BRIEF REPORT • CID 2010:51 (15 July) • e7

B R I E F R E P O R T

Successful Treatment of Balamuthiamandrillaris Amoebic Infectionwith Extensive Neurologicaland Cutaneous Involvement

Dalila Y. Martınez,1 Carlos Seas,1,2 Francisco Bravo,1,2 Pedro Legua,1,2

Cesar Ramos,2 Alfonso M. Cabello,1 and Eduardo Gotuzzo1,2

1Instituto de Medicina Tropical “Alexander von Humboldt,” Universidad PeruanaCayetano Heredia, and 2Departamento de Enfermedades Infecciosas, Tropicalesy Dermatologicas, Hospital Nacional Cayetano Heredia, Lima, Peru

Granulomatous amoebic encephalitis caused by Balamuthia

mandrillaris is an uncommon infection for which there is

no optimal therapy. We describe a young, female patient who

presented with extensive cutaneous and neurological involve-

ment and who recovered after receiving prolonged treatment

with miltefosine, fluconazole, and albendazole.

Balamuthia mandrillaris is a free-living amoeba that has been

recognized as an uncommon human pathogen since 1990 [1].

More than 150 cases of human encephalitis due to B. man-

drillaris have been reported worldwide; most have been re-

ported from Latin America and from the southwestern region

of the United States [2]. The disease induced by this amoeba

is characterized by involvement of the skin, especially around

the central face following a chronic course, with subsequent

extension to the central nervous system (CNS), where it causes

multifocal granulomatous encephalitis, leading almost invari-

ably to a fatal outcome [3–5].

No specific treatment is available to manage this lethal con-

dition. A number of antimicrobials (alone and in combination)

have been tried with unsuccessful results, including ampho-

tericin B, azoles, paromomycin, albendazole, pentamidine is-

ethionate, macrolides, metronidazole, sulfadiazine, and some

others [5–7]. However, 6 patients (4 in the United States and

2 in Peru) who presented with extensive CNS involvement

survived after receiving several antimicrobial regimens [4–6, 8].

We report, to our knowledge, the first successful treatment of

Received 22 December 2009; accepted 7 April 2010; electronically published 15 June 2010.Reprints or correspondence: Dr Dalila Y. Martınez, Universidad Peruana Cayetano Heredia,

Av. Honorio Delgado 430, Lima 31, Peru (dalmaext@gmail.com).

Clinical Infectious Diseases 2010; 51(2):e7–e11� 2010 by the Infectious Diseases Society of America. All rights reserved.1058-4838/2010/5102-00E1$15.00DOI: 10.1086/653609

a young patient with Balamuthia encephalitis with a combi-

nation regimen of miltefosine, fluconazole, and albendazole.

Case report. A 21-year-old woman presented in August

2006 with a long-term history of cutaneous lesions on her right

knee. Four years before admission, she had noticed several

papular, erythematous, and painless lesions that had appeared

2 weeks after a fall in front of her house. The lesions coalesced

to form a violaceus and indurate plaque covering the entire

right knee. Empirical therapy was started at another institution

with topical antifungal creams that contained fluconazole and

clotrimazole plus topical steroids, which were administered for

almost 1 year, followed by a combination of oral fluconazole

(150 mg per day for ∼45 days) and subsequent addition of

clarithromycin (1500 mg per day) and trimethoprim-sulfa-

methoxazole (TMP-SMX; 320 mg/1600 mg per day) for 8

months, without improvement.

