An outbreak of bovine besnoitiosis in beef cattle born in central Italy.

An outbreak of bovine besnoitiosis in three female, 15-18 months old beef cattle in central Italy is here described. All the animals were born in central Italy without any recent contact with imported animals. The animals were in poor body conditions and showed symptoms and clinical signs consistent with chronic besnoitiosis. The diagnosis was confirmed by histopathologic examinations of skin biopsies and whole body at necropsy, showing typical 50-100 µ cysts engulfing superficial dermis in skin and lamina propria in mucosae; lesions were confined to skin and respiratory mucosae, and cysts were not seen in any other tissue. Bovine besnoitiosis is rapidly spreading among European countries and in our case the affected animals were born in the farm and not recent admission was referred, so it is likely to consider this as an autoctone outbreak of the disease in Italy. This case, taken together with other recently reported ones, suggest to consider Italy among potentially endemic areas for bovine besnoitiosis.

A survey on canine leishmaniasis and phlebotomine sand flies in central Italy.

Zoonotic visceral leishmaniasis (ZVL) is a vector-transmitted zoonosis caused by the parasitic protozoan Leishmania infantum. Bloodsucking sand flies of the subfamily Phlebotominae are the obligatory insect hosts, and the dog is the only domestic reservoir. This study reports data from a survey of canine infection and sand fly phlebotomine monitoring in the province of Perugia in central Italy. The overall seroprevalence in a total of 100 dogs tested was 8% (95% confidence interval: 3.8-15.6%). Data analysis revealed that serological positivity was statistically associated with age (p-value=0.03) and the area where dogs lived. Standard blacklight traps employed for sampling Culicoides midges in bluetongue disease surveillance were used in phlebotomine monitoring. A total of 5698 sand flies were collected and the two species, Leishmania competent vectors, were identified, Phlebotomus perfiliewi (50%) and Phlebotomus perniciosus (30%).

Dientamoeba fragilis in swine population: a preliminary investigation.

Dientamoeba fragilis, a protozoan with worldwide distribution is considered to be responsible for enteric disease in humans. A wide spectrum of clinical symptoms including; diarrhoea (acute or prolonged), flatulence, abdominal pains and other unspecific bowel symptoms have been ascribed to this parasite. Asymptomatic infection has also been reported. Dientamoeba fragilis is as its name indicates an extremely delicate protozoon and only the trophozoite has ever been demonstrated in stool samples. The definitive diagnosis of this infection is based on demonstration in permanently stained stool samples. In Italy examination of ova and parasite (O&P) samples are not currently performed. This protozoan is extremely difficult to cultivate but molecular techniques such as the Polymerase Chain Reaction offer promise as a means of diagnosing infection. The epidemiology of Dientamoebiasis is not clear. This paper will present preliminary results from a study looking for the parasite's presence in swine faeces. The possible role of pigs as a reservoir of infection was studied; 121 faecal samples from breeding and fattening pigs were examined using a Giemsa permanent stain. Dientamoeba fragilis was found in 53 (43.8%) of the stool samples examined.

Canine filariosis in Umbria: an update of the occurrence one year after the first observation of autochthonous foci.

Following the first observation of two autochthonous foci of canine filariosis occurred in Umbria region in the year 2001, a survey on prevalence and risk factors was conducted 12 months later to better understand the actual entity of the Dirofilaria problem in Umbria region. Blood samples were collected between January and December 2002 from 2406 dogs living in a total of 7 towns located in the identified areas at risk. Blood samples were tested by a modified Knott's technique to evaluate the microfilaraemia and, by a commercial ELISA kit, to detect in the sera adult antigens of D. immitis. The results were subject to statistical analysis. A total of 439 dogs were found to be infected. The true prevalence (LC 95%) was of 18%. Microfilariae of D. immitis were detected in 286 dogs (13%) while 112 dogs (6%) showed only microfilariae of D. repens and 41 dogs (1.6%) microfilariae of both D. immitis and D. repens. The prevalence ratio (PR) for each species of Dirofilaria (LC 95%) calculated in association with different risk factors (age, sex, use, outdoor night status, position, living together with other dogs, breed) and the statistical significance between the risk factors and the presence/absence of the infection, evaluated for each species of Dirofilaria, are discussed.

Experimental trichinellosis in fallow-deer (Dama dama L.).

Herbivora can play a very important role in spreading trichinellosis, as showed by the massive epidemics in man, caused by the consumption of horse meat in the last years. In this context, the present study has been undertaken to verify, through an experimental infection, the susceptibility, together with other biological parameters, of fallow-deer to Trichinella infection. The four animals, 8-9 months of age and 18-25 Kg body weight, were orally infected with low doses of Trichinella britovi and T. pseudospiralis (2,000 larvae/animal). After day 30 p.i., the animals were necropsied and, using artificial digestion methods, larval burden of Trichinella in muscle tissues was determined. Histopathological, serological (IgG monoclonal blocking ELISA) and biochemical data were assessed during the experiment. The results showed the susceptibility of fallow-deer to T. britovi and T. pseudospiralis infection; under the same inoculum size, the number of larvae/g was higher in group infected with T. britovi. The animals showed a higher immunological response to T. pseudospiralis infection. The results are discussed.

Trichinella spp. in ostrich meat: a public health risk?

