Detection of antibodies to Borna disease virus in Turkish cats by using recombinant p40.

Recombinant p40 produced by baculovirus was used in an ELISA to screen samples of serum taken from 80 cats in Istanbul. The sera were also analysed for feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). Antibodies to Borna disease virus- (BDV) p40 were detected in 34 (42-5 per cent) of the 80 cats. Seventy-three per cent of the sera which were positive for FIV and 26 per cent of the sera which were negative for FIV had antibodies to BDV. There was no difference in the percentage of sera which were positive for BDV between the cats that were positive or negative for FeLV. Three of the cats had neurological disease and two of these had antibodies to BDV. Six sera with low, medium or high optical densities (ODS) by ELISA were analysed by Western blotting. Only the sera with medium and high ODS reacted specifically with p40 at a dilution of 1 in 1,000.     

Markers of Borna disease virus infection in cats with staggering disease

Borna disease virus (BDV) is a RNA-virus causing neurological disorders in a wide range of mammals. In cats, BDV infection may cause staggering disease. Presently, staggering disease is a tentative clinical diagnosis, only confirmed at necropsy. In this study, cats with staggering disease were investigated to study markers of BDV infection aiming for improvement of current diagnostics. Nineteen cats fulfilled the inclusion criteria based on neurological signs and pathological findings. In 17/19 cats, BDV infection markers (BDV-specific antibodies and/or BDV-RNA) were found, and antibodies in serum (13/16, 81%) were the most common marker. BDV-RNA was found in 11/19 cats (58%). In a reference population without neurological signs, 4/25 cats were seropositive (16%). The clinical history and neurological signs in combination with presence of BDV infection markers, where serology and rRT-PCR on blood can be helpful tools, improve the diagnostic accuracy in the living cat.     

Prevalence of Borna disease virus antibodies in healthy Japanese black cattle in Kyushu

Epidemiological studies have demonstrated that asymptomatic infection of Borna disease virus (BDV) is found in various species of animals in Japan. Recent reports have also revealed that neurological diseases caused by this virus could exist in horses, cattle, a dog, and cats in this country. In this study, we investigated seroprevalence of BDV antibodies in Japanese black cows reared in Kyushu, the southernmost main island of Japan, using ELISA and Western-immunoblotting. Of 101 serum samples, 11 (10.9%) and 21(20.7%) sera were identified as having antibodies to the BDV N and P antigens, respectively. Among the positive sera, three cows (2.9%) were seropositive for both of the antigens. Furthermore, interestingly, only female cows showed antibodies to P, whereas N antibodies were detected in male and female cows with a comparative ratio. Together with previous studies, our results indicate that BDV might be widely spread in cattle raised in Japan. Furthermore, this is the first report to show that beef cattle, Japanese black cattle, have antibodies against a possible zoonotic pathogen, BDV.     

Prevalence of feline leukemia virus and antibodies to feline immunodeficiency virus in cats in Norway.

Serum samples from 224 Norwegian cats were analyzed for the presence of feline leukemia virus (FeLV) p27 common core antigen, and for antibodies to feline immunodeficiency virus (FIV). Ninety specimens originated from the serum bank at the central referral clinic at the Norwegian College of Veterinary Medicine, which had been collected during the years 1983-1989; 67 sera were submitted from veterinarian practitioners; while 67 sera originated from cats presented for euthanasia. The cats were classified into one "healthy" and one "sick" group. Only 2.2% of sick cats and 1.2% of healthy cats showed FeLV antigenemia, a finding which is lower than which has been reported from many other countries. The prevalence of FIV antibodies was 10.1% in sick cats and 5.9% in healthy cats. Antibodies to FIV was most prevalent in male cats (14.7%) than in female cats (2.1%), and more prevalent among domestic cats (12.0%) compared to pedigree cats (2.4%). Antibodies to FIV in the cats demonstrated increasing prevalence with increasing age. It may be concluded that FeLV causes minor problems in Norwegian cats, while FIV is present in a similar prevalence to what is reported from other countries.     

