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1.
A sero‐epidemiological study on canine leptospirosis was conducted in house, stray, farm and hunting dogs, as well as in suspect cases of clinical canine leptospirosis. Serum samples were collected from apparently healthy (vaccinated and non‐vaccinated), house dogs. A questionnaire was administered to the owners to elicit information on risk factors for leptospirosis. The microscopic agglutination test was used to screen for leptospirosis using 17 international serovars. Reciprocal titres of between 100 and <800 were considered as evidence of past exposure while reciprocal titres of 800 or greater were classified as suggestive of acute/current infection. Of a total of 419 serum samples tested, 61 (14.6%) were seropositive for Leptospira agglutinins, 23 (5.5%) had mixed infections and 16 (3.8%) had current infection. Amongst 50 suspected cases of clinical leptospirosis, 24 (48.0%) were seropositive and only 13 (26.0%) had current infection compared with 10 (6.3%) and three (1.9%) of 160 apparently healthy house dogs respectively. The difference was statistically significant (P < 0.05; χ2). Twelve (25.5%) of 47 hunting dogs, 10 (20.4%) of 49 farm dogs and five (4.4%) of 113 stray dogs were seropositive (P < 0.05; χ2). Overall, a total of nine serovars were detected with serovars mankarso, icterohaemorrhagiae RGA, autumnalis and copenhageni being involved in 29 (47.5%), 20 (32.8%), 25 (41.0%) and 10 (16.4%) respectively in 61 seropositive dogs (P < 0.05; χ2). Serovar mankarso was most predominant in seropositive apparently healthy dogs, 37.8% (14/37), suspected clinical cases of leptospirosis, 62.5% (15/24) compared with serovar icterohaemorrhagiae with a frequency of 21.6% (8/37) and 50.0% (12/24), the difference being statistically significant (P < 0.05; χ2). Although all vaccines used for prevention of canine leptospirosis in the country contain serovars canicola and icterohaemorrhagiae, serovar mankarso was mostly associated with infection and disease and may be a good candidate for inclusion in the vaccine used locally. The public health risk posed to owners of dogs infected with Leptospira cannot be over‐emphasized considering the zoonotic nature of the disease.  相似文献   

2.
Two dogs with clinical histories suggestive of leptospirosis were examined serologically and culturally for evidence of leptospiral infection. Antibodies to Leptospira interrogans serovar bratislava were detected in serum from one dog, and the organism was isolated from urine of that dog. In a serologic survey of dogs in the state of Illinois, reactor rates to bratislava were higher than those to canicola or icterohaemorrhagiae. In cases of suspect canine leptospirosis, serovars such as bratislava, not contained in canine vaccines, should be considered in a differential diagnosis.  相似文献   

3.
Seroprevalence of five different Leptospira interrogans serovars, Toxoplasma gondii and Leishmania infantum in stray dogs in Ankara was investigated. A total of 116 dog sera collected from apparently healthy stray dogs were tested for L. interrogans serovars by microscopic agglutination test (MAT), for T. gondii antibodies by Sabin-Feldman dye test (SFDT), and for L. infantum antibodies by indirect fluorescence antibody test (IFAT). Of the 116 dogs, 51 (43.96%) were seropositive for leptospirosis, 72 (62.06%) for T. gondii and 3 (2.58%) for L. infantum. No statistically significant difference was observed between male and female dogs in the seroprevalences of toxoplasmosis and leptospirosis (P>0.05), but statistically significant difference was observed among different age groups in the seroprevalences of toxoplasmosis and leptospirosis (P<0.05). Although the seroprevalence of L. infantum was low, asymptomatic animals should be considered as a reservoir for the spread of the disease.  相似文献   

4.
Two hundred and forty-five dogs were examined serologically for the presence of antibodies against different serovars of Leptospira interrogans. The dogs belonged to five different groups: group 1 was composed of clinically healthy pet dogs referred for a regular veterinary check-up visit or for vaccination; group 2 was composed of stray dogs; and groups 3, 4 and 5 were composed of dogs maintained in three different kennels which had varying standards of hygiene. Seventy-two out of the 245 dogs examined were seropositive for leptospirosis. In group 1, there were 3-4 per cent seropositive dogs; in group 2, 30.3 per cent; in group 3, 13.8 per cent; in group 4, 38.6 per cent; and in group 5, 49.2 per cent. This study demonstrates that leptospiral infection is common in dogs housed in kennels, despite most of them being vaccinated, and that crowding of animals into unsanitary quarters is associated with a high prevalence of infection. The most common infecting serovars found were bratislava and grippotyphosa, confirming recent observations that demonstrate a significant change in the epidemiology of canine leptospirosis.  相似文献   

