Powerpoint
Blastomycosis
Clinical Presentation
Patient is a 36 year-old African American male from Baton Rouge, La. He was admitted into the ER suffering from shortness of breath and productive cough for two weeks. Ulcerative lesions are found on the patient’s left calf. Patient reports pain located at the knees. HIV test was positive. Chest x-rays and tissue biopsy were performed. The tissue biopsy of the ulcerative lesions showed fungal organism that suggest Blastomyces dermatidis. In addition, a sputum test was performed and found fungal organism present confirming Blastomyces dermatidis.
Patient began working on a construction site along the river about two months ago. Reports of patients suffering similar symptoms have been found in the past year in the same area that this patient worked at. Officials are testing the soil to determine if conidia of Blastomyces dermatidis are present. Patient was put on itraconazole for two weeks. Initial progress was slow but the fungal infection eventually cleared up. Lesions are beginning to heal and patient reports that he no longer have trouble breathing. His coughs are reduced as well. Long-term treatment with itraconazole is required in order to prevent a reoccurrence.
What is Blastomycosis?
Blastomycosis is a fungal infection caused by a fungus called Blastomyces dermatidis
It is found in moist soil, specifically in rotting vegetation
It is contracted through inhalation, and it starts by infecting the lungs
From the lungs it disseminates into the bloodstream and lymphatics where it spread to the rest of the body
Also involves the skin, joint, bones, organs, central nervous system
weakened immune systems, such as those with HIV or who have had an organ transplant
Uncommon but can deadly in adults
Clinical Manifestation
Chronic illness
low-grade fever
productive cough
fatigue
night sweats
weight loss
Respiratory Signs of Blastomycosis
Rapidly progressive, and severe disease, eg, multilobar pneumonia or ARDS
fever
shortness of breath
tachypnea
hypoxemia
finally hemodynamic collapse
Acute illness analogous to bacterial pneumonia
high fever
chills
productive cough
pleuritic chest pain
mucopurulent or purulent sputum
Flu like symptoms
fever
chills
myalgia
headache
nonproductive cough
Clinical Manifestation
Osteoarticular lesions
bone or joint pain
soft-tissue swelling
involvement of any bone may be involved
most common sites
vertebrae and pelvis
Extrapulmonary manifestations present in 25-40% of cases
Genitourinary
prostatitis and epididymitis
asymptomatic or painful urination
Central nervous system
Intracranial abscesses
Epidural abscesses
meningitis
Cutaneous lesions
verrucous or ulcerative
asymptomatic
Other organ sites reported include the eye, liver, breast, thyroid, and adrenal gland.
Initial Diagnosis
Clinically, blastomycosis can be difficult to recognize even in the endemic areas where clinicians are aware of this problem.
At the University of Mississippi Medical Center (Jackson, MS), the suspected initial diagnosis of blastomycosis was only correctly suspected in 18% of 123 patients.(7)
Most Common misdiagnosis
Pneumonia (40%)
Malignant tumors (16%)
Tuberculosis (14%)
Cutaneous involvement makes recognition easier, percentage of correct initial diagnosis to 64%.
Another associated disease commonly found in blastomycotic patients was diabetes mellitus (22%).
Underlying immunodepressive conditions & diabetes mellitus (22%)
Diagnostic Tests
In order to make a diagnosis healthcare providers will use your history and physical along with diagnostic tests.
Imaging Tests
Chest x-rays
Chest CT
Lab Tests-cultures may be done to see if Blastomyces will grow from the sample
Sputum test - culture and exam
Urinalysis - culture
Skin biopsy
Tissue biopsy
Diagnostic Tests cont.
Blastomycosis may be asymptomatic, therefore diagnostic tests may not provide the results needed to make a conclusive diagnosis.
In order to provide a definitive diagnosis it is crucial that B dermatitidis is visualized.
This should be done prior to doing a culture to confirm the diagnosis.
To have an absolute diagnosis, it is important to isolate and identify the organism on a sputum culture
Skin tests are not reliable unless sample is viewed under a microscope
Diagnosis and etiology
Definitive diagnosis is done by isolating the fungus from tissue samples.
A previous review of 153 cases of blastomycosis noted a wide variation in morphology, including size, shape, staining, and wall thickness. Variation included different fields of the same specimen
The fungus, B. dermitidis, that causes Blastomycosis only grows and makes spores under specific conditions of humidity, temperature, and nutrients
Spore-like appearance, with fluffy white mycelium
D
B
Organism cultured on blood agar
Organism stained on slide presentation
Treatment
You may not need to take medicine for a mild blastomycosis infection that stays in the lungs. Your doctor may recommend the following anti-fungal medications when the disease is severe or spreads outside of the lungs. (7)
Fluconazole
Itraconazole
Ketoconazole
Amphotericin B may be used for severe infections.
Ongoing follow-ups with your doctor may be needed to make sure the infection doesn't return.
