1589110838-atypical-pneumonia.pngmgmgmgpt

pneumonia

1. Atypical pneumoniaAtypical pneumonia

2. Atypical pneumoniaAtypical pneumonia

A pneumonia is atypical whenA pneumonia is atypical when
I.I.Causative agent cannot be isolated Causative agent cannot be isolated
on ordinary culture mediaon ordinary culture media
II.II.When its clinical picture does not When its clinical picture does not
resemble that of typical resemble that of typical
pneumococcal pneumoniapneumococcal pneumonia

3. Causative organisms Causative organisms

““TypicalTypical”:”:

S.pneumoniae, Haemophilus influenzae, S.pneumoniae, Haemophilus influenzae,
Staphylococcus aureus, Group A streptococci, Staphylococcus aureus, Group A streptococci,
Moraxella catarrhalis, Klebsiella, anaerobic Moraxella catarrhalis, Klebsiella, anaerobic
and aerobic gram-negative bacteriaand aerobic gram-negative bacteria

““Atypical” - 20-28% CAP worldwideAtypical” - 20-28% CAP worldwide

Legionella spp, Mycoplasma pneumoniae Legionella spp, Mycoplasma pneumoniae
(most common type of atypical pneumonia), (most common type of atypical pneumonia),
Chlamydophila pneumoniae and C. psittaciChlamydophila pneumoniae and C. psittaci

Mainly Mainly distinguished fromdistinguished from typical by not being typical by not being
detectable on Gram stain or cultivable on detectable on Gram stain or cultivable on
standard mediastandard media

4. Legionella pneumophilaLegionella pneumophila

5. HistoryHistory

Legionnaires’ disease was first Legionnaires’ disease was first
recognized in 1976, when an recognized in 1976, when an
outbreak of pneumonia took place outbreak of pneumonia took place
at a hotel in Philadelphia during the at a hotel in Philadelphia during the
American Legion Convention.American Legion Convention.

6. Legionella
pneumophila
A thin and flagellated gram-negative bacterium
Motile, Non-capsulated
Poorly stained by gram stain (Increase time of
safranin stain)
Don’t stain with H&E but with Dieterle Silver
impregnation stain
Require high concentration of iron and cysteine
for growth
Incubation period: two to ten days.

7. Clinical syndromesClinical syndromes

Pontiac fever: an acute, febrile, an Pontiac fever: an acute, febrile, an
influenza-like self limited illnessinfluenza-like self limited illness

Legionnaires’ disease: Legionnaires’ disease:
designation for severe form of designation for severe form of
pneumoniapneumonia

8. Grows best in warm
water (25-40℃) sources
such as: hot tubs, cooling
towers, hot water tanks,
large plumbing systems,
or parts of the air-
conditioning systems of
large buildings.
Sinks, showers,
nebulizers and ventilators
in hospitals
Environment

9. Risk FactorsRisk Factors
Opportunistic Disease: underlying
illness/weak immune system.
Nosocomial infections are major
concerns. Community acquired
pneumonia also occurs.
Patients who are middle-aged,
elderly with, COPD, AIDS, Cancer,
transplant, smokers and other
genetically susceptible patients are
primary targets.

10. Transmission Transmission
L. pneumophilia is NOT
spread by human-human
interaction.
Mist or vapor
contaminated with the
bacteria.
Warm stagnant water in
complex systems is ideal.

11. PathogenesisPathogenesis

Major virulence factor is endotoxin and Major virulence factor is endotoxin and
ability to multiply in macrophages ability to multiply in macrophages

Multilobular consolidation, Multilobular consolidation,
inflammation and abscesses in lungsinflammation and abscesses in lungs

BacteremiaBacteremia

Damage to vascular endothelium Damage to vascular endothelium
(multiple organs, brain and kidney)(multiple organs, brain and kidney)

12. SymptomsSymptoms
Early Symptoms
Malaise, muscle aches, lethargy and slight
headaches(influenza like symptoms).
Fever, non productive cough, pleuritic and
non-pleuritic chest pain, dyspnoea, abdominal
pain, diarrhea.
Late Symptoms
Extreme lethargy, comatose state
Impaired kidney and liver functioning
Nervous System disorders, confusion
Non bloody diarrhea, protienuria, microscopic
hematuria
Hyponatremia; Serum Na less than130mEq/L

13. DiagnosisDiagnosis
Gram stain shows many neutrophils but no
bacteria.
Organism fails to grow on ordinary culture
medias
Serology……… IF
Florescence antibody staining of lung tissue
Urinary Antigen
Culture BCYA (Buffered charcoal yeast agar)
Colonies have appearance of ground-glass

14. TreatmentTreatment
 Wide-range antibiotics
to treat pneumonia
 Macrolides
(azithromycin)
 Fluoroquinolones
(levofloxacin,
moxifloxacin)

15. Chlamydophila psittaciChlamydophila psittaci

Psittacosis (Parrot fever)Psittacosis (Parrot fever)

All birds can carryAll birds can carry

16. Disease spectrumDisease spectrum

Mild influenza like illness to fatal pneumoniaMild influenza like illness to fatal pneumonia

HeadacheHeadache

High feverHigh fever

ChillsChills

Malaise Malaise

Non productive cough Non productive cough

On examination rales and conslidation, On examination rales and conslidation,
enlargement of liver and spleenenlargement of liver and spleen

Encephlitis, endocarditis, pericarditis and Encephlitis, endocarditis, pericarditis and
deathdeath

17. Laboratory Diagnosis - Laboratory Diagnosis - C. psittaciC. psittaci

Serology (Complement fixation test)Serology (Complement fixation test)

fourfold rise in titerfourfold rise in titer

requires paired samplesrequires paired samples

IFIF

ELISAELISA

18. Treatment and Prevention - Treatment and Prevention - C. psittaciC. psittaci

Tetracycline or erythromycin Tetracycline or erythromycin

Quarantine of imported birdsQuarantine of imported birds

Control of bird infectionControl of bird infection

Antibiotic supplementation of food Antibiotic supplementation of food
but this may lead to resistant strainsbut this may lead to resistant strains

19. Chlamydophila pneumoniaeChlamydophila pneumoniae

Chlamydophila pneumoniaeChlamydophila pneumoniae is a species  is a species
ofofChlamydophila bacteria that infects  bacteria that infects
humans and is a major cause of humans and is a major cause of 
pneumonia..

Previously known as the TWAR agent Previously known as the TWAR agent
(Taiwan Acute Respiratory Agent)(Taiwan Acute Respiratory Agent)

20. Disease spectrumDisease spectrum

PneumoniaPneumonia

PharyngitisPharyngitis

BronchitisBronchitis

Sinusitis Sinusitis

21. DIAGNOSISDIAGNOSIS

Antigen detection testAntigen detection test

ELISAELISA

DFADFA

PCRPCR

SERODIAGNOSISSERODIAGNOSIS

CFTCFT

ELISAELISA

IFIF