TDK conference 2017

Bovine anaplasmosis is an infectious, non-contagious, tick-born disease caused by the intraerythrocytic pathogen Anaplasma marginale. The organism has a global distribution, and in affected animals the infection may result in anemia, icterus, fever, abortions and death, thus it is a pathogen of great economical impact of mainly tropical and subtropical regions. Due to global warming the distribution of vectors is changing, consequently the disease will mean higher risk potential in Hungary too, mainly in cattle herds grazing tick-infested pastures. Recent publications on Hungarian cases described acute outbreaks of anaplasmosis, proving the infection only of the investigated herd and area. To our recent knowledge no data has been published on distribution of anaplasmosis in Hungary. The aim of this study was to investigate the geographic prevalence of Anaplasma marginale infection, and to evaluate the applied diagnostic procedures.

Between April and August of 2017 samples were collected from 32 grazing cattle (Bos taurus) and one buffalo (Bos bubalus) herd representing all regions of Hungary. Overall 564 individual blood samples were analysed by indirect ELISA (iELISA) and pooled for PCR assays investigating different genomial regions (16S DNS, msp5, msp4) of the organism. Relevant data of herds were collected supporting evaluation of iELISA and PCR results.

Out of the 33 herds in 29 cases (87,88%) no clinical manifestation of anaplasmosis was recognised, in one case (3,03%) disease was suspected, in another one (3,03%) infection was proved and in 2 cases (6,06%) no related data was provided. In contrast of this 23 (69,69%) of the 33 herds were PCR positive and antibodies against Anaplasma marginale could be detected in 31 herds (93,94%). Regular antiparasitic mesures against ectoparasites are common among herds (20/33) but have no relevant influence on the prevalence of vectors and the pathogen.

The high percentage of Anaplasma marginale infection and the low numbers of related clinical cases suggest endemical stability in the concerned herds and endemicity of anaplasmosis in Hungary. Our results call attention to risk potential of clinical anaplasmosis both in immunsupressed and in imported and commingled naïve individuals. To our best knowledge this is the first investigation on prevalence of Anaplasma marginale from all regions of Hungary.