Describe the organism and how it causes the disease
Infection occurs from exposure to conidia of B. dermatidis
conidia: a spore produced asexually by various fungi at the tip of a specialized hypha
Inhalation of aerosolized conidia from soil are deposited into pulmonary alveoli
Conversion of B. dermatitidis to yeast occurs in the lung where the host inflammatory response are triggered
Disease is spread to skin or other organs by yeasts that have not been phagocytized through the blood or lymphatic system
a low power view of hyphae growing away from the point of inoculation of a slide culture
another view of the "lollipop-like" conidiophore-conidia structures extending along the length of hyphae
more is better, another photo
BLASTOMYCES†DERMATITIDIS
PATHOGEN SAFETY DATA SHEET INFECTIOUS
SUBSTANCES
Public Health of Canada http://dictionary.reference.com/browse/conidia http://www.emedicinehealth.com/blastomycosis/page4_em.htm
Pathology
• Primary site of infection is usually in the pulmonary system. This is ‘Pulmonary blastomycosis’
Sub-Categories of blastomycosis are:
Single organ system disease such as lymphatic system, liver system, skin and other organs
May also cause generalized multi-organ disease which can lead to end stage hemodynamic collapse
Chronic dermatologic manifestations of the disease includes cutaneous manifestations that appear ‘verrucous’ and ‘ulcerative.’
Cutaneous blastomycosis: a clue to a systemic disease* Five categories of blastomycosis have been defined:
Close up of lesion along right jawline
Close up of lesion beside left nasal
Patient with a couple of verrucous and eroded plaques on the face
Blastomycosis Ulceration
Blastomycosis Ulceration
Primary Cutaneous Blastomycosis
Blastomycosis Verrucous Plaques
Virulence factors
BAD1: 120-kDa major surface protein adhesin
when BAD1 sticks on to our cells, the humoral and cell-mediated immune responses targets them and fights off the virulence factor
α-1,3 glucan: cell surface carbohydrate
mask BAD1 on surface of Blastomyces dermatitidis yeast cells so immune responses do not detect them
Both are found on surface of Blastomyces dermatitidis yeast cells
It has been found that more virulent strains of Blastomyces dermatitidis possess less BAD1 on the surface of yeast cells
http://www.scientificjournals.org/journals2007/articles/1021.htm
Epidemiology
Epidemic or sporadic
Found in United Kingdom, United States, Canada, central Europe, Africa, India, and some parts of the Middle East
Blastomycosis is more common in North America, endemic to the Midwestern, southeastern, and southcentral United States along the Ohio and Mississippi rivers.
In areas where outbreaks occur, three to six cases requires hospitalization per million persons per year
Those who frequents or work along rivers or streams are exposed to decayed vegetation in moist soil which increases their chance to contract blastomycosis.
Adults > Children
Men > Women
References
Barnes, Lauren BS, Al-Dabagh, Amir BS, BA, and Feldman,Steven R. MD, PhD Treating Rare Fungal Infections: Cutaneous Blastomycosis Volume 21 - Issue 5 - May 2013 http://www.the-dermatologist.com/content/treating-rare-fungal-infections-cutaneous-blastomycosis
Conidia. (n.d.) . In Dictionary.com online. Retrieved from http://dictionary.reference.com/browse/conidia
Davis, Charles Patrick, MD, PhD 2015, March. Blastomycosis. Retrieved on February 21, 2015 http://www.emedicinehealth.com/blastomycosis/page4_em.htm
Nguyen, Tuyet and Ortega-Loayza, Alex G. 2013, April. Blastomycosis: a clue to a systemic disease. Retrieved from https://www.researchgate.net/publication/237059549_Cutaneous_blastomycosis_A_clue_to_a_systemic_disease
Pathol, Ann Diagn. 2002 Jun;6(3):194-203. Blastomycosis: The great pretender can also be an opportunist. Initial clinical diagnosis and underlying diseases in 123 patients Retrieved on February 20, 1026 from http://www.ncbi.nlm.nih.gov/pubmed/12089732
Public Health Agency of Canada (2010) Blastomycis Dermatitidis. Retrieved from: http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/blastomyces-dermatitidis-eng.php
Scalarone, Gene M. and Sestero, Christine M. (2007) Detection of the surface antigens BAD1 and α-(1,3)-glucan in six different strains of Blastomyces dermatitidis using monoclonal antibodies. Journal of Biology, 1(1). Retrieved from http://www.scientificjournals.org/journals2007/articles/1021.htm
Vyas, Jatin M. MD, PhD. 2014 Aug. MedlinePlus. Blastomycosis. Retrived February 20, 2016 from https://www.nlm.nih.gov/medlineplus/ency/article/000102.htm
Yuri (2012, December 2) Blastomyces Dermatitidis [Web blog]. Retrieved from http://thunderhouse4-yuri.blogspot.com/2012/12/blastomyces-dermatitidis.html