Japanese monkey (Macaca fuscata) with alveolar echinococcosis after treatment with albendazole for 10 years: serodiagnosis and determination of albendazole metabolites.

In 1997, an outbreak of alveolar echinococcosis in Japanese monkeys (Macaca fuscata) occurred in a zoo in Hokkaido, Japan. Twelve infected monkeys from a colony (n = 57) were diagnosed serologically by Western blotting, and ultrasonography showed the presence of tumor-like tissue in the livers of nine monkeys. The 12 infected monkeys have been treated with albendazole for 10 years without surgical resection. Ten of these monkeys have died so far; diagnoses were confirmed histopathologically through autopsy. Two of these monkeys are still alive. Recently, a significant difference between the two living monkeys was recognized. A difference in curative effect was demonstrated between the two living monkeys by radiography, contrast enhanced computed tomography, and contrast ultrasound. One showed metastasis to various organs, and the other appeared to be almost cured, as demonstrated by size reduction and calcification of the lesion after albendazole treatment for 10 years. This time, serological reexamination was performed to corroborate this apparent difference. The serological tests supported the preliminary imaging findings. In addition, the presence of albendazole metabolites in sera was confirmed by high-performance liquid chromatography. In this study, it was demonstrated that tests which have been used in human cases were also effective for diagnosing alveolar echinococcosis and for assessing curative effects in nonhuman primates such as M. fuscata.