Pulmonary tuberculosis is a bacterial infection caused by Mycobacterium tuberculosis (BK), transmitted by air. After contamination, M. tuberculosis multiplies slowly in the lungs: the primary infection.
In the absence of immunosuppression, pulmonary lesion heals in 90% of cases, but 10% of patients develop active TB.
There are also extrapulmonary (meningitis, miliary, lymphatic, bone, etc.).
Infection with HIV promotes progression to active tuberculosis. Tuberculosis is the first opportunistic infection may reveal the AIDS disease. In some countries, up to 70% of TB patients are co-infected with HIV.
Clinical signs:
Prolonged cough (> 2 weeks), sputum, chest pain, weight loss, anorexia, fatigue, mild fever and night sweats.
The most characteristic sign is hemoptysis (blood in the sputum), but it is not always present and any hemoptysis is not due to tuberculosis.
If direct sputum is negative, think of a Paragonimiasis (page 149), melioidosis (Southeast Asia), a deep mycosis, a lung cancer.
In practice, in endemic areas, the diagnosis of tuberculosis should be considered in any patient consulting for respiratory symptoms for more than 2 weeks and not responding to a non-specific antibiotic treatment.
Diagnosis:
– Direct sputum microscopy; culture.
– Chest radiography is useful in smear-negative patients and in children.
Treatment:
The treatment is based on the combination of several anti-TB among the following
[Isoniazid (H), rifampin (R), pyrazinamide (Z), ethambutol (E), streptomycin (S)].
It is divided into two phases (attack phase and maintenance phase), according to a standardized scheme.
The duration of treatment of tuberculosis bacteria sensitive is at least 6 months.
The healing of a TB patient requires a significant commitment from both the health care team that from the patient.Only a few months continuous treatment provides healing and prevent the emergence of resistance, which complicates further processing. It is essential that the patient understands this and has the opportunity to follow the treatment to completion.
Prevention:
When administered properly, BCG confers protection probably superior to 50%. It is shown that BCG protects against severe forms of the disease, especially against tuberculous meningitis and miliary tuberculosis.
The BCG vaccination does not reduce the transmission of TB.
For more information on the diagnosis, treatment, prevention of tuberculosis and the monitoring of a TB patient, refer to Tuberculosis guide, MSF.
