Toxoplasma gondii and Neospora caninum infection in epileptic dogs.

OBJECTIVES: Studies in humans have demonstrated the role of Toxoplasma gondii, a protozoan parasite, in epileptic seizures. This study aimed to investigate the serological correlation between T. gondii and N. caninum and epilepsy in dogs. MATERIALS AND METHODS: The medical record database of the Veterinary Teaching Hospital, University of Perugia, was searched for dogs serologically tested by IFAT for T. gondii and N. caninum and following specific inclusion criteria. Dogs were stratified by having a clinical diagnosis of epilepsy or suffering different conditions. RESULTS: One-hundred and twenty-eight dogs were included, 64 with epilepsy and 64 without clinical signs of epilepsy. Seventeen of the 64 epileptic dogs (26.6%; 95% CI: 15.7% to 37.4%) and twenty-one of the 64 non-epileptic dogs (32.8%; 95% CI: 21.3% to 44.3%) tested positive for T. gondii. Eight of the epileptic dogs (12.5%; 95% CI: 4.4% to 20.6%) and three of the non-epileptic dogs (4.7%; 95% CI: 0% to 9.9%) tested positive for N. caninum. There was no statistically significant difference in the rate of T. gondii or N. caninum seroreactivity between epileptic and non-epileptic dogs. CLINICAL SIGNIFICANCE: The results obtained do not seem to support the role of T. gondii and N. caninum as causative agents of dog epilepsy.

Nitrogen dioxide pollution increases vulnerability to COVID-19 through altered immune function.

Previous ecological studies suggest the existence of possible interplays between the exposure to air pollutants and SARS-CoV-2 infection. Confirmations at individual level, however, are lacking. To explore the relationships between previous exposure to particulate matter < 10 µm (PM10) and nitrogen dioxide (NO2), the clinical outcome following hospital admittance, and lymphocyte subsets in COVID-19 patients with pneumonia. In 147 geocoded patients, we assessed the individual exposure to PM10 and NO2 in the 2 weeks before hospital admittance. We divided subjects according to the clinical outcome (i.e., discharge at home vs in-hospital death), and explored the lymphocyte-related immune function as an index possibly affecting individual vulnerability to the infection. As compared with discharged subjects, patients who underwent in-hospital death presented neutrophilia, lymphopenia, lower number of T CD45, CD3, CD4, CD16/56 + CD3 + , and B CD19 + cells, and higher previous exposure to NO2, but not PM10. Age and previous NO2 exposure were independent predictors for mortality. NO2 concentrations were also negatively related with the number of CD45, CD3, and CD4 cells. Previous NO2 exposure is a co-factor independently affecting the mortality risk in infected individuals, through negative immune effects. Lymphopenia and altered lymphocyte subsets might precede viral infection due to nonmodifiable (i.e., age) and external (i.e., air pollution) factors. Thus, decreasing the burden of air pollutants should be a valuable primary prevention measure to reduce individual susceptibility to SARS-CoV-2 infection and mortality.

Cross-sectional survey on Tritrichomonas foetus infection in Italian cats.

The feline genotype of Tritrichomonas foetus is a widespread cause of large-bowel diarrhoea in cats. The aim of this study was to determine the prevalence of the T. foetus infection in cat populations across Italy. Fresh, individual faecal samples were collected from 267 cats, kept in different environments (i.e., private households, breeding structures, municipal catteries and colonies) in three different sites across Italy. The faecal samples were tested by PCR to detect T. foetus. Moreover, the same samples were subjected to a concentration-flotation technique and a commercial direct fluorescent-antibody (DFA) test to detect additional enteric parasites, including Giardia duodenalis. The overall prevalence of T. foetus infection was 5.2%. All the infected cats showed diarrhoea at the time of sampling: 9 out of 14 positive cats were co-infected with G. duodenalis, 1 with Toxocara cati and 3 with Dipylidium caninum. The risk factor analysis showed that not only the breed, but also co-infections with G. duodenalis and Dipylidium caninum were significantly associated with the presence of T. foetus. This study confirms the presence of T. foetus in cats living in Italy, suggesting that this protozoan parasite should always be included in the differential diagnosis of patients referred with large-bowel disease symptoms, especially if they were purebred animals, or affected by other enteric protozoa, such as G. duodenalis.

Epidemiological survey on equine cryptosporidium and giardia infections in Italy and molecular characterization of isolates.

Cryptosporidium and Giardia are two of the most common enteric pathogens of domestic and wild animals and humans. However, little is known on the prevalence, clinical manifestations and economic and zoonotic significance of these infections in horses. This study was undertaken to investigate the prevalence, excretion patterns and risk factors related to the faecal shedding of Cryptosporidium oocysts and Giardia cysts in horses and the zoonotic potential of species/genotypes isolated. The survey was performed on 120 foals and 30 broodmares reared in five Italian farms. Foals were divided in four homogeneous groups of 30 animals each (age classes: 0-2, 2-4, 4-8, >8 weeks). Three sequential faecal samples were collected from each animal and analysed by three techniques: direct fluorescent antibody test (DFA), faecal flotation (FF) and stained faecal smears (SFS). The DFA results showed a prevalence of 8% for Cryptosporidium and of 13.33% for Giardia; the prevalence values obtained by FF and SFS were lower and in poor agreement with DFA results. Giardia and Cryptosporidium infections were more common in foals (23.33% and 26.66% respectively) and higher excretions were observed in the youngest foals. Distribution of Cryptosporidium prevalence was statistically related to farms (P < 0.01), age of animals (P < 0.01), but was unrelated to the presence of diarrhoea. In the case of Giardia, the prevalence was only related to age (P < 0.01). Pattern sheddings were related to intestinal diseases and horse age (P < 0.01). Risk factors for shedding included residence farms and age older than 8 weeks for both parasites. All DFA-positive faecal samples were submitted to DNA extraction and PCR to determine Giardia and Cryptosporidium species/genotypes. Sequence analysis of the COWP gene of Cryptosporidium and of the SSU-rRNA gene of Giardia revealed that they were identical to each other and identified Cryptosporidium parvum and Giardia duodenalis assemblage E. The potential role of infected horses in zoonotic transmission of Cryptosporidium was supported by the findings of this study.

Neospora caninum infection and congenital transmission: serological and parasitological study of cows up to the fourth gestation.

In this paper, a parasitological and serological study performed in three cows up to the fourth gestation is reported in order to clarify the extent of vertical propagation and, secondly, in which period of gestation the recrudescence of previous infection occurs. The cows selected for the study delivered healthy but congenitally infected calves in first pregnancy. The parasite was found, by biological tests in Swiss mice, in all the placentas of the three cows examined, during the three subsequent gestations, at calving. The parasite was found, at slaughtering, in the brains of all nine calves born clinically healthy from the three cows as well. The serological profile, performed at monthly intervals on serum of the cows, showed that IgG and IgM increased in the third trimester of gestation; this rise of antibodies was constantly observed during the three gestations and in all three cows. In the calves, the IgG titres increase after colostrum consumption and an IgM peak at birth, were indicative of a late infection. These findings, along with negative results obtained by a serological study conducted simultaneously on 38 cows housed in the same stable as the experimental animals and the negative results obtained in isolating parasite or antibodies from farm dogs, suggest that N. caninum infection can be maintained over several bovine generations and that recrudescing persistent infection, rather than a new infection, explains the Neospora infection of calves.

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.