5.
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.  相似文献   

6.
Fourteen dogs which had died from acute leptospirosis, three dogs which survived an acute attack of leptospirosis and seven healthy dogs living in close contact with the animals which died were examined for the presence of lepto-spiral antibodies by the microscopic agglutination test. Twelve dogs had titres of 1:3200 or greater. The predominant titre was directed against serovar bratislava in seven cases, serovar grippothyphosa in two cases and both these serovars in two cases. In one case the predominant titre was directed against serovars bratislava, grippothyphosa, copenhageni (serogroup icterohaemorrhagiae) and pomona. The present study and other recent reports suggest that the epidemiology of canine leptospirosis is changing with the emergence of serovars differing from those typically infecting dogs, namely canicola and icterohaemorrhagiae.  相似文献   

7.
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.  相似文献   

8.
OBJECTIVE: To measure the prevalence of canine leptospirosis in Queensland and to detect infection, if present, in New South Wales, Victoria, South Australia, Western Australia and the Northern Territory by measuring the serological titres of dogs held in animal shelters. PROCEDURE: Samples were collected through stratified sampling from multiple dog shelters in Queensland and New South Wales, and from one dog shelter located in close proximity to a major urban area in Victoria, South Australia, the Northern Territory and Western Australia. All samples were analysed using the microscopic agglutination test at the WHO/FAO/OIE Collaborating Centre for Reference & Research on Leptospirosis, Queensland Health Scientific Services in Brisbane, Queensland. RESULTS: Of a total of 956 samples submitted, 18 (1.9%) had positive leptospirosis titres. True prevalence measured in Queensland was estimated to be 2.5%, and the true prevalence in New South Wales, Victoria, South Australia, Western Australia and the Northern Territory was estimated to be 2.3%, 2.8%, 0%, 1% and 1.1% respectively. An association was found between seropositive status and female dogs (odds ratio (OR) 1.92) and seropositive status and the age group 1 to < 3 years (OR 1.41). Although 11 different serovars were detected, Leptospira interrogans serovar Copenhageni was the most prevalent and was found in 4 of the 18 positive dogs as a single infection. CONCLUSION: Serological evidence of canine leptospirosis in five states in mainland Australia indicates that the disease is more broadly distributed than previously thought.  相似文献   

9.
All leptospirosis microscopic agglutination test titers for the Leptospira serovars icterohaemorrhagiae, canicola, grippotyphosa, bratislava, hardjo, and pomona conducted on 1,260 blood samples from dogs at the University of Illinois Veterinary Diagnostic Laboratory between March 1996 and March 2001 were evaluated. Low titers (1:100 to 1:400) were predominantly L. icterohaemorrhagiae and L. canicola, which represented the predominant serovars (65.4%) among all positive samples with low titers. L. grippotyphosa was the predominant serovar (72.1%) among samples with clinically significant titers (greater than 1:800). The medical records of 87 dogs with a titer greater than 1:800 that were patients at the Veterinary Teaching Hospital of the University of Illinois were reviewed. A clinical diagnosis of leptospirosis was made in 15 cases (17.2%) based on the elevated titer, appropriate clinical signs, lack of recent vaccination, and lack of concurrent disease that could explain the clinical signs present. Renal disease was present in 10 of the cases, concurrent renal and hepatic disease in two, and hepatic disease in three. In 12 cases, the predominant serovar was L. grippotyphosa; titers to L. grippotyphosa and L. bratislava were equal in magnitude in three cases.  相似文献   

