1. Community Acquired PneumoniaBy
Dr. Adel Hamada
Lecturer of Chest Diseases
Faculty of Medicine Zagazig University

2. Definition of community acquired pneumonia
Pneumonia is defined as inflammation and consolidation of lung tissue due to an infectious agent.
Definition of community acquired pneumonia
CAP may be defined as pneumonia occurring in patients who have not been hospitalized or living in a nursing home during the 2 weeks prior to the onset of symptoms.
This pneumonia develops in the outpatient setting or within 48 hours of admission to a hospital

3. Respiratory Infections are responsible for more office visits than chronic diseases
180
100 80 60 40 20
161 73
Number of Office Visits (millions) 55 35
Prevalence of Respiratory Infections
Respiratory infections are the #1 reason for office visits to physicians and account for a total of 161 million visits per year.1
That’s more than twice the number of office visits made for hypertension and more than all the office visits made for gastrointestinal disorders, diabetes, and depression combined.
1. IMS America NDTI (National Disease Therapeutics Index) 26
Respiratory infections Hypertension Gastrointestinal diabetes Depression
IMS America NDTI (National Disease Therapeutics Index)

4. Top 20 Indications for Antibiotics 1998-2001
Petersen et al J Antimicrob Chemother 2007;60 (Suppl 1);i43-i47

5. RISK FACTORS OF CAP Age Alcoholism
Increased age favors infection with S. pneumoniae, group B streptococci, Moraxella catarrhalis, H. influenzae, gram-negative bacilli, and Chlamydophila pneumoniae. Aspiration pneumonia risk increases with age as well as risk for pneumonia due to multiple organisms.
Alcoholism
Reduce bacterial clearance from the airways.
S. pneumoniae infections tend to be more severe in alcoholic patients.
Also, infections caused by gram-negative bacilli and L. pneumophila occur more frequently in heavy drinkers.

6. Airway Colonization
Airway colonization is common in patients with chronic obstructive pulmonary disease (COPD) specially H. influenzae and M. catarrhalis become more prevalent.
Very pronounced decrease in forced expiratory volume in 1 second (FEV1), along with bronchiectasis, predisposes affected patients to infection with Pseudomonas aeruginosa.
Conditions leading to altered level of consciousness, poor dental hygiene, history of head and neck surgery affecting swallowing mechanisms, and upper gastrointestinal tract disease all are predisposing factors for development of aspiration pneumonia.
Organisms such as S. pneumoniae, S. aureus, group B streptococci, and H. influenzae frequently cause superinfections after viral illnesses such as influenza and RSV infection.

7. Altered Immunity

8. Environmental Factors
Occupations associated with exposure to dusts, fumes, and various chemicals increase the risk of acquiring CAP in general, with S. pneumoniae being the most likely pathogen.
Exposure to contaminated water supply and cooling towers of air-conditioning units increases the chance of acquiring Legionnaire’s disease.
Contact with animals may lead to pneumonia due to Yersinia pestis (plague, for which rodents constitute a natural reservoir), Francisella tularensis (tularemia, with rabbits, voles, and muskrats as carriers), C. burnetii (Q fever, transmitted by sheep, dogs, and cats), Rhodococcus (present in horses) or Chlamydophila psittaci (psittacosis, transmitted by birds).
In certain settings, bioterrorism must be considered as well. Potential agents utilized for such purposes include those organisms causing anthrax, tularemia, and plague.

9. Institutionalization
Both the frequency and the severity of pneumonia increase in institutionalized patients.
colonization by gram-negative bacilli or S. aureus plays a major role here.
Nutrition
Smoking
Smoking alters mucociliary transport, humoral and cellular defenses, and epithelial cell function and increases adhesion of S. pneumoniae and H. influenzae to the oropharyngeal epithelium.
Also, smoking predisposes to infection by influenza viruses, L. pneumophila, and S. pneumoniae

10. Approach to the Patient with Suspected Pulmonary Infection
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11. (Community-acquired pneumonia)
CAP
(Community-acquired pneumonia)

12. IS IT INFECTION?

13. WHAT TYPE OF INFECTION IS IT?

14. HOW SEVERE IS THE ILLNESS?
Pneumonia severity index

15. CURB 65

16. WHAT IS THE LIKELY PATHOGEN?

17. Microbiology of CAP
Bartlett JG. Management of Respiratory Tract Infections 1st Ed Williams & Wilkins, 1997:1-117

18. CAUSATIVE PATHOGENS IN CAP 5755 ADULTS ADMITTED TO HOSPITAL%
S pneumoniae
H influenzae
Legionella sp
Staph aureus
M catarrhalis
GNEB
Mycoplasma
C pneumoniae
C psittaci
Coxiella
Viruses
Other
No Pathogen 45

19. Most Common Etiologic Agents of Community-Acquired Pneumonia

20. PNEUMOCOCCAL PNEUMONIA
COMMUNITY-ACQUIRED
PNEUMOCOCCAL PNEUMONIA
Frequency %
ICU
HOSPITAL
COMMUNITY
42 Individual studies in Europe

21. Individual studies COMMUNITY-ACQUIRED MYCOPLASMA PNEUMONIA Frequency %
HOSPITAL
ICU
Individual studies

22. Frequency % Individual studies COMMUNITY-ACQUIRED LEGIONELLA PNEUMONIA
ICU
HOSPITAL
COMMUNITY
Individual studies

23. HOW CAN THE CAUSATIVE PATHOGEN BE IDENTIFIED?
Minimally Invasive Tests:
Throat Swab Examination and Other Modalities
predominantly intracellular pathogens such as viruses (including influenza viruses), Mycoplasma, and Chlamydophila, by direct immunofluorescence (Chlamydophila, viruses) or cell culture.
Increasingly, polymerase chain reaction (PCR) techniques are best for noncommensal organisms.

