INVASIVE FUNGAL INFECTION

INVASIVE FUNGAL INFECTION

BUI THI VAN NGA
Microbiology depaterment


Invasive fungal infection

 Invasive fungal infection are a significant cause of morbidity and mortality
worldwide.

 Candida species are the most common fungal pathogens encountered.
 The term invasive candidiasis: candidemia, endocarditis, meningitis and
other forms of deep organ involvement.


Fungal species
 Candida species: C.albicans, C.tropicalis, C.krusei, C.glabrata….
 Aspergillus.
 Cryptococcus.spp
 Fusarium.spp.
 Zygomycetes
(mucormycose).


Risk factors for invasive candidiasis
 Candida colonization
 Broad- spectrum antimicrobials
 Malignancy
 Chemotherapy/immunosuppressive medications.
 Transplantation.

 Renal failure.
 ….


Invasive Candidiasis

 The presence of candida in a blood culture should never be perceived
simply as a contaminant and always investigation for possible soures.

 Blood culture are positive in only 50% to 70% of patients with invasive
candidiasis


Invasive Candidiasis
 However, a positive culture from a nonsterile site often provides little
evidence to distinguish between infection and colonization.

 Nonculture – based method has been vigorously sought: 1,3-β- D
glucan,which is a major component of fungal cell wall, can be detected.


Invasive Candidiasis
 This test has sensitivity of 75% to 100% and a specificity of 88% to 100%.
 It is s broad – spectrum assay that detects Aspergillus, candida, fusarium,
and saccharomyces species, thus careful intepretation is needed.

 Early empiric therapy in high-risk patients pending culture results is
justifiable

Empiric treatment of candidemia
 Fluconazole is an appropriate choice for nonneutropenic, hemodynamically
stable patients .

 In patients who are neutropenic, hemodynemically unstable,or who are
being treated in units with high rates of infection with fluconazole resistant
specsies. treatment with an echinocandin is preferred until species
identification of the Candida isolate is made


Invasive Aspergillosis
 Although a much less common cause of invasive disease.
 But it is important for high risk patients?


Risk factors for invasive aspergillus
 Prolonged neutropenia (>10 days)
 Heamatopoietic stem cell transplantation
 Solid organ transplantation
 Corticosteroid/other immunosuppressive therapy
 Advanced HIV
 Chronic granulomatous disease


Invasive Aspergillosis
 Sinopulmonary involvement is the most common manifestation .
 Computed tomography may suggest the diagnosis with findings such as the
‘ halo sign’.

Invasive Aspergillosis
 However, this feature can be seen with other angioinvasive infection, So it is
far from diagnostic.
 Serological tests: galactomannan ( sensitivity 29% to 100%, specificity
greater than 85%, false positive results may aslo occur in patients receiving
Piperacillin-tazobactam), 1,3-β- D glucan.
 This assays can be used as a diagnostic adjunct but should not be used as
sole criterion for diagnostic.


Therapy for invasive aspergillosis

 Voriconazole is recommended as fist – line therapy
 The comparing amphotericin B and voriconazole as initial therapy,
voriconazole was associated with improved survival 71% and 58% with
amphotericin B.


Activity of antifungal agents

Fungus

Fluconazole

Voriconazole

Echinocadin

*

Aphotericin B

C.albicans

+

+

+

+

C.parapsilosis

+

+

+/-

+

+

+

+

DD/-

+/-

+

+

C.krusei

-

+

+

+

Aspergilus spp

-

+

+

+

C.tropicalis
C.glabrata

(+) susceptibility, (-) resistance, DD dose dependent - susceptibility

* Only caspofungin and anidulafungin approved for candidemia.


THANKS FOR ATTENTION