1. PNEUMONIA
Prof T Rogers

2. THE IMPORTANCE OF PNEUMONIA
A major killer in both developed and developing countries
Accounts for more deaths than other infectious diseases
Mortality rates vary but can be as high as 25%
A major cause of death in children in developing countries
Incidence here (?) 2-5/1000 population

3. PNEUMONIA
Neither radiological or microbiological criteria are specific for predicting the cause of pneumonia
A better approach is to first consider the clinical circumstances under which pneumonia acquired
Add the clinical background of the particular patient…

4. Classification of pneumonia
Community-acquired
Hospital-acquired
Aspiration and anaerobic
Pneumonia in immunocompromised
AIDS-related
Geographically restricted
Recurrent

5. COMMUNITY-ACQUIRED PNEUMONIA: INTRODUCTORY POINTS
More common at the extremes of age
Twice as common in winter months
A General Practitioner is likely to see up to 10 cases per yr
Represent <10% of all respiratory infection cases prescribed antibiotics
Most will be managed in the community

6. TYPES OF COMMUNITY ACQUIRED PNEUMONIA
In a previously healthy individual
Here the infection may have been acquired by droplet spread from another
Alternatively, in patients with underlying diseases endogenous colonizing bacteria may be the cause
These are more likely to be resistant to first-line antibiotics

7. SYMPTOMS OF PATIENTS WITH COMMUNITY-ACQUIRED PNEUMONIA(%) [Mc Farlane unpublished]
Cough
Fever
Breathlessness 67
Pleural pain 62
Headache 55
New sputum production 54
Muscle aches 44
Nausea/vomiting 48

8. British Thoracic Society CAP severity assessment: CURB 65 score
Any of: confusion, urea> 7mmol/l, respiratory rate>30/min, blood pressure systolic <90mmHg diastolic<60mmHg, age>65 years
Low (0-1), moderate (2), high (3+) severity
Will help determine where treated (home vs hospital), and likely mortality.
ICU admission indicated by CURB score of 4-5

9. COMMUNITY ACQUIRED PNEUMONIA: WHAT’S CAUSING IT?

10. MICROBIOLOGICAL CAUSES (%) OF COMMUNITY ACQUIRED PNEUMONIA FROM HOSPITAL BASED STUDIES (N=3,000)
CAP Severe CAP
No cause found
Pneumococcus
Influenza virus
Legionella spp*
Haem. Influenzae
Other viruses
Psittacosis/Q fever 3 2
Gram neg. bacilli
Staph aureus*

11. INVESTIGATIONS FOR DIAGNOSIS OF PNEUMONIA
Non-invasive: blood count, urea, albumin,LFT’s, sputum gram, chest X-ray, CT scan
Culture of sputum, blood, pleural fluid
Serology: pneumococcal, Legionella antigen
Invasive: induced sputum, bronchoscopy, open lung biopsy

12. TYPICAL GRAM APPEARANCE OF Strep pneumoniae IN SPUTUM
GRAM POSITIVE CHAINS
DIPLOCOCCI

13. Streptococcus pneumoniae (pneumococcus)
A gram positive coccus that grows in short chains
Alpha haemolytic on blood agar
Identified by its susceptibility to optochin
Polysaccharide capsule confers pathogenicity-at least 80 serotypes
There are multivalent vaccines for prevention of pneumococcal disease

14. SOME COMPLICATIONS OF PNEUMOCOCCAL SEPSIS
Bacteraemia (10%+)
Empyema (1%)
Meningitis (<0.5%)
Mortality rates of 10-25%
Splenectomy or asplenia a major risk factor

15. Pneumococcal vaccine is recommended for:
Age >65 years
Underlying chronic lung disease
Asplenia
Alcoholism
Diabetes mellitus
Chronic renal failure
HIV infection

16. VIRUSES THAT CAUSE COMMUNTIY ACQUIRED PNEUMONIA

17. INFLUENZA

18. © March Issue of Epi-Insight, Vol 6, Issue 3, Health Protection Surveillance Centre, Ireland

19. Pandemic influenza H1N1 An acute respiratory illness
Sudden onset of: fever (>38oC), headache, cough, sore throat, muscle aches, pneumonia
Transmitted by respiratory droplets from coughing, sneezing, and from “infected” surfaces.
1,613 cases confirmed with 4 deaths in Ireland up to 3rd October

20. Underlying diseases with an increased risk of severe influenza
Chronic lung, liver, CNS, conditions,
Immunosuppression
Diabetes mellitus
Asthma
Age <5 years or >65 years
Severely obese (BMI 40 or more)
Pregnancy
haemoglobinopathies

21. Preventing the spread of pandemic (swine) influenza
Wash hands with soap and water
Avoid unnecessary contact with cases
Avoid touching eyes, nose , mouth
Cover mouth and nose with tissue
Patients admitted to hospital who have a confirmed diagnosis will be nursed in a negative pressure room
HCW’s wear protective clothing

22. Treatment and prevention of pandemic influenza H1N1
Oseltamivir treatment of severe cases
Can also be considered as antiviral prophylaxis in selected high risk patients
Should be used prudently because of risk of drug resistance
Vaccine about to be issued, will include provision for health care workers

