Pulmonary Tuberculosis-Transmission,Symptoms and Diagnosis

Tuberculosis is an infection disease that may involve any part of the body,though the majority of cases re pulmonary.

Sources and Transmission:
1.MAN: open cases of active pulmonary TB are the sources of infection for the human tubercle bacillus.
The infection is exit by respiratory secretions,on coughing and expectoration..

Infectivity: persists so long the disease is active(open into the air pssages).
-proper chemotherapy of case controls infection whitin few months.
-untreated and drug-resistant case remain infective for long time.

Modes Of Transmission:
1.Direct respiratory infection:the most important favoured by repeated close association whit the case (at home,school,institute,cmp or work),specially in crowded badly ventilated places.

2.CATTLE:
Animals having respiratory TB are the reservoirs of infection,for the bovine tubercle bacillus.the orgnisms find exit in respiratory spray.

Mode of Transmission:inhalation of tubercle bcilli in cough spary of diseased animal.Infection is usually occupational in farmers and agriculture workers.

The infected individul is exposed to reinfection from the environent that he usually overcomes.Sometimes,however,reinfection is followed by active disease.This depends on the number and virulence of inhaled tubercle bacilli and the body resistance.

Symptoms:
Unmanaged cases of active tuberculosis show constitutional and local chest manifestations that vary according to stage and severity of disease.Cases are usually chronic and may show exacerbations and remissions.
Clinical picture: general and chest manifestations are not specific,but only suggestive like afternoon low-grade fever,night sweat.anorexia,mild loss of weight and hemoptysis.

Diagnosis:
-Chest X-ray:screens suspected cases.
-sputum examination: to demonstrate tubercle bacilli.It is the only evidence of conclusive diagnosis by:
direct smear microscopy and culture for particulary cses.