Canine piroplasmosis in Italy: epidemiological aspects in vertebrate and invertebrate hosts.

In Italy, canine piroplasmosis is believed to be widespread, but few data are available on its presence in most areas. In 2005 and 2006, vertebrate and invertebrate hosts were investigated in Central and Northern Regions of the Country. Microscopy on blood smears, molecular tools and serological tests were applied to 420 blood samples collected from dogs, in order to evaluate the presence of these protozoa and to identify possible risk factors. Moreover, ticks were analyzed by molecular techniques. Microscopy identified as positive 2.8% of the animals, all from Central Italy, and PCR detected 'piroplasm' DNA in 6.0%. Serology evidenced a mean prevalence of 34.0% with a decreasing trend from Central to Northern areas. The 507 collected ticks were identified as belonging to 8 species, mostly represented by Rhipicephalus sanguineus (n=376) and Ixodes ricinus (n=58). Molecular analyses evidenced the presence of babesial parasites (Babesia canis canis, B. canis vogeli, B. microti-like) in 25 (4.9%) of them; in Rh. sanguineus there was also demonstration of the vertical transmission of B. canis canis. Statistical analysis identified 'kennel' as risk factor for Babesia infection. Our findings evidenced that different species of piroplasms potentially infectious for dogs are circulating in Italy, and that epidemiological aspects of these infections are more complex than expected. Vector importance of both Rh. sanguineus and I. ricinus is hypothesized, but further investigation is needed.

A novel Giardia duodenalis assemblage A subtype in fallow deer.

The molecular identification of species and genotypes of Giardia spp. infecting wild mammals represents the most reliable tool to understand the role played by these animals as reservoirs of cysts infectious for human and other animals. Of 139 fecal samples collected from fallow deer (Dama dama L.) hunted in a Natural Reserve of northern Italy, the prevalence of Giardia sp. was 11.5% (16 of 139 animals), and it was higher in fawns than in older animals. Fragments of the betagiardin and triose phosphate isomerase (tpi) genes were successfully polymerase chain reaction amplified and sequenced from 8 isolates. No sequence variation was observed between isolates at the 2 genetic loci. Sequence and phylogenetic analyses identified a Giardia duodenalis subtype that clusters with assemblage A isolates and that shows homologies of 98 and 97% at the beta-giardin and tpi loci, respectively, compared with the A1 subtype. Because the G. duodenalis subtype found in fecal samples of fallow deer has never been detected previously, its role as a pathogen for humans and domestic animals is unknown, but, considering its genetic distinctiveness, it is likely to be low.

Effect of levamisole administration on bluetongue vaccination in sheep.

Levamisole is an anthelmintic drug with immunostimulant properties when administered at repeated doses of 2.5 mg/kg prior to a vaccine being administered. In order to assess the effect of levamisole administration on bluetongue (BT) vaccination in sheep, four groups of unvaccinated pregnant sheep (8 sheep per group) were used. Group A received vaccine only; Group B received levamisole+vaccine; Group C received Levamisole only; Group D was a non-treated control. Levamisole (Citarin L-10%) was administered three times weekly at an initial dose of 5.0 mg/kg of body weight and subsequently at 2.5 mg/kg of body weight. There was a significant decrease in faecal egg count of gastrointestinal strongyles in Groups B and C. At the beginning of the trial, all animals were serologically negative for BT antibodies; after vaccination, there was a difference in antibody response in animals in the treated groups. Significantly, more animals in Group B developed BT antibodies following vaccination than those in Group A. In conclusion, levamisole appeared to have an immunostimulating effect on the response of sheep to BT vaccination.

Aedes albopictus is a natural vector of Dirofilaria immitis in Italy.

