Mycotic Brain Abscess Caused by Opportunistic Reptile Pathogen

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Mycotic Brain Abscess Caused by Opportunistic Reptile Pathogen

Christoph Steininger,* Jan van Lunzen,* Kathrin Tintelnot,† Ingo

Sobottka,* Holger Rohde,* Matthias Ansver Horstkotte,* and Hans-

Jürgen Stellbrink*

*University Clinic Eppendorf, Hamburg, Germany; and † Koch-

Institut, Mykologie, Berlin, Germany

Suggested citation for this article

http://www.cdc.gov/ncidod/EID/vol11no02/04-0915.htm

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Figure. Chrysosporium sp. brain abscess in an HIV-seropositive

patient...

To the Editor: A 38-year-old, HIV-seropositive Nigerian man sought

treatment with an 8-month history of severe parietal headache,

impaired memory, fatigue, paresthesia of the left arm, and left-

sided focal seizures. He had no history of neurologic disorders,

including epilepsy. On physical examination, the patient appeared

well, alert, and oriented, with slurred speech. Evaluation of the

visual fields showed left homonymous hemianopsia. All other

neurologic assessments were unremarkable. The patient had a blood

pressure of 120/80, a pulse of 88 beats per minute, and a body

temperature of 37.3°C. Leukocyte count was 8,600/µL, total

lymphocyte count was 1,981/µL, CD4+ cell count was 102/µL, and

CD4/CD8 ratio was 0.07. HIV RNA-load was <50 copies/mL; all other

laboratory parameters were normal. The patient had received

antiretroviral therapy (stavudine, lamivudine, nevirapine) for 5

months before admission, but no prophylaxis for opportunistic

infections. Magnetic resonance imaging (MRI) of the brain disclosed

2 masses, 3.3 and 4.8 cm in diameter, respectively (Figure A), and

signs of chronic sinusitis. A computed tomographic chest scan showed

infiltration of both lower segments with multiple, small nodules

(Figure . Blood cultures were repeatedly negative. A computer-

guided needle-aspiration of the brain lesions yielded yellow-brown,

creamy fluid in which abundant septated fungal hyphae were detected

microscopically (Figure C). Cytologic investigation was consistent

with a necrotic abscess. The cycloheximide-resistant isolate was

strongly keratinolytic and identified as a Chrysosporium anamorph of

Nannizziopsis vriesii (1,2). High-dose antimicrobial treatment with

voriconazole (200 mg twice daily, subsequently reduced to 200 mg

daily) was added to the antiretroviral (ritonavir, amprenavir,

trizivir), anticonvulsive, and adjuvant corticosteroid treatment.

The isolate was highly susceptible to voriconazole in vitro (MIC,

<16µg/mL [Etest, AB-Biodisk Solna, Sweden]). Recovery was

complicated by a generalized seizure and severe, acute psychosis

associated with rapid refilling of the 2 lesions with mycotic

abscess fluid. After re-aspiration, the patient's psychosis improved

gradually, and no further seizures occurred. When last seen 4 months

later, the patient was healthy and without neurologic deficits. His

CD4+ cell count was 233/µL, HIV-load was <50 copies/mL, and a MRI

scan of the brain showed partial regression of the 2 brain lesions

(Figure D).

Chrysosporium spp. are common soil saprobes, occasionally isolated

from human skin. Invasive infection is very rare in humans, and most

were observed in immunocompromised patients, manifesting as

osteomyelitis (3,4) or diffuse vascular brain invasion (5). Here, we

report the first case of brain abscesses by the Chrysosporium

anamorph of N. vriesii. This fungus has been associated with fatal

mycosis in reptiles (6,7) and cutaneous mycosis in chameleons

originating from Africa (2).

In our patient, we were unable to determine the portal of entry and

the sequence of fungal dissemination; no skin lesions were present

at the time of admission. However, the multifocal nature, lung

infiltration, and involvement of the middle cerebral artery

distribution suggest hematogenous dissemination (8,9) after

replication of airborne conidia within the respiratory tract.

Fungi cause >90% of brain abscesses in immunocompromised transplant

patients with an associated mortality rate of 97% (10), despite

aggressive surgery and antifungal therapy (9). Our patient was

treated successfully with abscess drainage, antiretroviral therapy,

and oral voriconazole, a novel antifungal triazole drug. Despite

limited data available on voriconazole penetration into brain

abscess cavities (9), this drug was clinically and radiologically

effective in our patient.