Analysis of the environmental and host-related factors affecting the distribution of the tick Dermacentor marginatus.

Understanding and responding to the ecological, social and economic conditions that facilitate disease emergence and transmission represents a substantial challenge for epidemiologists and health professionals. In this article we integrate knowledge about the human and the vector population, to provide a context from which to examine the underlying causal factors of D. marginatus-borne diseases emergence in the study area. Within this framework we analyse the biotic and abiotic factors that drive D. marginatus population dynamics and the role of its typical host for dispersal. These investigations suggest that D. marginatus is a tick species prone to spatially overlap its presence with human population presence. Then we consider the public health implications for the residents, when simply carrying out trivial outdoor activities may increase the risk to contact an infected tick.

Rickettsia spp. in Dermacentor marginatus ticks: analysis of the host-vector-pathogen interactions in a northern Mediterranean area.

In this work, we have analyzed the key features of Rickettsia spp. maintenance in Dermacentor marginatus ticks in four regions of the northern Mediterranean area, where extensive investigations are currently lacking. For this purpose, 380 adult D. marginatus ticks were collected from vegetation and wild ungulates during a 3-year study. A host-vector-pathogen interaction approach was applied to investigate the key components of the disease systems and evaluate their respective weight in the intensity of infection in natural foci. A high variability in the R. slovaca infection rate among sampling sites was observed, whereas R. raoultii was sporadically present and at low infection rates. Dermacentor marginatus presence was confirmed in all the investigated regions. The local wild boar population showed a strong association with adult D. marginatus ticks. The results of this investigation suggest that wild boars not only maintain D. marginatus populations by feeding adult ticks, but may also have a potential role in the eco-epidemiology of rickettsioses, as carriers of rickettsiae-infected ticks. The public health implications of these results are discussed.

Presence of host-seeking Ixodes ricinus and their infection with Borrelia burgdorferi sensu lato in the Northern Apennines, Italy.

Host-seeking ticks were collected in the Northern Apennines, Italy, by dragging at 35 sites, at altitudes ranging from 680 and 1670 m above sea level (asl), from April to November, in 2010 and 2011. Ixodes ricinus (4431 larvae, 597 nymphs and 12 adults) and Haemaphysalis punctata (11,209 larvae, 313 nymphs, and 25 adults) were the most abundant species, followed by Haemaphysalis sulcata (20 larvae, five nymphs, and 13 adults), Dermacentor marginatus (42 larvae and two adults) and Ixodes hexagonus (one nymph). Greatest numbers of ticks were collected at locations characterised by southern exposure and limestone substratum, at altitudes <1400 m asl; I. ricinus was most abundant in Turkey oak (Quercus cerris) wood, whereas H. punctata was mostly collected in hop hornbeam (Ostrya carpinifolia) wood and on exposed rocks. Ixodes ricinus was also found up to 1670 m asl, in high stand beech (Fagus sylvatica) wood. The overall prevalence of Borrelia burgdorferi sensu lato (sl) in 294 host-seeking I. ricinus nymphs was 8.5 %. Borrelia garinii was the most frequently identified genospecies (64.0 % of positive nymphs), followed by B. valaisiana, B. burgdorferi sensu stricto, B. afzelii, and B. lusitaniae. Based upon the comparison with the results of previous studies at the same location, these research findings suggest the recent invasion of the study area by the tick vector and the agents of Lyme borreliosis.

Hunting dogs as sentinel animals for monitoring infections with Trichinella spp. in wildlife.

BACKGROUND: Nematode parasites of the genus Trichinella are important foodborne pathogens transmitted by ingestion of striated muscles harbouring infective larvae. Wild carnivorous and omnivorous animals are the most important reservoirs of these parasites. Hunting activities play an important role in Trichinella spp. EPIDEMIOLOGY: The aim of the present work was to assess if serological detection of anti-Trichinella IgG in hunting dogs can be a tool to indirectly monitor Trichinella spp. infections in wildlife. METHODS: An ELISA and a Western blot (Wb) were developed and validated. To validate the assays, serum samples were collected from 598 dogs considered to be Trichinella-free, 15 naturally infected dogs, and six experimentally infected foxes. Sera were tested by ELISA with Trichinella spiralis excretory/secretory antigens. The diagnostic sensitivity and specificity of ELISA were 100 % (95 % CI: 83.89-100 %) and 95.65 % (95 % CI: 93.69-97.14 %), respectively. Sera from Trichinella-infected dogs/foxes tested by Wb showed a three-band pattern ranging from 48 to 72 kDa. Since the prevalence of Toxocara canis is very high in dogs, the specificity of the ELISA and Wb was further assessed by testing sera for anti-T. canis IgG using T. canis excretory/secretory antigens. No cross-reactivity was observed. To evaluate the test's reliability in the field, serum samples were collected from wild boar hunting dogs from Central Italy where Trichinella britovi was circulating among wildlife. RESULTS: Out of 384 hunting dog sera, 189 (49.2 %) tested positive by ELISA and of these, 56 (29.6 %) tested positive by Wb, showing an overall prevalence of 14.6 % (56/384) in the wild boar hunting dog population of the investigated area. The serological prevalence in hunting dogs was significantly (P < 0.001) associated with the hunting district's altitude. This is in agreement with previous investigations, which had shown that the prevalence of T. britovi in wildlife was higher in mountainous areas than in lowland areas of Italy. CONCLUSION: The results suggest that the circulation of Trichinella spp. among wildlife can be monitored by testing sera from hunting dogs, which could act as sentinel animals of Trichinella spp. circulation in wildlife.

