Human Mozdok leptospirosis first diagnosed by serum agglutinin-absorption tests in the Slovak Republic.

INTRODUCTION: The serovar Mozdok related leptospirosis in humans were not yet feasibly diagnosed using merely the standard micro-agglutination test (MAT) what was perhaps due to the impossibility to distinguish them from illnesses that are caused by Leptospira strains belonging to other serovars of the serogroup Pomona. On the contrary, leptospires of the Mozdok serovar were cultured from rodents and domestic animals world-wide including Central Europe where only Leptospira strains of the serovars Pomona and Mozdok are known to be present till now. STUDY OBJECTIVE: The aim of the study was to discover if leptospires of Mozdok serovar may cause human leptospirosis that remained hidden till now among infections diagnosed merely by MAT as Pomona illnesses. MATERIAL AND METHODS: The reference Leptospira strains of Pomona and Mozdok serovars (Pomona and 5621), as well as three endemic, and in some tests only two strains of human and pig origin (Simon, S-23, Pöstényi), and two strains of rodent provenance - Apodemus agrarius (M-210/98 and M-71/01) were used for this purpose. First, the endemic strains were assigned to one of the afore-mentioned two serovars by agglutinin cross-absorption tests performed using rabbit immune sera, monoclonal antibodies and random amplified polymorphic DNA methods. Afterwards, twenty-one sera of patients with a Pomona leptospirosis confirmed by MAT were examined by agglutinin absorption test (AAT). RESULTS: Based on the results of the mentioned laboratory method used, the endemic Leptospira strains of human and pig origin could be affiliated to the serovar Pomona, while those of rodent origin were classified as serovar Mozdok strains. Out of the 21 patients sera, an illness caused by the serovar Mozdok strains was found out in 13 cases and a disease caused by serovar Pomona strains in 8 cases. Their differentiation was made on the strength of the following results of AATs: All strains from the serovar Mozdok have completely absorbed antibodies (anti-Pomona and anti-Mozdok) from the tested sera, however following the absorption of these sera with the Pomona strains, high levels of residual antibodies reacting in MAT with the Mozdok strains have still persisted. In this way, it was possible to prove the Mozdok infection in thirteen patients. On the contrary, following the absorption of the sera with the strains of the serovar Pomona, a complete absorption of all antibodies (anti-Pomona and anti-Mozdok) was achieved in seven cases using the strain Simon, and in one case with the strain S-23, whereas after absorption using the Pomona strain, the residual antibodies were still present in all sera, and also in the majority of them when they were absorbed using the strains S-23 and Pöstényi. In this context, the Pomona infection was determined in the case of eight patients. Hence it follows that not all strains of the Pomona serovar were suitable for the AATs. CONCLUSION: The presence of the human Mozdok leptospirosis was confirmed for the first time by the use of the agglutinin absorption test. A clear correlation between the habitat areas of the A. agrarius and the patients who were infected with the strains of the Mozdok serovar was determined.

Fleas (Siphonaptera) in the Nests of Dormice (Gliridae: Rodentia) in Lithuania.

Negative effects of flea (Siphonaptera) parasitism on the host may be expressed in different ways. The aim of this study was to assess distribution of the flea fauna in nests of dormice in Lithuania. Nests of Glis glis (L.), Dryomys nitedula (Pallas), and Muscardinus avellanarius (L.) were collected from nest boxes in 2012 and 2013. Fleas were collected from nests in the laboratory and put into plastic tubes with 70% ethanol. Flea species were identified using morphological keys. From 400 nest boxes, 112 nests of dormice were collected from eight sites from mixed forests of central Lithuania. Twenty-three nests of G. glis were collected from nest boxes, with 16 of them containing 286 fleas belonging to four species: Ceratophyllus sciurorum (Schrank) (259), C. gallinae (Schrank) (23), Hystrichopsylla talpae (Curtis) (3), and Megabothris turbidus (Rothschild) (1). Fourteen nests of M. avellanarius were collected from nest boxes, 4 of which contained 224 fleas belonging to two species: C. sciurorum (221) and C. gallinae (3). Twenty-four nests of D. nitedula were collected from nest boxes, including 17 containing 207 fleas belonging to two species: C. sciurorum (205) and C. gallinae (2). Fifty-one nests of undetermined dormice species also were collected from nest boxes, 12 of them contained 395 fleas belonging to three species: C. sciurorum (374), Ctenophthalmus agyrtes (Heller) (19), and Ctenophthalmus assimilis (Taschenberg) (2). C. sciurorum was a predominant species in the nests of dormice. The occurrence of C. gallinae was documented in Lithuania for the first time.

