Human Parainfluenza 2-Related Illness and Death in Captive Western Lowland Gorillas (Gorilla gorilla gorilla)
Habituated free-ranging and captive ape populations share proximity with humans and are at risk of anthroponotic infections, especially by viruses transmitted through aerosolized droplets such as human respiratory viruses.1-3 In July 2016, an onset of respiratory disease in a captive bachelor group (n=3) of western lowland gorillas (Gorilla gorilla gorilla) was concomitant with peak attendance of visitors and with occurrences of food items being thrown to the gorillas over the moat of their outdoor enclosure. Lethargy and clear nasal secretions rapidly progressing to purulent discharge were noted in the three individuals at 4–5-day intervals between each case. The condition of two gorillas improved with supportive therapy and antibiotics, while the third gorilla was found dead 3 days following initiation of treatment. A fatal bacterial pneumonia, secondary to an infection by a human parainfluenza virus 2 (HIPV-2), was considered to be the cause of death based on histopathology, lung cultures, and reverse transcription PCR. HPIV-2 activity in the human population of the province was detected for that period, and an F gene sequence 99% homologous to the gorilla HPIV-2 was detected in an infant residing in a region approximately 400 km from the zoo. To the authors’ knowledge, this is the first report of a confirmed HPIV-2 respiratory illness and associated death in a gorilla. This infection was suspected in the two other animals based on clinical presentation. The specific source of this viral infection remains undetermined. Nevertheless, contaminated food thrown by visitors is considered a likely source.
The authors would like to thank the Zoo de Granby personnel for their extraordinary animal care during the respiratory illness outbreak, Judith Viau for her invaluable necropsy assistance, and Anthony Estienne for technical assistance on the IHC assay.
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