High prevalence of Borna disease virus in domestic cats with neurological disorders in Japan

A total of 15 (T-1–T-15) domestic cats with neurological disorders in Tokyo area were examined for association with Borna disease virus (BDV). None had detectable antibodies to feline immunodeficiency virus (FIV), feline leukemia virus, feline infectious peritonitis virus and Toxoplasma gondii, and only cat T-8 had detectable antibody to FIV. Serological and molecular epidemiological studies revealed a significantly high prevalence of BDV infection in these cats: antibodies against BDV p24 and/or p40 proteins in 10/15 (66.7%) and p24 and/or p40 RNA in peripheral blood mononuclear cells in 8/15 (53.3%). Further, in situ hybridization and immunohistochemistry analyses of the autopsied brain samples derived from one of the cats (T-15) revealed BDV RNA predominantly in neuronal cells in restricted regions, such as olfactory bulb and medulla of cerebrum. Thus, BDV is present in Japanese domestic cats with neurological disorders at a high prevalence.     

Expression of interferon gamma in the brain of cats with natural Borna disease virus infection

Borna disease virus (BDV) is a neurotropic, negative-stranded RNA virus, which causes a non-suppurative meningoencephalomyelitis in a wide range of animals. In cats, BDV infection leads to staggering disease. In spite of a vigorous immune response the virus persists in the central nervous system (CNS) in both experimentally and naturally infected animals. Since the CNS is vulnerable to cytotoxic effects mediated via NK-cells and cytotoxic T-cells, other non-cytolytic mechanisms such as the interferon (IFN) system is favourable for viral clearance. In this study, IFN-γ expression in the brain of cats with clinical signs of staggering disease (N=12) was compared to the expression in cats with no signs of this disease (N=7) by quantitative RT-PCR. The IFN-γ expression was normalised against the expression of three reference genes (HPRT, RPS7, YWHAZ). Cats with staggering disease had significantly higher expression of IFN-γ compared to the control cats (p-value ≤ 0.001). There was no significant difference of the IFN-γ expression in BDV-positive (N=7) and -negative (N=5) cats having clinical signs of staggering disease. However, as BDV-RNA still could be detected, despite an intense IFN-γ expression, BDV needs to have mechanisms to evade this antiviral immune response of the host, to be able to persist.     

Peripheral and intracerebral T cell immune response in cats naturally infected with Borna disease virus.

Borna disease virus (BDV) is a neurotropic agent with capacity to cause encephalomyelitis in a wide range of animal species, including horses and cats. Recent studies also point to a link between BDV and human neuropsychiatric disorders. The pathogenesis of Borna disease (BD) has been proposed to be immune-mediated, mainly through the effects of cytotoxic T cells. We used flow cytometric analysis in order to characterize the peripheral and intracerebral T cell immune response in cats naturally infected with BDV. Our results show the presence of two different CD8+ cell populations (CD8+low and CD8+high) in the blood, spleen and brain of these cats. In the brain, CD8+low cells predominated over CD8+high cells. Since CD8+low cells have been suggested to represent a non-MHC-restricted T cell population, the recruitment of such cells to the brains of BDV-infected cats could possibly be of importance for the clearance of virus from neurones.     

Prevalence of feline calicivirus, feline leukaemia virus and antibodies to FIV in cats with chronic stomatitis

The prevalence of feline calicivirus (FCV), feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) antibodies were assessed in 78 British and 18 North American household cats with chronic stomatitis and in appropriate controls. In British cats, FCV was significantly (P less than 0.005) more prevalent in both hospital (92 per cent) and general practice (79 per cent) cases compared to their controls (19 per cent in both cases). A similar difference in prevalence of FCV was noted in North American cats where 50 per cent of cases were positive compared to 0 per cent of controls (P less than 0.01). FeLV prevalence was low in all chronic stomatitis populations. A significantly higher prevalence of antibody to FIV was found in British hospital cases (81 per cent) compared with time-matched controls (16 per cent) (P less than 0.001): a similar rate was found in the general practice cases (75 per cent) for which no controls were available. In the North American sample, FIV antibody status was similar in cases (54 per cent positive) and their age, sex and breed matched controls (50 per cent). The possible role of FCV and FIV in the pathogenesis of feline chronic stomatitis is discussed.     

