About 4,000 cases of tuberculosis are reported each year in France. The highly contagious disease is caused by the bacillus “Kock’s bacillus”. It can affect different organs: lungs, bones… Know everything about tuberculosis.
There tuberculosis is a notifiable disease in France. Approximately 4000 cases are listed there each year, according to the figures from Public Health France. Until 2007, vaccination against tuberculosis was mandatory in France (BCG vaccine). Tuberculosis usually affects lungs but can also affect other organs such as lymph nodes and bone. What is tuberculosis? Pulmonary ? bone ? How we catch it ? What are the symptoms ? What is the incubation period ? THE signs of healing ? Answers.
What is tuberculosis?
“Tuberculosis is a contagious infectious disease caused by a bacterium of the genus mycobacterium, whose germ most often involved is Mycobacterium tuberculosis or Koch’s bacillus” explains Dr. Jacques Amselem, general practitioner in Seine-et-Marne. After a first contact with the bacillus which may go unnoticed or give some minor signsthe disease can localize at the level of an organ and remain latent. We distinguish two main forms, there pulmonary tuberculosis and the extra-pulmonary tuberculosis (when it develops outside the lungs and affects, for example, the bones (bone tuberculosis)).
What is Kock’s bacillus?
Kock’s bacillus is a bacteria that infects the lungs and causes tuberculosis. This bacillus was demonstrated by Robert Koch in 1882 who gave him his name. There bacteria enters the airways creating chest pain, fever and coughing up blood. In the lungs, the bacterium multiplies, invading the bronchi and lung tissue. Contamination is most often by air.
What is latent tuberculosis?
There are two stages in tuberculosis: the bacteria infection time and the time of declared illness and symptomatic. After an infectious contact, Koch’s bacillus most often remains silent without causing disease: we then speak of“latent” TB infection and the person is not sick or contagious. A minority of these people will develop tuberculosis disease. Thus, at the adultthe risk of passing from latent tuberculosis to tuberculosis is of the order of 10% during life. This risk is greater in young children, older adolescents and people with weakened immunity. The risk of developing the disease after being infected is higher in the 2 years following the infectious contact.
What is pulmonary tuberculosis?
The most common, it is manifested by coughing, sneezing and weight loss. It is a contagious disease that is transmitted through the air. Developing countries are the most affected because patients cannot always access treatment. Treatment is with medication (antibiotic therapy). Tuberculosis can also affect other organs than the lungs. For example, ganglia and bones.
What is lymph node tuberculosis?
The organ most often affected is the lung, but the lymph nodes can also be the target of quiescent bacilli. Tuberculosis is then manifested by the appearance of adenopathies, an increase in the volume of the affected lymph nodes. The diagnosis can be made by biopsy of an affected lymph node, that is to say a sample which will make it possible to search for the presence of Koch’s bacilli.
What is bone tuberculosis?
Bone tuberculosis is one of the extra-pulmonary forms of the disease. It affects the spine in one out of two patients (Pott’s disease), the knee or the hip. People with a weak immune system (immunocompromised) are particularly at risk. Medical imaging (MRI, scanner) strongly suggests the diagnosis. Only the demonstration of Koch’s Bacillus confirms the diagnosis. Treatment is based on taking antibiotics.
What is the incubation period for tuberculosis?
Tuberculosis has 2 incubation times distinct:
► The first concerns the primary infection: this is the time (4 to 12 weeks) separating the contact with Koch’s bacillus, and the positive turn of the tests tuberculin. This time is asymptomatic.
► Once this primary infection has been carried out, a time before onset of tuberculosis “disease” and first symptoms. This second incubation period can be short (immediate) or long (up to several years). THE risk to develop the disease after being infected is higher within 2 years that follow the infectious contact.
What are the symptoms of tuberculosis?
The symptoms of tuberculosis are easily recognizable:
- a cough that produces sputum, sometimes even with blood,
- chest pain,
- respiratory distress,
- bouts of fever,
- a lack of appetite,
- weight loss
- and night sweats.
As soon as the first symptoms appear, it is best to consult a doctor quickly in order to receive adequate treatment, especially if there has been contact with an infected patient.
Tuberculosis is a contagious disease that is transmitted through the air from man to man. Of the droplets contaminated are projected during the coughing, sneezing or spitting up. Whoever inhales these droplets therefore finds himself contaminated in turn. The risk of transmission of Koch’s bacillus is all the higher than the contacts were close, frequent and repeated. The transmission will be facilitated in a confined and poorly ventilated area. It is accepted thata patient is contagious within 3 months preceding the diagnosis.
Screening is done around a person with contagious tuberculosis in order to detect any symptoms as early as possible and be able to offer care that avoids any complications. He understands :
- a medical consultation,
- a blood or skin test
- and a chest X-ray
Screening is free. THE screening for latent tuberculosis (without symptoms) is classically based on the intra-dermo reaction (IDR) to tuberculin (Tubertest). This test requires a reading at 72 hours which means reviewing the people in consultation. In recent years, the IDR can be replaced by the blood assay of interferon gamma (Quantiferon) which requires only one consultation. Its use is only indicated for people over 15 years of age.
Who should get the BCG vaccine?
Vaccination against tuberculosis is called BCG from the name of its inventors (Bacille Calmette and Guérin). This vaccine mainly concerns infants in order to protect them from serious forms of tuberculosis. Its efficiency would vary from 75 to 85%. It has not been compulsory since 2007.
What are the treatments for tuberculosis?
Tuberculosis treatment usually lasts 6 months and involves taking several antibiotics simultaneously. However, with the development of resistance to antibiotics, some cases become more and more complicated to treat.
If you are going to a country where there are many cases of tuberculosis, remember to adopt reinforced hygiene, by washing your hands frequently. Take care of your immune system by eating and sleeping well, and limiting stressors. Primary prevention of tuberculosis, including infant vaccination with BCG for children exposed to a high risk of tuberculosis in their surroundings or in their environment, protects against serious forms of this disease.
Thanks to Dr Jacques Amselem, general practitioner. Comments collected in 2019.