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CDC has received reports of patients with a febrile rash illness who had close contact with pet prairie dogs and other animals. The Marshfield Clinic, Marshfield, Wisconsin, identified a virus morphologically consistent with a poxvirus by electron microscopy of skin lesion tissue from a patient, lymph node tissue from the patient's pet prairie dog, and isolates of virus from culture of these tissues. Additional laboratory testing at CDC indicated that the causative agent is a monkeypox virus, a member of the orthopoxvirus group. This report summarizes initial descriptive epidemiologic, clinical, and laboratory data, interim infection-control guidance, and new animal import regulations.
As of June 10, a total of 53 cases had been investigated in Illinois, Indiana, and Wisconsin. Of these, 29 (49%) cases were among males; the median age was 26 years (range: 4-53 years). Data were unavailable for sex and age for two and 14 patients, respectively. A total of 14 (26%) patients have been hospitalized, including a child aged <10 years with encephalitis.
Detailed clinical information was available for 30 cases reported in Illinois and Wisconsin. Among these, the earliest reported onset of illness was on May 15 (Figure 1). For the majority of patients (22 [73%]), a febrile illness has either preceded or accompanied the onset of a papular rash (Figure 2); respiratory symptoms (16 [64%]), lymphadenopathy (14 [47%]), and sore throat (10 [33%]) also were prominent signs and symptoms ( Table ). The rash typically progressed through stages of vesiculation, pustulation, umbilication, and encrustation. Early lesions became ulcerated in some patients. Rash distribution and lesions have occurred on the head, trunk, and extremities; many patients had initial and satellite lesions on palms, soles, and extremities. Rashes were generalized in some patients.
All patients have had contact with animals; however, at least two patients also reported contact with another patient's lesions or ocular drainage. A total of 51 patients reported direct or close contact with prairie dogs (Cynomys sp.), and one patient reported contact with a Gambian giant rat (Cricetomys sp.). One patient had contact with a rabbit (Family Leporidae) that became ill after exposure to an ill prairie dog at a veterinary clinic. Traceback investigations have been initiated to identify the source of monkeypox virus introduced into the United States and have identified a common distributor where prairie dogs and Gambian giant rats were housed together in Illinois. A search of imported animal records revealed that Gambian giant rats were shipped from Ghana in April to a wildlife importer in Texas and subsequently were sold to the Illinois distributor. The shipment contained approximately 800 small mammals of nine different species that might have been the actual source of introduction of monkeypox.
As of June 9, specimens obtained from 10 patients in Illinois, Indiana, and Wisconsin had been forwarded to CDC for testing; nine patients with skin lesions had DNA sequence signatures specific for monkeypox. No skin lesions were observed in one patient who tested negative by polymerase chain reaction. Skin biopsies were available for five patients; four showed orthopox viral antigens by immunohistochemical testing. Skin lesions from four of the 10 patients were evaluated by negative stain electron microscopy, and pox viral particles were found in three patients. Monkeypox specific DNA signatures also were found in a viral isolate derived from lymphoid tissue of a patient's ill prairie dog.
Reported by: J Melski, MD, K Reed, MD, E Stratman, MD, Marshfield Clinic and Marshfield Laboratories, Marshfield; MB Graham, MD, J Fairley, MD, C Edmiston, PhD, KS Kehl, PhD, Medical College of Wisconsin; SL Foldy, MD, GR Swain, MD, P Biedrzycki, MPH, D Gieryn, Milwaukee Health Dept; K Ernst, MPH, Milwaukee-Waukesha Consortium for Emergency Public Health Preparedness, Milwaukee; D Schier, Oak Creek Health Dept, Oak Creek; C Tomasello, Shorewood/Whitefish Bay Health Dept, Shorewood; J Ove, South Milwaukee Health Dept, South Milwaukee; D Rausch, MS, N Healy-Haney, PhD, Waukesha County Health Dept, Waukesha; N Kreuser, PhD, Wauwatosa Health Dept, Wauwatosa; MV Wegner, MD, JJ Kazmierczak, DVM, C Williams, DVM, DR Croft, MD, HH Bostrom, JP Davis, MD, Wisconsin Dept of Health and Family Svcs; R Ehlenfeldt, DVM, Wisconsin Dept of Agriculture, Trade and Consumer Protection; C Kirk, Wisconsin State Laboratory of Hygiene. M Dworkin, MD, C Conover, MD, Illinois Dept of Public Health. R Teclaw, MD, H Messersmith, MD, Indiana State Dept of Health. Monkeypox Investigation Team; MJ Sotir, PhD, G Huhn, MD, AT Fleischauer, PhD, EIS officers, CDC.
Morbidity and Mortality Weekly Report. 2003;52(23) © 2003 Centers for Disease Control and Prevention (CDC)
Cite this: Multistate Outbreak of Monkeypox - Illinois, Indiana, and Wisconsin 2003 - Medscape - Jun 13, 2003.