10.
All leptospirosis microscopic agglutination test titers for the Leptospira serovars icterohaemorrhagiae, canicola, grippotyphosa, bratislava, hardjo, and pomona conducted on 1,260 blood samples from dogs at the University of Illinois Veterinary Diagnostic Laboratory between March 1996 and March 2001 were evaluated. Low titers (1:100 to 1:400) were predominantly L. icterohaemorrhagiae and L. canicola, which represented the predominant serovars (65.4%) among all positive samples with low titers. L. grippotyphosa was the predominant serovar (72.1%) among samples with clinically significant titers (greater than 1:800). The medical records of 87 dogs with a titer greater than 1:800 that were patients at the Veterinary Teaching Hospital of the University of Illinois were reviewed. A clinical diagnosis of leptospirosis was made in 15 cases (17.2%) based on the elevated titer, appropriate clinical signs, lack of recent vaccination, and lack of concurrent disease that could explain the clinical signs present. Renal disease was present in 10 of the cases, concurrent renal and hepatic disease in two, and hepatic disease in three. In 12 cases, the predominant serovar was L. grippotyphosa; titers to L. grippotyphosa and L. bratislava were equal in magnitude in three cases.  相似文献   

11.
One study described the frequency of pre-breeding vaccination for leptospirosis in 205 cow-calf herds from across western Canada and the prevalence of positive Leptospira antibody titers in unvaccinated, weaned calves from 61 of these herds. The percentages of herds vaccinated for leptospirosis were 13.7% in 2001 and 8.4% in 2002. Of 1539 calves examined, 13 (0.8%) had a positive antibody titer for a Leptospira serovar; the most common serovar detected was hardjo. A second study examined the prevalence of positive Leptospira antibody titers during the summer grazing season in 313 vaccinated and 478 unvaccinated cows from 40 cow-calf herds in southern Saskatchewan. Antibody titers for 7 Leptospira serovars were measured during the grazing season. Of the non-vaccinated cows, 9.6% were positive in the spring for serovar pomona, 6.7% for serovar grippotyphosa, and 6.1% for serovar icterohaemorrhagiae; the corresponding percentages for the fall were 5.5%, 3.0%, and 1.3%, respectively. Of 781 vaccinated and unvaccinated cows that were sampled twice, 11.3% of vaccinated cows and 2.3% of unvaccinated cows had increases in Leptospira antibody titers during the grazing season.  相似文献   

12.
Serum samples from Asian elephants (Elephas maximus) in the Kanchanaburi, Chiang Mai and Lampang provinces of Thailand were tested using the microscopic agglutination test against 22 serovars of Leptospira interrogans. A titre of more than 1:100 was used as evidence of infection. In northern Thailand, the seroprevalence was 58 per cent and the prevalent serovars were Leptospira interrogans serovar Sejroe, Leptospira interrogans serovar Tarassovi, Leptospira interrogans serovar Ranarum and Leptospira interrogans serovar Shermani. In western Thailand, the seroprevalence was 57 per cent and the prevalent serovars were L Tarassovi, L Sejroe, L Ranarum, Leptospira interrogans serovar Bataviae and L Shermani. These results were similar to studies in domestic livestock and stray dogs in the Bangkok district. Among the elephants from Kanchanaburi there were significant associations between seropositivity and between the camp and between the prevalent serovars and the camp.  相似文献   

13.
Duration of immunity in dogs induced with current commercial inactivated leptospirosis vaccines and evaluated against experimental infection, to date, has hardly been documented. The purpose of the present work was to assess the duration of immunity in dogs that is attainable with a commercial inactivated bivalent leptospirosis vaccine. For this purpose, young dogs were vaccinated twice followed by challenge with either Leptospira interrogans serovar canicola or L. interrogans serovar icterohaemorrhagiae 5 weeks, 27 weeks or 56 weeks after the second vaccination. For assessment of the duration of immunity, titres of agglutinating serum antibodies were measured before and after challenge, and the effects of challenge on a variety of parameters were determined including reisolation of challenge organisms from blood, urine and kidney. Both challenge strains induced a generalised infection in control dogs, the canicola strain being most virulent. From the results with different parameters it appeared that the two vaccinations induced a high rate of protection from generalised infection with canicola and icterohaemorrhagiae at 5, 27 and 56 weeks after the second vaccination. In addition, after 56 weeks, still a high level of immunity against renal infection with sv. canicola and, as a consequence, urinary shedding of sv. canicola bacteria, was demonstrated. It was, therefore, concluded that with this vaccine, using this vaccination schedule, a duration of immunity of 1 year can be attained against infection with both serovars.  相似文献   