In the present work the biological behaviour of T. spiralis and T. pseudospiralis in ostriches is reported. Oral infections were performed in eight ostriches with two infective doses (10,000 and 80,000 larvae) for each species of Trichinella. On day 0, 30 and 60 p.i. blood samples were collected to assay the serum changes concerning specific muscle enzyme activities and total proteins. The immunological study, to determine specific IgG in sera, was conducted employing a monoclonal blocking ELISA. From the carcasses of sacrificed animals, samples of various muscle tissues were examined by the digestion method and by standard histopathologic procedures. The study showed a low susceptibility of the ostriches to T. pseudospiralis; preferential sites of larval distribution were muscle tissues of the legs. T. spiralis could be found in muscle tissues only when a high number of larvae were inoculated. Immunological reactivity was found only in animals infected with higher doses of T. pseudospiralis.

Susceptibility of nutria (Myocastor coypus) to Trichinella infection: biological aspects.

Experimental infections with three different species of Trichinella in nutria in order to evaluate the susceptibility and the role of these rodents in the spreading of parasitosis in nature were carried out. The nutria is present in many italian wet areas and its distribution is expanding. The nutria meat is utilized as food in different countries and is retained responsible for trichinellosis in man. Two groups of ten animals were infected per os with 500 and 5,000 (n. 10) infective larvae of T. britovi; an additional study was arranged with two groups of animals infected with 5,000 larvae of T. spiralis and T. pseudospiralis, respectively. After 45 days, all animals were slaughtered and samples of different muscles were processed by standard artificial digestion and by routine histological methods. Serological investigations (specific IgG) have been carried out on sera samples by employing a monoclonal blocking ELISA. The animals showed a significant susceptibility to the infection with all species of tested Trichinella and immunological reactivity. Data obtained are discussed.

Intraerythrocytic administration of a synthetic Plasmodium antigen elicits antibody response in mice, without carrier molecules or adjuvants.

The synthetic peptide (NANP)40, reproducing the tandem-repeated epitope of the circumsporozoite protein of Plasmodium (Laverania) falciparum, was entrapped into murine, autologous erythrocytes by a hypotonic dialysis method. Mice immunized intravenously with minute amounts of encapsulated peptide produced considerable antibody titres. This result indicates that intraerythrocytic antigen administration may have a potential as an immunization system for humans, since it dispenses with adjuvants and carrier molecules.

Trichinella spiralis as a modulator of Shope fibroma virus.

After the works on the promoting effect of trichinellosis on some viral infections in rodents, many studies successively demonstrated that Trichinella spiralis confers resistance to many unrelated antigens including pathogens, such as Protozoa, Bacteria and tumour cells (B16 melanoma). Considering the above contradictory results, the present work was undertaken to study, in rabbits, T. spiralis as a modulator of Shope's fibroma virus, an oncogenic virus responsible for a benign neoplasia. Four groups of 6 rabbits each were used. The rabbits of group I, II and III were inoculated per os with 3000; 6000 and 12,000 T. spiralis larvae, respectively. The rabbits of group IV were used as controls. Thirty-five days after the inoculation, all the animals were injected at the fixed doses of 0.5 ml with dilutions (10(-1) to 10(-8] of Shope's fibroma virus given intradermally into 8 different points of the skin of each pretreated and untreated rabbits. After 9 days tumour lesions affecting the inoculating area were noticed and the DI 50/0.5 of Shope's fibroma virus was then determined for each of the 4 experimental groups. The rabbits pretreated with T. spiralis exhibited much lower virus titres than the controls, which was evidently related to a certain degree of aspecific immunity conferred by the parasite. The results indicated that T. spiralis produces, in rabbits, resistance to Shope's fibroma virus and its neoplastic effect.

Avian toxoplasmosis: experimental infection of chicken and pigeon.

Two groups of 13 new-laying hens each were infected by crop-route with 5000 and 50,000 infective oocysts of T. gondii. Four groups of 5 pigeons each were inoculated by crop-route with 50, 500, 1000 and 5000 infective oocysts. To each group of infected birds suitable controls were added. Hens from the experiment with 5000 infective oocysts were apparently resistant to the infection and they had no clinical signs in the succeeding 40 days p.i. Hens from the experiment with 50,000 infective oocysts showed an egg-drop and mortality in embryonated eggs, especially during the first 2 weeks p.i. Isolation of the parasite was unsuccessfully attempted from 720 embryonated eggs, produced by infected groups, and tested on various days p.i. and at different stages of infection. The parasite was isolated from the brain, heart, liver, spleen and lung of infected birds 7 and 15 days p.i.; 40 days p.i. it was evident only in brain and heart. IgG onset and mean course were monitored by ELISA and high titers were reached by both groups. Pigeons from groups 500, 1000 and 5000 developed rapidly progressive clinical signs as diarrhea, trembling, incoordination, torticollis and death. They had enlargement of liver and spleen and focal necrosis, nodular features in the crop. Pigeons from expt 50 had no clinical signs in spite of the presence of the parasite in their organs for over 45 days p.i. Parasite was isolated from brain, heart, liver, spleen, lung, kidney, crop and muscles from all infected groups. Histopathological and ultrastructural features revealed the presence of multiplying tachizoites even within cells of the crop. Seroconversion, as monitored by ELISA, was recorded in all infected groups although high ELISA-titres were never reached. One of the negative controls from expt 5000 developed specific antibodies but the parasite was not isolated from its organs.