Katarína Reiterová

The first finding of Neospora caninum and the occurrence of other abortifacient agents in sheep in Slovakia

Neosporosis is an infection of animals caused by an intracellular coccidian parasite, Neospora caninum, closely related to Toxoplasma gondii. The parasite is one of important abortifacient agents of bovine abortions worldwide. The aim of the study was to detect the prevalence of anti-Neospora antibodies in dairy aborting sheep from two eastern Slovak regions and to compare it with the occurrence of other potential abortifacient agents. Sera of 382 sheep, mainly the Improved Valachian and Merino breed, were tested for the presence of anti-Neospora and anti-Toxoplasma antibodies by ELISA, anti-Leptospira sp. by micro-agglutination-assay and anti-Chlamydophila antibodies using the complement fixation test. The mean seroprevalence of N. caninum was 3.7% and of T. gondii, 24.3%. This phenomenon of higher susceptibility of sheep to T. gondii is in the opposite of N. caninum infection in cattle. Anti-Leptospira antibodies were observed in 2.9% of serum samples with titres from 800 to 1600, whereas IgG antibodies against Chlamydophila abortus were found in 13.6% with titres from 64 to 1024. Half of N. caninum positive sera were simultaneously positive for T. gondii and one sample for C. abortus. From examined abortifacient agents the most important, from the frequency point of view, were toxoplasmosis (24.3%) and chlamydiosis (13.6%). No significant association between the frequencies of the abortions and mean seroprevalence of the abortifacient agents in Kosice region was determined. Likewise, no significant differences between the mean seroprevalence of neosporosis and toxoplasmosis in the two regions were detected. The first survey of neosporosis in aborting sheep from eastern Slovakia revealed a low prevalence resulting in a lower impact on reproduction losses in these small ruminants.

The First Finding of Echinococcus multilocularis in Dogs in Slovakia: An Emerging Risk for Spreading of Infection

Alveolar echinococcosis, caused by the metacestode Echinococcus multilocularis, is a zoonosis of public health significance. Apart from red foxes, other carnivore species can also serve as definitive hosts of this parasite. This study aimed to determine the occurrence of E. multilocularis in dogs in the Slovak Republic and identify risk factors for acquiring the infection. Out of 289 dogs examined, E. multilocularis was detected in eight samples (2.8%). Positive results were observed in shepherd dogs (12.5%), guard dogs (7.1%), hunting dogs (2.4%) and in one dog with unknown usage (2.5%). Catching rodents and feeding with raw viscera were confirmed to be the most important risk factors for E. multilocularis infection. On the contrary, the way of dog use, frequency of going to the rural areas, the age and gender of animals seem not to be risk factors for infection. No significant association was observed between the positivity of dogs coming from high endemic or non‐endemic regions. This is the first report of E. multilocularis in dogs in the Slovak Republic that confirms substantial contribution of dogs to the transmission of the tapeworm in this territory and urges the necessity of prophylactic measures for dog owners.

Neospora caninum, potential cause of abortions in dairy cows: the current serological follow-up in Slovakia.

Neosporosis is considered to be a contributing risk factor for abortions in dairy cows and other farm animals and has negative economic impact on their breeding. In respect of the rapid spread of neosporosis in herds throughout the world, our aim was to detect the prevalence of anti-Neospora antibodies in cows post-abortion (PA) (PA Group n=716) and in cows without any reproduction problems (Control Group n=247) on large breeding farms from Eastern Slovakia. The overall mean seropositivity in PA Group (20.1%) was significantly higher (p<0.0001) in comparison with the Control Group (2.3%), and this demonstrates the causal dependency of abortions on neosporosis. On farms from south-east region, 15.6% of cows were seropositive on average ranging from 7.8% to 25.8% in different districts. In the northern region, significantly (p=0.0002) higher 26.2% mean seropositivity was detected. The seroprevalence in different districts ranged from 2.9% to 39.4%. In the PA Group a high seropositivity to infectious bovine rhinotracheitis (41.5%) and sporadic occurrence of Q-fever, leptospirosis and chlamydiosis was also detected. From 11 Toxoplasma-seropositive cows, only one animal was simultaneously positive to Neospora. The relatively high prevalence rate in cows warrants the attention and a need of surveillance in Slovak herds. A better knowledge of epidemiology of this etiological agent and the mechanisms of its transmission may help in the introduction of more effective preventive and control measures.

