Fungus - Systemic Pathogenic Mycoses - Histoplasmosis

Question 1

Talk about Histoplasmosis

Answer 1

Histoplasma capsulatum
The most common gunfal pathogen affecting humans

US, SA and Africa

Moist soils with high nitrogen levels (Bats and Birds)

Inhalation of spores (wind, human activivties)

H.Capsulatum is an intracellular parasite

• It is phagocytized by alveolar macrophages in the lungs
• Macrophages disperse the fungi beyond the lungs via the blood and lymph

Usually asymptomatic (or mild respiratory symptoms) and resolves without damage

1- Chronic Pulmonary Histoplasmosis: severe coughing, bloddy sputum, resembles TB
2- Chronic cutaneous Histoplamosis : Ulcerative skin lesions
3- Systemic histoplasmosis: Enlargement of spleen and liver, severe, fatal, in AIDS patients
4- Ocular histoplasmosis: Type 1 hypersensitivity reacvtion: inflammation

Identification of yeast samples in patients and dimorphism in culture

In healthy individuals, they resolve it on their own

1- Amphotericin B
2- Ketoconazole

Question 2

What is the causative agent of Histoplasmosis?

Answer 2

Histoplasma capsulatum

The most common gunfal pathogen affecting humans

Question 3

Where is the disease common?

Answer 3

US, SA and Africa

Question 4

Where are they found?

Answer 4

Moist soils with high nitrogen levels (Bats and Birds)

Question 5

What are theyre mode of transmission?

Answer 5

Inhalation of spores (wind, human activivties)

Question 6

How does it infect humans?

Answer 6

H.Capsulatum is an intracellular parasite

• It is phagocytized by alveolar macrophages in the lungs
• Macrophages disperse the fungi beyond the lungs via the blood and lymph
• Cell-mediated immuntiy develops clearing the organism

Question 7

what are the symptoms?

Answer 7

Usually asymptomatic (or mild respiratory symptoms) and resolves without damage

Question 8

What are the diseases of clinical histoplasmosis ?

Answer 8

1- Chronic Pulmonary Histoplasmosis: severe coughing, bloddy sputum, resembles TB
2- Chronic cutaneous Histoplamosis : Ulcerative skin lesions
3- Systemic histoplasmosis: Enlargement of spleen and liver, severe, fatal, in AIDS patients
4- Ocular histoplasmosis: Type 1 hypersensitivity reacvtion: inflammation

Question 9

Diagnosis

Answer 9

Identification of yeast samples in patients and dimorphism in culture

Question 10

Infections

Answer 10

In healthy individuals, they resolve it on their own

Question 11

Treatment

Answer 11

1- Amphotericin B

2- Ketoconazole