Coccidioidomycosis/histo

Question 1

Coccidioidomycosis

general
Reservoir

Answer 1

Also known as San Joaquin Valley fever
Pulmonary or hematogenously spread disseminated disease caused by the fungiCoccidioides immitis and Coccidioides posadasii
Endemic to the southwestern United States:
California, Arizona, Utah, Nevada, New Mexico
Can cause 15%–30% of communitypneumonia in these areas

Reservoir:
Soil in endemic regions
Rodents may serve as animal reservoirs

Question 2

cocci

Disseminated disease patho

Answer 2

Disseminated disease occurs via hematogenous spread (particularly in immunocompromisedand pregnantpatients)

Cutaneous disease can result from either:
Dissemination
Direct inoculation

Question 3

cocci

RF

Answer 3

Progressive coccidioidomycosis is uncommon in otherwise healthy people
More likely to occur in the following:
HIV+ patients
Patients taking immunosuppressants/chronic steroid use
Patients of advanced age
Women in the 2nd half of pregnancy or postpartum

Individualswith highsporeexposure:
Construction workers
Farmers
Archaeologists

Question 5

cocci.

Constitutional Sx

Answer 5

Constitutional symptoms
Low-grade fever
Night sweats
Anorexia
Weight loss
Weakness
Chills

Question 6

cocci

pulm involvement

Answer 6

Pulmonary involvement – primary site
Chest pain
Dyspnea
Cough
Dry or with sputum
May present withhemoptysis

Question 7

cocci

cutaneous involvement

Answer 7

Cutaneous involvement
May occur in conjunction with pulmonary involvement, with direct inoculation, or from disseminated disease
Single or multiple granulomatous skinlesions
Abscesses
Draining sinus tracts

Question 8

cocci

disseminated infection

Answer 8

Disseminated infection
Defined as disease outside the thoracic cavity
Considered an AIDS-defining illness

Patientscan present with:
Meningitis
Myalgias
Arthritis (particularly involving the knee)
Osteomyelitis

Question 9

cocci

Answer 9

Granulomatous skinlesions

Question 10

cocci

Dx

Answer 10

Fungal cultures
Microscopy for spherules in body fluid samples (sputum, pleural fluid, cerebrospinal fluid, exudate from draining lesions)

Serologic testing for anti-coccidioidal antibodies includes:
Enzyme immunoassay
Complement fixation (IgGantibodies) - estimate disease severity
Immunodiffusion kit (IgM orIgG antibodies)
Titers≥1:4 in serum → current or recent infection
Titers ≥1:32 in serum → extrapulmonary dissemination

PCRfor lower respiratory tract samples
Urineantigentesting

Question 11

cocci

chest xray

Answer 11

Chest radiography
Pulmonary infiltrates, nodules, and cavitary lesions
Pleural effusions
Adenopathy

Question 12

cocci.

Tx

Answer 12

Antimicrobial therapy
Fluconazole(preferred) or itraconazolefor mild-to-moderate disease

Amphotericin B:
Preferred for severe disease or persistentinfections
Switch to oral -azole therapy once stabilized

Patients withHIV- or AIDS-associated coccidioidomycosisrequire maintenance therapy to prevent relapse

Question 13

Histo

general
Transmission

Answer 13

Pulmonary and hematogenous disease caused by the dimorphic fungusHistoplasma capsulatum

Fungus exists as a mold at low temperatures and as yeast at high temperatures

“Moldin the cold. Yeastin theheat”
Most common endemic fungal infection in the United States

Most prevalent in the midwestern and central states along the Ohio and Mississippi River valleys

Transmission:
By inhalation
Exposure to soils containing bird or bat droppings

Question 14

Histo

RF
Meds

Answer 14

Immunosuppressive disorders:
HIV infection
Transplant recipients
Immunosuppressive drugs:
Most common fungal infection inpatientson TNF-αinhibitors
Glucocorticoids
Antirejection therapies for solid organ transplants
Extremes of age (infants and adults ≥ 55 years)
Heavy, prolonged inoculation exposure

Question 15

histo

Clin man

Answer 15

Varies depending on host immune status and underlying risk factors
Most infections are asymptomatic or so mild that patients do not seek medical attention

Pulmonary histoplasmosis
Symptomatic pulmonary histoplasmosis:
Presents several weeks after exposure
Symptoms:
Fever/chills
Cough
Headache
Myalgias
Pleuritic chest pain
Malaise

Question 16

histo

PE and CXr

Answer 16

Physical examination: rales or signs of consolidation, increased tactile fremitus, decreased lug sounds.

CXR - may show focal infiltrates with/without hilar or mediastinallymphnode involvement

Question 17

histo

Acute diffuse pulmonary histoplasmosis clin man

Answer 17

Associated with large inoculum
Abrupt onset of symptoms → ARDS can develop within days
Symptoms:
Fever/chills
Cough
Headache
Myalgias
Pleuritic chest pain
Malaise
Dyspnea andfatiguemay persist for months after treatment

CXR - diffuse pulmonary infiltrates

Question 18

Histo

Chronic pulmonary histoplasmosis

Answer 18

Patients with underlying lung disease are at risk
Symptoms - progressive
Productive cough
Fatigue
Fever
Sweats
Dyspnea
Dissemination does not occur

CXR or CT scan - pulmonary lesions often apical and resemble cavitary tuberculosis

Question 19

histo

Disseminated histoplasmosis

Answer 19

Mostpatientsexperience asymptomatic dissemination

Can present acutely or years later

Acute:
In infants andimmunocompromisedindividuals
Can be rapidly fatal

Chronic:
Olderpatientswho are immunocompetent

Generalized symptoms:
Fever
Malaise
Weight loss
Systems most commonly affected: CNS, GI, skin (10%), adrenal glands

Question 20

know

Answer 20

in both cocci and histo there is lung or disseminated and disseminated is pointing towards immunocompromised.

who are at risk?

how do you treat?

Question 21

histo

Dx

Answer 21

Approach will vary depending on presentation
Multiple tests including:
Culture, direct microscopy, antigen detection, and histopathology
Culture is the most effective when the fungal burden is high
Antigen detection:
ELISAforantigentesting – urine, serum, CSF
Allows for rapid diagnosis, particularly in disseminated disease
Sensitivity increases with disease severity (most sensitive test in disseminated disease)

Imaging
CXR or chest CT

Question 22

histo

Tx

know this

Answer 22

Treatment varies depending on disease severity
Most cases areself-limiting
Asymptomatic or mild symptoms → no required treatment

Individuals with large inoculum exposure and patients who areimmunocompromisedusually require treatment

Antifungaldrugs are the mainstay of treatment
Itraconazole – acute moderate pulmonary or chronic presentation

Amphotericin B – acute severe pulmonary presentation

Itraconazole and amphotericin B – disseminated disease
Monitor response with chest imaging and monitor forrelapse(several years)

ForpatientswithHIVhaving CD4 counts < 150 cells/µL → long-termitraconazole