We evaluated prevalence of cystic echinococcosis (CE) in a central Peruvian Highland district by using 4 diagnostic methods: ultrasonography for 949 persons, radiography for 829, and 2 serologic tests for 929 (2 immunoblot formats using bovine hydatid cyst fl uid [IBCF] and recombinant EpC1 glutathione S-transferase [rEpC1-GST] antigens). For the IBCF and rEpC1-GST testing, prevalence of liver and pulmonary CE was 4.7% and 1.1% and seropositivity was 8.9% and 19.7%, respectively. Frequency of seropositive results for IBCF and rEpC1-GST testing was 35.7% and 16.7% (all hepatic cysts), 47.1% and 29.4% (hepatic calcifi cations excluded), and 22.2% and 33.3% (lung cysts), respectively. Weak immune response against lung cysts, calcifi ed cysts, small cysts, and cysts in sites other than lung and liver might explain the poor performance of the serodiagnostic tests. We confi rm that CE is highly endemic to Peru and emphasize the limited performance of available serologic assays in the fi eld.

Human, canine and ovine echinococcosis prevalence was determined in a highland community located in the central Peruvian Andes during 1997 and 1998. Human echinococcosis was determined using portable ultrasonography, chest X-ray examination, and an enzyme-linked immunoelectrotransfer blot (EITB) assay. Canine echinococcosis was determined using microscopy stool examinations and a coproantigen detection enzyme-immunoassay (EIA) for Echinococcus granulosus. Ovine echinococcosis was determined by an EITB assay for sheep echinococcosis and necropsy examination of viscera from domestic slaughtered animals. An abdominal ultrasound, a chest X-ray examination and an EITB for echinococcosis were performed on 214 subjects (45% of the village population). The frequency of presumptive liver/abdominal, lung and liver-lung hydatid cysts was 5.1% (11/214), 3.7% (8/214) and 0.5% (1/214), respectively. The overall prevalence of human cystic echinococcosis was 9.3% (20/214). The frequency of canine echinococcosis was 46% (23/50) and 32% (16/50) by the coproantigen EIA test and arecoline purging, respectively. The frequency of sheep echinococcosis was 65% (22/34) by the EITB and 38% (13/34) by necropsy. We demonstrated a high prevalence of human and animal echinococcosis in this Peruvian village. In remote areas where echinococcosis is endemic, both the coproantigen EIA and arecoline purging may be used for the study of canine echinococcosis; the EITB is useful in establishing the diagnosis of echinococcosis in sheep prior to necropsy.

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Cystic echinococosis (CE) is a public health problem caused by Echinococcus granulosus. We aimed to determine the efficacy of nitazoxanide (NTZ) and oxfendazole (OXF) against CE in naturally infected sheep. A total of 151 ewes were assigned to the following groups: 15 mg/kg of NTZ weekly for five weeks (NTZ5); two rounds of 15 mg/ kg of NTZ a day for five days (NTZ5x2) two weeks apart; 30 mg/kg of OXF a week for 11 weeks (OXF11); 30 mg/kg of OXF plus 15 mg/kg of NTZ a week for 11 weeks (OXF/NTZ); and the control group. OXF11 and OXF/NTZ decreased the number of fertile cysts, increased the number of degenerated cysts, and were more efficacious (49.6-61.2%) against lung cysts and liver cysts (91.8-100%) than any other treatment group. OXF might be an additional strategy for control programs and an optional treatment of human CE after it is licensed.

No evidence of Echinococcus granulosus infection has been described in the coastal region of Peru, with the exception of the capital city of Lima. Anecdotal evidence suggests the existence of a focus of echinococcosis in the coastal city of Chincha, located south of Lima. We conducted a preliminary epidemiologic study in Chincha, which included an ultrasound, chest radiography, and serologic survey of abattoir workers, a review of medical records from local hospitals, and examination of the intestines of stray dogs to determine the presence of canine echinococcosis. Among 25 abattoir workers examined for the presence of cystic echinococcosis, we found three (12%) subjects with echinococcal cysts. A review of medical records showed a surgical incidence of 32/100,000 for the period 1996-1998. Three of 48 dogs (6.25%) were found to be infected with E. granulosus tapeworms. This study demonstrates the existence of an undocumented endemic focus of E. granulosus previously unknown in the coastal region of Peru.