The detection of monkeypox in humans in the Western Hemisphere.
BACKGROUND
During May and June 2003, an outbreak of febrile illness with vesiculopustular eruptions occurred among persons in the midwestern United States who had had contact with ill pet prairie dogs obtained through a common distributor. Zoonotic transmission of a bacterial or viral pathogen was suspected.


METHODS
We reviewed medical records, conducted interviews and examinations, and collected blood and tissue samples for analysis from 11 patients and one prairie dog. Histopathological and electron-microscopical examinations, microbiologic cultures, and molecular assays were performed to identify the etiologic agent.


RESULTS
The initial Wisconsin cases evaluated in this outbreak occurred in five males and six females ranging in age from 3 to 43 years. All patients reported having direct contact with ill prairie dogs before experiencing a febrile illness with skin eruptions. We found immunohistochemical or ultrastructural evidence of poxvirus infection in skin-lesion tissue from four patients. Monkeypox virus was recovered in cell cultures of seven samples from patients and from the prairie dog. The virus was identified by detection of monkeypox-specific DNA sequences in tissues or isolates from six patients and the prairie dog. Epidemiologic investigation suggested that the prairie dogs had been exposed to at least one species of rodent recently imported into the United States from West Africa.


CONCLUSIONS
Our investigation documents the isolation and identification of monkeypox virus from humans in the Western Hemisphere. Infection of humans was associated with direct contact with ill prairie dogs that were being kept or sold as pets.
Reed
Kurt D
KD
Department of Pathology, Marshfield Clinic, Marshfield, Wisc, USA. reed.kurt@mcrf.mfldclin.edu
Melski
John W
JW
Graham
Mary Beth
MB
Regnery
Russell L
RL
Sotir
Mark J
MJ
Wegner
Mark V
MV
Kazmierczak
James J
JJ
Stratman
Erik J
EJ
Li
Yu
Y
Fairley
Janet A
JA
Swain
Geoffrey R
GR
Olson
Victoria A
VA
Sargent
Elizabeth K
EK
Kehl
Sue C
SC
Frace
Michael A
MA
Kline
Richard
R
Foldy
Seth L
SL
Davis
Jeffrey P
JP
Damon
Inger K
IK
D000293:Adolescent; D000328:Adult; D000818:Animals; D002648:Child; D002675:Child, Preschool; D004279:DNA, Viral / Q000032:analysis; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D008297:Male; D045908:Mpox, Monkeypox / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary / Q000821:virology*; D008993:Monkeypox virus / Q000235:genetics / Q000302:isolation & purification*; D009115:Muridae / Q000821:virology; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012589:Sciuridae / Q000821:virology*; D012867:Skin / Q000821:virology; D014922:Wisconsin / Q000453:epidemiology; D015047:Zoonoses / Q000453:epidemiology / Q000635:transmission / Q000821:virology
D004279:DNA, Viral