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Abstract. Serum samples collected from 237 dogs in Catalonia (northeastern Spain) were screened by Western blot analysis to detect the presence of antibodies specific to different Leishmania infantum polypeptide fractions. Leishmaniasis was confirmed in 72 of these dogs by direct examination and/or culture. Another 165 animals from the Priorat region were studied periodically for 2-8 years between 1987 and 1995, giving a total of 565 determinations. A control group of 93 dogs from nonendemic areas was also studied. Sera from dogs with leishmaniasis recognized antigens with molecular weights ranging from 12 to 85 kD. The most sensitive antigens were those of 70, 65, 46, 30, 28,14, and 12 kD, which were recognized by 75%, 75%, 78%, 75%, 81%, 79%, and 75%, respectively, of the sera from dogs with positive parasitologic examination results. Antigens of 70 and 65 kD were also recognized by two dogs from nonendemic areas. Antigens of 14 and 12 kD were the first to be recognized by sera of asymptomatic dogs with titers less than the cut-off value of the dot-ELISA that increased during the longitudinal study, and the presence of antibodies specific for these fractions was observed for up to six years before seroconversion observed by dot-ELISA. These antibodies were also the first to disappear in dogs in which the disease was self-limited. The study corroborates the high sensitivity and specificity of Western blots in the diagnosis of canine leishmaniasis when the bands of low molecular weight (less than 46 kD) are considered, and indicates that fractions of 14 and 12 kD are useful in detecting early forms of the disease.

Abstract. Two polypeptide fractions of 72-75 kD were detected in the urine of 14 of 15 patients with visceral leishmaniasis (VL) and another fraction of 123 kD was found in 10 of the 15 patients by using a Western blot technique. None of these fractions was detected in the urine of 20 controls. These results suggest that antigen detection in urine could be a powerful, noninvasive method for VL diagnosis.

Abstract.A dot-enzyme-linked immunosorbent assay (ELISA) using protein A-peroxidase was evaluated as a diagnostic test for canine leishmaniasis. The test results were in agreement with parasitologic diagnosis and indirect immunofluorescence assay results. The sensitivity of the test calculated on 31 dogs with positive parasitologic examination was 90% when a titer of 1/800 was established as a cutoff and 100% when a titer of 1/400 was established. The specificity calculated on the canine population from nonendemic areas was 100% when both titers were established. Nevertheless, in endemic areas titers near the cutoff need careful interpretation. The results of this study demonstrate that dot-ELISA protein A using a bio-dot apparatus is highly suitable for seroepidemiologic field work.Canine leishmaniasis is endemic throughout the Mediterranean basin. The disease is caused by the same parasite as that causing human leishmaniasis, Leishmania infantum. 17 The domestic dog and the European fox (Vulpes vulpes) are incriminated as being the main reservoir of the parasite. 1,16,22 The clinical features of canine leishmaniasis vary widely. The 3 major symptoms are depilation, onycogryphosis, and emaciation, and their observation in an endemic area strongly suggests leishmaniasis.3 Nevertheless, because of the variability of the symptoms and the high frequency of asymptomatic or oligosymptomatic dogs in endemic areas, 2,10 the clinical diagnosis of the disease is difficult.A definitive diagnosis of leishmaniasis is established by direct observation of the intracellular stage of the parasite in bone marrow, lymph node aspirates, or skin lesions. The conventional parasitologic methods of diagnosis have low sensitivity; 2,15 their usefulness is limited by the number of parasites in the target organs, contamination of cultures, and the ability of strains to grow in vitro. For effective screening of infected dogs, it is necessary to adopt a simple, sensitive, and specific diagnostic test.Indirect immunofluorescence assay (IFA) is one of the most commonly used immunologic tests for the detection of L. infantum infections in humans and in the dog reservoir, 2,14 but its application requires a high level of skill and experience and large laboratory facilities.In 1983, a dot enzyme-linked immunosorbent assay (ELISA) for the serologic diagnosis of visceral human Received for publication April 12, 1996. leishmaniasis was described as a rapid and economical method that was as sensitive, specific, and reproducible as the more time-consuming ELISA procedure. 18 The test has been used 4,8,11,12 in the diagnosis of human visceral leishmaniasis in the Old World and the diagnosis of cutaneous and mucocutaneous human leishmaniasis and canine visceral leishmaniasis in the New World.In this paper, we report a similar dot-ELISA for the serodiagnosis of canine leishmaniasis following a previously described procedure.19 Modifications introduced in this assay, like the use of a polyvalent conjugate as protein A and the use of a bio-dot apparat...