Tuberculosis is a chronic bacterial infection caused by Mycobacterium tuberculosis and characterized by the formation of granulomas (once called tubercles, hence the name “tuberculosis”) in infected tissues and by a marked cell-mediated hypersensitivity.
The classic site of the disease is the lung, but other organs may be affected.
In the absence of effective treatment there is a chronic progression of the disease with a grave prognosis in most cases.
The infection occurs from human to human through the respiratory tract: the sick person emits tiny droplets containing tubercle bacilli into the surrounding air by coughing.
Patients who cough high quantities of tubercle bacilli are considered contagious: this means that only those affected by respiratory tuberculosis (lungs, bronchi, larynx) can transmit the disease, provided that their expectorates contain tubercle bacilli in sufficient quantity.
Latent tuberculosis infection is where a subject has been infected without showing signs (radiological, clinical and bacteriological) of tubercular activity: it occurs when the immune system of the infected person has expressed specific antibodies for which the bacterial load is kept under control, i.e. in a state of inactivity (dormant bacilli).
Epidemiological analyses of latent tuberculosis reveal that 90% of infected people do not develop the disease while 10% may develop the most active lung disease in the period between two and five years after the infection, but also during the remainder of their lives.
It is therefore necessary to identify and submit to preventive pharmacological treatment all the subjects that could more easily manage the disease.
According to Mantoux, the tuberculin skin test is the test of choice for the screening of infected persons; however, its low sensitivity and specificity and the possibility of false positives and false negatives are well-known.
Anti-tuberculosis preventive chemotherapy is aimed at preventing progression following infection and tuberculosis in individuals with tuberculin cuticonversion or who are positive for tuberculin testing. Before starting chemotherapy (isoniazid) it is essential to perform an X-ray of the thorax and any other examination considered necessary to rule out the presence of active tuberculosis.
Tuberculous chemoprophylaxis is instead the intake of isoniazid to prevent the development of the disease in those at risk that have been exposed to the infection.
The normal regimen of preventive therapy consists of isoniazid (children: 10 mg / kg / day, adults 5 mg / kg / day up to a maximum of 300 / mg / day) for at least 6 consecutive months in adults and 6-9 months continuously in children.
The actual tuberculosis disease develops in those who have failed to stem the primary infection: in these subjects, which do not exceed 10% of infected individuals, tuberculosis can occur within a few weeks. At other times, however, the bacilli may remain in a state of latency for many years: in these cases the outcome, normally, is a complete recovery, but there remains the possibility of re-igniting the primary focus (post-primary tuberculosis).
The development of the disease in the lungs causes subtle symptoms that are often confused with other diseases; these are: weight loss, asthenia, slight fever, night sweats, coughing, chest pain, hemoptysis (spitting blood) and dyspnea (difficulty breathing).
Standardized therapy and treatment adherence are the cornerstones for a rapid and stable recovery: numerous pharmacokinetic studies show that a high percentage of therapeutic failures are due to insufficient doses of the antimycobacterial drugs, the patient’s non-adherence to therapy or the doctor being misinformed regarding the correct approach to the pathology.
In order to avoid the emergence of multidrug-resistant strains, the WHO recommends adopting for “all patients, including HIV-infected patients not previously treated, an internationally recognized treatment of first-line anti-tuberculosis drugs with known bioavailability”.
The treatment is divided into two phases:
PIAM, a historically-significant protagonist in the area of tuberculosis and the first company in the world to market an effective anti-tuberculosis vaccine, today confirms its unconditional commitment to make available in Italy the necessary treatments for the prevention and therapy of this important pathology.