SHIGELLOSIS IN CAPTIVE WESTERN LOWLAND GORILLAS (GORILLA-GORILLA-GORILLA)

A 10-yr retrospective study was performed at the International Wildlif e Conservation Park/Bronx Zoo (IWCP) to evaluate the incidence and ass ess the implications of shigellosis in western lowland gorillas (Goril la gorilla gorilla). Nine animals had confirmed Shigella flexneri grou p B isolated from fecal or rectal culture. Bacterial isolates from two individuals were further categorized as subtype 2. Two additional ani mals that were exposed to S, flexneri-infected gorillas developed diar rhea, but the organism was not isolated from them. Ten of these 11 cas es (91%) were infants between 7 and 40 mo of age; one was an 18-yr-old male. Ten of the 11 infants (91%) introduced to the main gorilla colo ny developed shigellosis. One of the 26 (4%) adult gorillas living at the Great Ape House during the 10-yr period was noted to have shigello sis, The most common clinical presentation was mild to severe diarrhea , lethargy, and anorexia, In all cases, onset of illness in an individ ual was temporally associated with its introduction to a different gor illa group. Treatment of individual cases varied greatly depending upo n the severity of disease, response to therapy, shigella antimicrobial susceptibility pattern, age, and size of the gorilla. All gorillas re sponded to treatment and recovered. In 1990 S. flexneri isolates from IWCP gorillas demonstrated increased antimicrobial resistance patterns . In 1992, multiple-drug-resistant S. flexneri isolates were also note d in five gorillas at two additional zoological parks that developed s higellosis after arrival of asymptomatic gorillas from the IWCP. DNA f ingerprint analysis of the S. flexneri isolates from the IWCP and the other two zoological parks was performed. Plasmid and chromosomal anal ysis of the S. flexneri isolates suggested that the organism had only been transmitted to one of the zoological parks by an asymptomatic IWC P gorilla. These tests also identified three distinct multidrug-resist ant S. flexneri strains from the gorillas; one had originated at the I WCP and the other two were unique to another zoological park.