Pandemic (H1N1) 2009 in skunks, Canada.

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LETTERS
should include virus culture. Physi-
cians should be aware of the limita-
tions of laboratory diagnostic assays
for LASV.
Financial support was provided to the
diagnostic facilities of the Bernhard Nocht
Institute by the German Ministry of Health
under a contract supporting the National
Reference Centre for Imported Infections.
Marcus Panning,
Petra Emmerich,
Stephan Ölschläger,
Sergiusz Bojenko,
Lamine Koivogui, Arthur Marx,
Peter Clement Lugala,
Stephan Günther,
Daniel G. Bausch,
and Christian Drosten
Author affi liations: Bernhard Nocht Institute
for Tropical Medicine, Hamburg, Germany
(M. Panning, P. Emmerich, S. Ölschläger,
S. Günther, C. Drosten); United Nations
Mission in Sierra Leone, Freetown, Sierra
Leone (S. Bojenko); Program on Hem-
orrhagic Fevers, Conakry, Guinea (L.
Koivogui); World Health Organization, Ge-
neva, Switzerland (A. Marx); World Health
Organization, Monrovia, Liberia (P.C. Luga-
la); and Tulane University Health Sciences
Center, New Orleans, Louisiana, USA (D.G.
Bausch)
DOI: 10.3201/eid1606.100040
References
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Address for correspondence: Christian Drosten,
Institute of Virology, University of Bonn
Medical Centre, Sigmund Freud-Str. 25, 53127
Bonn, Germany; email: drosten@virology-
bonn.de
Pandemic (H1N1)
2009 in S kunks,
Canada
To the Editor: In March 2009,
a novel infl uenza virus A (H1N1)
emerged in Mexico, and, because of
widespread human-to-human transmis-
sion, a global pandemic was declared
in June 2009 (1). Although most cas-
es have involved humans, pandemic
(H1N1) 2009 has sporadically infected
swine and turkeys and has also been
reported in a small number of pet fer-
rets, cats, and captive cheetahs, and in
a dog (2). Many of these animals were
cared for by persons who experienced
infl uenza-like illness and the owner
of 1 cat who died had confi rmed pan-
demic (H1N1) 2009 respiratory disease
before the cat became ill, which sug-
gests probable human-to animal-trans-
mission of the virus (2).
During mid-December 2009–mid-
January 2010, eight striped skunks
(Mephitis mephitis) died on a mink
farm near Vancouver, British Colum-
bia, Canada. On January 12, 2010,
two of the skunks were brought to the
Animal Health Centre in Abbotsford,
British Columbia, for postmortem ex-
amination. One skunk exhibited pu-
rulent nasal exudates. In both skunks,
investigators observed splenomegaly
and severe pneumonia, character-
ized by heavy, dark red to purple,
lung lobes involving >70% of the
lung fi eld. Microscopic examination
showed moderate rhinitis and severe
bronchopneumonia with intralesional
bacteria, areas of interstitial pneumo-
nia, and occasional nematode larvae.
Also observed were splenic extramed-
ullary hematopoiesis, plasmacytosis
of both lymph nodes and spleen, and
mild plasmacytic glomerulonephritis
with proteinuria.
Routine bacteriologic culture of
lung showed heavy growth of Strep-
tococcus dysgaslactiae subsp. equi-
similis, Staphylococcus aureus, and
Hafnia alvei. That death was caused
Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 16, No. 6, June 2010 1043

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LETTERS
by uncomplicated mixed bacterial
bronchopneumonia in 2 (and possibly
up to 8) adult skunks over a 6-week
period was considered unlikely. The
presence of lungworm was considered
incidental. However, the areas of in-
terstitial pneumonia suggested that a
primary viral pathogen was likely.
Molecular testing was conducted
initially on fresh lung, liver, kidney,
and spleen for canine distemper vi-
rus and, subsequently, for infl uenza
A virus. The splenic and nodal plas-
macytosis and plasmacytic glomeru-
lonephritis also prompted testing for
Aleutian disease virus (ADV). Organ
samples were negative for canine dis-
temper virus and positive for ADV.
Detection of infl uenza A virus
nucleoprotein and matrix genes and he-
magglutinin and neuraminidase typing
was performed with real-time reverse
transcription–PCR. Organ samples
were positive for pandemic (H1N1)
2009, which was confi rmed by se-
quence analysis of DNA fragments ob-
tained in the hemagglutinin, neuramin-
idase, and matrix gene testing.
Primary viral interstitial pneu-
monia is frequently complicated by
opportunistic bacterial bronchopneu-
monia and infl uenza virus A infection
has been shown to predispose to pul-
monary bacterial toxicity (3). Thus,
we concluded that primary pandemic
(H1N1) 2009 interstitial pneumonia
had predisposed the 2 skunks to mixed
bacterial bronchopneumonia
death. The skunks were also infected
with ADV, presumably as a result of
viral shedding by the minks, which
are known to be ADV carriers. Striped
skunks can be experimentally infected
with ADV, and antibodies to ADV
have been detected in wild skunks (4).
