Evaluation of four variants of the indirect hemagglutination test for human hydatidosis.

The comparative sensitivity and specificity of four technical variants of the indirect hemagglutination test (IHA) for hydatidosis with tannic acid, glutaraldehyde, benzidine and formol treated cells, the same pool of hydatid cyst fluid and sera from hydatid and non-hydatid persons was studied. The number of reactors in each group of sera and the degree of reactivity of each serum sample varied with the type of IHA test. The sensitivity and specificity of each technique was related to the criterion on which IHA test positivity was based and to the group of sera examined. Of the four techniques, that employing tannic acid was considered as the choice IHA test for hydatid immunodiagnosis. The findings are discussed in terms of their implications to the use of a standard serum of known IHA test titer for reference purposes and to the significance of IHA test results for diagnostic and seroepidemiological studies.

Evaluation of three immunodiagnostic tests for human hydatid disease.

The comparative sensitivity and specificity of the immunoelectrophoresis (IEP), latex agglutination (LA) and indirect hemagglutination (IHA) test for hydatidosis were evaluated using a single hydatid cyst fluid pool as antigen and the same hydatid and nonhydatid sera and were found to vary with the type of IHA test, the criterion for IHA test positively and the group of sera selected for study. The sensitivity of the LA and IEP tests was comparable, both tests correlated well and neither gave a positive result in the nonhydatid sera studied. The sensitivity of the IEP test was higher when IHA test positivity was based on diagnostically significant titers but not when all IHA test reactors were considered as positive to this test. The merits and limitations of the LA and IHA tests in diagnostic and seroepidemiologic studies of human hydatidosis are discussed. On the basis of the present findings, the use of the LA test and possibly of the tannic acid IHA test, to screen for IEP test positive sera is proposed as the most reliable immunodiagnostic approach to estimate the prevalence of human hydatidosis for seroepidemiologic purposes and also for detecting hydatidosis cases in the field.

Evaluation of immunodiagnostic techniques for the detection of human hydatid cyst carriers in field studies.

In a study of 662 sera from a hydatidosis endemic area, the indirect hemagglutination test based on a minimal nonspecificity criterion of positivity and the latex agglutination (LA) test were found to be suitable screening techniques for the detection of sera positive to the arc 5, diagnostic of hydatid infection. The lower nonspecificity of the LA test, its greater simplicity and its excellent correlation with the immunoelectrophoresis test suggest that it is the choice screening technique for use in field surveys or seroepidemiologic studies of hydatid disease. The advantages and limitations of this serologic approach for the detection of human hydatid cyst carriers in field studies are discussed.

Efficacy of divided doses of fospirate against immature Echinococcus granulosus infections in dogs.

Seventy dogs were used to evaluate efficacy of divided doses of fospirate against immature Echinococcus granulosus infections in dogs. Dose rates of 10 to 80 mg/kg given on 1 or 2 occasions resulted in the clearance of 70.6 to 94.5% of expected worm numbers. At least 3 treatments may be required before dogs can be free from E granulosus. Vomiting, which occurred in dogs given doses of 40 mg or more/kg, seemed to interfere with anthelmintic efficacy in some dogs.

Efficacy of droncit against Echinococcus granulosus infection in dogs.

A study was made on 120 dogs to evaluate the effectiveness of droncit against Echinococcus granulous infection. The drug was administered orally in tablet form at dose rates of 1.25, 2.5, 5.0,and 10.0 mg/kg of body weight against immature stages of the parasite and at a dose rate of 5.0 mg/kg against gravid worms. Droncit was found to be 100% effective against both immature and gravid worms at the dose rate of 5.0 mg/kg. Adverse reactions were not observed in the treated dogs, and no risk was involved in administering the drug. The use of droncit in hydatidosis control programs in discussed.

Efficacy of divided doses of GS-23654 against immature Echinococcus granulosus infections in dogs.

One hundred dogs were used to evaluate the efficacy of GS-23654 (4-nitro-4'-isothiocyano-diphenyl-ether) against immature Echinococcus granulosus. A 25% suspension of active ingredient was administered at dose rates of 100, 200, or 400 mg/kg of body weight on 1, 2, or 3 occasions. Anthelmintic efficacy was dosage dependent and increased with the number of times the dosage was repeated. At none of the treatment schedules tested were all worms eliminated from all dogs, although 92.6% of the expected number of worms were eliminated from dogs given 400 mg/kg on 3 occasions.

Sylvatic echinococcosis in Argentina. II. Susceptibility of wild carnivores to Echinococcus granulosus (Batsch, 1786) and host-induced morphological variation.

Domestic dogs and cats, 3 fox species, Dusicyon culpaeus (Molina,1782), D, griseus (Gray, 1837) and D. gymnocercus (Thomas, 1914), Geoffroy's cats, Felis geoffroyi (D'Orbigny and Gervais, 1843), and grisons, Galictus cuja (Molina, 1782) were fed larvae of Echinococcus granulosus (Batsch, 1786) from domestic sheep in Argentina. Dogs and the 3 species of foxes became infected. The susceptibility of D. culpaeus compared favorably to that of dogs. Most D. griseus and D. gymnocercus were less susceptible than dogs but gravid strobilae were recovered from some animals of both species. Eggs from strobilae in dogs and Dusicyon spp. were infective to CF1 mice. The mean strobilar length and the diameters of the rostellar pad and suckers of worms in foxes were significantly reduced when compared with previously reported data for strobilae from dogs. The potential significance of Dusicyon spp. as reservoir hosts of E. granulosus in Argentina is discussed as is the confusion surrounding the taxonomic identification of cestode infections previously reported from these wild carnivores. It is suggested that Echinococcus spp. reported from Argentine foxes are E. granulosus and that foxes become infected by killing and scavenging on sheep in localities where E. granulosus is endemic.