14.
In 1998, a total of 424 sows had sera collected in the Mekong delta in Vietnam. Of these, 283 sows were from 151 small-scale family farms in 19 villages, and 141 from seven large-scale state farms. The sera were subjected to the microscopic agglutination test (MAT) for antibodies to 13 Leptospira serovars. The overall leptospiral seroprevalence for titres > or =1:100 and > or =1:400, was 73 and 29%, respectively, and was higher (P=0.001) at small- than at large-scale farms. The highest seroprevalence was recorded for Leptospira interrogans serovar (sv) bratislava (52%). At small-scale farms, higher prevalences were found to serovars L. interrogans sv icterohaemorrhagiae (P=0.04) and L. interrogans sv pomona (P=0.02).Epidemiological information (at the individual-animal and herd-levels) was collected with a questionnaire. The data were analysed using logistic multiple regression. At the animal-level, sows seropositive for L. interrogans sv australis and sv autumnalis had less direct contact with sows in neighbouring pens (odds ratio (OR)=0.3 and 0.4, respectively) and sows seronegative for L. interrogans sv bratislava were of lower age (OR=0.1 for seropositivity). Also, sows seropositive for L. interrogans sv icterohaemorrhagiae had higher odds (OR=5.8) if they had not been born on the farm (had been introduced to it as gilts).Herds seropositive for sv javanica showed association with farms not taking measures to control the local rodent population (OR=7.8). Serovar pomona was also linked to the use of artificial insemination (AI), as opposed to natural-breeding services (OR=11.2).These results indicate that housing and management could affect the seroprevalence of Leptospira infection in pigs.  相似文献   

15.
Serology plays an important role in the diagnosis of leptospirosis. Few laboratories have the resources, expertise, or facilities to perform the microscopic agglutination test (MAT). Thus, there is a need for a rapid and simple serological test that could be used in any diagnostic laboratory. In this study, a genus-specific, heat-stable antigenic preparation from Leptospira interrogans serovar pomona was used in an enzyme-linked immunosorbent assay (ELISA) for the detection of leptospiral antibodies in dog sera. This antigenic preparation reacted with rabbit antisera against L. interrogans serovars bratislava, autumnalis, icterohaemorrhagiae and pomona and with rabbit antiserum against L. kirschneri serovar grippotyphosa. The ELISA showed a relative specificity of 95.6% with 158 dog sera which were negative at a dilution of 1:100 in the MAT for serovars pomona, bratislava, icterohaemorrhagiae, autumnalis, hardjo, and grippotyphosa. The relative sensitivity of this assay with 21 dog sera that revealed serovars MAT titres of > or =100 to different serovars was 100%. This assay is easily standardized, technically more advantageous than MAT, and uses an antigenic preparation that can be routinely prepared in large amounts. It was concluded that this ELISA is sufficiently sensitive test to be used as an initial screening test for the detection of leptospiral antibodies in canine sera, with subsequent confirmation of positive test results with the MAT.  相似文献   

16.
AIM: To determine the prevalence of the two most commonly diagnosed pathogenic Leptospira spp. serovars, Hardjobovis and Pomona, in sheep in a sheep-only abattoir in New Zealand, and to determine the prevalence of kidneys which were leptospire culture-positive collected from sheep seropositive or seronegative to the microscopic agglutination test (MAT). METHODS: A repeated cross-sectional observational study was conducted of serological and kidney culture prevalences of Leptospira borgpetersenii serovar Hardjobovis and Leptospira interrogans serovar Pomona. Lines of sheep and individual sheep were systematically randomly selected at a sheep-only abattoir during 18 May 2004 to November 2004 and 06 December 2004 to 14 June 2005. Additionally, a cross-sectional study examined prevalences in a purposively selected line of sheep from a flock with clinical evidence of an outbreak of leptospirosis. RESULTS: In the study population of 15,855 sheep of which 2,758 were sampled, 5.7 (95% CI=4.9-6.7)% were seropositive to one or both serovars; 44.2 (95% CI=34.6-54.2)% of 95 lines of sheep and 44.9 (95% CI=35.0-55.3)% of 89 farms showed serological evidence of infection. The serological prevalence of serovar Hardjobovis was significantly higher than that of serovar Pomona both at line (33% and 4%, respectively) and individual (5% and 1%, respectively) levels. A low but persistent seroprevalence of Hardjobovis throughout both years suggested low-level endemicity to this serovar, whereas Pomona infections appeared to be sporadic. Leptospires were isolated from kidneys of 8/37 (22%) Hardjobovis- and 1/6 (17%) Pomona-seropositive, and 5/499 (1%) seronegative animals. Of the animals purposively sampled from a farm with a clinical outbreak of leptospirosis, all kidneys from the 13 seropositive animals were culture-positive, indicating a high risk of exposure of meat workers in outbreak situations. Kidneys of MAT-seropositive sheep were 21.7 (95% CI=7.6-61.9) times more likely to test culture-positive than kidneys from animals with negative MAT titres. In general, the results indicated that 13/1,000 sheep slaughtered were potentially shedding leptospires. CONCLUSIONS: The study demonstrated the presence of a definite risk of occupational exposure of meat workers in a sheep-only slaughterhouse to the two most commonly diagnosed pathogenic Leptospira spp. serovars in New Zealand.  相似文献   