Although ADV does not cause pneu-
monia (4), co-infection with ADV and
infl uenza A virus is associated with
higher mortality rates in minks with
respiratory disease (5). Thus, ADV
co-infection may have contributed to
the severity of the pneumonia and the
death of the skunks.
and
The source of the pandemic
(H1N1) 2009 virus is unclear. Nasal
discharge was also observed in many
of the minks, which suggests that they
had a respiratory viral infection. How-
ever, no diagnostic workup was under-
taken. Although severe outbreaks of
interstitial pneumonia on mink farms
can occur (6), most natural infl uenza
A virus infections in minks are either
mild or asymptomatic (5). Thus, the
minks may also have been infected
with pandemic (H1N1) 2009. Many
of the pandemic (H1N1) 2009 infec-
tions reported in animals are believed
to have been the result of exposure to
infected humans (2). Workers on the
mink farm did not experience infl uen-
za-like illness. However, humans with
asymptomatic pandemic (H1N1) 2009
infection may have transmitted it to
the mink. Because the skunks visited
the mink farm daily, transmission of
pandemic (H1N1) 2009 from humans
to minks to skunks is a possibility.
In view of the detection of pan-
demic (H1N1) 2009 virus in 2 striped
skunks with fatal pneumonia, this
species should now be regarded as
a potential source of infl uenza A vi-
rus. Wild animals participate in the
transmission of infl uenza A viruses
between species, and the presence
of wildlife on farms is known to be
a risk factor for infection of poultry
(7). Similar to raccoons, skunks ex-
press both α2,3 and α2,6 sialic acid
receptors for avian and human infl u-
enza viruses in the respiratory tract
(M. Shrenzel, San Diego Zoo, pers.
comm.), which is believed to create
the opportunity for mixed infl uenza
infections with potential for genetic
reassortment (8). Skunks, like rac-
coons, are highly mobile animals with
large home ranges in rural and urban
areas, which provides numerous op-
portunities for infl uenza A virus ex-
posure and transmission to poultry,
livestock, pets, and, ultimately, hu-
mans. The inclusion of striped skunks
in wildlife infl uenza surveillance pro-
grams may be warranted.
Acknowledgments
We thank Sandra Etheridge, Joanne
Taylor, and Erin Zabek for their assis-
tance and technical expertise; and Helen
Schwantje, John Robinson, and Victoria
Bowes for their valuable contribution to
the case workup.
Ann P. Britton, Ken R. Sojonky,
Andrea P. Scouras,
and Julie J. Bidulka
Author affi liation: Animal Health Centre,
British Columbia Ministry of Agriculture
and Lands, Abbotsford, British Columbia,
Canada
DOI: 10.3201/eid1606.100352
References
1. World Health Organization. Programmes
and projects, media centre, statements
2009 [cited 2010 Feb 11]. http://www.who.
int/mediacentre/news/statements/2009/
h1n1_pandemic_phase6_20090611/en/
2. American Veterinary Medical Associa-
tion. Public health, infl uenza, 2009 H1N1
fl u virus outbreak, February 8, 2010 [cit-
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public_health/infl uenza/new_virus/
3. Jakeman KJ, Rushton DI, Smith H, Sweet
C. Exacerbation of bacterial toxicity to
infant ferrets by infl uenza virus: possible
role in sudden infant death syndrome. J
Infect Dis. 1991;163:35–40.
4. Kenyon AJ, Kenyon BJ, Hahn EC. Prot-
ides of the mustelidae: immunoresponse
of mustelids to Aleutian mink disease vi-
rus. Am J Vet Res. 1978;39:1011–5.
5. Gagnon CA, Spearman G, Hamel A, God-
son DL, Fortin A, Fortin G, et al. Char-
acterization of a Canadian mink H3N2 in-
fl uenza A virus isolate genetically related
to triple reassortant swine infl uenza virus.
J Clin Microbiol. 2009;47:796–9. DOI:
10.1128/JCM.01228-08
6. Englund L, Klingeborn B, Mejerland T.
Avian infl uenza A virus causing an out-
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in mink. Acta Vet Scand. 1986;27:497–
504.
7. Vandalen KK, Shriner SA, Sullivan
HJ, Root JJ, Franklin AB. Monitoring
exposure to avian infl uenza viruses in
wild mammals. Mammal Rev. 2009:1–
11 [cited 2010 Feb 11]. http://www.
aphis.usda.gov/wildlife_damage/nwrc/
publications/09pubs/vandalen091.pdf
1044 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 16, No. 6, June 2010

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LETTERS
8. Hall JS, Bentler KT, Landolt G, Elmore
SA, Minnis RB, Campbell TA, et al. Infl u-
enza infection in wild raccoons. Emerg In-
fect Dis. 2008;14:1842–8. DOI: 10.3201/
eid1412.071371
Address for correspondence: Ann P. Britton,
Animal Health Centre, British Columbia
Ministry of Agriculture and Lands, 1767 Angus
Campbell Rd, Abbotsford, British Columbia
V3G 2M3, Canada; email: ann.p.britton@gov.
