the INH-resistance.
Tuberculosis treatment
Tbc is normally treatable with a combination of antibiotics. The most commonly used antibiotics are isoniazid (INH), Rifampicin, Pyrazinamide and Ethambutol. The treatment lasts at least 6 months and can have side effects. The treatment usually takes place at home with insulation measures. A minority of TB patients for treatment in a hospital or sanitarium. In recent years, the number of patients is risen up in a sanatorium without which is still not clear how this is.
As the most widely used medications provide insufficient results, second line medication is applied. There are six main groups of second-line drugs against tuberculosis: aminoglycosides, polypeptides (eg Capreomycin), fluoroquinolones, thioamides, cycloserine and PAS.
In TB patients with a poorly functioning immune system such as AIDS, it is possible that the patient receives during TB treatment more complaints and increased abnormalities in research. This may be the result of a better-functioning immune system. This syndrome is known by the acronym IRIS Immune Reconstitution Inflammatory Syndrome.
Not all people who are infected with the TB bacterium also get TB disease. To prevent active TB can people who are only infected preventative medicine to swallow. Usually, that means INH tablets for 6 months or a combination preparation of isoniazid and rifampicin for 3 months. People who have a poor immune system (AIDS, cancer, some drugs after organ transplants, etc.) are more at risk of developing TB than sent after infection. Also, then the test is to demonstrate infections, the Mantoux test, become less reliable. The preventive treatment in this group usually takes longer, is 9 months INH advised instead of 6 months.
Worldwide, increasing the DOTS strategy (Directly Observed Therapy Short course) is used as a treatment method. It is, inter alia, the medication supplied under the control. Other elements of DOTS is a government that continues to actively participate in TB control, access to good microscopic examination of sputum (ZN staining), presence of good quality medicines and recording information during TB treatment.
Most Dutch doctors, including medical specialists, see rarely tuberculosis patients and often do not know much why. Therefore, the disease should be handled by a small number of doctors to keep the knowledge and experience to date. This is the hospital's lung (including TB in places other than the lungs) and outside the hospital's TB doctor of the GGD that relatively more concerned with hard to reach patients, such as drug addicts, alcoholics, asylum seekers and illegal immigrants with tuberculosis.
Outdated treatments
By knowingly causing a pneumothorax wanted to give the affected lung rest by TB in the hope that the patient could be better faster. A similar technique is to create a pneumoperitoneum. This air is introduced into the abdominal cavity through which the diaphragm is pushed upwards which will give the onderkwabben especially of the lungs less space. Regularly, for example weekly, had air refill because the spontaneous pneumothorax or pneumoperitoneum reduced. Another way the lung to give less space and therefore "to appease" was bruising or cutting of the left or right phrenic nerve, causing the diaphragm became paralyzed halfzijdig. An alternative was the injection of phenol at the n. phrenic nerve. In particular, in the forties were ping-pong balls introduced into the thoracic cavity so that the lung was compressed. Alternatives for ping pong balls were paraffin or fat. More drastic was the thoracoplasty, in this operation a number of the upper ribs was removed. As a result, the upper lung segments were compressed. This operation previously held a significant risk in death.
In early twenty-first century appeared occasionally studies from countries such as Russia where the pneumothorax was revived as a treatment in cases in which drugs would work well enough.
In 1943, Streptomycin came on the market, the first antibiotic against tuberculosis, in combination with ethambutol. It can only be administered by injection, and may cause irreparable hearing loss with prolonged use. Since the advent of isoniazid and rifampicin in the 50s into the 70s, it has gradually fallen into disuse in western countries; in the Netherlands is no longer registered. The value of streptomycin in multi-drug resistant forms of TB is still uncertain.
Tuberculosis prevention
Source and contact investigation
Around every TB patient, if necessary done a resource and / or contact tracing and infected people treated preventively. Here the ring principle is maintained. The people with the most intensive contacts (eg, family members, colleagues at work) are first investigated. As clearly more infections than are found normally the investigation is extended to the less intense. And so forth. The Dutch 50-year-olds is about 5% once infected with TB bacteria. The older, the better the chance. The younger the less likely an earlier infection. When staying in countries with high TB, as is the case with many non-Western immigrants, it is more likely an earlier infection than in the Netherlands. These people come over to the Netherlands, including tuberculosis bacterium and have a (small) chance to get active tuberculosis here.
Vaccination
Vaccination with BCG vaccine can protect against the serious effects of infection with the TB bacterium. The protective effect against include TB meningitis and miliary TB is properly demonstrated in children. BCG vaccination is not included in the Dutch national vaccination program. He is only offered to people who are at increased risk of getting the disease, for example, to people and children who have frequent or long for a country to go where TB is prevalent.
A disadvantage of vaccination is that the Mantoux test is less specific to demonstrate TB. In the past, it was thought that the Mantoux test would no longer be usable after BCG vaccination, however, this is, in practice, not usually the case. Often the Mantoux test is negative over time or reacts only slightly. The Mantoux test results of children vaccinated before their first birthday, may be interpreted as if they are not vaccinated. Many countries are not taken into account in the interpretation of the Mantoux test with a possible BCG vaccination. In the Netherlands, have made a difference in the evaluation of the Mantoux rash. Repeated Mantoux testing may boosting occur in previously BCG vaccinated or in people who long ago have been infected once. This can be confused with recent infection with tuberculosis bacteria.
Prophylaxis
People infected with TB bacteria but does not suffer from the disease tuberculosis, have a latent tuberculosis infection (LTBI). Left untreated, will lead to healthy adults at about 10% once to active tuberculosis, which most tuberculosis patients within a few years after infection will be found. In people with immune disorders and small children under five the disease occurs more frequently and more often than adults in a severe form. To prevent tuberculosis later, starting a preventive treatment under certain conditions. This means that the infected patient preventive medications are going to use in order to avoid later the disease tuberculosis. Commonly used regimens are 6 or 9 months INH, 3 months INH with rifampicin or rifampicin for 4 months only. A longer duration of treatment with INH (up to a maximum of 12 months) reduces the risk of developing tuberculosis even further. Even longer-term preventive treatments do not seem to add much more. Even after a successful prophylaxis the Mantoux test remains positive. Often by laymen - but also by doctors - the term latent tuberculosis infection (LTBI) confused with tuberculosis.