Leptospirosis in horses in Ontario.

Sera from Thoroughbred and Standardbred horses in southwest Ontario were tested for antibody to seven Leptospira interrogans serovars (autumnalis, bratislava, canicola, grippotyphosa, hardjo, icterohaemorrhagiae, pomona), using the microscopic agglutination test. There was significantly higher seroprevalence of bratislava than of other serovars, in which prevalence was low. Seroprevalence of bratislava increased significantly with age; only 5% of two to three year old horses had titers greater than or equal to 1:80 compared to 52% of horses older than seven years. Eight of 16 foals from two farms seroconverted at low titers to bratislava between four and eight months of age. Leptospires were not detected by immunofluorescence and isolation techniques in 50 kidneys collected from horses at slaughter. Fetal tissues from 52 aborted horse fetuses were also examined by these methods and serovar kennewicki was identified by immunofluorescence and by isolation in one fetus. Serovar bratislava appears to be widespread in horses in Ontario but unimportant in abortion. The clinical significance of this infection in horses in Ontario is unclear.     

Leptospira interrogans serovar bratislava infection in two dogs

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.     

The isolation and identification of Leptospira interrogans serovar bratislava from a pig in Germany.

During a study on the improvement of selective media for the isolation of leptospires from clinical material, leptospires were isolated from the kidneys of a pig. Test material was cultured in EMJH-medium containing 0.4% rabbit serum and 3 inhibitory substances (Rifampicin 10 micrograms/ml, Amphotericin B 2 micrograms/ml, 5-Fluorouracil 100 micrograms/ml). The cultured leptospira-strain (Berlin 406) was identified to serogroup level using the cross agglutination method and it was further typed to serovar level by MAB's, factor analysis and restriction endonuclease analysis (REA). MAB typing of Berlin 406 gave an agglutination pattern profile typical of serovar bratislava. Factor serum identification clearly identified this strain as serovar bratislava. On REA examination, Berlin 406 gave a profile identical to that of the serovar bratislava type strain Jez Bratislava i.e. genotype B1. This is the first report of a confirmed isolate of Leptospira interrogans serovar bratislava from domestic animals in Germany. There exist a number of possibly important implications as this agent is being incriminated in the cause of clinical disease not only in pigs, but also in horses and dogs in other countries.     

Reproductive failure associated with Leptospira interrogans serovar bratislava infection of swine

Specimens from 17 swine herds experiencing reproductive failure were examined for Leptospira interrogans serovar bratislava. Clinical signs observed in these herds included stillborn pigs, weak neonatal pigs, and abortion. Diagnostic tests used to determine L. interrogans serovar bratislava infection were bacteriologic culture, serologic assays to detect antibodies, and immunofluorescence. Examination of fetal serum for antibodies against serovar bratislava and a fluorescent antibody test were the most practical diagnostic procedures.     

Effect of vaccination with a bacterin containing Leptospira interrogans serovar bratislava on the breeding performance of swine herds

Swine herds suspected to be infected with Leptospira interrogans serovar bratislava were vaccinated with bacterins containing 5 or 6 leptospiral serovars in which serovar bratislava was the unique component. The principal diagnostic feature indicating an infection by this organism was demonstration of antibody against serovar bratislava in sera from stillborn pigs. For 1 breeding cycle after vaccination of herds on 3 farms, 255 of 266 (95.9%) sows and gilts given the 6-serovar bacterin farrowed. In contrast, 233 of 311 (74.9%) sows and gilts given the 5-serovar bacterin farrowed. These results, as evaluated by analysis of variance techniques, showed a significant improvement (P less than 0.01) in reproductive performance for groups vaccinated against serovar bratislava.     

An experimental study with a Leptospira interrogans serovar bratislava vaccine

The intramuscular vaccination of pigs with two doses, two weeks apart, of a Leptospira interrogans serovar bratislava bacterin, protected pigs against renal infection when challenged with bratislava strains six weeks later but did not protect pigs challenged after 26 weeks.     

Isolation of Leptospira interrogans serovar bratislava from stillborn and weak pigs in Iowa

Leptospira interrogans serovar bratislava was isolated from a herd of swine in Iowa with a history of stillborn and weak neonatal pigs. Placentas, kidneys, and lungs of stillborn and weak pigs from 3 litters were processed to detect leptospires by use of bacteriologic culture and fluorescent antibody testing. Sera from stillborn and weak pigs were tested to detect agglutinating antibody against leptospires. A low antibody titer against L interrogans serovar bratislava was detected in the sera of stillborn and weak pigs. Small numbers of leptospires were sometimes detected in tissues by use of the fluorescent antibody test. Serovar bratislava was isolated from placentas, stillborn pigs or weak pigs from each of the 3 litters.     