The patient was born in Lima, Peru, and has resided there

for her entire life. She denied travel or specific occupational

exposure, including gardening and swimming in brackish, fresh,

or sea water. She noticed enlargement of the lesion on the right

knee and the appearance of 3 new papular lesions—2 of them

around the plaque on the right knee, and the third on the left

thigh—in February 2006. Both lesions subsequently evolved

into violaceus plaques. She was first seen at our institution 4

months later, where a skin biopsy of the lesion on the right

knee was performed (Figure 1A). Histopathologic examination

revealed a dense inflammatory infiltrate of the dermis com-

posed of lymphocytes, plasma cells, and ill-defined granulomas,

with great number of multinucleated giant cells located inside

and outside the granulomas. A microorganism with a nucleus

that has a large, central karyosome and a vacuolated cytoplasm,

compatible with an amoebic trophozoite, was observed (Figure

1B). In addition, B. mandrillaris was isolated from a skin sample

cultivated in an axenic culture prepared with monkey kidney

cells [7]. Polymerase chain reaction of a skin sample also yielded

positive results for B. mandrillaris (the amplification was per-

formed using the primer mitochondrial 16S rRNA gene from

B. mandrillaris as a target) [9]. A skin biopsy sample was sent

to the Public Health Department of California (Sacramento)

and to the Centers for Disease Control and Prevention (Atlanta,

GA), where B. mandrillaris infection was confirmed by im-

munohistochemical staining in September 2006. A brain com-

puted tomograph, without contrast enhancement, yielded nor-

mal findings at this time. Empirical therapy was started with

itraconazole (200 mg per day), and albendazole (400 mg per

day).

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e8 • CID 2010:51 (15 July) • BRIEF REPORT

Figure. 1. A, Cutaneous lesion on the right knee observed in February 2006 showing an indurated and violaceous plaque covering the entire kneewith 2 papular lesions. B, Skin biopsy specimen showing a dense inflammatory infiltrate of the dermis with granulomas (hematoxylin and eoisin stain).An amoebic trophozoite is observed, with a nucleus that has a large, central karyosome and vacuolated cytoplasm. C, Fluid-attenuated inversionrecovery (FLAIR) magnetic resonance image (MRI) obtained 7 days after the onset of neurologic symptoms (June 2007) showing hypersignal in theleft temporal lobe. D, Axial gadolinium-enhanced T1-weighted sequence (June 2007) showing a ring-enhancing lesion in the left temporal lobe. E,Follow-up of the left knee lesion 1 week after the patient had commenced treatment with miltefosine, albendazole, and fluconazole. The lesionsabruptly changed, developing a scaly and crusty surface. F, Axial gadolinium-enhanced MRI obtained 5 months after the start of treatment, showingsignificant improvement on the neurological lesions without evidence of contrast enhancing. G, Gadolinium-enhanced MRI image 4 months aftercompletion of treatment, showing the disappearance of the brain lesions. H, Follow-up of the healed left knee lesions (May 2008).

The enlargement of the lesions continued despite medical

treatment, and the patient was hospitalized in October 2006 to

receive amphotericin B (cumulative dose, 1.5 g), in addition

to itraconazole and albendazole. The lesions improved initially,

but reactivation of the lesion on the left thigh and the ap-

pearance of 2 new small papular lesions (one on the left breast

and the other one on her back) were observed in February

2007. Biopsy of the lesion on the back was performed; the

biopsy findings were the same as described above. A surgical

resection of the new lesions was performed, and TMP-SMX

(320 mg/1600 mg by day) was added to the treatment regimen,

without improvement.

The patient was readmitted to the hospital in May 2007

because of reactivation of the lesion on the surgical wound on

Tabl

e.1.

Dem

ogra

phic

Char

acte

ristic

s,Cl

inic

alD

ata,

and

Ther

apeu

ticRe

gim

ens

for

7Su

rviv

ors

ofB

alam

uthi

am

andr

illar

isIn

fect

ion

Pat

ient

Age

,ye

ars

Sex

Reg

ion

Type

ofle

sion

(s)

Trea

tmen

tre

gim

enO

utco

me

Dur

atio

nof

follo

w-u

pR

efer

ence

164

MC

alifo

rnia

Ski

n:ra

ised

lesi

onon

the

right

fore

arm

;C

NS

:4

ring-

enha

ncin

gle

sion

s(p

arie

tala

ndoc

cipi

tal

lobe

s)

