Clinical Aspects of Respiratory Infection

Question 1

What’s the most common, new symptomatic presentation of HIV?

Answer 1

Pneumocystis pneumonia

Question 2

What organism is responsible for Histoplasmosis infection?

Answer 2

Histoplasmosis

• Fungus: Histoplasma capsulatum
• soil and bat or bird poo -> disrupted soil may release infectious elements that can

be inhaled into the lungs

• common in immunocompromised patients
  (e. g. HIV)

Question 3

Pathophysiology of Histoplasmosis

Answer 3

When inhaled into the alveoli, they can survive phagocytosis -> in fact the phagocyte (that engulfed fungi) is a place where fungi multiply -> as macrophages travel in lymphatic circulation -> potential to spread to other organs

Question 4

Symptoms of histoplasmosis

Answer 4

A. Acute phase: non-specific respiratory symptoms (cough, flu-like); chest X ray is normal in

40-70% of cases

B. Chronic histoplasmosis -> similar to TB

Question 5

Possible complications of Histoplasmosis

Answer 5

occur if treatment is not provided, especially in immunocompromised patients:

• recurrent pneumonia
• respiratory failure
• fibronising mediastinitis -> serious complication, may be fatal
• superior vena cava syndrome
• pulmonary vessel obstruction
• progressive fibrosis of lymph nodes

Question 6

Diagnosis of Histoplasmosis

Answer 6

• samples containing fungus taken from sputum, blood or infected organs
• ELISA or PCR -> detection of antigen in blood or urine samples
• Blood test -> antibodies against Histoplasma
• Histoplasma skin tests -> indicate if a person has been exposed (but not able to tell if a person

has the disease)

Question 7

Treatment of Histoplasmosis

Answer 7

• immunocompetent individuals -> infection resolves on its own
• severe infection (severe cases of acute histoplasmosis and ALL cases of disseminated histoplasmosis) -> anti-fungal medication: Amphotercin B -> followed by itraconazole

*itraconazole treatment needs to continue for at least a year in severe causes

But in acute pulmonary histomatosis -> 6 - 12 weeks of treatment is usually sufficient

Individuals taking itraconazole should be monitored in view of hepatic function

Question 8

What is the arrow pointing at?

Answer 8

• the cavity on the top of the lung -> perhaps TB (or other caveating lung infections)
• (cavity identified as darker spot with white borders -> where the arrow points)

Question 9

What’s ground glass appearance?

Answer 9

‘Grand glass shadowing’ -> multiple flu -> patchy areas = acute inflammation in the lungs -> caused by

infections

Question 10

Treatment of pulmonary TB

Answer 10