A modified agglutination test for the diagnosis of Besnoitia besnoiti infection

Abstract

Bovine besnoitiosis is caused by Besnoitia besnoiti, an obligate intracellular apicomplexan parasite. Affected animals present cutaneous and systemic manifestations and the disease may lead to considerable economic losses. Although generally associated to tropical and subtropical areas, bovine besnoitiosis is now considered an emergent disease in Europe, due to the increasing number of new cases and apparent geographical expansion. In this study we evaluated the performance of a modified agglutination test (B-MAT) in the serodiagnosis of bovine besnoitiosis in comparison to the indirect immunofluorescent-antibody test (IFAT). To establish optimal protocol conditions we used bovine sera with a known infection status for B. besnoiti infection. Positive animals (n=36) presented B. besnoiti dermal cysts and anti-B. besnoiti specific antibodies, as determined by the indirect immunofluorescence test (IFAT). Negative animals (n=103) were from non-endemic areas in Portugal and negative by the IFAT. From here, we evaluated the sensitivity and specificity of the B-MAT relative to the IFAT with a panel of sera from herds with history of bovine besnoitiosis in Portugal, Spain and France (n=402), using three serum dilutions (1:80, 1:160, 1:320). Considering the positive cut-off at 1:160 serum dilution, the B-MAT showed an almost perfect test agreement with the IFAT; (κ=0.968; 95% CI: 0.941-0.996) with a relative sensitivity of 97.2% (95% CI: 94.1-100%) and a relative specificity of 99.3% (95% CI: 98.4-100%). As a simple and inexpensive technique the B-MAT represents a valuable tool for the diagnosis and study of the epidemiology of bovine besnoitiosis.

An Inter-Laboratory Comparative Study of Serological Tools Employed in the Diagnosis ofBesnoitia besnoitiInfection in Bovines

“…The success of this kind of comparative study evidences the need for further validation of future tests, such as the sensitive and specific recently published agglutination test developed by Waap et al. (2011).…”

A review on bovine besnoitiosis: a disease with economic impact in herd health management, caused byBesnoitia besnoiti(Franco and Borges, )

“…The direct agglutination test, based on the complex formation of formalin-treated parasites in the presence of diluted serum containing specific IgG antibodies, has been used for the diagnosis of closely related apicomplexans such as T. gondii (Fulton and Turk, 1959) and N. caninum (Packham et al 1998; Romand et al 1998). Waap et al (2011) developed a modified agglutination test for B. besnoiti. This method avoids the use of secondary host-specific antisera, and can thus be used to test different species which may be implicated in the life cycle and could therefore specifically contribute to the elucidation of the definitive host for B. besnoiti.…”

Eerste bevestigd geval van boviene besnoitiose in België bij een ingevoerde stier

“…An indirect fluorescence antibody test (IFAT) (Shkap et al, 2002) is considered the gold standard for serology. Alternatively, a modified direct agglutination test developed by Waap et al (2011) or western blotting (Schares et al, 2010) can be used. Western blotting has been recommended as a confirmation test in combination with other methods (García-Lunar et al, 2013).…”