Serological survey of Neospora caninum in dogs in the Czech Republic and a long-term study of dynamics of antibodies

The main aim of the present study was to establish the prevalence of antibodies against Neospora caninum dogs from the Czech Republic and to examine the dynamics of antibody titers during a long-term period. For this purpose, sera of 858 dogs were examined for the presence of anti-N. caninum antibodies using an indirect immunofluorescent antibody test (IFAT). Four groups of dogs of various origins were included in the survey: the first group (A, n=470) comprised dogs purchased by the Czech Army from the civilian sector throughout the Czech Republic, with 22 (4.7%) N. caninum-positive dogs, second group (B, n=115) represented police dogs with no seropositive animal, third group (C, n=195) were pet dog sera collected for veterinary clinic with 5 (2.6%) anti-N. caninum sera and the fourth group (D, n=78) of canine shelter dogs with the seroprevalence of 19.2%. The differences in seroprevalence were significant (P< or =0.01) between groups B and A, and between D and A. None of the serologically positive animals had clinical signs of neurological disorders. Coprological examination did not reveal any dog shedding N. caninum oocysts. The seropositivity rates for N. caninum were analyzed in relation to other data, such as age, breed and gender. Increased prevalence rates of anti-N. caninum antibodies were found in the older age strata of the dog population sample tested in the present study. We found significantly higher (P=0.02) prevalence in 3-3.5-year-old dogs (11.1% of 36), as compared to 1-1.5-years-old dogs (2% of 98). A longitudinal study of antibody dynamics was carried out in 19 initially seropositive dogs over a period of 4 years. The second and third examinations revealed that antibody titers decreased in majority of positive dogs (10, 52.6%), of which in seven cases (36.8%) the titers fell to levels that are currently considered as being seronegative (titer <1:50), or even became undetectable (titer <1:25).     

Seroepidemiology of Toxoplasma gondii and Neospora caninum in dogs from the state of Paraíba, Northeast region of Brazil

A cross-sectional study was conducted to determine the seroprevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies and to investigate the risk factors related to antibodies against T. gondii and N. caninum in dogs of the city of Campina Grande, state of Paraiba, Northeast region of Brazil. For this purpose, 286 blood samples were collected from dogs during the rabies vaccination campaign, in September 2003, and on this occasion questionnaires addressing epidemiological aspects of the infections were given to each dog owner. The sera were analyzed for anti-T. gondii and anti-N. caninum antibodies by indirect fluorescent antibody tests. Of the total of 286 dogs, 129 were positive for T. gondii (titer16) with a prevalence value of 45.1% (95% CI=39.24-51.07%). For N. caninum, 24 dogs were positive (titer50), with a prevalence value of 8.4% (95% CI=5.45-12.23%). Antibodies to T. gondii and N. caninum were found simultaneously in 14 dogs (4.9%; 95% CI=2.7-8.08%). For T. gondii infection, the risk factors associated with seroprevalence was the age of the animals, with dogs older than one year presenting higher values of odds ratio, and co-habitation of cats in the household. For N. caninum infection, dogs that have street contact had higher odds of seropositivity than dogs that remained exclusively in a domestic environment.     

A health evaluation in a colony of captive collared peccaries (Tayassu tajacu) in the Eastern Amazon

This study pretends to determine baseline data on the health and mortality of a colony of captive collared peccaries in the Eastern Amazon (Belém, State of Pará, Brazil) during a 65-months survey. Thirty-nine out of 166 animals (23.5%) died and were examined post-mortem. Monthly mortality averaged 1.2%. The highest mortality rate was observed in newborns (74.4%). Abandonment by the mother and aggression were responsible for 24.1% and 13.8% of the total newborn deaths, respectively. Most frequent causes of non-neonatal death were food poisoning (50.0%) due to an episode of accidental bitter cassava leaves ingestion and traumatism due to aggressions between animals (10.0%). Results from serology for different infectious diseases showed that 4.9% (2/41) collared peccaries had antibodies against Brucella spp. and 9.8% (4/41) animals had antibodies to two different Leptospira spp. serovars, butembo and autumnalis. This is the first survey of morbidity and mortality in captive collared peccaries in the Amazon region.     

