Seroepidemiological Research of Canine Monocytic Ehrlichiosis in the Autonomous Province of Vojvodina, Serbia

Background: Monocytic ehrlichiosis is an important disease in canine pathology and is present worldwide and has a potentially lethal outcome. This infection as a 'new' infective disease of dogs and people and it has not been sufficiently researched, especially from the aspect of clinical picture, pathogenesis, diagnostics and differential diagnostics. The aims of this seroepidemiological research of the E. canis infection with dogs are to determine the values of G class antibodies prevalence to E. canis antigens, also to determine a agreement of positive serological findings between two immunodiagnostic tests (iELISA and IFAT), and to make an overview of the epidemiological characteristics of this canine infection. Materials, Methods & Results: One hundred dogs were involved in the seroepidemiological research of the E. canis infection. These dogs were from the City of Novi Sad area and its outskirts, Autonomous Province of Vojvodina, Serbia. The epidemiological survey of the closed type has been used in the research. The survey has been conducted with all of the dogs involved in this research. Apart from identifying veterinary practices and the patients (breed, sex, age), the survey was designed to collect data ab out the tick bites (first bite or a repeated one); the number of the removed ticks; the dogs' lifestyles and information on whether the dogs had been abroad. An overall of 62 ticks were collected from the bodies of these dogs. By applying the screening iELISA test, the seroprevalence of class G specific antibodies was determined with dogs to E. canis antigens in 25%, while 75% of dogs were negative to the presence of specific antibodies of IgG class to E. canis. Out of 25 seropositive dogs, with antibodies to E. canis discovered through iELISA test, 12 (48%) dogs were in contact with ticks for the first time, while the repeated contact with ticks was experienced by 9 (36%) dogs. For 4 (16%) dogs, the owners negated that their dog had been bitten by a tick. Upon the application of a confirming IFAT, a seroprevalence was determined of specific class G antibodies with dogs to E. canis antigens in 16%, while 84% were negative to the presence of specific antibodies of IgG class antibodies to E. canis. Out of 16 seropositive dogs, in which antibodies were discovered with IFAT to E. canis, 9 (56%) dogs had been in contact with ticks for the first time, while 4 dogs (25%) had repeated contacts with ticks. For 3 dogs (19%), the owners negated that ticks had bitten their dogs. Through a statistical processing of the results gained from the applied immunodiagnostic tests, a moderate agreement (Kappa value of 0.48) was determined. In the group of dogs that had been bitten by a tick, three types were determined: Dermacentor marginatus, Rhipicephalus sanguineus and Ixodes ricinus. Overall 35 ticks of Dermacentor marginatus ticks were replaced from the dogs' bodies just as were 15 Rhipicephalus sanguineus ticks and 12 Ixodes ricinus ticks. Discussion: The determined values of the seroprevalence in our country (iELISA - 25% and IFAT - 16%) are in harmony with the acquired values in other countries with warm climate. The values of seroprevalence determined in this research point to the fact that this disease must be taken into consideration in everyday health protection of dogs, especially after a registered tick bite within a differential diagnostics procedure.