23. A V I N F L U

24. OTHER VIRAL CAUSES Respiratory syncytial virus (RSV)
Parainfluenza viruses
Enteroviruses
(Cytomegalovirus)

25. S A R
© July 2003 issue of Virus Alert, bulletin of the National Virus Reference Laboratory

26. Severe Acute Respiratory Syndrome (SARS)
Identified in Guangdong Province, China, in November 2002
Rapidly spread to Hong Kong, South East Asia, North America..The World
By the end of outbreak in June 2003 more than 8,000 cases had occurred with >800 deaths
Person to person transmission demonstrated

27. CAUSES OF ‘ATYPICAL’ PNEUMONIA
Mycoplasma pneumoniae
Chlamydia pneumoniae
Legionella pneumophila
Coxiella burnetii

28. Mycoplasma pneumoniae
Has no cell wall, therefore doesn’t respond to beta lactams
Causes atypical pneumonia in adolescents and young adults
Dry hacking cough, low grade fever, headache feature
Isolation by culture of the organism is difficult therefore diagnosis is confirmed by a high CFT or rising titre of specific antibodies
Cold agglutinins also typical
Macrolides or tetracyclines most active

29. Chlamydia pneumoniae An obligate intracellular bacterium
Causes mild pneumonia but may cause protracted symptoms
Sore throat, hoarseness, URT symptoms feature
Serological diagnosis rather than culture
Tetracyclines, macrolides, quinolones active

30. Legionnaires’ disease
A severe pneumonia due to Legionella pneumophila
Can be community or hospital acquired
Organism is acquired from environmental sources eg, humidified air conditioning, showers
Usually attacks debilitated individuals

31. Radiology

32. Microbiology Gram –ve, flagellated rod, aerobic
Facultative intracellular parasite in both amoeba and human monocytes/macrophages

33. RISK FACTORS Male sex Advanced age Cigarette smokers Alcoholism
Chronic lung disease
Immmunosuppression, malignancy

34. Legionnaires’ disease
Hyponatremia, confusion, nausea, vomiting, abnormal LFT’s a feature
Diagnosis often confirmed by urinary antigen test (specific for serogroup 1)
Can be cultured on special media
Must be notified to Public Health as it can cause outbreaks
Most active antibiotics are: macrolides, quinolones, rifampicin

35. Antibiotic Treatment of Community Acquired Pneumonia
The priority is to cover pneumococcus
Penicillin, amoxycillin, cephalosporins, new quinolones and macrolides have all been used as monotherapy
Choice will be influenced by local resistance rates for pneumococcus

36. Examples of antibiotics for CAI
Benzylpenicillin
Penicillin V
Ampicillin, amoxycillin, Augmentin
Cefuroxime, cefotaxime, ceftriaxone
Moxifloxacin (a quinolone)
Erythromycin, clarythromycin, azithromycin

37. ACID ALCOHOL FAST RODS SUGGESTING TUBERCULOSIS

38. KLEBSIELLA PNEUMONIA (RARE)

39. COMMUNITY ACQUIRED PNEUMONIA IN INFANTS AND CHILDREN
Group B streptococcus and E coli cause pneumonia in neonates
RSV an important pathogen in infants
Bordetella pertussis (cause of whooping cough) important in young children
As is Haemophilus influenzae type b

41. SOME FEATURES OF NOSOCOMIAL PNEUMONIA
Often ventilator associated, therefore seen in ITU most commonly
Due to both endogenous organisms and others acquired by cross infection
MRSA, gram negatives predominate
High associated mortality because of co-morbidity and antibiotic resistance

42. HOSPITAL ACQUIRED PNEUMONIA: Pseudomonas aeruginosa

43. TREATMENT OF HOSPITAL ACQUIRED PNEUMONIA
Will depend on the local epidemiology of the unit/hospital
Often require good cover for MRSA and gram negative enterobacteria
Therefore vancomycin and carbapenem or Tazocin may be used

44. PNEUMONIA IN THE IMMUNOCOMPROMISED HOST
Cause depends on the underlying immunodeficiency
More likely to present as a diffuse interstitial pneumonia
Treatment often empirical as establishing the cause is often difficult

45. MAJOR CAUSES OF PNEUMONIA IN IMMUNOCOMPROMISED
Pneumocystis jiroveci (carinii)
Cytomegalovirus
Other respiratory viruses
Tuberculosis
Fungi

46. Pneumocystis jiroveci (Lung biopsy)
Cyst stage

47. NOCARDIOSIS (Cause: Nocardia asteroides, acid fast rod)

48. Geographically restricted pneumonias
Typhoid
Melioidosis
Brucellosis
Endemic mycoses: histoplasmosis
Helminthic: paragonimiasis

49. Recurrent pneumonia
May be caused by local bronchial or pulmonary abnormality
Obstruction due to eg, foreign body, carcinoma, lymph node
Chronic obstructive lung disease: bronchiectasis
Neurological disorders: motor neurone disease
Structural: tracheo-oesophageal fistula
Aspiration (alcoholics): anaerobic organisms
Immunodeficiency state: hypogammaglobulinaemia

50. EMPYEMA May arise as an acute complication of pneumonia
Characterised by collection in pleural cavity, malaise, fever, pleuritic pain, leucocytosis
Chronic empyema usually occurs after failure to diagnose or treat adequately an acute empyema
May be loculated, or associated with a broncho-pleural fistula
Organisms are those causing the original pneumonia, or anaerobes
Treat by drainage of the collection and antibiotics after microbiological findings