Low prevalence of antibodies against the zoonotic agents Brucella abortus, Leptospira spp., Streptococcus suis serotype II, hantavirus, and lymphocytic choriomeningitis virus among veterinarians and pig farmers in the southern part of The Netherlands.

Serum samples from 102 veterinarians and 191 pig farmers from the southern part of the Netherlands were investigated for antibodies against Brucella abortus, Leptospira spp, Streptococcus suis serotype II, Hantavirus (HV), and lymphocytic choriomeningitis virus (LCMV). All samples were collected in 1993 and stored until this study was performed. The prevalence of antibodies against B.abortus in veterinarians (4.5%) was significantly higher (P = 0.01) than in pig farmers (0%). None of the veterinarians (0%) and only one pig farmer (0.5%) had antibodies against Leptospira spp. Furthermore, significantly (P = 0.015) more veterinarians (6%) than pig farmers (1%) had antibody titres against muramidase-released protein (MRP),a protein of pathogenic S. suis serotype II strains. None of the veterinarians and a total of 3 (1.6%) pig farmers had antibody titres against HV. The prevalence of antibodies against LCMV tended to be higher in pig farmers (2.6%) than in veterinarians (0%) (P = 0.10). It can be concluded that the prevalence of antibodies against the investigated zoonotic agents in veterinarians and pig farmers is low.     

Prevalence of antibodies to Leptospira interrogans serovar hardjoin bulk tank milk from unvaccinated irish dairy herds

: Bulk tank milk samples, collected from 347 herds throughout the Republic of Ireland using a sampling frame based on seven milk-recording organisations, were tested by ELISA for antibodies to Leptospira interrogans serovar hardjo. These herds, which had not been vaccinated against leptospirosis within the previous five years, were categorised according to their province, milk-recording organisation and size. Two-hundred-and-seventy-three herds (79%) had a positive ELISA titre. Both the probability of a herd being seropositive and the antibody level in the herd milk sample were affected by the province (P < 0.05 and P < 0.01, respectively) and the herd size category (P < 0.05 and P < 0.01, respectively). Larger herds were significantly more likely to have positive reactions and higher mean concentrations of antibody. It was concluded that a high proportion of unvaccinated Irish dairy herds have been exposed to infection with Leptospira hardjo.     

Serologic survey of California wild hogs for antibodies against selected zoonotic disease agents

Blood samples were collected from trapped or hunter-killed wild hogs (Sus scrofa) in 4 areas of California. Sera were tested for antibodies against 7 zoonotic disease agents. Antibodies against Brucella sp were detected in 21 (15%) of 136 samples. Antibodies against Coxiella burnetii were found in 50% of the collected samples (67 of 135 tested). Of the 135 wild hogs screened for pseudorabies virus, 4 (3%) were seropositive. Leptospira interrogans antibodies were discovered in 118 (87%) of the 136 samples tested. Of the 130 samples screened for antibodies against Mycobacterium avium complex, 111 (85%) were seropositive. Antibodies against Toxoplasma gondii were detected in 17 (13%) of 135 wild hogs. Antibodies against Yersinia pestis were found in 9 (15%) of 59 sera tested.     

Evaluation of truncated LipL32 expressed by Escherichia coli and Pichia pastoris for serodiagnosis of Leptospira infection in rodents

The applicability of the recombinant LipL32 for serodiagnosis of leptospiral infection in field rodents was assessed in this study. An immunodominant region of LipL32 was determined by monoclonal antibodies, and then, truncated LipL32 (tLipL32) was designed to contain the region (87–188th amino acid). The tLipL32 was compared between two recombinant expression hosts Escherichia coli and Pichia pastoris in ELISA. With field rat sera, tLipL32 expressed by P. pastoris (tLipL32p) had high antigenicity without background reactions, while tLipL32 expressed by E. coli (tLipL32e) showed high background reactions, which were reduced by pre-adsorption of sera with E. coli. To evaluate tLipL32-ELISA, field rat sera were tentatively divided into a Leptospira infection positive (12 sera) and a negative group (12 sera) based on the results from flaB gene PCR of kidney samples and WB with whole Leptospira cell. Consequently, the sensitivity of tLipL32p-ELISA for field rat sera was 83% . A similar result was obtained from tLipL32e-ELISA with adsorbed sera, (92%). However, sensitivity of tLipL32e-ELISA using sera without an adsorption treatment was 50%. Regardless of the expression host, tLipL32-ELISA had 100% specificity and sensitivity in experimentally infected laboratory rats. These results suggest that recombinant LipL32 expressed by P. pastoris is more applicable for serodiagnosis in field rats due to a lack of background reaction.     

