1 figure, 1 table omitted
CDC and state and local health departments continue to investigate cases
of monkeypox among persons who had contact with wild or exotic mammalian pets
or persons with monkeypox.1,2 This
report updates epidemiologic, laboratory, and smallpox vaccine use data for
As of June 25, a total of 79 cases of monkeypox had been reported to
CDC from Wisconsin (39), Indiana (20), Illinois (16), Missouri (two), Kansas
(one), and Ohio (one); these include 29 cases laboratory-confirmed at CDC
and 51 cases under investigation by state and local health departments. A
total of 19 cases were excluded from those reported in the previous update
because they met the exclusion criteria outlined in the updated case definition,2 and 11 were added. Of the 79 cases, 37 (47%) were
among males; the median age was 28 years (range: 1-51 years). Age data were
unavailable for two patients. Among 75 patients for whom data were available,
19 (25%) were hospitalized. Two patients have had a serious clinical illness.
The first patient was a child with a previously reported laboratory-confirmed
case of severe monkeypox-associated encephalitis1,2;
the child subsequently improved and was discharged after requiring hospitalization
for 14 days. A second child, who was exposed to three ill prairie dogs, was
hospitalized with profound painful cervical and tonsillar adenopathy and diffuse
pox lesions, including lesions in the oropharynx. Although the child had difficulty
breathing and swallowing, mechanical ventilation was not required. The adenopathy
peaked 5 days after rash onset and 7 days after onset of initial prodromal
symptoms of general malaise, myalgia, and fever. Preliminary testing of skin
rash lesions was positive for orthopox virus; confirmatory testing for monkeypox
virus is pending at CDC.
Of the 79 reported cases, 29 (37%) have been laboratory confirmed at
CDC for monkeypox by detection of virus in skin rash lesions by using culture,
polymerase chain reaction (PCR), immunohistochemical testing, and/or electron
microscopy. One patient had monkeypox virus detected by PCR and culture in
throat and nasopharyngeal swabs obtained when the patient was ill with prodromal
symptoms and a macular rash. In addition, an IgM response to orthopox viral
antigen was detected in an acute serum sample. For these laboratory-confirmed
cases, dates of illness onset ranged from May 16 to June 11. All confirmed
patients reported a rash and at least one other clinical sign or symptom,
including fever, respiratory symptoms, and/or lymphadenopathy. The median
incubation period (i.e., first exposure date to illness onset date) was 12
days (range: 2-26 days). The majority of confirmed patients reported exposure
to wild or exotic mammals, including prairie dogs; some patients also had
contact with other persons with monkeypox virus infection in a household setting.
No cases of monkeypox that could be attributed exclusively to person-to-person
contact have been confirmed.
To prevent further transmission of monkeypox, 26 residents of five states
have received smallpox vaccine since June 13; recipients included 24 adults
and two children. Vaccine was administered to two laboratory workers pre-exposure
and to 24 persons post-exposure (11 health-care workers, seven household contacts,
three laboratory workers, two public health veterinarians, and one work contact).
One adult who was vaccinated as a child did not have a major vaccine reaction
or "take" 7 days after vaccination and required revaccination.
CDC has issued updated interim guidance on the use of smallpox vaccine,
cidofovir, and vaccinia immune globulin for prevention and treatment in the
setting of an outbreak of monkeypox.3 Principal
changes in the updated guidance include a revision of the definition of close
contact with an ill animal, recommendations for vaccination of clinical laboratory
workers handling specimens from ill animals and persons infected with monkeypox
virus, and instructions for reporting smallpox vaccine–related serious
adverse events to the Vaccine Adverse Event Reporting System (VAERS).
Health-care providers, veterinarians, and public health officials who
suspect monkeypox in animals or humans should report such cases to their state
and local health departments. State health departments should report suspect
cases to CDC, telephone 770-488-7100. Clinical specimens should be submitted
for testing after consultation with the state and local health department.
Interpretation of laboratory results requires completion of specimen submission
forms, which are available at http://www.cdc.gov/ncidod/monkeypox/diagspecimens.htm.
Additional information about monkeypox is available at http://www.cdc.gov/ncidod/monkeypox.
State and local health departments. Monkeypox investigation team, CDC.
This report is based on data contributed by MG Anderson, MD, Crusader
Clinic; S Homann, MD, Rockford Infectious Disease Consultants, Rockford; L
Frenkel, Dept of Pediatrics, Univ of Illinois, Chicago, Illinois.
Update: Multistate Outbreak of Monkeypox—Illinois, Indiana, Kansas, Missouri, Ohio, and Wisconsin, 2003. JAMA. 2003;290(4):454-455. doi:10.1001/jama.290.4.454