The role of wild boars (Sus scrofa) in circulation of trichinellosis, toxocarosis and ascariosis in the Slovak Republic

SummaryWild boars (Sus scrofa) can play a significant role in circulation and maintenance of certain parasites in the environment. The aim of this study was to determine the seroprevalence of trichinellosis, toxocarosis and ascariosis in wild boars hunted in the Slovak Republic in 2003 and 2004. Anti-Trichinella antibodies were detected in 1.3 % out of 1035 wild boars investigated. No significant differences were observed regarding the positivity of wild boars according to age and sex in both years. The examination of 1173 wild boars for anti-Toxocara antibodies revealed 7.2 % seropositive individuals. Anti-Ascaris antibodies were detected in 6.1 % out of 411 animals examined. Both, anti-Trichinella and anti-Toxocara antibodies were determined in 0.6 % cases. Presence of anti-Trichinella and anti-Ascaris antibodies was recorded in 0.8 % animals. Concurrent infection caused with Toxocara and Ascaris was observed in 1.5 % individuals. This study concentrates on the role of wild boars in circulation and on the maintenance of trichinellosis, toxocarosis and ascariosis in the Slovak Republic.

Occurrence and genetic characterization of Toxoplasma gondii in naturally infected pigs

The protozoan Toxoplasma gondii is an obligate intracellular parasite that infects a wide range of warm-blooded vertebrates. The data about the occurrence of toxoplasmosis in slaughter pigs in the Slovak Republic are still missing. The aim of our study was to estimate the prevalence of toxoplasmosis in pigs from Slovakia during the period of 2006–2010 by ELISA and PCR methods. In sera of 970 slaughter pigs, 2.16% seropositivity to T. gondii was detected. In tissue samples of seropositive pigs the presence of T. gondii DNA was confirmed. In six monitored Slovak regions the seropositivity varied between 1.11 and 3.48%. The statistically significant differences were recorded between the Košice and Prešov region. The seroprevalence of toxoplasmosis in sows (4.26%) was two times higher than that in slaughter pigs (2.06%) (OR = 2.12; 95% CI = 0.48–9.36). Presence of Toxoplasma gondii in tissues of seropositive pig isolates was confirmed by TGR1E and B1 genes and analysis of DNA polymorphism at SAG2 and ROP1 genes revealed the presence of virulent strain of genotype I in 85.7% of infected pigs and an avirulent strain (genotype II) in 14.3% of pigs.

Trichinella spiralis-outbreak in the Slovak Republic.

Background:Trichinellosis is a zoonosis caused by nematode worms of the genus Trichinella and acquired through the consumption of raw or undercooked meat or meat products that harbour parasite larvae. The present report was designed to evaluate the course and circumstances surrounding the trichinellosis outbreak that occurred due to consumption of pork from a backyard pig in the southwest area of Slovakia in 2001.Patients and Methods:Patients suspected of acquiring infection were serologically examined by ELISA, sera of patients with symptoms of clinical trichinellosis were additionally tested by Western Blot. In symptomatic patients haematological and biochemical parameters were assessed on day 45 p.i.Results:An epidemiological investigation showed that the disease was linked to the consumption of infected pork and/or smoked pork products and affected the household members of four families. Out of 23 persons who had consumed the infected meat, 11 showed anti-Trichinella IgA, IgM and IgG antibodies in their sera by an ELISA against somatic and excretory-secretory antigens. Six of them developed clinical symptoms. Sera from symptomatic patients recognised bands of 64, 47, 45 and 43 kDa of crude T. spiralis antigens by Western blot. Using multiplex PCR analysis, parasite larvae isolated from pork were identified as T. spiralis, rarely occurring in Slovakia.Conclusion:The outbreak of human trichinellosis in an area where feral animals have been previously considered free of Trichinella was unexpected. Following the suspicion of trichinellosis being addressed, larvae were detected in meat and meat products from pig and the course of disease in patients was successfully controlled and managed.