The prevalence of leptospirosis and its association with multifocal interstitial nephritis in swine at slaughter.

An abattoir survey was undertaken to determine the prevalence of leptospirosis and its association with lesions of multifocal interstitial nephritis (so-called "white spotted kidneys") in swine at slaughter. Both cross-sectional and case-control study designs were used. Of 197 kidneys from hogs randomly selected at slaughter, 11 (5.6%) had generalized grey-white foci typical of multifocal interstitial nephritis (MFIN). Antibody titers greater than or equal to 1:80 against Leptospira pomona were detected in nine (4.6%) hogs and against L. bratislava in 63 (32%) of these hogs. Leptospira pomona (kennewicki) was detected by immunofluorescence in 5/197 (2.5%) of randomly selected hogs. Leptospires identified as genotype kennewicki were isolated from six (9.8%) of 61 kidneys cultured. Leptospira bratislava was not detected by immunofluorescence or culture. There was a highly significant (p = 0.00) and strong association (odds ratio (OR) = 195) between high L. pomona titer (greater than or equal to 1:80) and the presence of leptospires in the kidneys, as detected by culture. There was also a significant (p = 0.046) and strong (OR = 8.10) association between multifocal interstitial nephritis and the presence of renal leptospires as detected by culture. The association between leptospiral titer and MFIN lesions in the prevalence survey group of animals was statistically significant (p = 0.031), but this association was not significant in the case-control study group (p = 0.071) The failure to identify L. bratislava despite serological evidence of infection suggests that some of these seropositive animals may have been transiently infected at an early age, that serological findings were falsely positive, or that immunofluorescence and isolation attempts failed to detect L. bratislava if they were indeed present in the kidneys.(ABSTRACT TRUNCATED AT 250 WORDS)     

Seroepidemiology of Neospora caninum and Toxoplasma gondii in cattle and water buffaloes (Bubalus bubalis) in the People's Republic of China

A seroepidemiological survey of Neospora caninum and Toxoplasma gondii in cattle and water buffaloes was carried out in the People's Republic of China. Serum samples were obtained from dairy (n=262, 9 herds in 9 provinces) and beef cattle (n=10, 1 herd) and water buffaloes (n=40) in China. All sera were tested for antibodies to N. caninum and T. gondii by an enzyme-linked immunosorbent assay (ELISA) and an indirect agglutination test (IAT), respectively. The overall seroprevalence of N. caninum in dairy cattle was 17.2% (45/262), and the herds seroprevalence of N. caninum was 88.9% (8/9), and antibodies to T. gondii were present in 6 cows (2.3%). None of the cows had antibodies against both T. gondii and N. caninum. Antibodies to T. gondii or N. caninum were not found in beef cattle or water buffaloes. The seroprevalence of N. caninum in aborting cows (20.2%) was higher than that in non-aborting cows (16.6%) with an odds ratio of 1.26 (95% CI, 0.54-2.95), but the difference was not statistically significant (P>0.05). There was no apparent association of N. caninum seropositivity with age or number of pregnancies. This is the first report on the seroprevalence of N. caninum in cattle and water buffaloes in China.     

Development of an antibody-detection ELISA for Fasciola hepatica and its evaluation against a commercially available test

An ELISA was developed for the detection of Fasciola hepatica antibody in serum of cattle. The assay was applied to sera from 258 naturally infected cattle, 256 non-infected cattle and six calves experimentally infected with F. hepatica. The diagnostic sensitivity and specificity of the ELISA test was 98% (95% confidence intervals, 96-100%) and 96% (95% confidence intervals, 93-98%) respectively at a cut-off value of 15% positivity. The results using sera from the experimentally infected calves showed that antibodies were first detected 2-4 weeks after infection. The ELISA test was also compared to the commercially available Bio-X bovine F. hepatica ELISA kit. A subset of 39 positive sera and 47 negative sera were selected from the samples used to evaluate the in-house test. The results indicated that the agreement between the two tests was almost perfect (k statistic=0.82).     

