Reliability of serological methods for detection of leishmaniasis in Portuguese domestic and wild reservoirs

A direst agglutination test (DAT) and an immunofluorescence (IFAT) were compared for detection of Leishmania infantum infection in 43 dogs and five foxes from Alto-Douro and Arrabida, two known endemic areas in Portugal. In four dogs with proved canine leishmaniasis, both DAT and IFAT showed positive readings (titres ò1:320 and ò1:128). Of 34 samples collected form apparently healthly dogs, ten were positive by both serological tests and eight were serologically positive by one test or the other. Three foxes out of five captured in this area, scored titres indicative of leishmaniasis in both DAT and IFAT. The concordance between DAT and IFAT in all collected samples (48) was 81.25 per cent. Considering these and previous studies in the adjancent Mediterranean areas, the seroprevalence of L. infantum infection in the canine and vulpine populations appear to be high magnitude.

Reliability of serological methods for detection of leishmaniasis in Portuguese domestic and wild reservoirs.

A direct agglutination test (DAT) and an immunofluorescence technique (IFAT) were compared for detection of Leishmania infantum infection in 43 dogs and five foxes from Alto-Douro and Arrábida, two known endemic areas in Portugal. In four dogs with proved canine leishmaniasis, both DAT and IFAT showed positive readings (titres > or = 1:320 and > or = 1:128). Of 34 samples collected from apparently healthy dogs, ten were positive by both serological tests and eight were serologically positive by one test or the other. Three foxes out of five captured in this area, scored titres indicative of leishmaniasis in both DAT and IFAT. The concordance between DAT and IFAT in all collected samples (48) was 81.25%. Considering these and previous studies in the adjacent Mediterranean areas, the seroprevalence of L. infantum infection in the canine and vulpine populations appear to be of high magnitude.

Evora district as a new focus for canine leishmaniasis in Portugal.

On the basis of information acquired from local health authorities in Evora district of Portugal on cases of visceral leishmaniasis (VL), an epidemiology survey study was conducted. To determine the prevalence of anti-Leishmania antibodies in the local human and canine populations residing in Evora town and 14 adjacent villages, blood samples collected from 885 children and 3,614 dogs were tested in a direct agglutination test (DAT). Seropositivity for Leishmania parasite obtained by DAT in both endemic populations was further confirmed by an enzyme-linked immunosorbent assay (ELISA) and immunofluorescence test (IFAT). For identification of the responsible sandfly vector, 79 biotopes within the study areas were surveyed. In the infantile population assessed, none of the children screened showed an antibody level indicative (titer, > = 1:3200) of visceral leishmaniasis in the DAT. However, agglutinating antibody rates ranging from 0.7% to 6.9% were obtained in dogs residing in Evora and 11 adjacent villages. Concordant seropositivity of 94.04% was obtained by ELISA and IFAT in the same canine population (141) identified by DAT. Of the 159 sandflies captured, 67 were identified as Phlebotomus sergenti; 15, as P. ariasi; 58, as P. perniciosus; and 19, as Sergentomyia minuta. Unlike the results previously reported in Alto-Douro and Algarve districts of Portugal, as compared with the other three species, P. sergenti appears to be more abundant in Evora district.(ABSTRACT TRUNCATED AT 250 WORDS)

[Canine leishmaniasis in the region of Enfidha (Central Tunisia). Assessment of seroprevalence with direct agglutination (DAT) and indirect immunofluorescence (IFAT)]. / La leishmaniose canine dans la région d'Enfidha (Tunisie centrale). Estimation de la séro-prévalence par agglutination directe (DAT) et immunofluorescence indirecte (IFAT).

In order to assess canine leishmaniasis prevalence rate in Enfidha area, considered to be the most important kala-azar focus in Sousse Governorate, a serological survey was carried out in 6 localities. 265 sera were examined by DAT and IFAT. 16 (6.03%) showed positive results for anti-leishmania antibodies with significant variations according to the locality. A fairly DAT-IFAT good correlation was observed.

A killing disease epidemic among displaced Sudanese population identified as visceral leishmaniasis.

A fatal disease epidemic affected the Bentiu area in southern Sudan and led to a mass migration of the Nuer tribe searching for treatment. The initially available information revealed a high mortality rate due to a possible occurrence of tuberculosis, malaria, enteric fever or visceral leishmaniasis (VL). Serological screening of 53 of the most severely affected patients in an enzyme-linked immunosorbent assay (ELISA) or an improved direct agglutination test (DAT) revealed positivity for VL. In 39 of those patients, diagnosis was confirmed by identification of Leishmania donovani amastigotes in lymph node or bone-marrow aspirates. In a total of 2714 patients observed, 1195 (44.0%) had clinical symptoms suggesting VL: DAT positive titers (1:3200-greater than or equal to 1:12800) were obtained in 654 (24.1%), of whom 325 were confirmed parasitologically. Forty-two VL cases died before or during treatment, giving a mortality rate of 6.4%. Among the intercurrent infections diagnosed in the VL population (654), respiratory involvements (31.7%) and malaria (10.7%) were most prevalent. With the exception of four (0.6%), all other VL patients (509) responded readily to sodium stibogluconate. The factors initiating the outbreak are discussed. Malnutrition and nomadic movements to potential VL endemic areas appeared to be the most important. HIV infection as a possible predisposition seemed remote considering the clinical and epidemiological similarity to VL occurring in East Africa, adequate humoral response in DAT, and immediate positive response to specific anti-Leishmania chemotherapy.