Fluc

ytos

ine

(8g

per

day)

,flu

cona

zole

(400

mg

per

day)

,an

dsu

lfadi

azin

e(6

gpe

rda

y)fo

r5

year

s;cl

arith

rom

y-ci

n(5

00m

gpe

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r2

year

s;an

dpe

ntam

idin

eis

e-th

iona

te(4

mg/

kgpe

rda

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dtr

ifluo

pera

zine

(20

mg

per

day)

for

18da

ys

Per

form

ing

alla

ctiv

ities

ofda

ilyliv

ing,

with

good

com

mun

icat

ion

skill

s5

year

s[5

]

25

FC

alifo

rnia

CN

S:

2rin

g-en

hanc

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sion

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empo

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Fluc

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per

day)

for

2.4

year

s;pe

ntam

idin

eis

ethi

onat

e(1

mg/

kgpe

rda

y)fo

r34

days

;cl

arith

rom

ycin

(14

mg/

kgpe

rda

y)fo

r2.

4ye

ars;

and

thio

ridaz

ina

(1m

g/kg

per

day)

for

1.8

year

s

Typi

cals

choo

lper

form

ance

,w

ithou

tgr

oss

neur

olog

icse

quel

a2.

4ye

ars

[5]

372

FN

ewYo

rkC

NS

:2

ring-

enha

ncin

gle

-si

ons

(fro

ntal

and

tem

-po

rall

obes

)

Fluc

onaz

ole

(400

mg

per

day)

,su

lfadi

azin

e(6

gpe

rda

y),

clar

ithro

myc

in(1

500

mg

per

day)

,an

dpe

ntam

idin

eis

ethi

onat

e(3

00m

gpe

rda

y);

dura

tion

ofth

erap

yis

unkn

own

No

sign

ifica

ntne

urol

ogic

alse

quel

a6

mon

ths

[6]

435

MC

alifo

rnia

CN

S:

foca

lenh

anci

ngle

sion

sN

AA

live

and

ingo

odco

nditi

ons

3m

onth

s[8

]

58

MP

iura

,P

eru

Ski

n:la

rge

plaq

ueon

the

cent

ralf

ace;

CN

S:

mul

ti-pl

efo

call

esio

ns(b

oth

hem

isph

eres

)

Alb

enda

zole

(400

mg

per

day)

and

itrac

onaz

ole

(200

mg

per

day)

for

14m

onth

sS

kin

and

CN

Sle

sion

she

aled

;be

low

-ave

r-ag

eto

aver

age

scho

olpe

rfor

man

ce;

mild

left

hem

ipar

esis

3ye

ars

[4]

610

FP

iura

,P

eru

Ski

n:la

rge

plaq

ueon

the

cent

ralf

ace;

CN

S:

2rin

g-en

hanc

ing

lesi

ons

(rig

htfr

onta

llob

e)

Alb

enda

zole

(600

mg

per

day)

,itr

acon

azol

e(1

00m

gpe

rda

y),

and

TMP

-SM

X(3

20m

g/16

00m

gpe

rda

y)fo

r6

mon

ths;

surg

ical

rese

ctio

n

No

neur

olog

ical

sequ

elae

18m

onth

s[4

]

721

FLi

ma,

Per

uS

kin:

mul

tiple

plaq

ues

(rig

htkn

ee,

left

thig

h,br

east

,an

dba

ck);

CN

S:

1en

hanc

ing

lesi

on(t

empo

rall

obe)

Itra

cona

zole

(200

mg

per

day)

and

albe

ndaz

ole

(400

mg

per

day)

for

10m

onth

s;am

phot

eric

inB

(cum

ulat

ive

dose

,1.