Seroprevalence of Leptospira spp. in clinically healthy horses in Switzerland

A retrospective, cross-sectional study was conducted to determine the leptospiral seroprevalence in clinically healthy horses in Switzerland. A representative sample of 615 horse sera was examined by microscopic agglutination test for the presence of antibodies against 15 Leptospira?spp. serovars. In total, 58.5?% (n?=?360) of the horses were positive for one or more of the antigens analysed, with 20.3?% of them showing titres >=?400. The most prevalent serovar was Pyrogenes (22.6?%), followed by serovars Canicola (22.1?%) and Australis (19.2?%). Older horses, mares, ponies and animals spending increased time on pasture exhibited significantly higher prevalence rates (p?相似文献   

A serosurvey for antibodies to Leptospira in dogs in the lower North Island of New Zealand

AIMS: To investigate the prevalence of antibodies to endemic and exotic Leptospira serovars in samples from a serum bank, collected from dogs in the lower North Island of New Zealand. METHODS: Sera (n=466), which had been collected from apparently healthy dogs, were screened using the microscopic agglutination test (MAT) for antibodies to serovars L. borgpeterseni serovar hardjo, L. interrogans serovars pomona, copenhageni and canicola, and L. kirschneri serovar grippotyphosa. RESULTS: Antibody to Leptospiral antigen was found in 14.2% of dogs tested. The highest level of reactivity was with serovar copenhageni, to which 9.5% (41/433) of sera were positive. Antibodies to serovars grippotyphosa and canicola were not detected in this population of dogs. CONCLUSIONS: Leptospira infection is relatively common in dogs in the lower North Island . CLINICAL RELEVANCE: Vaccination of dogs against leptospirosis should be considered using vaccine containing antigen to serovars hardjo, pomona and copenhageni. The presence of moderate levels of copenhageni antibody in dogs in the lower North Island raises the possibility that this serovar has become established in rodent populations in this region.     

Prevalence of IgG antibodies to Encephalitozoon cuniculi and Toxoplasma gondii in cats with and without chronic kidney disease from Virginia

Kidney disease is a common and serious condition in domestic cats. There are numerous causes of kidney disease including parasitic infection. Encephalitozoon cuniculi is a microsporidian parasite that develops in the kidneys of rabbits and causes chronic renal disease. Little has been reported concerning E. cuniculi in cats and no serological studies on this parasite in cats have been conducted in the United States to date. The present study explored the possibility that E. cuniculi is an unrecognized contributor to the high prevalence of kidney disease observed in cats. A serological survey was conducted to determine the prevalence of IgG antibodies to spores of E. cuniculi in cats with and without a diagnosis of chronic kidney disease (CKD) according to the International Renal Interest Society (IRIS) staging system. Likewise, samples were examined for IgG antibodies to Toxoplasma gondii, a common well studied protozoan of cats. Plasma and sera were obtained from 232 feline patients at the Virginia-Maryland Regional College of Veterinary Medicine teaching hospital. With the investigators blinded to the renal status of test subjects, samples were screened via indirect immunofluorescent antibody assay (IFA). Thirty-six of the 232 cats met the IRIS staging system criteria for CKD. Antibodies to E. cuniculi were found in 15 of the 232 samples, which included 4 of the 36 cats with CKD. Sera from cats serologically positive to E. cuniculi did not react to spores of E. intestinalis or E. hellem when examined in the IFA. Antibodies to T. gondii were found in 63 of the 232 samples, which included 10 of the 36 cats with CKD. The prevalence of antibodies in cats with CKD to either protozoan was not significantly different (P>0.05) from the cats without CKD in the study. Collectively the results do not support the hypothesis that either E. cuniculi or T. gondii play a significant etiologic role in the occurrence or progression of CKD in cats.     

