Tuberculosis - SpeedyLook encyclopedia

History

The history of tuberculosis is more difficult to expose in a systematic and synthetic way. It relates, indeed, to an infection whose origins seem to go back to that of mankind and the life in society, but the unit Nosologique and the effective cause were known only as from the 19th century. Tuberculosis was isolated from the other lung diseases by Laennec in 1819. In 1839, the German doctor Schönlein gives its final name to the disease, joining together in a unified description its disparate clinical demonstrations.

In 1865, the doctor Jean-Antoine Villemin proves by the experimental method the transmission of tuberculosis and affirms consequently that this disease, of nature hitherto unknown, is due to an invisible microbe with average the techniques of the time. One can thus protect oneself some by measurements aiming at avoiding the contagion.

Lastly, following work of Pasteur, it is a German doctor, Robert Koch, which discovers the bacillus, in 1882: at this time, tuberculosis was in Europe the cause of a death over Sept.

According to a study of the Institute Pasteur, based on the African stocks, the bacilli of tuberculosis existed three million years ago, whereas the preceding estimates counted on an appearance going back only to 35.000 years. The original stock would have appeared in East Africa, considered also as the cradle of humanity. The disease would be thus as old as the humanity and its expansion throughout the world would be closely related to that of the man.

Epidemiology

One considers the number annual of new cases in the world at nearly 9 million (2004) of which only less than half is officially declared, causing 1,7 million death.

The majority of the new cases (nearly 48%) are in the populated zones of Asia: Bengladesh, Pakistan, India, China and Indonesia. The incidence however clearly decreased in these countries. There exists on the other hand a strong increase in the countries of Eastern Europe (Russia included/understood, even if this increase seems to be stabilized). The growth remains very strong in Africa with a significant proportion of seropositivity HIV (nearly 13% compared with less than 1% in the Asian countries).

It is primarily about an infection concerning the young adult and the men close to twice are reached than the women.

The economic decline and the increase in precariousness are recognized causes of the increase in the number of cases.

Resistance to the traditional anti-tuberculous drugs remains rare (less than 3% of the new cases) but reached 10% in certain countries of Eastern Europe.

Tuberculosis deserves its qualifier of " three times over; disease sociale" :

its frequency in a community is an good indicator of the degree of social evolution of this one. The principal factors of reduction in tuberculosis are the conditions of habitat, occupational hygiene (ventilation and de-dusting of the workshops, examination of recruiting and monitoring of the workers), medical education, nutrition.
the fight against tuberculosis requires to be effective a well developed medical equipment and an social organization, and financial means the important ones.
the main victims are young adults in full professional output, undergoing a long disability considering the slow evolution and the need for a prolonged treatment.

Clinical demonstrations

Pulmonary tuberculosis

Fortuitous discovery

The realization of a Intradermoréaction makes it possible to detect the people whose organization lodges the bacillus of Koch before the clinical demonstrations of the disease in the absence of vaccination by the BCG.

The interpretation of a intradermoréaction is purely based on the size of the induration and not on the visualization of an erythema.

The intradermoréaction for tuberculosis bears also the name of Test Mantoux.

A radiography of the lungs will seek radiological signs.

A search for contamination in the family and professional entourage is essential.

Clinical signs

The Symptôme S are a fébricule (38-38,5 °C) with the long course, a Toux sometimes accompanied by Hémoptysie, a slimming from 5 to 10 kg occurring in a few months and of night sweats. A positive (IDR) intradermoréaction with tuberculin. The risk factors are the Immunodépression, the life out of hearth, the intravenous Toxicomanie, the absence of fixed residence, the direct contact with people infected and certain professions of health.

Radiological signs

Radio of the Thorax: classically, reached Apex (higher end of the Lung S) with, in an evolved/moved tuberculosis, caves (cavities in pulmonary fabric, containing many air and BK, this bacterium being indeed Aerobic). These caves do not disappear with the cure; they calcify and produce radiological after-effects formerly called “spots with the lung”.

Bacteriological proof

Expectorations : contain BK when the patient is contagious. This contagiousness usually disappears after 10 to 20 days from well led treatment.

