Clearance of Shigella flexneri carriers in a zoologic collection of primates

In 1990, a high prevalence of Shigella flexneri was documented in the gibbon population at the National Zoological Park. The enzootic strain had been determined to be resistant to most antibiotics and had been responsible for animal deaths. Prevalence of Shigella spp was high in the entire primate population. To address the clinical problem, eradication was attempted by use of enrofloxacin. Facilities disinfection comprised a large part of Shigella clearance efforts. After the clearance protocol was completed gibbons, vs other primate species, were closely monitored for 16 months by subjecting their feces to bacteriologic culturing. The program was successful, with eradication of the problematic strain of S flexneri. However, 10 to 12 months after completion of treatments, S sonnei was isolated from feces of 3 animals living in the same housing facility.