Ovine Lentivirus is Aetiologically Associated with Chronic Respiratory Disease of Sheep on the Laikipia Plateau in Kenya

A study was undertaken to investigate the occurrence of ovine lentivirus (OvLV) infection in sheep with chronic respiratory disease on the Laikipia Plateau, Kenya. All seven Merino crossbred sheep with chronic dyspnoea and emaciation examined for gross and microscopic lesions had lymphoid interstitial pneumonia (LIP), and one also had pulmonary abscesses. Two of the sheep with LIP also had lesions of ovine pulmonary carcinoma (OPC, jaagsiekte). Using in situ hybridization, OvLV DNA localized to a high proportion of pulmonary macrophages in lungs with lesions of LIP. Lung tissue samples from six of these sheep were positive for a syncytium-inducing virus in cultures of lamb testis cells. Thin-section electron microscopy of infected cells showed virions with morphogenesis typical of lentiviruses. In a western blotting assay, monoclonal antibodies to the OvLV capsid (CA, p27) and matrix (MA, p15) proteins of a North American OvLV isolate reacted with similar-sized bands of the virus, and serum from six of the sheep were reactive with CA from the Kenyan viral isolate. Using an OvLV agar gel immunodiffusion (AGID) test, all seven sheep were positive for serum antiviral antibody, as were 29% of 63 clinically normal sheep from Laikipia District. However, when sera from the healthy sheep were tested in a western blot assay, only 52% had IgG reactive to the OvLV CA, indicating a high rate of false negative reactions with the AGID test. Serum samples from 87 Red Maasai or Dorper crossbred sheep from two farms in other parts of Kenya were OvLV seronegative by both the AGID test and the western blot assay. These results document the first identification of OvLV as a cause of chronic respiratory disease in sheep in Kenya and show a high rate of infection in sheep flocks, with a high prevalence of chronic respiratory disease.     

Leptospiral antibodies in captive lion tamarins (Leontopithecus sp) in Brazil

Serum samples from 73 lion tamarins of three species living at the Centro de Primatologia do Rio de Janeiro were tested for antibodies against serovars of Leptospira interrogans by microscopic agglutination test. Antibodies were detected in serum samples of 15% of tested samples. Seroreactivity prevalence was lower than that described in other non-human primates and could be explained by the arboreal behaviour of these animals. Icterohaemorrhagiae was the most common serogroup.     

Occurrence of antibodies to Toxoplasma gondii and Lepstospira spp. in manatees (Trichechus inunguis) of the Brazilian Amazon

The presence of Toxoplasma gondii and Leptospira spp. antibodies was investigated in 74 manatees (Trichechus inunguis [Mammalia: Sirenia]) kept in captivity in two rescue units in the northern region of Brazil. Antibodies to T. gondii were detected in 29 (39.2%) of 74 animals by using the modified agglutination test (titer, 1:25). For antibodies against Leptospira spp., sera were diluted 1:50 and tested against 24 strains ofleptospires by microscopic agglutination microtechnique, and positive samples were end titrated. Twenty-three (31.1%) of 74 animals were reactive to four serovars (Patoc 21/23, Castellonis 2/23, Icterohaemorrhagiae 1/23, and Butembo 1/ 23), with titers ranging from 100 to 1,600. This is the first report of antibodies against T. gondii and Leptospira spp. in T. inunguis from the Brazilian Amazon.     

Prevalence of Neospora caninum and bovine viral diarrhoea virus in dairy cows in Southern Vietnam

The main purpose of this study was to investigate the prevalence of Neospora caninum and bovine viral diarrhoea virus (BVDV) in some dairy herds in Southern Vietnam, and to ascertain whether there were differences in seroprevalences between herds with imported and locally bred cows. Serum samples collected on five state farms and 97 smallholder herds were analysed for the presence of antibodies to N. caninum and BVDV. All BVDV antibody-negative sera were further tested by antigen-ELISA in order to identify persistently infected individuals. The N. caninum prevalence varied between 16% and 53% in the state herds, and was higher in the four herds that had imported cows than in the herd that only had locally bred cows. Nineteen percent of the samples collected on smallholder farms, which all had only locally bred cows, had antibodies to N. caninum. The BVDV seroprevalence varied between 58% and 93% on the state farms. In smallholder herds, the prevalence of BVDV among the sampled cows was 18% and even lower on the state farms. Despite the high seroprevalence for BVDV in the state herds, no persistently BVDV infected cows were found. Given the high prevalence for Neospora and BVDV among herds with imported cows, it seems advisable to test for both infections before cattle are imported into the country.     

