MAT cross-reactions or vaccine cross-protection: retrospective study of 863 leptospirosis canine cases

Geneviève André-Fontaine,Laetitia Triger

doi:10.1016/j.heliyon.2018.e00869

Abstract

Dogs are naturally exposed to numerous pathogenic serogroups. Leptospirosis vaccines are claimed to afford a clinical protection restricted to the serogroups of which they are composed. ObjectivesDogs exhibiting liver and kidney injury were suspected of having leptospirosis. The purpose of this study was to compare the microscopic agglutination test (MAT) results in naive and vaccinated dogs experiencing leptospirosis outcomes. Only MAT-positive animals were included in the study. MethodsOver five years, 3 512 dogs were suspected of having leptospirosis. For each case, biochemical parameter results were recorded. Leptospirosis involvement was investigated by MAT performed against 6 major serogroups (Icterohaemorrhagiae, Canicola, Australis, Autumnalis, Grippotyphosa and Sejroë). MAT-positive results confirmed leptospirosis cases in 147 naïve dogs and in 580 fully vaccinated dogs. Serological titres of agglutinating antibodies were related to the severity of liver and kidney failure. ResultsThe most prevalent outcome of leptospirosis in unvaccinated dogs was liver failure (57.8%) compared to 51.7% for kidney disease, but the most severe onset (90.8%) was found among the cases of acute kidney injury compared to the severe (42.3%) hepatitis cases. In dogs vaccinated by bivalent Icterohaemorrhagiae and Canicola bacterins, hepatitis decreased from 57.8 to 46.5% and acute kidney injury from 51.7 to 21.6%. The decrease was shown in leptospirosis cases induced by field strains belonging to the six most prevalent serogroups, including the 4 serogroups heterologous to the vaccine. ConclusionCommon vaccination was efficient in decreasing hepatitis and kidney failure induced by field Leptospira spp infection regardless of the MAT-prominent serogroup and limited the disease severity in the remaining cases.

Highlights

Acute leptospirosis with fatal outcome is commonly recorded in dogs, which are highly receptive to this type of infection [1]
From the 997 microscopic agglutination test (MAT)-positive dogs, 863 leptospirosis cases were MAT confirmed according to the decision algorithm
Several limits of this study performed in privately owned pets exposed to field strains of pathogenic Leptospira species throughout France [17] depended of the selected criteria

Summary

Introduction

Acute leptospirosis with fatal outcome is commonly recorded in dogs, which are highly receptive to this type of infection [1]. More than 8 pathogenic serogroups have been detected worldwide in canines [2, 3, 4, 5]. The agglutinating antibodies raised against these pathogenic serogroups were shown by the serological microscopic agglutination test (MAT) from the tenth day after disease onset. MAT has been widely used to confirm leptospirosis cases [2, 6], indicating the most infectious serogroups. Canine vaccination was performed worldwide by bivalent whole cell vaccines, including the two major serogroups, Icterohaemorrhagiae (IH) and Canicola (CAN). The bacterins trigger agglutinating antibodies, which afford clinical protection. This protection is believed to be restricted to the composing serogroups of the vaccine [3]. The goal of this study was to estimate the clinical protection afforded by vaccination in the field

Objectives

Methods

Results

Conclusion