Wild boar (Sus scrofa) – reservoir host of Toxoplasma gondii, Neospora caninum and Anaplasma phagocytophilum in Slovakia

Abstract

In Central Europe the wild boar population is permanently growing and consequently Cf foodborne infections. In this study serological and molecular detection of Toxoplasma gondii and Neospora caninum in wild boars was evaluated. Moreover, same samples were screened for the presence and genetic variability of tick-borne bacterium Anaplasma phagocytophilum. Blood samples collected from 113 wild boars from Southern Slovakia were examined for antibodies to T. gondii by indirect and to N. caninum by competitive ELISA. The presence of parasitic DNA in blood samples was determined by standard or real time PCR techniques. Antibodies against T. gondii and N. caninum were detected in 45 (39.8%) and 38 (33.6%) animals, respectively. Females were more frequently infected for both pathogens than males. The high seropositivity against both coccidia indicates a permanent occurrence of these pathogens in the studied locality. T. gondii DNA was confirmed in five seropositive boars (4.4%) and N. caninum in 23 blood samples (20.4%). Three out of 23 N. caninum PCR positive animals did not show seropositivity. Three out of 113 blood samples of wild boars were positive for A. phagocytophilum (2.7%). The obtained A. phagocytophilum sequences were 100% identical with GenBankTM isolates from Slovak dog (KC985242); German horse (JF893938) or wild boar (EF143810) and red deer (EF143808) from Poland. Coinfections of T. gondii with N. caninum and N. caninum with A. phagocytophilum were detected in single cases. Results suggest a potential zoonotic risk of toxoplasmosis transmission to humans and the spread of neosporosis to farm animals.

Diverse tick-borne microorganisms identified in free-living ungulates in Slovakia

“…The 88.9% infection rate in mouflon is higher than the values previously reported from Slovakia [57] and other European countries, where the prevalences ranged from 4% to 74.4% [42, 106, 110, 111]. The lower infection rate in wild boar compared to that estimated in cervids and mouflon supports former findings from Slovakia (0–16.7%) [24, 57, 112, 121] as well as from other sites in central and western Europe (0–14.3%) [28, 58, 105, 106, 110, 122–127]. However, it is necessary to note that, in addition to geographical location and habitat, the reported variations of prevalence could be due to the application of molecular detection methods of different sensitivity.…”

“…Identification of the 16S rRNA gene variant “B” (the prototype variant of the HGA agent) and of groEL sequences that are 100% identical with the HGA agent isolated from human blood from Slovenia (AF033101) in wild boars suggests that they could be potential reservoirs of the HGA strain in the study area. To our knowledge, this is the first confirmed occurrence of this strain in wild boars from Slovakia, whereas sequences of former GenBank isolates from Slovak wild boars were identical with sequences from wild ruminants, horses, dogs or wild boar and showed a lower degree of identity with the HGA sequence [24, 121]. However, further research is required to find out if wild boars in Slovakia are involved in the enzootic cycle of A. phagocytophilum variants pathogenic to humans.…”

The European Union summary report on trends and sources of zoonoses, zoonotic agents and food‐borne outbreaks in 2015

“…The information reported by the MS in 2015 shows that Toxoplasma exposure occurs in most livestock species across the EU and supports the findings in recent publications on the high incidence of toxoplasmosis in sheep (Bacci et al., ), pigs (Djokic et al., ; Herrero et al., ; Wallander et al., ), goats (Deng et al., ), horses (Aroussi et al., ), small mammals including rodents (Machačová et al., ), pets (Cano‐Terriza et al., ) and wild animals (Formenti et al., ; Reiterova et al., ). However, the high incidence of Toxoplasma in sheep and goats, detected by serological methods, may be partly due to vaccination in these species.…”

The European Union summary report on trends and sources of zoonoses, zoonotic agents and food‐borne outbreaks in 2016

“…Furthermore, as the tissue cysts are not uniformly distributed in the edible tissues, a negative result obtained by a direct detection method in a serologically positive animal, cannot exclude the presence of infectious cysts in other edible portions. Literature data show a high incidence of toxoplasmosis as parasite–animal contacts in sheep (Bacci et al., ), pigs (Djokic et al., ; Herrero et al., ; Wallander et al., ), goats (Deng et al., ), horses (Aroussi et al., ), small mammals including rodents (Machacova et al., ), pets (Cano‐Terriza et al., ) and wild animals (Formenti et al., ; Reiterova et al., ) suggesting that the control of this parasite is extremely difficult and can be reached only for livestock reared under strict housing conditions. A critical review of data on the prevalence of Toxoplasma in pigs shows a 90% decline in Toxoplasma prevalence in commercially marketed pigs over the last two decades (Dubey, ; Davies, ; Bayarri et al., ).…”