Seroepidemiological studies of the detection of leptospires of the sejroe group in cattle in middle Thuringia]

From 1983 to 1989 14,361 head of cattle from the middle Thuringia region were investigated by means of microagglutination test for the presence of Leptospira serovars hardjo, saxkoebing and sejroe. 4,484 samples from cattle with abortion (1983-1985) and a random sample of 5,284 cattle sera (1985) were investigated giving priority to L. hardjo. Furthermore 3,293 samples from cattle with abortion (1986/87) and a random samples test of 1,300 cattle sera (1989) were tested giving priority to L. saxkoebing. 2.5 percent of the cows having aborted and 10.3 percent of cattle tested out of the whole livestock showed antibodies against L. hardjo. The test for presence of L. saxkoebing demonstrated in cattle with abortion a seroprevalence of 14 percent and in the random samples tests a portion of reagents of 11.3 percent. The degree of infection differed regionally, the highest degree was found in livestocks of the northern part of the Thuringia forest. The prevalence of L. saxkoebing in cattle with abortion from large dairy farms was 18.6 percent, which is higher than the average in the region examined. Antibodies against hardjo and sejroe were interpreted as caused by cross reactivity.     

Development of two immunochromatographic tests for the serodiagnosis of bovine babesiosis

In this study, we developed two immunochromatographic tests (ICTs), which are nitrocellulose membrane-based immunoassays for the convenient and rapid serodiagnosis of bovine babesiosis caused by Babesia bovis (BoICT) and Babesia bigemina (BiICT). The efficacy of two ICTs was evaluated using 13 positive sera from experimentally infected cattle with B. bovis or B. bigemina. Clear results showed that the BoICT and ELISA detected antibodies in sera collected from 14 to 93 days post-infection, while BiICT and ELISA detected from 13 to 274 days post-infection. In additon, non-infected cattle, Neospora caninum, and Cryptosporidium parvum were negative in two ICTs. To evaluate the field utility of the ICTs, we tested 186 field bovine sera collected from cattle living in Yanbian (China) and Mato Grosso do Sul (Brazil). The results of ICTs were compared to those of classical serodiagnostic methods, enzyme-linked immunosorbent assay (ELISA) and the indirect immunofluorescence assay (IFAT). The overall concordances of BoICT were determined as 92.5 and 90.3% when the results of ELISA and IFAT were set as the reference standards, respectively. In contrast, those of BiICT showed 96.8 and 92.5% relative to the results of standard ELISA and IFAT, respectively. Conventional and rapid diagnosic devices for bovine babesiosis may provide a valuable tool in clinical and field applications.     

Prevalence of serum antibodies against six Leptospira serovars in healthy dogs

OBJECTIVE: To determine the prevalence of antibodies against 6 Leptospira serovars and determine risk factors associated with positive Leptospira titers in healthy client-owned dogs in Michigan. DESIGN: Cross-sectional study. ANIMALS: 1,241 healthy dogs at least 4 months of age. PROCEDURES: Dogs were examined by veterinarians at private practices. Vaccinated and unvaccinated dogs were enrolled in the study, which occurred prior to the availability of a 4-serovar (Canicola, Grippotyphosa, Icterohaemorrhagiae, and Pomona) Leptospira vaccine. Sera were tested by use of the microscopic agglutination test to determine antibody titers against Leptospira serovars Bratislava, Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, and Pomona. A questionnaire was used to collect demographic information about each dog to identify risk factors associated with seropositive status. RESULTS: 309 of 1,241 (24.9%) dogs had antibody titers against at least 1 of the 6 Leptospira serovars, which suggested exposure to Leptospira spp. Prevalence of antibodies was highest to serovar Grippotyphosa, followed by Bratislava, Canicola, Icterohaemorrhagiae, and Pomona. Age, travel outside Michigan, exercise outside fenced yards, and exposure to livestock and wildlife were significant risk factors for positive titers. CONCLUSIONS AND CLINICAL RELEVANCE: Among healthy dogs from the lower peninsula of Michigan, > 20% have antibodies against leptospiral serovars historically considered uncommon but more recently incriminated as causing clinical canine leptospirosis. Wildlife and livestock may be of increasing importance as reservoirs for canine leptospirosis as urbanization continues to occur. Expanded vaccination strategies may partially mitigate these trends.