Tuberculosis can be caused by various germs:

Mycobacterium tuberculosis (Bacillus of Koch), most frequent
Mycobacterium bovis
Mycobacterium africanum
Mycobacterium canetti (essentiellemnt in Djibouti)

Pulmonary extra tuberculosis

Genital tuberculosis

Woman

Circumstances of discovery

Amenorrhoea
Infertility

Tuberculosis of the bones

Spondylodiscite tubercular patient or Badly of Pott
white Tumor of the knee
Spina ventosa

Ganglionic tuberculosis

lymphatic Ganglion Body ovalaire surrounded by a fibrous capsule under which one identifies the lymphatic sine under capsulaire. Two distinct zones are present:
- the cortical where are different the lymphoid follicules,
- the medullary , not very visible here, containing the vascular network.
Lesion Within cut, this ganglion contains multiple nodular lesions corresponding to the tuberculous Follicules (fig. a). Within the same ganglion, several lesions tubercular patients can be observed:

follicular Lesion (fig. a): round hearth formed of giant cells and epithelioid cells, surrounded by a crown of lymphocytes. The giant cells are plurinucléées cells, with the eosinophilic Cytoplasme abundant slightly (fig. b) (H). The cells epithelioid S are lengthened cells, with the cytoplasmic limits evil visible and the core lengthened in sole of shoe (fig. b) (T). caséofibreuse
Lésion (fig. c): necrose central eosinophilic anhist: necrose caseous (H) encircled by a fibrous hull.
Lesion caséofolliculaire: hearth centered by a beach of Necroses caseous, surrounded by epithelioid cells, giant cells and a crown of lymphocytes. The presence of bacilli of Koch can be revealed on the coloring of Ziehl Neelsen (fig. d)
Dignostic Ganglionic tuberculosis.

Meningitis tubercular patient
How to diagnose quickly meningitis tubercular patient in an adult?

Antituberculeux treatment

In 1921, Albert Calmette and Camille Guerin successfully test the first vaccine against tuberculosis, baptized BCG. This discovery made it possible to advance considerably the antituberculeux treatments.

the treatment must be taken the morning, with jeun, 1/2 hour before lunching.

Rifadine
tuberculosis of the bones

Rimifon
tuberculosis of the bones

Isoniazid

Rifampicine
The rifampicine is usually used with the amount of 10mg/kg/jour, throughout one 6 month, for the treatment of tuberculosis. This antibiotic is a strong enzymatic inductor: it accelerates the degradation of the other drugs, in particular the oral contraceptives. The women under contraceptives are thus invited to re-examine their treatment the rise (after consultation of the gynecologist), to see to even pass to a mechanical contraception (condom,…) throughout treatment. The rifampicine causes an orange coloring of the urines. It is a good means of objectifying the observance of the treatment.

Pyrazinamide
The pyrazinamide is usually used with the amount of 20mg/kg/jour in the treatment of tuberculosis.

Streptomycine
The Streptomycine (discovery by Waksman about 1946) was the first active antibiotic against the bacillus of Koch. It is contra-indicated in the expectant mother and must imperatively be associated with the other antituberculeux ones (INH and NOT).

Posology:

By intramuscular way in the adult: 15 to 25 Mg per kg and day.

By way intrarachidienne : For the adult, twenty five to hundred milligrams per day, for a child, twenty to forty milligrams per kilogram and day in 2 or 4 injections.

Monitoring of the treatment: The auditive and renal functions will have to be supervised regularly.

Éthambutol
The éthambutol is usable in the expectant mother.

Posology for adult: The morning with jeun in only one catch, fifteen to twenty milligrams per kilogram. Not to exceed twenty five milligrams per kilogram by 24:00 without exceeding 60 days, then to reduce to fifteen milligrams per kilogram and day.

Monitoring

Diarylquinolines
The R207910 , a molecule of the family of the Diarylquinoline S, could appear promising against Mycobacterium tuberculosis . She gives birth to three hopes:

to shorten the duration of the treatment;

only once to consider catches per week in partnership with another antituberculeux;

to be active on stocks multirésistantes, with a bactericidal effectiveness good higher than that of the Isoniazid and Rifampicine.

This drug is currently in very early phase of its development. Only in-depth studies at the man will make it possible to check that these hopes are founded.

Flow diagram for treatment
Treatment: six months for a pulmonary tuberculosis with sensitive BK at a patient Immunocompétent, including/understanding 2 months of Antibiotic quadri-therapy (Isoniazid + Rifampicine + Pirilène + Ethambutol) then 4 months of Bi-therapy (isoniazid and rifampicine).

in 2006, the recommendations of WHO are to continue the quadrithérapie for 6 months.

