Human monkeypox infection: a family cluster in the midwestern United States.
BACKGROUND
The outbreak of monkeypox in the Midwestern United States during June 2003 marks the first documented human infection in the Western Hemisphere. Consistent with those in outbreaks in Africa, most cases in this outbreak were associated with febrile rash illness. We describe a cluster of monkeypox in a family with a spectrum of clinical illness, including encephalitis, and outline the laboratory confirmation of monkeypox.


METHODS
Standardized patient information was collected by questionnaire and medical chart review; all cases described were laboratory confirmed. Laboratory methods included nucleic acid detection, viral culture, serologic testing, histopathologic evaluation, and immunohistochemical testing.


RESULTS
Of 3 family members with monkeypox, 2 had rash illness only, and 1 required hospitalization for severe encephalitis. The family member with the mildest clinical course had previously received smallpox vaccination. Diagnostic testing by both polymerase chain reaction and culture revealed infectious monkeypox virus in skin lesions of all 3 patients; 2 patients had orthopoxvirus detected by immunohistochemistry in skin lesions. The patient with encephalitis had orthopoxvirus-reactive immunoglobulin M (IgM) in cerebrospinal fluid. All patients had detectable IgM responses to orthopoxvirus antigens.


CONCLUSIONS
These 3 patients illustrate a spectrum of clinical illness with monkeypox despite a common source of exposure; manifestation and severity of illness may be affected by age and prior smallpox vaccination. We report that monkeypox, in addition to causing febrile rash illness, causes severe neurologic infection, and we discuss the use of novel laboratory tests for its diagnosis.
Sejvar
James J
JJ
Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30033, USA. zea3@cdc.gov
Chowdary
Yalamanchali
Y
Schomogyi
Mark
M
Stevens
James
J
Patel
Jayesh
J
Karem
Kevin
K
Fischer
Marc
M
Kuehnert
Matthew J
MJ
Zaki
Sherif R
SR
Paddock
Christopher D
CD
Guarner
Jeannette
J
Shieh
Wun-Ju
WJ
Patton
Joanne L
JL
Bernard
Nikeva
N
Li
Yu
Y
Olson
Victoria A
VA
Kline
Richard L
RL
Loparev
Vladimir N
VN
Schmid
D Scott
DS
Beard
Bradley
B
Regnery
Russell R
RR
Damon
Inger K
IK
D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D002648:Child; D016000:Cluster Analysis; D018792:Encephalitis, Viral / Q000821:virology; D004797:Enzyme-Linked Immunosorbent Assay; D005076:Exanthema; D005192:Family Health; D005260:Female; D005334:Fever; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D015146:Midwestern United States; D045908:Mpox, Monkeypox / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology / Q000821:virology; D008993:Monkeypox virus / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012867:Skin / Q000473:pathology; D014776:Virus Cultivation
D000914:Antibodies, Viral; D007075:Immunoglobulin M