Cold stress-induced recurrences of herpetic keratitis in the squirrel monkey.

PURPOSE Models of recurrent herpetic keratitis that depend on tissue damage or immunosuppression have been described. The authors report a model that depends only on minimal temperature stress to produce clinical recurrences in a small primate. METHODS Squirrel monkeys (Saimiri sciureus) infected by the ocular route with the Rodanus strain of herpesvirus type 1 (HSV-1) were exposed to temperatures approximately 5 degrees C lower than the usual ambient temperature for periods as short as 12 hours. RESULTS The corneas showed more or larger lesions typical of recurrent herpetic keratitis than are usually seen in these animals under normal conditions. Statistical analysis showed that there were significantly higher frequencies of epithelial keratitis at 18 degrees C and 20 degrees C (P < 0.0001). CONCLUSIONS A minimal temperature change produced significant recurrences in this small animal within a short time. Tissues were not damaged to produce the recurrences. This approach may provide an efficient primate model for rapid testing of drugs to prevent clinical recurrence of ocular herpetic keratitis.