50g)

was

adde

dw

ithou

tim

prov

emen

t;TM

P-

SM

X(3

20m

g/16

00m

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rda

y)w

asad

ded

for

3m

onth

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rgic

alre

sect

ion

ofsm

alll

esio

nsw

ithpo

ste-

rior

reac

tivat

ion;

anad

ditio

nalc

ours

eof

amph

oter

icin

B(c

umul

ativ

edo

se,

1.35

g),

itrac

onaz

ole

(300

mg

per

day)

,TM

P-S

MX

(640

mg/

3200

mg

per

day)

and

albe

n-da

zole

(800

mg

per

day)

was

give

nfo

r45

days

and

did

not

yiel

dim

prov

emen

t;cl

arith

rom

ycin

(150

0m

gpe

rda

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dar

tesu

nate

(100

mg

per

day)

wer

ead

ded

for

2w

eeks

,w

ithou

tim

prov

emen

t,an

d1

CN

Sle

sion

appe

ared

inth

ebr

ain

MR

I;th

erap

yw

asch

ange

dto

al-

bend

azol

e(8

00m

gpe

rda

y)an

dflu

cona

zole

(450

mg

per

day)

for

7.5

mon

ths,

asw

ella

sm

iltef

osin

e(1

50m

gpe

rda

yfo

r12

days

,fo

llow

edby

100

mg

per

day

for

7m

onth

s),

atw

hich

time

skin

and

CN

Sle

sion

she

aled

Ski

nan

dC

NS

lesi

ons

heal

ed30

mon

ths,

incl

udin

g12

with

out

ther

apy

and

nore

curr

ence

PR

NO

TE

.C

NS

,ce

ntra

lner

vous

syst

em(c

onfir

med

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RI);

MR

I,m

agne

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sona

nce

imag

ing;

NA

,no

tav

aila

ble;

PR

,pr

esen

tre

port

;TM

P-S

MX

,tr

imet

hopr

im-s

ulfa

met

hoxa

zole

.

e10 • CID 2010:51 (15 July) • BRIEF REPORT

the left thigh. A second course of amphotericin B was started

(cumulative dose, 1.350 g), in addition to an oral regimen of

itraconazole (300 mg per day), albendazole (800 mg per day),

and TMP-SMX (640 mg/3200 mg per day), for 1 month with-

out improvement. In June 2007, clarithromycin (1500 mg per

day) and oral artesunate (100 mg per day) were added to the

regimen. At this time, the patient developed fever, headache,

and childish behavior, with no other neurologic complaints.

The results of serological tests for human immunodeficiency

virus and human T lymphotropic virus–1 were negative. Mag-

netic resonance imaging of the brain performed 7 days after

the beginning of neurologic symptoms demonstrated hyper-

signal in the left temporal lobe in the fluid-attenuated inversion

recovery (FLAIR) sequence and a ring-enhancement lesion with

gadolinium in the temporal lobe (Figure 1C and 1D). Treatment

with amphotericin B, TMP-SMX, clarithromycin, and artesu-

nate was discontinued; itraconazole was changed to fluconazole

to optimize the penetration of the azole into the CNS; alben-

dazole treatment was continued, and oral miltefosine (150 mg

per day for 12 days and 100 mg per day thereafter) was added

in mid-June 2007. The cutaneous lesions on the knee abruptly

changed, developing a scaly, crusty surface (Figure 1E 1 week

after the patient started this regimen. The headache disappeared

by the second week of this regimen, and fever waned by the

fourth week. The skin lesion improved, becoming less scaly and

flat, until it eventually disappeared. The patient did well, with

regression of all neurological symptoms. She was discharged

home with the prescribed antibiotics in August 2007.

Significant improvement on the size of the neurological le-

sions was documented after 5 months of treatment (Figure 1F).

The patient continued to take miltefosine, albendazole, and

fluconazole for 7 months. The intracerebral lesions disappeared,

as documented by magnetic resonance imaging performed in

May 2008 (Figure 1G). She remains asymptomatic, all cuta-

neous lesions have healed (Figure 1H), and no recurrence has

been recognized as of May 2010.