Empirical evaluation of neutral interactions in host-parasite networks.

While niche-based processes have been invoked extensively to explain the structure of interaction networks, recent studies propose that neutrality could also be of great importance. Under the neutral hypothesis, network structure would simply emerge from random encounters between individuals and thus would be directly linked to species abundance. We investigated the impact of species abundance distributions on qualitative and quantitative metrics of 113 host-parasite networks. We analyzed the concordance between neutral expectations and empirical observations at interaction, species, and network levels. We found that species abundance accurately predicts network metrics at all levels. Despite host-parasite systems being constrained by physiology and immunology, our results suggest that neutrality could also explain, at least partially, their structure. We hypothesize that trait matching would determine potential interactions between species, while abundance would determine their realization.

Small mammals: paratenic hosts for species of Toxocara in eastern Slovakia.

Toxocara spp., an aetiological agent of a serious helminthozoonosis, is a common roundworm of domestic and wild carnivores worldwide. The study aimed to estimate the seroprevalence of Toxocara in small mammals from different localities in eastern Slovakia. Anti-Toxocara antibodies were detected in 6.4% out of 2140 examined animals trapped in eastern Slovakia. Due to their high density and observed high seroprevalence of toxocariasis, Apodemus agrarius, A. flavicollis, Myodes glareolus and Mus spicilegus (10.9, 4.2, 3.6 and 11.2%, respectively) represent important sources of the infection. A significant correlation between type of food and Toxocara positivity was detected: granivores (7.2%) and invertebratophages (7.1%) were positive more frequently than herbivores (2.1%). In the years monitored, cyclic changes of seroprevalence were observed. A higher prevalence of antibodies in the spring was followed by a decrease in summer. In autumn, seroprevalence started to rise and stayed at a similar level through the winter. Seroprevalence of the examined animals confirms their contact with Toxocara spp. and demonstrates the presence of the aetiological agent in the monitored locality. Areas with a high prevalence of infected animals present constant infectious pressure on definitive hosts, thus also increasing infection risk for humans and paratenic hosts. The study confirmed the contact of small mammals with Toxocara spp. and demonstrated the presence and circulation of an aetiological agent in the localities monitored in eastern Slovakia.

Effects of deer density on tick infestation of rodents and the hazard of tick-borne encephalitis. I: empirical assessment.

Tick borne encephalitis (TBE) is endemic to eastern and central Europe with broad temporal and spatial variation in infection risk. Although many studies have focused on understanding the environmental and socio-economic factors affecting exposure of humans to TBE, comparatively little research has been devoted to assessing the underlying ecological mechanisms of TBE occurrence in enzootic cycles, and therefore TBE hazard. The aim of this study was to evaluate the effect of the main ungulate tick hosts on the pattern of tick infestation in rodents and TBE occurrence in rodents and questing adult ticks. In this empirical study, we considered three areas where endemic human TBE occurs and three control sites having no reported human TBE cases. In these six sites located in Italy and Slovakia, we assessed deer density using the pellet group count-plot sampling technique, collected questing ticks, live-trapped rodents (primarily Apodemus flavicollis and Myodes glareolus) and counted ticks feeding on rodents. Both rodents and questing ticks were screened for TBE infection. TBE infection in ticks and rodents was positively associated with the number of co-feeding ticks on rodents and negatively correlated with deer density. We hypothesise that the negative relationship between deer density and TBE occurrence on a local scale (defined by the minimum overlapping area of host species) could be attributed to deer (incompetent hosts) diverting questing ticks from rodents (competent hosts), know as the 'dilution effect hypothesis'. We observed that, after an initial increase, the number of ticks feeding on rodents reached a peak for an intermediate value of estimated deer density and then decreased. Therefore, while at a regional scale, tick host availability has already been shown to be directly correlated with TBE distribution, our results suggest that the interactions between deer, rodents and ticks are much more complex on a local scale, supporting the possibility of a dilution effect for TBE.

Serological and molecular detection of Borrelia burgdorferi sensu lato and Anaplasmataceae in rodents.