24. However Sputum Examination
The main problem is that organisms identified in sputum may not be representative of what is happening in the lung.
Second, bacteria may colonize the normally sterile airways when host defenses are compromised .
However
some organisms are always pathogens (e.g., Mycobacteria, Pneumocystis, Legionella), their identification in sputum is always helpful.
Various tests can be performed on sputum; Gram stain and routine culture are the best known

25. Serologic Testing Blood Culture
In CAP, serologic studies may be the only method of diagnosis available for detection of Mycoplasma, Chlamydia, Coxiella, Legionella, and viral infections
it is necessary to identify a four-fold rise in specific antibody titers to at least 1 : 128 between acute and convalescent samples. A single high titer of 1 : 256 is presumptive evidence of infection.
Blood Culture
Blood culture is readily available and highly specific if positive. Its drawback is its relative insensitivity: Positive culture results are obtained in only 10% to 20% of hospitalized adult patients who have CAP.

26. Pleural Fluid/Tissue Sampling
When present, pleural fluid should be sampled, because the results are highly specific.
Urine Testing
(ELISA) testing of urine for Legionella antigen is now the most frequently performed test, yielding the most rapid results, for the diagnosis of Legionella infection .
Urine antigen tests for S. pneumoniae probably are more sensitive and specific than is sputum examination.
Invasive Tests
Rarely needed in CAP and is reserved for patient admitted to ICU or non responder to empirical antibiotic therapy.
Transtracheal Aspiration.
Bronchoscopy
Percutaneous Fine Needle Aspiration
Open Lung Biopsy

27. Other Techniques
polymerase chain reaction (PCR) techniques, are beginning to be used selectively for pathogen identification.
Other roles of PCR analysis may be to detect multiple organisms at the same time in a single sample (so-called multiplex PCR assay) and to identify antibiotic resistance by detection of the specific gene defect that determines such resistance (e.g., rifampicin resistance in tuberculosis).

28. Clinical Indications for Diagnostic Testing for Community-Acquired Pneumonia
(Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults, 2007).

29. TREATMENT SITE OF CARE DECISION Home ( Outpatient)
Hospital( Not in ICU)
Hospital( ICU)

30. American Thoracic Society Criteria for Admission of Patients with Community-Acquired Pneumonia to an Intensive Care Unit ICU admission is warranted for patients who fulfill three minor criteria or one major criterion.

31. HYDROPHILIC ANTIBIOTICS
LIPOPHILIC ANTIBIOTICS
BETA-LACTAMS
PENICILLINS
CEPHALOSPORINS
CARBAPENEMS
MONOBACTAMS
GLYCOPEPTIDES
AMINOGLYCOSIDES
MACROLIDES
FLUOROQUINOLONES
TETRACYCLINES
CHLORAMPHENICOL
RIFAMPICIN
LINEZOLID
LOW VOLUME OF DISTRIBUTION
INABILITY OF DIFFUSING THROUGH MEMBRANES
INACTIVE AGAINST INTRACELLULAR PATHOGENS
RENAL ELIMINATION AS UNCHANGED DRUG
HIGH VOLUME OF DISTRIBUTION
ABILITY OF DIFFUSING THROUGH MEMBRANES
ACTIVE AGAINST INTRACELLULAR PATHOGENS
ELIMINATION AFTER LIVER METABOLIZATION
Pea F, Viale P, Furlanut M. Clin Pharmacokinet 2005, 44:

32. ATS/IDSA Recommendations for Empirical Antibiotic Treatment of Community-Acquired Pneumonia

33. Empirical Coverage for Uncommon Pathogens Causing Community-Acquired Pneumonia

34. ROUTE AND DURATION OF THERAPY; HOSPITAL DISCHARGE
Most patients with CAP severe enough to warrant hospital admission are treated with intravenous antibiotics. Switching to oral therapy should be considered once the patient
1- has achieved clinical stability
2- is able to tolerate oral medication
3- and has a functioning gastrointestinal tract.
Criteria for Clinical Stability in Management of Community-Acquired Pneumonia

35. ATS/IDSA guideline recommendations denoting 5 days as minimal duration of therapy. Antibiotics can be discontinued once clinical stability has been achieved and maintained for 48 to 72 hours.
More than 7 to 10 days of total antibiotic administration is rarely required, unless extrapulmonary infections such as endocarditis or meningitis are present, initial therapy was not active against a subsequently identified offending pathogen, or P. aeruginosa infection, S. aureus bacteremia, or tissue necrosis was present.

36. non-responding/deteriorating pneumonia
Failure to achieve clinical stability using the aforementioned criteria within the first 3 days is suggestive of nonresponse to therapy, although in up to 25% of patients (especially those of advanced age and with multiple comorbid conditions), 6 days or longer may be needed to meet these criteria.

37. common causes of non-responding/deteriorating pneumonia

38. SPECIFIC COMPLICATIONS of PNEUMONIA
ASPIRATION PNEUMONIA
LUNG ABSCESS
PARAPNEUMONIC EFFUSION AND EMPYEMA
BRONCHOPLEURAL FISTULA
ORGANIZING PNEUMONIA

39. Recommendations for Vaccine Prevention of Community-Acquired Pneumonia

40. THANK YOU