C9 (Clinical Case) Monkeypox Virus Infection in a 2-Month-Old Infant

Abstract

Abstract Introduction/Background The 2022 Monkeypox virus outbreak shed attention on an illness that is rare in non-endemic countries. Children are at risk of severe disease based on case series from previous outbreaks. Tecovirimat may be considered as a therapy in young children. Its efficacy and safety profile, however, have never been formally studied. This case report presents the first laboratory-confirmed case of monkeypox virus infection in a Canadian infant and its management. Case Description A 2-month-old infant presented to an emergency department with a vesiculopustular skin rash. A week before, parents noticed an eruptive cluster of 3 fluid-filled vesicles on the infant’s forehead. In the next days, vesiculopustular lesions appeared on his body. One spike of temperature was reported with no other sign of illness. On physical examination, a dozen umbilicated well-circumscribed vesico-pustules were observed with minimal skin inflammation. They ranged from 2 to 5 mm in size and were scattered over the face, trunk and limbs including palms and soles. In addition, 3 confluent crusted umbilicated lesions were present on the forehead. Discussion Differential diagnosis included varicella zoster virus, herpes simplex virus, and enteroviral infections. Empiric intravenous acyclovir was initiated pending specimen analysis. Bacterial culture and viral PCRs were negative on CSF and skin specimens. Due to transmission of monkeypox in the local adult population, orthopoxvirus was tested by PCR. The result was positive on a skin specimen and was later confirmed by the National Microbiology Laboratory of Canada. Because of the patient’s age and ongoing new lesions, tecovirimat was initiated. After 24 hours, new lesions stopped appearing and regression and crusting of active lesions were noted. Treatment was continued for 14 days without adverse events. Although parents denied similar symptoms, an epidemiological link was postulated, given work exposure in a setting with high risk of transmission in one of them. This case adds insight on the clinical features, the course of disease and management in infants. This 2-month-old infant did not develop any complication from the illness and was among the youngest patients with monkeypox to be treated with tecovirimat. Conclusion As monkeypox infection remains rare in children and may convey a higher risk for severe disease, a high degree of suspicion is warranted for clinicians caring for children. Monkeypox should be included in the differential diagnosis of an unexplained vesiculopustular rash. Finally, tecovirimat as a treatment for monkeypox infection in children was shown here to be safe and effective, even when started late in the evolution.