The presence of Anaplasma spp. and Borrelia burgdorferi sensu lato in rodents from Eastern Slovakia were followed by serological and molecular methods. The seroprevalence for Borrelia was detected in 16.6 %, for Anaplasmataceae (APT) in 13.2 % and co-occurrence of Borrelia and APT in 7.5 %. Out of 110 ear biopsies of rodents, 5 were B. afzelii-positive. Five biopsies tested positive with the Ehr521-Ehr747 primers amplifying all the members of the family APT. A. phagocytophilum was detected in 1.8 %, 2.7 % were infected with Anaplasma-like organisms. Co-occurrence of Borrelia and Anaplasma in ear biopsies was found in 1.8 %. The circulation of both Borrelia and Anaplasma in the region of Eastern Slovakia was confirmed.

Simple epidemiological model predicts the relationships between prevalence and abundance in ixodid ticks.

We tested whether the prevalence of ticks can be predicted reliably from a simple epidemiological model that takes into account only mean abundance and its variance. We used data on the abundance and distribution of larvae and nymphs of 2 ixodid ticks parasitic on small mammals (Apodemus agrarius, Apodemus flavicollis, Apodemus uralensis, Clethrionomys glareolus and Microtus arvalis) in central Europe. Ixodes trianguliceps is active all year round, occurs in the study area in the mountain and sub-mountain habitats only and inhabits mainly host burrows and nests, whereas Ixodes ricinus occurs mainly during the warmer seasons, occupies a large variety of habitats and quests for hosts outside their shelters. In I. ricinus, the models with k values calculated from Taylor's power law overestimated prevalences. However, if moment estimates of k corrected for host number were used instead, expected prevalences of both larvae and nymphs I. ricinus in either host did not differ significantly from observed prevalences. In contrast, prevalences of larvae and nymphs of I. trianguliceps predicted by models using parameters of Taylor's power law did not differ significantly from observed prevalences, whereas the models with moment estimates of k corrected for host number in some cases under-estimated relatively lower larval prevalences and over-estimated relatively higher larval prevalences, but predicted nymphal prevalences well.

Circulation of Toxocara spp. in suburban and rural ecosystems in the Slovak Republic.

Toxocara spp., the common roundworms of domestic and wild animals, are the causative agents of larval toxocarosis in humans. The migration of Toxocara larvae in men causes clinical syndrome, called larva migrans visceralis or larva migrans ocularis. The objective of the present work was to investigate the prevalence of toxocarosis in dogs, red foxes (Vulpes vulpes), and small mammals in the Slovak Republic. T. canis infection was diagnosed in 16.6% out of 145 dogs examined. Young animals showed significantly higher positivity (50.0%) than adults (12.4%). Coprological investigation of 310 red foxes showed 8.1% prevalence of T. canis, with higher occurrence in animals from rural conditions (8.6%) than from suburban environment (5.6%). Out of 710 small mammals examined, anti-Toxocara antibodies were detected in 7.7% of the animals. The most frequently seropositive species was Apodemus agrarius (15.9%). Seropositivity of small mammals from suburban localities was higher (10%) compared with rural areas (5.8%), with adult animals exhibiting higher seropositivity (8.0%) than subadults (6.8%). Our results have confirmed the importance of dogs, red foxes and small mammals in circulation of this serious helminthozoonosis in suburban and rural ecosystems.

Is sex-biased ectoparasitism related to sexual size dimorphism in small mammals of Central Europe?

Sexual size dimorphism (SSD) in mammals reveals the extent of sexual selection, which may in turn explain why males are often more infected by parasites than females and that parasites may contribute to the association between SSD and male-biased mortality. Here, we investigated the relationship between SSD in small mammals of Central Europe and the differences in sex infection by fleas. A comparative analysis was conducted for 10 species of rodents and insectivores. We found that males harbour higher flea species richness than females and that the abundance of fleas is higher in males than in females. This difference is not related to male-biased density. However, contrary to our hypothesis, we found that an increase in SSD is not related to an increase in male infection by fleas compared with female infection. We discuss our results in term of sex-differences in immunocompetence and/or sex-differences in behaviour.

Immunoglobulin G antibodies to Borrelia burgdorferi in game animals and small mammals in eastern Slovakia.