Investigations were carried out in Padova town (Veneto region, NE Italy) to define the actual role of Aedes albopictus in the natural transmission of Dirofilaria nematodes, and to assess the risk that its presence might represent for veterinary and medical health. During summer 2000-2002 daytime captures of human-attracted mosquitoes were carried out in three areas of the town. The presence of filarial parasites in mosquitoes was evaluated by PCR, and sequencing confirmed species assessment. DNA extraction was performed separately on pools of the insect abdomen and thorax-head, to discriminate between Dirofilaria infected/infective specimens. A total of 2721 mosquitoes were caught and A. albopictus was the most abundant species (2534). Filarial DNA was found in 27.5% (19/69) of the abdomen pools formed with mosquitoes collected in summer 2000, and in 11.1% (16/144) and 4.9% (6/123) thorax-head pools coming from samplings 2001 and 2002, respectively. Filarial DNA was belonging to D. immitis and all studied areas harboured infective specimens. These results prove A. albopictus as natural vector of D. immitis in Italy. Moreover, they support the hypothesis that the presence of the mosquito could affect the transmission pattern of canine heartworm disease in urban environment and, considering the aggressive anthropophylic behaviour of the species (30-48 bites/h) proven in Padova town, could enhance the circulation of filarial nematodes from animals to humans.

Mosquitoes as vectors of Setaria labiatopapillosa.

An infected bovine-baited trap was utilised in summer 1994 to catch possible intermediate hosts of S. labiatopapillosa in northeastern Italy. Collections were made for 21 nights from 8.00 p.m. to 6.00 a.m. every 2 h and, after 12 September, every 30 min. Among the 16,159 mosquitoes sampled, 11,052 were freshly blood-fed. Most of the unfed females and a representative sample of those which had fed were identified as follows: Culex pipiens, Aedes caspius, A. vexans, Culiseta annulata, Anopheles maculipennis s.l., A. claviger and Coquillettidia richiardii. In spite of having the highest relative density, C. pipiens is the species which fed the least frequently and showed lower susceptibility and efficiency. The 2 Aedes species appear to act as vectors, particularly A. caspius, which proved to be the most efficient vector (K.I. = 0.8). A. claviger and A. maculipennis contribute to S. labiatopapillosa transmission, but their scarce presence reduces their epidemiological relevance. The other species identified showed a complete refractoriness to the infection. The risks for veterinary and medical health are discussed.

Development of Dirofilaria and Setaria nematodes in Aedes albopictus.

The development of Dirofilaria repens, D immitis and Setaria labiatopapillosa up to L3 stage was documented in a laboratory colony of Aedes albopictus originating from specimens collected in Civitavecchia (Central Italy). The susceptibility of Ae albopictus and its plastic trophic habits, strongly suggest that this mosquito may contribute to the spreading of these nematodes in the country. It is particularly emphasized the danger for human health of an increased probability of transmission of Dirofilaria in urban areas.

[Bovine setariasis (Note I):trap for the capture of possible intermediate hosts of Setaria labiatopapillosa]. / Setariosi bovina (Nota I): trappola per la cattura dei possibili ospiti intermedi di Setaria labiatopapillosa.

The authors describe a trap utilized in the field to catch possible intermediate hosts of Setaria labiatopapillosa attracted by naturally infected bovine. The trap was bulky and stable but also decomposable and removable. It was tested in an area of Friuli Venezia Giulia (Udine province, NE Italy) during 21 nights in the summer 1994 (29/6-29/9) and allowed to catch 16159 mosquitoes and 218 other Diptera, showing a very good efficiency.

[Bovine setariasis in Friuli Venezia Giulia]. / Indagine sulla setariosi bovina in Friuli Venezia Giulia.

Blood samples from 407 bovines of "Azienda Marianis", a farm in Friuli Venezia Giulia, Italy, were examined for microfilariae; 143 (35.1%) were positive. A survey in other 23 farms of dairy cattle from 6 Communes of the Province of Udine revealed a prevalence of 11.28%. The prevalence was significantly correlated with the age of animals; in cow was lower than in young animals. Blood microfilariae (210) and adult females (15) were identified as Setaria labiatopapillosa.