Prevalence estimation and genotypization of Toxoplasma gondii in goats

In this study we aimed to determine seroprevalence of antibodies against Toxoplasma gondii and parasite DNA presence in the milk of goats from a farm in eastern Slovakia. Anti-Toxoplasma antibodies were detected in 43 goat sera out of 87 examined (49.43%). The highest prevalence was recorded in the goats aged more than 72 months (76.19%; OR = 4.62; 95% CI = 1.51-14.14) and the lowest one in animals aged from 12 to 36 months (17.65%; OR = 0.09; 95% CI = 0.03-0.27). Statistically significant correlation (P < 0.0001) was found between the prevalence of antibodies against T. gondi and animal age in comparing age groups - goats up to 36 months of age and above 37 months of age. The presence of T. gondii DNA was confirmed in 32.56% of milk samples using molecular methods. Based on the DNA polymorphism at the SAG2 locus of T. gondii we identified the goats as being infected with genotype II of T. gondii. Presence of DNA in milk refers to the risk of human infection through consuming raw milk.

First molecular detection of Neospora caninum in European brown bear (Ursus arctos)

Neospora caninum is an important intracellular protozoan parasite with an affinity to the central nervous system of many animals and a major causative agent of repeated abortions in cattle. In total, 45 muscle, liver, or spleen samples of brown bear sampled in different locations of Central Slovakia were examined by PCR. Genotyping of N. caninum was based on amplification of Nc-5 gene and ITS1 rRNA fragments and subsequent sequencing. Presence of N. caninum DNA was confirmed in 24.4% (11/45) of tested animals. The results obtained in study confirm the first molecular evidence of N. caninum DNA in European brown bear (Ursus arctos) in Slovakia.

Humoral immune response of mice infected with low doses of Trichinella spiralis muscle larvae.

Serological techniques are frequently used to detect parasite status and to monitor epidemiology and disease prevalence in important reservoir hosts of zoonotic diseases. Small mammals present the most important link in the epidemiological chain in the spread of trichinellosis. In experimental studies, high infective doses are used to provoke strong immune response of laboratory animals. Wild animals, however, could be infected with very low numbers of Trichinella larvae. The aim of this work was to reveal the size of infective doses that can evoke an adequate immune response with detectable level of specific antibodies in mice. Sixty inbred (Balb/c) mice were infected with 50 L1 and 60 outbred (ICR) mice were infected with 5 L1 T. spiralis. The total larval burdens (TLB) in the intestinal and muscle phases, reproductive capacity index (RCI), and the kinetics of development of specific antibodies by iELISA with different conjugates were determined. In the first 10 days post infection (dpi), more adults were found in the intestines of inbred mice. In both mice strains, the first muscle larvae were observed at 20 dpi. The RCI was significantly higher in outbred mice. Sero-conversion of IgM antibodies was detected at 30 dpi. The IgG antibodies appeared at 40 dpi in inbred mice, and at 50 dpi in outbred mice. Using a polyvalent conjugate, the earliest sero-conversion was recorded at 30 dpi. Antibody levels increased until the end of the experiment (80 dpi). Our results support the suitability of ELISA in large epidemiological surveys to detect low-level infection in naturally infected small mammals, and are useful in epidemiological studies of the sylvatic circulation of trichinellosis to determine likely modes of transmission.

Influence of anthelmintic baits on the occurrence of causative agents of helminthozoonoses in red foxes (Vulpes vulpes)

SummaryRed fox (Vulpes vulpes) presents major wildlife reservoir of parasitozoonoses, transmissible to humans and domestic animals. The study was aimed to find out the effect of anthelmintic baits on the occurrence of Echinococcus multilocularis and other intestinal helminths in red foxes. In two bait areas (B1 and B2) 20 baits per km2 were distributed monthly between August 2004 and April 2005. Fox fecal samples were collected in both bait areas and two control areas (C1 and C2) between August 2004 and August 2005. In bait area B1 the decrease of parasite species number, decrease of their prevalence and prevalence of E. multilocularis was observed. No significant decline was observed in bait area B2, probably due to consumption of baits by wild boars. Bait distribution represents the possibility of reduction of environmental contamination with parasites and their propagation stages. Especially on the periphery of towns and villages and in recreational areas it seems to be suitable way of human health protection.