Resistance to the anti-tuberculous treatments
It is due to insufficient treatments in amounts or duration. It poses important problems because tuberculosis is much more delicate to look after, especially in the event of resistances to several anti-tuberculous ( multi resistance ). Its incidence is approximately 10% of the new cases (for only one antibiotic) and of 1% (for several antibiotics). In certain countries, these figures can reach more than 50% of the cases (in particular in Russia).

Pneumothorax (historical)
Before the Antibiotic discovery of S effective, one practiced the collapsothérapie (depression of the part reached of the lung and part of the thorax by blowing of air (pneumothorax) or mutilating Chirurgie).
These methods disappeared from the Western countries in the years 1950.

Tuberculosis in the world
In 2003, the number of patients of tuberculosis dropped in China (China is still the second country more touched in the world after the India) of 30 % thanks to the treatment of short duration under direct monitoring (DOWRIES) of the WHO, only really effective to date, but which had sorrow to be essential in the world. There would be today (at the end of 2006) more than 80.000 cases in all the Congo against 60.000 in 2002. In spite of the support of the international organizations, the situation worsens because of poverty, of promiscuity, but also of the insecurity and combat, which push people to be moved, from where more contamination. The propagation of the virus of the AIDS plays also its part: an HIV positive risks, more than another, to develop the disease of tuberculosis. The treatment rests on preventive measures individual and collective, like on a rigorous and complete treatment of the sick subjects:

engagement of the public authorities to fight without slackening against tuberculosis;

tracking of tuberculosis by microscopic examination of the Smear at the subjects which present Symptôme S;

regular and uninterrupted supply antituberculeux drugs of great quality;

antibiotic treatment of six to eight month under regular monitoring (at least during the first two months, direct monitoring of the patients to make sure that they take their drugs well);

systems of notification to check the action of the treatment and the results of the program.

Prevention

Tracking of the cows carrying the bacillus

Vaccination by the BCG
The bacillus of Calmette - Guerin (BCG) is an attenuated alive stock of Mycobacterium bovis . The effectiveness of vaccination by BCG is limited to protection against the evolution mortal of tuberculosis, particularly meningitis tubercular patient and the disseminated disease (Miliaire). The vaccine is more effective in the newborn and the child that in the adult.
It thus does not make it possible to prevent the transmission of the disease and to stop the world epidemic. The future is in the research of genes of virulence of the bacillus.
Let us announce in the passing which if one attentively looks at the evolution of the regression of the Tuberculose since the XIXe century (made noted in many countries), one objectively notes that it regressed before the discovery of the antituberculeux one, or of vaccination. The epidemiologists primarily interpret it by the improvement of the conditions of hygiene, the nutritional conditions, etc
On the basis of study made with large scales and organized by the World Health Organization (WHO), some think that the effectiveness of the BCG is low: in a study made on 260.000 people in a country of endémie tubercular patient (in India), the authors did not find a difference significant between the group which had received the BCG and that which had not received it. Another study also made in India on 366.625 people showed that the BCG did not have any preventive action on the forms of pulmonary tuberculoses adult.
In July 2007, the French Minister for health, Roselyne Bachelot, announced the suspension of the obligation to vaccinate all the children and the teenagers against tuberculosis by the BCG, at the time of the presentation of the new program of fight against this disease.
After more than two years of debates, and in accordance with the recommendations of the Superior council of French public health and the technical Committee of vaccinations, France, with the image of other European countries, wants to optimize his strategy of vaccination by targeting it towards the children known as " with risque" and by reinforcing tracking.

Obligatory declaration
In France, Belgium and Switzerland, this disease is on the list of the Infectious illness to obligatory declaration.
In France, in particular, it is the setting under antituberculeux treatment which belongs to the declaration. That makes it possible to include the cases confirmed bactériologiquement and the probable cases resting on a beam of arguments epidemiologic, clinical and of imagery in the absence of formal bacteriological proof. Indeed these probable cases requiring the same investigations of epidemiological investigation to seek possible cases contact or contaminating around them.

Research and development
According to a study of Olivier Neyrolles of the Pasteur Institute, the bacillus of Koch would hide in the fat cells. Thus it would resist the most powerful antibiotics and which it would be able to reappear after many years at cured people.

Note

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