In a survey of game animals and small mammals, the sera of 185 animals were examined for the presence of immunoglobulin G antibodies to the spirochete Borrelia burgdorferi sensu lato, which causes Lyme borreliosis. These animals comprised 59 fallow deer (Dama dama), 56 mouflons (Ovis musimon) and 70 small mammals of six different species. The sera of the fallow deer and the mouflons were examined by indirect haemagglutination assay. The sera of the small mammals were examined by modified enzyme-linked immunosorbent assay, which is available in a commercial kit. The sera of the 59 fallow deer demonstrated positivity of 40.77% (titres 1:40-1:80). The 56 mouflons demonstrated seropositivity of 17.8% (1:40-1:80). The sera of the small mammals were highly positive in the yellow-necked field mouse (Apodemus flavicollis) at 42.1% (titres 1:200-1:1,600), followed by the bank vole (Clethrionomys glareolus) at 14.3% (1:400-1:800), the common vole (Microtus arvalis) at 12.5% (1:200) and the black-striped field mouse (A. agrarius) at 10.0% (1:200-1:400-800). The authors also report the rate of infestation of these small mammals by the tick Ixodes ricinus, as these mammal species are potential reservoirs for this vector. The study focuses on the relationship between the possibility of infestation by I. ricinus and the reservoir competence of the different species under study, as well as the possible spread of disease. The detected rate of seroprevalence indicates that all the investigated animals have had contact with infected ticks.

[Morphometric features of tarsus in Dermacentor reticulatus (Fabricius, 1794) (Acari: Ixodida: Ixodidae) larvae from Polish and Slovakian populations]. / Cechy morfometryczne stóp larw Dermacentor reticulatus (Fabricius, 1794) (Acari: Ixodida: Ixodidae) z populacji Polskiej i Slowackiej.

Dermacentor reticulatus is widely distributed dangerous tick that usually lives in the river valleys, boggy forests, meadows, and wooded pastures. Tick populations from various regions may exhibit morphological differences. In our study we compared morphometric features of tarsus in larvae D. reticulatus from Polish and Slovakian populations. I tarsus width, III tarsus length, and length of dorsal setae of I tarsus were significantly higher in Polish populations. Indices of width to length of tarsus I and tarsus III were also significantly different in both populations. The other examined morphologic features were similar, what may result from the same environmental conditions of both populations.

[Relation between characteristics of the small mammal population and occurrence of Leptospira antibodies]. / Vztah struktúry populácií drobných cicavcov a výskyt protilátok proti leptospíram.

Five rodent species (Apodemus flavicollis, A. agrarius, A. microps, Clethrionomys glareolus and Microtus arvalis) were examined serologically for presence of antibodies to leptospira. Small mammals were caught in several areas of eastern Slovakia, an important part of host material coming from East Slovakian Lowland (45.7%), south part of Kosice basin (26.5%) and Slovak carst (10.1%). Serological examinations were used by Kmety and Bakoss (1978), the sexual condition of rodents were ascertained after Pelikán (1965). Altogether, 2,113 individuals of rodent species were examined during five years (1991-1995), antibodies to leptospires were demonstrated in 5.02% of examined hosts. In examined hosts antibodies to six serovars of leptospira (Leptospira grippothyphosa, L. sejroe, L. bataviae, L. bratislava, L. pomona and L. sorex-jalna) were found. The most frequently observed antibodies were those of the serovar L. grippothyphosa (65.1%) and L. sejroe (25.5%). Slightly higher percentage of positive hosts in mature group rodents (5.4%) comparing with immature rodents (4.6%) were statistically insignificant. Similarly, no differences were found between percentage of positive rodent females (5.3%) and group of males (4.7%). No statistical differences were found in positivities to leptospira antibodies among sexual and age groups of individual rodent species, too. Proportion of serological positivities to L. grippothyphosa and L. sejroe in compared sex and age rodent groups were very similar. In evaluated rodent species trend of increases of serological positive values from spring to autumn was observed, but it was statistically confirmed only in A. agrarius.

[Leptospira antibodies in small mammals in Eastern Slovakia]. / Výskyt protilátok proti leptospíram u drobných cicavcov na východnom slovensku.

During the five years (1991-1995) mostly free living small mammals were examined serologically for the presence of antibodies to leptospira. Serological examinations were used by Kmety and Bakoss (1978). Altogether, 2493 individuals of 22 species were examined, an important part of host material (69.6%) was caught in two lowland areas which are intensively cultivated landscapes (East Slovakian Lowland and Kosická kotlina basin). The remaining material comes from submontane areas with less agricultural activities. Apodemus flavicollis, A. agrarius, Clethrionomys glareolus were the most frequently examined species. Antibodies to leptospira were demonstrated in 123 mammals (i. e. in 5.0% of hosts) of eleven species. The highest percentage of positive hosts were recorded in 1993 (8.8%) and the lowest (2.6%) in 1995, but the examined samples were different in size and structure of host species. In six most dominant species higher values of antibodies to leptospira were detected in Microtus arvalis (9.2%), followed by Apodemus flavicollis (5.6%), A. agrarius (5.4%) and A. microps (4.9%). The lowest values were found in Clethrionomys glareolus (2.5%) and Sorex araneus (2.3%). In examined hosts we found antibodies to six serovars of leptospira. The most frequently observed antibodies were to leptospira of the serovar L. grippotyphosa (63.2%) and leptospira of the serovar L. sejroe (26.4%). We recorded nonsignificant differences between the values of prevalence to antibodies in small mammal communities from lowland and submontane areas, resp. Our results confirmed differences in the leptospira serovar structure in small mammals of Bohemia and Slovakia, they were connected with different historical development of both areas. Comparing our results with previous examinations (about 20 years ago) in small mammals from eastern Slovakia, a decline of positivity and lower number of leptospira serovars were recorded.

