TuberculosisBY:

KARIM HUSSEIN 727

Tuberculosis is ..

A very common highly infectious inflammatory disease

caused by mycobacterium tuberculosis and is the

deadliest infectious disease in history.

It typically affects the lungs but can also affect other

parts of the body.

Most infections are asymptomatic and latent but about

one in each ten cases progress to active disease.

A suspected case should have ..

prolonged cough (>3 weeks)

fever,

decreased appetite, weight loss,

night sweats,

and coughing up blood (hemoptysis)

acid-fast bacilli are seen on sputum smear or in other body tissues or

fluids,

by culturing M. tuberculosis from sputum or other respiratory specimens,

Nucleic acid amplification tests are more rapid than culture and

specific for M. tuberculosis. They are also more sensitive than the

acid-fast bacillus smear but less sensitive than culture

(chest x-ray) radiological abnormalities

Or using clinical criteria in the absence of microbiologic confirmation.

laboratory testing should be performed when feasible to confirm the

diagnosis and to conduct drug susceptibility testing to guide treatment

Confirmation by ..

Risk factors ..

Poverty & crowding

Malnutrition

Lack of medical care

International travelers

Some diseases “which disables the T-cell mediated immunity”, as:

1. Diabetes Mellitus

2. Chronic lung disease

3. Chronic renal failure

4. Alcoholism

5. AIDS

6. Hodgkin’s lymphoma

Descriptive epidemiology ..

1. Person:

Globally, nearly 9 million new TB cases and approximately 1.5 million

TB-related deaths occur each year.

Incidence is 40/100,000 new cases yearly in Egypt and <4/100,000 in

usa

Personal characteristics

Age & sex

race

Genetic and Congenital TB

Occupation (silicosis-mine workers-health care workers-those under

mental and physical stress)

2. Place:

TB is a worldwide disease, more prevalent in developing countries

Most of the estimated number of cases in 2007 were in Asia (55%)

and Africa (31%), with small proportions of cases in the Eastern

Mediterranean Region (6%), the European Region (5%) and the

Region of the Americas (3%).

The five countries that rank first to fifth in terms of total numbers of

cases in 2007 are India (2.0 million), China (1.3 million), Indonesia

(0.53 million), Nigeria (0.46 million) and South Africa (0.46 million)

3. Time:

It has a secular trend; since the mid-20th century morbidity and

mortality markedly declined to the verge of eradication.

nowadays it is an emerging public health problem in developed

countries especially in low socio economic areas d.t:

Negligence of the TB control program

Rapid population growth with unmet health and social needs

Increase of the life expectancy (+chronic cases)

• Agent

• Reservoir

• Portal of Exit

• Mode of transmission

• Portal of Entry

• Susceptible host

Cycle of infection

1. Agent: human type of mycobacterium tuberculosis

2. Reservoir: cases of TB with positive sputum for acid fast bacilli

3. Exit: nose and mouth

4. Mode of transmission: contact droplet from sputum +ve case and a

host

5. Inlet: nose and mouth

6. Susceptible host: depends on personal characteristics and

immunity status as mentioned before.