Case 7- pneumoniae

Question 1

Which conditions make you more susceptible to LRTI’s?

Answer 1

COPD and asthma

Question 2

Types of LRTI’s

Answer 2

Pneumonia, Bronchitis (mianly viral), Bronchiolitis, Exacerbation of chronic obstructive pulmonary disease/ asthma.

Question 3

What causes Bronchiolitis?

Answer 3

The RSV virus

Question 4

Difference between bronchitis and pneumonia?

Answer 4

Bronchitis is mostly caused by virus’s. It causes inflammation in the bronchial airways

Question 5

Pneumonia

Answer 5

Pneumonia is an infection of the lung tissue in which the air sacs of the lungs become filled with microorganisms, fluid and inflammatory cells affecting the function of the lung. Tends to be more serious then Bronchitis. You will see consolidation in an x-ray

Question 6

Incidence of pneumonia

Answer 6

Occurs more in autumn and winter. Annual incidence of CAP is 5-10 per 1000, for those who get it hospital admission is 22-42%

Question 7

What classes of organisms cause pneumoniae?

Answer 7

Viruses, bacteria or fungi

Question 8

How can you prevent pneumonia

Answer 8

Immunization, adequate nutrition and addressing environmental factors

Question 9

Most common cause of CAP

Answer 9

S.pneumoniae (streptococcus)

Question 10

Most common cause of CAP in COPD

Answer 10

H.influenzae

Question 11

Most common cause of CAP secondary to influenza

Answer 11

S.aureus

Question 12

Cause of atypical pneumonias

Answer 12

Mycoplasma pneumoniae and Legionella spp (causes sporadic outbreaks)

Question 13

Symptoms of pneumonias

Answer 13

Acute illness, Cough, Fever, Purulent sputum (smells), sometimes Haemoptysis (blood streaks in sputum), Breathlessness, Wheeze, Pleuritic pain, Abnormal (consolidation) CXR and Confusion (especially in the elderly).

Question 14

Risk factors for pneumonia

Answer 14

• Younger than 16, older than 65.
• Co morbidities= HIV, Diabetes mellitus, Renal disease, Malnutrition, recent viral respiratory infections, immunosuppressant therapy.
• Other respiratory infection= COPD, CF, Bronchiectasis, neoplasms.
• Lifestyle: Cigarette smoking, Alcohol misuse, IDVU (intravenous drug usage).

Question 15

Mycoplasma pneumoniae

Answer 15

Small bacteria which is rod shaped. Transmission is through airborne droplets through close contact. Onset can be gradual and sub-acute, slowly progressing to a high fever and persistent cough. It is frequently mild and self resolving. It is a mild self-limiting disease ‘Walking Pneumonia.’

Question 16

Legionella spp- pneumonia

Answer 16

Gram negative bacteria. Infection is caused by inhalation of contaminated aerosols. Precense is particularly associated with cooling towers, air conditioning units, fountains, hot-tubs and shower heads. There are local and sporadic outbreaks. Legionnaires disease is 2 to 5 times more common in men. Mortality 10-15%.

Question 17

CAP examination

Answer 17

Focal chest signs present such as dullness to percussion, course crepitation and vocal fremitus
Temperature above 38 degrees, respiratory rate above 20 beats per minute, heart rate above 100 beats per minute, new confusion. Consolidation in the X-ray

Question 18

Lab diagnostics for CAP

Answer 18

You can use a culture from sputum or bronchioalveolar lavage and a blood culture.
• Antigens in the urine for pneumococci, legionella.
• Antibodies in the blood- for Staphylococci.
• Enzyme linked immunosorbence (ELISA) or polymerase chain reaction / detection of IgM antibodies for M.pnuemioniae.

Question 19

CURB-65 score

Answer 19

Used to test for CAP and measure its severity
• C: confusion present (mental test score <8/10)
• U: plasma urea level >7mmol/L
• R: respiratory rate >30/min
• B: Systolic BP <90mm Hg / diastolic <60mm Hg.
• 65: older than 65.
You get 1 point for each category you qualify. 0-1 outpatient treatment. 2 admit to hospital. Higher then 3 and you should be admitted to ICU.

Question 20

HAP - hospital acquired pneumonia

Answer 20

Defined as new onset of cough with purulent sputum in patients beyond 2 days after initial admission. Second most common type of nosocomial (originating in hospital) infection after a UTI. Significant mortality risk in elderly with co-morbidities. Caused by different types of organisms from CAP, can be linked to antibiotic resistance

Question 21

Causes of HAP

Answer 21

• Gram -ve rods: E.coli, Klebsiella spp, Pseudomonas spp.
• Anaerobic bacteria: Enterobacter
• S.aureus (MRSA)
• Acinectobacter spp.

Question 22

Treatment for CAP

Answer 22

• Mild disease: Amoxicillin.
• Moderate disease: Amoxicillin and Clarithromycin (if atypical suspected) or Doxycycline.
• Severe disease: Co-amoxiclav, it is a mixture of Amoxicillin and Clavulanic acid which is a beta lactamase inhibitor

Question 23

Treatment for atypical pneumonias

Answer 23

Clarithromycin

Question 24

Treatment for HAP

Answer 24

Co-amoxiclav

Question 25

Causes of endemic fungal pneumonias

Answer 25

• Histoplasma capsulatum causing histoplasmosis- endemic in mid central and the eastern half of USA. From bat and bird faeces.
• Coccidioides immitis causing coccidioidomycosis- Central America, Mexico, S.America. It is found in the soil.
• Paracoccidioides brasiliensis causing paracoccidiodomycosis- found in Mexico, central and S.America. It is water borne.

Question 26

Causes of opportunistic fungal pneumonia

Answer 26

• Candida spp. Causing candidiasis.
• Aspergillus spp. Causing asperillosis- seen in the UK a lot. Causes localised pulmonary infection in people with underlying lung disease, allergic bronchopulmonary disease, allergic sinusitis and allergic alveolitis.
• Mucor spp. Causing mucormycosis
• Cryptococcus neoformans causing cryptococcosis.

Question 27

Aspergillus spp

Answer 27

A.fumigatus, A.flavus and A.niger. Can cause necrotising inflammation of the lungs. Leads to infarction -> necrosis -> oedema -> bleeding. Granulomas will form (immune complexes which try to restrict the movement of infection) and there will be a cavity wall invasion. This may cause damage to the lung tissue.