Prevalence of feline leukaemia virus and antibodies to feline immunodeficiency virus in cats in the United Kingdom

A representative sample of the pet cat population of the United Kingdom was surveyed. Blood samples from 1204 sick and 1007 healthy cats of known breed, age and sex were tested for antibodies to feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). The prevalence of FIV was 19 per cent in sick cats and 6 per cent in healthy cats, and the prevalence of FeLV was 18 per cent in sick cats and 5 per cent in healthy cats; both infections were more common in domestic cats than in pedigree cats. Feline immunodeficiency virus was more prevalent in older cats but FeLV was more prevalent in younger cats. There was no difference between the prevalence of FeLV in male and female cats but male cats were more likely to be infected with FIV than female cats. No interaction was demonstrated between FIV and FeLV infections. Of the cats which were in contact with FIV in households with more than one cat, 21 per cent had seroconverted. The prevalence of FeLV viraemia in cats in contact with FeLV was 14 per cent. The clinical signs associated with FIV were pyrexia, gingivitis/stomatitis and respiratory signs, and with FeLV, pyrexia and anaemia. It was concluded that both viruses were significant causes of disease, and that the cats most likely to be infected with FIV were older, free-roaming male cats and for FeLV, younger, free-roaming cats.     

Presence of antibodies to non-structural proteins of foot-and-mouth disease virus in repeatedly vaccinated cattle

For the purpose of removing infected animals by detecting humoral immune responses to non-structural proteins of the foot-and-mouth disease (FMD) virus, antibodies induced by contaminated residual non-structural proteins contained in less pure FMD vaccine can be problematic for serological screening. The aim of the present study was to measure the possible presence of antibodies against these non-structural proteins in repeatedly vaccinated calves and beef cattle. Five imported FMD vaccines were examined using two commercial ELISA kits, UBI FMDV NS EIA and Ceditest FMDV-NS, for serological testing. After five doses of vaccination, the serum of one calf tested positive, and two vaccines induced a significant increase in anti-3ABC antibodies in calves. This finding demonstrated that a positive reaction to non-structural proteins due to impurities in the FMD vaccine was detectable using commercial tests. A low percentage of field sera sampled from beef cattle in Kinmen also tested positive, but the key factor resulting in the positive reactions could not be positively identified based on our data.     

Prevalence of antibodies to bovine virus diarrhoea-mucosal disease virus in Tanzanian cattle

A serological survey to determine the prevalence of antibodies to bovine virus diarrhoea-mucosal disease (BVD-MD) virus was conducted on 419 bovine serum samples originating from 18 of 20 regions (except Mwanza and Shinyanga) of the Tanzania mainland. The sera were a small proportion of samples collected for the appraisal of immune response to rinderpest vaccination. The survey indicated that the virus is prevalent in cattle populations and approximately 12% of sera tested contained demonstrable neutralising antibodies against BVD-MD virus.     

Prevalence of disease in nonviremic cats previously exposed to feline leukemia virus

Feline leukemia virus status and antibody titer to feline oncornavirus-associated cell membrane antigen (FOCMA) were determined on plasma from 183 outpatient cats and 61 cats from 2 closed, FeLV-positive, multiple-cat households. Cats with FOCMA antibody titer had a significantly (P less than 0.02) higher prevalence of history of disease than did cats without FOCMA antibody. Diseases included upper respiratory tract infections, abscesses, ear infections, lower urinary tract infections, gastrointestinal disease, pneumonia, uterine infection, lymphadenopathy, fever of unknown origin, and bacterial infections. The FOCMA antibody titer was determined by use of an indirect fluorescent antibody test; titer greater than or equal to 1:16 was considered to be positive results. Lower mean FOCMA antibody titer was observed in young cats with history of disease (P less than 0.05) than in young cats without history of disease or in older cats with or without history of disease. Prevalence of FOCMA antibody titer was identical (38%) in young and adult cats, indicating cats likely were exposed to FeLV as kittens because a higher prevalence of FOCMA antibody titer in older cats would otherwise be expected.     