bc.ca
Community-
ac quired
Oseltamivir-
Resistant Pandemic
(H1N1) 2009 in
Child, Israel
To the Editor: During the spring
of 2009, a pandemic infl uenza A
(H1N1) virus emerged and spread
globally. Initial testing of the virus
found it susceptible to neuraminidase
inhibitors and resistant to adamantanes
(1,2). As of March 5, 2010, only 264
cases of oseltamivir-resistant pandem-
ic (H1N1) 2009 infection had been re-
ported to the World Health Organiza-
tion, but the number of cases has been
steadily increasing (2). These viruses
were carrying the H275Y mutation,
which conferred resistance to oselta-
mivir (2). Most of the reported cases
were in immunocompromised patients
who had prolonged viral shedding or
in patients who had received oseltami-
vir prophylaxis or treatment (1–4). We
describe an otherwise healthy 2-year-
old boy with oseltamivir-resistant pan-
demic (H1N1) 2009 infection and a
traumatic lung contusion, complicated
by acute respiratory distress syndrome
(ARDS). He had not received prior
chemoprophylaxis or treatment with
oseltamivir.
In November 2009, a healthy
2-year-old boy was admitted to the
pediatric intensive care unit at the
Western Galilee Hospital in Nahariya,
Israel, after he had been hit by a car.
One day before the accident, he had
exhibited fever and cough (for which
he was treated with acetaminophen).
His 4-year-old brother had recovered
recently from an infl uenza-like illness
without antiviral treatment. The other
household contacts were his parents,
who did not have a respiratory illness.
On admission, small, bilateral
lung contusions, right pneumothorax,
and liver lacerations were shown on
computed tomographic scan. The pa-
tient was treated with a chest tube for
drainage, supplemental oxygen, and
oseltamivir from hospital day 1 (30
mg 2 ×/day; child’s body weight = 13
kg) and was placed in droplet isola-
tion. Respiratory swab specimens, ob-
tained on hospital day 1, were sent to
the Israel Central Virology Laboratory
(ICVL) and found to be positive for
pandemic (H1N1) 2009 by real-time
reverse transcription–PCR (RT-PCR).
On hospital day 3, the child was intu-
bated because of worsening respira-
tory distress and hypoxemia, and he
required a second chest tube drain.
His chest fi lm showed bilateral pulmo-
nary infi ltrates. His condition was then
treated with nitric oxide, dopamine,
and milrinone for ARDS and failure of
the right side of the heart. The dosage
of oseltamivir was doubled on hospi-
tal day 4 because of gastric residuals.
Antimicrobial drug therapy with van-
comycin and piperacillin-tazobactam
was added because sepsis and sec-
ondary bacterial lung infection were
suspected. Because of the severity of
his symptoms and persistence of fe-
ver, additional lower and upper airway
specimens were sent to ICVL on hos-
pital days 5 and 10; they were positive
for pandemic (H1N1) 2009.
After these results were received,
oseltamivir resistance was suspected,
and his respiratory specimens were
also checked by ICVL. A mixture of
both wild-type and mutant pandemic
(H1N1) 2009 was found in the speci-
mens from hospital days 1, 5, and 10
by an in-house q-RT-PCR assay de-
signed to detect the H275Y mutation
(4,5). Further testing by sequence
analysis of the neuraminidase gene
showed a mixed population of wild-
type and mutant pandemic (H1N1)
2009; the mutant virus was carrying
the histidine-to-tyrosine substitution
at position 275, which conferred the
quantitative RT-PCR result and the
H275Y phenotype of oseltamivir-
resistant pandemic (H1N1) 2009. By
the time these laboratory results were
known, the patient’s respiratory con-
dition was improving without chang-
ing the oseltamivir therapy. Cultures
of blood and endotracheal specimens
were sterile and antimicrobial drug
therapy was stopped. On hospital day
15, he was extubated, oseltamivir ther-
apy was ended, and he was weaned off
oxygen a few days later. The respira-
tory specimen on hospital day 20 was
negative for pandemic (H1N1) 2009.
No secondary infl uenza cases were de-
tected among healthcare personnel or
patients in the unit.
In Israel, oseltamivir resistance
has been detected by ICVL in 6 cases
(5). The fact that our patient had os-
eltamivir-resistant pandemic (H1N1)
2009 without a previous oseltamivir
exposure is surprising because almost
all cases of oseltamivir-resistance
have been associated with previous
oseltamivir prophylaxis or therapy and
with prolonged viral shedding (which
is often combined with oseltamivir
therapy) in immunocompromised pa-
tients (1–5). Our patient did not at-
tend daycare and his parents had not
been ill recently. Therefore, he likely
was infected by his older brother who
probably had pandemic (H1N1) 2009
but was neither diagnosed nor treated
with antiviral medications. This theory
suggests that oseltamivir-resistant vi-
ruses circulate in the community with
the potential to be transmitted between
persons.
Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 16, No. 6, June 2010 1045