Cryptococcosis

Cryptococcus neoformans.

CryptococcosisCryptococcosis• Cryptococcosis is a chronic, subacute to acute

pulmonary, systemic or meningitis disease

• Cryptococcus neoformans var. neoformans and Cryptococcus neoformans var. gattii

– encapsulated yeast

– The species has 4 serotypes (A,B,C,D) based on capsular polysaccharide antigen

– C. neoformans var neoformans serotype A

CryptococcosisCryptococcosis

• Epidermiology– distributed worldwide, pigeon feces,

eucalyptus trees (var. gattii)

• Transmission by inhalation of basidiospore or yeast cells

• Cryptococcal infections in hosts who are immunosuppressed, including patients with AIDS

Transmission

Inhalation respiratory infection dissiminated

Clinical features

- sub acute meningitis

- meningoencephalitisCNS cryptococcosis

– Most common clinical presentation of cryptococcosis: Cryptococcal meningitis

– Prolong evolution of several months

– headache, vomiting, neck stiffness, mental status

: 1/3 have evidence of pulmonary involvement

- cough , dyspnea

- abnormal CXR

: Disseminated infection

CryptococcosisCryptococcosis

• Pulmonary cryptococcosis– asymptomatic – x-ray

Right upper lobe

This is Cryptococcus neoformans infection of the lung. There are numerous organisms that have a large mucoid capsule, giving the appearance of a clear zone around a faint round nucleus.

CryptococcosisCryptococcosis

• Cutaneous & mucocutaneous cyptococcosis

• Osseous cyrtococcosis : bone

• Visceral crytococcosis : heart, kidneys, liver,

Cryptococcus antigen

: highly sensitive and specific ( > 1:8 )

: screening test for febrile patient

Laboratory diagnosisLaboratory diagnosis

India ink test Mucicarmine stain

capsule

capsule

India ink test : detect the extensive capsule

This is an India ink preparation of cerebrospinal fluid in a patient with Cryptococcus neoformans meningitis. Note the clear zone of the capsule around the central nucleus of the organisms.

• Examination of CSF : - mildly elevation CSF protein- normal or slightly low glucose- a few lymphocytes.- numerous organism

• Latex agglutination test : detect cryptococcal antigen

• Patient improves : titer • No respond to therapy ; titer

• Culture: 370C, 1-2 days– SDA with out cyclohexamide:

creamy, white and mucoid – Birdseed agar: brown to black

colony– Urease positive

Laboratory diagnosisLaboratory diagnosis

Birdseed agar

SDA

- ve/+ve

Diagnosis and treatment of Cryptococcus meningitis

HIV positive patient CD4 lymphocyte count <200,000/ml

History suggestive of cryptococcal meningitis( CM )

( and /or )

Headaches , fever ,with/without mental status changes

Positive serum cryptococcal antigen

Lumbar puncture Lumbar puncture

Evidence of CM Positive culture for Cryptococcus neoformans, positive India ink stain

No evidence of CM continue diagnostic evaluation

No evidence of CM fluconazole 200 mg orally indefinitely

Amphotericin 8 ( 0.7 mg/kg/day ) iv plus flucytosine (25mg/kg) q6h for 2 week , then fluconzole 400 mg po for 8 weeks, then fluconazole 200mg po for life