Range expansion of Ixodes ricinus to higher altitude, and co-infestation of small rodents with Dermacentor marginatus in the Northern Apennines, Italy.

Immature ticks (Ixodes ricinus and Dermacentor marginatus) were collected from small rodents (Apodemus spp. and Myodes glareolus), in the Northern Apennines, Italy, at an altitude up to 1650 m above sea level (a.s.l.), from 2009 through 2012. While D. marginatus had been found at the same location in studies carried out in 1994, I. ricinus was very rare or absent. Prevalence (95% confidence interval) of infestation by I. ricinus larvae on Apodemus spp. was 54.4% (47.5, 61.2), and it was greater than prevalence of D. marginatus larvae on the same hosts (23.3%, 17.8, 29.5). The mean (standard deviation) numbers of I. ricinus and D. marginatus larvae per individual Apodemus spp. were similar: 2.3 (4.1) and 2.1 (9.8), respectively. The monthly infestation pattern of the two tick species on Apodemus spp. were different. I. ricinus larvae were more frequent in June and September, than in July-August. I. ricinus nymphs were generally rare, and were most frequently found in July. The prevalence of D. marginatus larvae peaked in July-August, whereas nymphs were mostly active in August-September. Increasing population densities of roe deer (Capreolus capreolus), and increasing temperatures, in the last decades, in the Apennine area might have contributed to the observed range expansion of I. ricinus.

Rickettsia slovaca in immature Dermacentor marginatus and tissues from Apodemus spp. in the northern Apennines, Italy.

Immature Dermacentor marginatus ticks and tissues from small rodents were tested for infection with Rickettsia slovaca in the northern Apennines, Lucca Province, where tick-borne lymphadenopathy (TIBOLA) was previously reported in people. Prevalence of infestation with D. marginatus was 30.5% (n=131, 95% CI: 22.8-39.2%) in Apodemus spp. and 26.5% (n=34, 95% CI: 12.9-44.4%) in Myodes glareolus, which were captured during 1980 trap nights in 2009 and 2010. Rickettsia slovaca was identified by polymerase chain reaction, targeting the gltA and OmpA genes, in ear biopsies from 8 out of 37 tested Apodemus (22%, 95% CI: 9.8-38.2%), but not from 9 M. glareolus. The prevalence of R. slovaca in D. marginatus feeding on Apodemus spp. was 53% in larvae (n=51, 95% CI: 38.5-67.1%) and 47.5% in nymphs (n=59, 95% CI: 34.3-60.9%). No larvae (0.0%, 95% CI: 0-36.9%), but one nymph removed from M. glareolus was positive (10%, 95% CI: 0.3-44.5%). Prevalence of R. slovaca in host-seeking D. marginatus larvae, collected in the same area, was 42% (n=38; 95% CI: 26.3-59.2%). Prevalence of R. slovaca was greater in larvae feeding on PCR-positive Apodemus than in those feeding on negative mice (78.6% vs. 37.1%). Furthermore, levels of infestation with D. marginatus larvae were greater for R. slovaca-positive mice. The infection of Apodemus spp. was probably the result of repeated bites by transovarially infected larvae. On the other hand, the finding of R. slovaca in mice tissues would be compatible with transmission from these hosts to feeding D. marginatus. Based on such a hypothesis, the most heavily infested Apodemus might play a role as amplifiers of the infection.

Contaminated commercial dehydrated food as source of multiple Salmonella serotypes outbreak in a municipal kennel in Tuscany.

The authors describe a large outbreak of canine salmonellosis in a municipal kennel in Tuscany. During the outbreak, 174 samples of 'diarrhetic' and 'normal' faeces and two batches of commercial dehydrated dog food were cultured for pathogenic bacteria. The results of 25, out of a total of 41 dogs (60.9%) revealed at least one faecal sample as being positive for Salmonella; incidence per sampling ranged from 12.5% to 34%. Nine of 10 samples of dehydrated food were positive. Ten totally different serotypes were isolated from dry food and faeces: the results of the pulsed-field gel electrophoresis referred to similarity between the Salmonella Montevideo, Muenster and Worthington isolates recovered from both the food and canine faecal samples.

Rickettsia slovaca and Rickettsia raoultii in Dermacentor marginatus ticks collected on wild boars in Tuscany, Italy.

During the hunting season 2007-2008, 494 Dermacentor marginatus (Sulzer) ticks were collected from 109 hunter-killed wild boars, Sus scrofa, in Lucca's province, Tuscany, Italy. Rickettsia slovaca, the causative agent of tick-borne lymphadenopathy (TIBOLA), was detected in 32.1% of ticks tested (n=112) by using polymerase chain reaction primers targeting gltA, ompA, and ompB rickettsial genes. Moreover, Rickettsia raoultii was found for the first time in Italy, with 1.8% infection prevalence. This study confirms the risk posed to humans by ticks and tick-borne pathogens in the study area, where cases of spotted fever rickettsiosis (TIBOLA) are reported.

Rickettsia slovaca in Dermacentor marginatus and tick-borne lymphadenopathy, Tuscany, Italy.

Of 263 patients in Tuscany, Italy, from whom ticks were removed during July 2005-May 2007, five showed signs of tick-borne encephalopathy. Of the ticks, 17 were Dermacentor marginatus; 6 (35.3%) of these were identified by sequence analysis as containing Rickettsia slovaca. Tick-borne lympadenopathy occurs in this area.