Discussion. Since the first report of a Balamuthia man-

drillaris amoebic infection affecting a baboon in the San Diego

Wild Animal Park in 1986 [1], 1100 human cases have been

reported worldwide, with only 6 survivors [4–8]. In 2003, Deetz

et al [5] described 2 patients with extensive CNS involvement

who responded to a prolonged treatment regimen (up to 5

years) that included fluocytosine, pentamidine isethionate, flu-

conazole, sulfadiazine, and a macrolide. A third patient with

CNS involvement who responded to a regimen similar to the

one described above, but without fluocytosine, was described

by Jung et al [6]. A fourth patient from the California En-

cephalitis Project (CEP) was reported alive and in good health

condition three months after diagnosis, details about his treat-

ment were not provided however [8]. Two additional Peruvian

patients survived this infection: one patient with CNS involve-

ment survived long-term therapy (6 months) with albendazole

and itraconazole, and another patient, who demonstrated cu-

taneous involvement alone, was treated with surgical resection

plus a combination of itraconazole, albendazole and ampho-

tericin B (cumulative dose, 2 g) [3, 4]. A description of the 7

patients who survived Balamuthia infection of the CNS, in-

cluding the patient in our study, is presented in Table 1.

Very few drugs have shown in vitro amebicidal activity

against B. mandrillaris, including miltefosine [10], propami-

dine, and gramicidin S [7]. The amebicidal activity was dem-

onstrated by drug efficacy test using axenic cultures inoculated

in tissue culture flasks with growing concentrations of anti-

microbials. Most of the available drugs are amebistatic: phe-

nothiazine compounds, pentamidine isethionate, macrolides,

azoles, TMP-SMX, and amphotericin B [7]. In addition, B.

mandrillaris escapes the effect of antimicrobials by encysting in

tissues, establishing chronic infections that may reactivate later

[11]. Use of amebicidal drugs for treating this condition may

not only kill trophozoites in active lesions, but may also prevent

the further dissemination of the infection to the CNS and other

organs, which has been invariably observed when amebistatic

drugs are used.

Miltefosine is an alkylphosphocholine compound originally

developed as an anticancer drug, which is now established as

an effective anti-leishmanial therapy. It acts on key enzymes

involved in phospholipid and sterol biosynthesis, suggesting

that the cell membrane is its main target [12]. In vitro, it

stimulates T cells and macrophages to secrete activating cyto-

kines, including interferon-g, and induces production of mi-

crobicidal reactive nitrogen and oxygen intermediates, caus-

ing cell death by an apoptosis-like effect [13]. A recent report

showed good in vitro activity of miltefosine against Balamuthia,

Acanthamoeba, and Naegleria species [10]. Miltefosine achieves

a high concentration of the active drug in the brain tissue as

a result of excellent passage through the brain-blood barrier.

In addition, miltefosine carries an acceptable safety profile [10].

This is a potentially critical property of any drug to be successful

in treating CNS involvement by free-living amebas.

Although the prognosis of amebic encephalitis caused by B.

mandrillaris is still ominous, it may not be invariably fatal. This

report on the successful use of a combination regimen that

includes 1 amebicidal drug (miltefosine) along with 2 amebi-

static drugs capable of crossing the brain-blood barrier (flu-

conazole and albendazole) provides hope for attaining clinical

cure for an otherwise lethal condition. More clinical experience

is needed before miltefosine can be recommended as the de-

finitive first-line treatment for amebic encephalitis.

Acknowledgments

We thank the Dermatology staff of the Hospital Nacional CayetanoHeredia for their assistance in the diagnosis and follow-up of the patient.We specially thank Dr Juan Cabrera (Universidad Peruana Cayetano He-

BRIEF REPORT • CID 2010:51 (15 July) • e11

redia) for his advice in this case and permanent inspiration. Sadly, DrCabrera passed away on 25 May 2009.

Potential conflicts of interest. C.S. has received recent research fundingfrom Schering-Plough and has served on the speakers’ bureau for Pfizer.All other authors: no conflicts.

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