Pulmonary tubercolosis

1
Pulmonary tubercolosis

• Dr Nawal N Binhasher
• Assistant professor, Medical consultant, Medical
  department

2
Epidemiology

• The incidence of TB has been slowly rising since
  the 1980s of the previous century esp in eastern
  southern Africa where HIV is common.
• By the beginning of this century, there were an
  estimated 8-9 million new cases 1.8 million
  people died of TB in 2000.
• With the present trend, 9-10 million new cases of
  TB are expected in 1020.

3
Epidemiology

• Across regions, sub-Saharan Africa has by far the
  highest annual incidence rate 290/100,000
  population, but Asia harbors the largest No of
  cases.
• India, China, Indonesia, Bangladesh, Pakistan
  together account for over half the global burden.
• The most striking rises have been seen in
  sub-Saharan Africa the former Soviet Union.
  These rises offset the fall in cases No in other
  parts of the world mainly west central Europe,
  the Americas, the Middle East.

4
Epidemiology

• Globally, 11 of TB cases are co- infected with
  HIV, 38 of that in sub-Saharan Africa lt 1 in
  china India.
• Risk Factors
• Geography (place date of birth) as mentioned
  above
• Immunocompromise mainly HIV/AIDS ( others like
  steroids, TNF inhibitors, drug injection
  abusers)
• Medical factors, like DM 8 folds higher,
• Cancer esp hematological head neck ca,

5
Risk Factors

• Celiac disease, ESRD, intestinal bypass or
  gastrectomy, chronic malabsorption syndromes,
  Cigarette smoking, Iron status ? dietary Fe is
  associated with an ? risk of pulmonary TB,
  Vitamin-D an inverse relationship between vit-D
  levels both active latent TB infection has
  been shown in several studies.
• Low socioeconomic status (poverty).
• Children aging.

6
Pathophysiology

• The disease is spread by airborne droplets,
  containing MTB, inhaled lodged in the distal
  AW.
• MTB is taken up by alveolar macrophages in which
  it replicates with spread via the lymphatics to
  hilar LN a few escape to blood stream. These
  cells interact with T lymphocytes with the
  development of cellular immunity that can be
  demonstrated 3-8 wks after initial infectn by a
  ve skin reaction to ID injection of protein
  from tubercle bacilli (tuberculin).

7
Pathophysiology

• The cell-mediated immunity leads to granuloma
  formation (central caseation may completely
  heal many become calcified 20 of these
  contain dormant tubercle bacilli reactivation
  when host cellular immunity is depressed)