An 18-year-old female, captive-born chimpanzee at the Maryland Zoo in Baltimore presented with clinical signs of inappetence, lethargy, and lower limb stiffness for 10 days, which then waxed and waned for 10 days prior to clinical workup. No notable abnormalities were found on exam or CBC and biochemistry.2 Due to the nature of the clinical presentation, serum was sent out for Ehrlichia canis, Rickettsia rickettsii, and Borrelia burgdorferi. Testing was negative for E. canis and R. rickettsii, but was strongly positive via IFA for B. burgdorferi, with a titer of 1:10240. Titers of this level in dogs are frequently associated with clinical disease, per the reporting laboratory. Western blot was also strongly positive for the B. burgdorferi organism at this time point. Treatment with doxycycline (100 mg BID x 28 d) was initiated and a clinical response was seen within one week.3 Clinical signs have not returned since completion of treatment. Convalescing serum collected two weeks after finishing treatment exhibited a rising titer at 1:81920, consistent with recent immune response to disease. Banked serum was sent out on several chimpanzees in the current troop, as well as on this chimpanzee from previous exams. While some low-positive titers were present and likely indicative of past exposure, no titer was near that of the affected chimp during her course of disease. To the authors’ knowledge, this is the first report of borreliosis in a great ape species and originates from an area of the country with a high incidence of human borreliosis.1
1. Centers for Disease Control and Prevention. Reported cases of Lyme disease—United States, 2009. 2010. www.cdc.gov/ncidod/dvbid/lyme/ld_Incidence.htm.
2. International Species Information System (ISIS). Pan troglodytes. Reference ranges for physiological values in captive wildlife (CD-ROM). 2002.
3. Wormser GP, Dattwyler RJ, Shapiro ED, Halperin JJ, Steere AC, Klempner MS, et al. The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis. 2006;43:1089–1134.