Use of streptomycin and isoniazid during a tuberculosis epizootic in a rhesus and cynomolgus breeding colony.

An epizootic of tuberculosis occurred following the addition of new cynomolgus monkeys to a nonhuman primate breeding colony. A total of 5/47 cynomolgus and 51/148 rhesus became tuberculin positive (reactors). Mycobacterium tuberculosis was cultured from reactors which were euthanatized and monkeys which died spontaneously. The isolates were sensitive to the standard antitubercular agents. Rhesus reactors and their unweaned infants were quarantined and given streptomycin and isoniazid by intramuscular injection. Isoniazid was added to the drinking water quarantined and given streptomycin and isoniazid by intramuscular injection. Isoniazid was added to the drinking water of the remainder of the breeding colony to curtail the outbreak. Isoniazid toxicity was observed in both infants and adults with an overall incidence of 3%. Forty-eight rhesus reactors and their infants born before the outbreak were alive and healthy at the end of the treatment period. In addition, nine surviving infants were born during the 6 month treatment period. Tuberculin tests were still positive in many of the treated reactors following treatment. In this epizootic, the institution of quarantine and chemotherapy instead of euthanasia resulted in significant savings.