CASE ANALYSIS

(H ISTOPL ASMOSIS )

T R I B E D E U T E R O M YC O TA

HISTORY OF THE CASE

• The patient is a 53-year old female Australian with no significant medical history.

• She works as a library attendant.

• In 1993, she travelled throughout Europe and to North-Eastern Coast of the US.

PERTINENT FINDINGS• Signs and Symptoms

–Positive chronic lesion affecting the gingiva and buccal mucosa of right mandible

–Positive untreated, generalized moderate periodontitis and localized advanced bone loss developing to ulcerative gingivitis

• Histology Results

–Granulomatous inflammation with giant cells and macrophages containing yeast-like bodies

Chronic lesion affecting the gingiva and buccal mucosa

of right mandible

macrophages containing yeast-like bodies

PERTINENT FINDINGS

• Culture–On BHI agar at 28 degrees: small white mold after

14 days

–Slide: positive for tuberculated macroconidia

–Subcultures at 35 degrees after 28 days: yeast form was observed

PRESUMPTIVE DIAGNOSIS

• Samples of tissue or body fluids are plated onto BHI and incubated at 25°C. After several weeks, and sometimes as long as 6 weeks, growth of a white to light tan mold occurs. Two types of conidia are produced on the hyphae. The macroconidia, or tuberculate conidia, are 8 to 15 μm in diameter and have distinctive projections on their surface; the microconidia are small (2 to 4 μm) and smooth walled.

• Identification of the tuberculate macroconidia allows a presumptive diagnosis of histoplasmosis; however, it should be noted that fungi belonging to the genus Sepedonium also form similar tuberculate macroconidia. A definitive test to verify that the mold is H. capsulatum should always be performed.

APPROACH TO THE

CAUSATIVE

AGENT

Granulomatous Disease

Growth on BHI

Small white mold (Mycelial form)

Tuberculated Macroconidia

Yeast form (at 35 degrees after 28

days)

giant cells and macrophages

containing yeast-like bodies

FINAL IDENTIFICATION

FINAL IDENTIFICATION

• The 53 year old Australian female has the systemic mycosis histoplasmosis which she may have acquired during her travel to the North-Eastern Coast of the US. Histoplasmosis is obtained by humans from airborne microconidia. More than 95% of cases have either no symptoms or mild symptoms like coughing, fever, and joint pain. Lesions may appear in the lungs and show calcification. Most infections resolve on their own and the disease rarely disseminate.

FINAL DIAGNOSIS• The fungus responsible for the said mycosis is

Histoplasma capsulatum which is evident from the results of the histology, culture, and subculture of the tissue specimen. The histology shown granulomatous inflammation with giant cells and macrophages with oval yeast-like bodies; the culture on BHI agar at 28°C shown growth of small white mold after 14 days; and the subculture incubated at 35°C shown growth of yeast after 28 days.

FACTS ABOUT HISTOPLASMOSIS• Histoplasmosis is disease caused by an infection with

a fungus, Histoplasma capsulatum.• The infection results from inhaling airborne spores of the fungus.• The fungus is common in the U.S. in the Ohio and Mississippi River valleys and is often found in soil contaminated by bird or bat droppings.• Most people who are exposed to the fungus do not develop the disease.

• Cases have also been found in other areas of N. America nad S. America.

FACTS ABOUT HISTOPLASMOSIS• The disease is most severe in people with reduced

immune function.• Symptoms of histoplasmosis are similar to those of pneumonia.• Mild cases of histoplasmosis do not require specific treatment; more severe or disseminated infections require antifungal medications.• There is no vaccine available to prevent histoplasmosis.

REFERENCES

• Delost, M. (1997). Introduction to Diagnostic Microbiology: A Text and Workbook.

• Prescott, L. (2002). Microbiology (5th Edition).

• http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1797635/

• http://www.medicinenet.com/histoplasmosis_facts/page2.htm

TRIBE DEUTEROMYCOTALeader: Gamboa, Lois Danielle

Bautista, Joseph Ryan

Garung, Ralph Jeric

Marilag, Maria Xenia Yves

Moral, Claire

Quiambao, Jaime Lorenzo

Ysais, Angelanna