Borna disease virus (BDV) infection in cats. A concise review based on current knowledge

Persistent viral infections of the central nervous system have been the subject of intense interest for decades. One of these viral agents has been identified as Borna disease virus (BDV) of the family Bornaviridae. There have been various reports that link BDV to staggering disease in cats, with symptoms that include ataxia and behavioural disorders, and the disease is often referred to as feline Borna disease. Serological and molecular detection of BDV has been reported at a higher prevalence in cats with neurological disorders in comparison to healthy cats. The transmission route(s) of BDV remain largely unknown, and the hypothesis that BDV is a zoonotic agent is yet to be proven. This review summarises the current knowledge on BDV infection in cats and discusses epidemiological aspects of infection.     

Prevalence of serum antibodies to Toxoplasma gondii in free-ranging cats on Tokunoshima Island,Japan

The prevalence of Toxoplasma gondii infection in free-ranging cats on Tokunoshima Island was assessed by testing 125 serum samples using anti-T. gondii IgG indirect enzyme-linked immunosorbent assay. The overall seropositivity rate was 47.2% (59/125). Seropositivity rates in cats with body weight >2.0 kg (57.4%) were significantly higher than in those with body weight ≤2.0 kg (12.5%, P<0.01). Analysis of the number of seropositive cats by settlement revealed the presence of possibly-infected cats in 17 of 23 settlements, indicating the widespread prevalence of T. gondii on the island. This is the first study to show the seroprevalence of T. gondii in free-ranging cats on Tokunoshima Island. The information revealed in this paper will help to prevent the transmission of T. gondii among cats and also in both wild and domestic animals and humans on the island.     

Prevalence of antibodies against feline panleukopenia virus in client-owned cats in Southern Germany

Feline panleukopenia is a frequent and commonly fatal disease of cats. Recent published studies have raised suspicions that some cats fail to develop antibodies after vaccination. The purpose of this study was to assess the prevalence of antibodies against feline panleukopenia virus (FPV) in cats in Southern Germany, and to identify factors that are associated with a lack of antibodies. In total, 350 cats presented to the Clinic of Small Animal Medicine, Ludwig-Maximilians-Universitaet were randomly included in the study. Information regarding signalment, origin, environment, lifestyle, housing conditions, health status, chronic diseases, glucocorticoid therapy, and vaccination status were collected. Antibodies were detected by haemagglutination inhibition test. Asymptomatic chi-squared tests and univariable logistic regression were used to investigate associations between a lack of antibodies and the different variables. Associations determined to be statistically significant at P < 0.1 were verified by a multivariable logistic regression analysis.Of the 350 cats, 103 (29.4%) had no antibodies against FPV. Chronic kidney disease, neoplasia, glucocorticoid therapy, and vaccination status were significantly associated with a lack of antibodies. The cats with no antibodies were likely to have inadequate immunity against panleukopenia and those with chronic diseases or receiving glucocorticoids were less likely to be protected.     

Prevalence of antibodies to Toxoplasma gondii in cats, dogs and horses in Sweden

Samples of serum or plasma taken during 1986 and 1987 from 244 pet cats, 303 dogs and 219 horses, randomly selected among animals referred to the Animal Clinics of the Swedish University of Agricultural Sciences, were screened by enzyme-linked immunosorbent assay (ELISA) for antibodies to Toxoplasma gondii. 42% of cats, 23% of dogs and 1% of horses examined were found seropositive.