17.
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18.
Prevention of urinary shedding of Leptospira interrogans spp. by chronically infected dogs remains a key objective of the vaccination in dogs against leptospirosis which is a zoonotic disease. An inactivated bivalent vaccine composed of Leptospira interrogans serovars icterohaemorrhagiae [L. icterohaemorrhagiae] and canicola [L. canicola] bacterins was tested for its ability to protect puppies against a challenge exposure with L. icterohaemorrhagiae. The vaccine was administered twice at a 3-week interval to six puppies aged from 8 to 9 weeks. Six other puppies were used as unvaccinated controls. All puppies were challenged 2 weeks after the second vaccine injection by intraperitoneal (IP) administration of L. icterohaemorrhagiae (day 0). Clinical signs, haematological and biochemical changes and evidence of Leptospira in blood, urine and kidney were monitored for 4 weeks after the challenge exposure (days 0-28). Puppies were euthanised on day 28 for post-mortem and histological examinations of liver and kidney. Control group presented clinical pictures of severe or subclinical infection. One dog developed severe clinical signs (hypothermia, depression, anorexia, abdominal pain, dehydration, icterus, weight loss) and died on post-infection day (PID) 7 due to an acute renal failure. Gross and microscopic lesions were in accordance with this clinical pattern. In the five remaining control dogs, the challenge exposure induced mainly a systemic infection including leptospiraemia, leptospiruria and renal carriage. The vaccinated group remained healthy throughout the study period. In conclusion, immunisation with a Leptospira vaccine was shown to protect dogs against symptomatology and leptospiraemia, urine shedding and renal infection.  相似文献   

19.
We surveyed a wild population of white-lipped peccaries (Tayassu pecari) in the Brazilian Pantanal for evidence of Leptospira interrogans. Serum samples from 71 free-ranging T. pecari were obtained between 2003 and 2005 in the southern Pantanal of Mato Grosso do Sul state. We used microscopic microagglutination to test for antibodies against 14 L. interrogans serovars (antibody titers ≥1:100 were considered seropositive). Seventy percent of captured animals tested positive for leptospirosis antibodies. Antibodies against icterohaemorrhagiae and autumnalis serovars were the most prevalent. We used log-linear analyses to test for associations among seropositivity, age class, and sex of captured animals. Seropositivity was strongly associated with animal age class, but independent of sex. Forty-six percent of animals less than 2 years old, 63% of adults during peak reproductive years, and 100% of the oldest age class were seropositive. A nonparametric multivariate procedure (MRPP) showed that the composition of serovar antibody types changed with age, and ANOVA models demonstrated that antibody titers increased with age, suggesting long-term exposure to a greater number and variety (i.e., serovar types) of L. interrogans infections. This study presents the first quantitative survey of antibodies against L. interrogans serovars in a T. pecari population of the Pantanal. The high prevalence of leptospirosis antibodies in free-ranging white-lipped peccaries and the potential impacts on reproduction and population dynamics emphasize the need for further studies investigating the roles of Pantanal wildlife and livestock in the transmission and maintenance of L. interrogans in the environment.  相似文献   

20.
In a nationwide survey carried out during 1990-91 of more than 5800 dogs to detect antibodies against Leptospira interrogans serovars copenhageni, ballum and canicola, only one weak reactor against serovar canicola was found. Reactors of varying titre were found against serovar ballum in 0.7% of dogs tested, indicating sporadic infection with this serovar. Reactors (0.9%) to serovar copenhageni came mainly from the Waikato, Northland and the Auckland region. This was in agreement with the reported occurrence of the clinical syndrome and with the results of a smaller survey in urban Auckland, in which more than 5% of dogs tested were seropositive to serovar copenhageni.  相似文献   

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