Ecology of Ixodes ricinus immatures on Apodemus agrarius (Muridae) in the lowland ecosystems conditions.

Ecology of Ixodes ricinus collected on black-striped field mouse (Apodemus agrarius) was studied in the lowland ecosystems. During the study period (1986-1991), 1483 specimens of A. agrarius were examined in southern Slovakia and 1319 larvae and nymphs were collected from hosts. The seasonal pattern--bimodal (peak in spring and autumn)--was distinct for larvae. Both prevalence and abundance of tick infestation of A. agrarius by nymphs were low. Prevailing material of nymphs was collected from May (pooled data from all years) on mature hosts. There were significantly higher infestation in mature males than in females as well as significantly higher tick infestation of mature hosts than immature ones. Higher abundance of tick infestation of A. agrarius in fields is probably influenced by great spatial mobility of hosts and by import of ticks from landscape verdure.

[Occurrence of Leptospira serovars in old foci of leptospirosis]. / Súcasný stav výskytu leptospírových sérovarov v starých ohniskách leptospiróz.

In two old natural foci of leptospiroses in an Eastern Slovakian area an epidemiological investigation was made to detect persisting carriership in basis reservoirs-small mammals and the contact with leptospirae in population groups with an occupational risk. Using the microagglutination reaction (MAR), the authors examined 1,106 small mammals and detected in 50 cases, i.e. 4.5%, the presence of specific antibodies against leptospirae, most frequently in species Apodemus agrarius and Ap. flavicollis. Only in one instance a positive reaction was found in the main reservoir--Microtus arvalis. As to serovars, Leptospira grippotyphosa and the group L. sejroe dominated. Of 1,740 examined human sera (832 men, 908 women) 56 samples (3.2%) reacted in MAR (4.1% men, 2.4% women). The spectrum of serovars in positive subjects was the same as in the above mentioned reservoirs with a predominance of L. grippotyphosa and group L. sejroe. As compared with previous examinations made 18 years ago in small mammals, a decline of positivity to almost half was recorded (from 7.8% to 4.5%), a reduction of the number of serovars from 7 to 4 was observed, however, the positivity of dominating serovars did not decline. In humans a higher percentage of positivity to specific antibodies was found, as compared with the past, i.e. 3.0% as compared with 2.0%. The authors found differences in the frequency of different serovars. In the past serovar L. bratislava dominated in the above area, followed by L. grippotyphosa. At present the first place was held by L. grippotyphosa and the group of L. sejroe.(ABSTRACT TRUNCATED AT 250 WORDS)

[Psychological analysis of factors for determining an attitude toward patients with epilepsy]. / Psychologiczna analiza uwarunkowan postaw spolecznych wobec chorych na padaczke.

Very important is an analysis of epilepsy in wider context--not only clinically--due to its chronic course and high incidence. A problem of non-medical consequences due to the disease and related to social functioning of epileptic patients is widely discussed. The author attempted to carry out psychological analysis of all factors determining an attitude toward epileptic patients, basing on the results of research on a role of social determinants in epilepsy.

Isolated ocular involvement in non-Hodgkin's lymphoma with immunocytochemical evaluation.

We report the case of a patient with isolated ocular involvement and non-Hodgkin's lymphoma (also known as reticulum cell sarcoma). Most non-Hodgkin's central nervous system lymphomas are large cell lymphomas derived from B-cells. The patient initially had iritis OD and vitreous cells OS. Eventually, rubeosis and vitritis developed OD. A systemic workup showed no extraocular lymphoma. Immunocytochemical analysis was done on the vitreous OD and detected a monoclonal B-cell population of large lymphoid cells. This case shows the frequent delay in making the diagnosis of this condition. This diagnosis must be remembered when a patient has vitreous opacities.