Serovar identification of leptospires of the Australis serogroup isolated from free-living and domestic species in the United Kingdom

Eighteen isolates from the Australis serogroup from free-living and domestic animals were identified using the cross agglutination absorption test. Serovar muenchen was found only in England and Wales in wood mice, short tailed and bank voles, a grey squirrel and a pig. Serovar bratislava was found in hedgehogs in England, Wales and Northern Ireland and also in a brown rat from Northern Ireland. Serovar bratislava was isolated from sheep in both England and Northern Ireland and from horses in Northern Ireland. The distribution of these serovars in relation to possible maintenance hosts is discussed.     

Serum antibodies to Leptospira bratislava in Swedish pigs and horses

Sera from 116 and 89 Swedish pigs and horses respectively were examined for the presence of antibodies to L. bratislava. Antibodies were found in 18.1 and 49.4% respectively of pigs and horses examined. Presence of serum antibodies was not associated with clinical signs of infection.     

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)     

Clinical Leptospira interrogans serogroup Australis serovar lora infection in a stud farm in The Netherlands

A Leptospira interrogans serogroup australis serovar lora infection in a stud farm is reported. During three successive years (1984-1986) clinical leptospirosis with a severe often rapid, fatal course was seen in 12 foals. Clinical examination revealed severe respiratory distress, depression and pyrexia. Other symptoms were diarrhea (2), jaundice (1), and an unsteady gait (1). Morphological characteristics of the disease were massive pulmonary haemorrhage and haemorrhagic-thrombotic or extracapillary glomerulonephritis with tubulonephrosis and interstitial oedema. In most foals high or increasing MAT titres to serovar bratislava were found; from one foal Leptospira interrogans serovar lora was isolated. Serological examination of all 56 mares at the farm (August 1986) revealed antibodies to serovar bratislava in 64 per cent of the animals. These findings support the idea that Leptospira interrogans serovar bratislava and closely related strains (in this study serovar lora) may be adapted to and maintained by the horse population.     

Treatment and outcome of dogs with leptospirosis: 36 cases (1990-1998)

OBJECTIVE: To characterize serologic and clinical features and outcome of dogs with leptospirosis that were treated conservatively (i.e., medical management alone) or with hemodialysis. DESIGN: Retrospective study. ANIMALS: 36 dogs with leptospirosis. PROCEDURE: History; results of physical examinations, ultrasonography, and serologic, hematologic, and serum biochemical analyses; time to resolution of azotemia; and outcome were obtained from medical records. Dogs were treated conservatively (n = 22) or with hemodialysis (14). RESULTS: Between 1990 and 1998, amount of rainfall was positively correlated with number of cases of leptospirosis identified per year. Serum antibodies against 6 Leptospira serovars were measured, and titers were highest to Leptospira pomona in 16 (44%) dogs, L bratislava in 9 (25%) dogs, and L hardjo in 1 (3%) dog. Eight (22%) dogs had equally high titers to L pomona and L bratislava, 1 (3%) had equally high titers to L grippotyphosa and L canicola, and 1 (3%) had high titers to L grippotyphosa, L pomona, L canicola, and L bratislava. During initial evaluation, all dogs were azotemic. Thirty (83%) dogs survived, including 12 of 14 (86%) dogs treated with hemodialysis and 18 of 22 (82%) treated conservatively. Serum creatinine concentration was similar in both groups after resolution of clinical signs. CONCLUSIONS AND CLINICAL RELEVANCE: Infection with L pomona and L bratislava was recognized as a cause of leptospirosis in dogs, and resulted in development of acute renal failure with various degrees of azotemia. Prognosis for dogs with mild to moderate azotemia was good with conservative treatment, whereas treatment with hemodialysis appeared to improve prognosis for dogs with severe azotemia.     

Prevalence and serovars of leptospira involved in equine abortions in central Kentucky during the 1990 foaling season.

A study to determine the prevalence of leptospira-induced abortions in the central Kentucky equine population during the 1990 foaling season and to determine the leptospira serovars responsible was conducted. From July 1, 1989 through June 30, 1990, 32 (4.4%) of 726 submissions (fetuses, stillborn foals, and/or placentas) were diagnosed as leptospirosis by the fluorescent antibody test and/or microscopic agglutination test. Attempts were made to isolate leptospires from the fetal tissues and/or the dam's urine in 31 of these cases. Leptospira interrogans serovar kennewicki was isolated from 11 (35.5%) and serovar grippotyphosa from 2 (6.5%) of the 31 cases. Of 12 cases that were culture negative with serologically positive fetal fluids, 8 had titers against serovar pomona, 1 against bratislava, 1 against grippotyphosa, 1 against hardjo, and 1 against both bratislava and pomona.     

Clinical Leptospira interrogans serogroup Australis serovar lora infection in a stud farm in the Netherlands

Summary

A Leptospira interrogans serogroup australis serovar lora infection in a stud farm is reported. During three successive years (1984–1986) clinical leptospirosis with a severe often rapid, fatal course was seen in 12 foals.

Clinical examination revealed severe respiratory distress, depression and pyrexia. Other symptoms were diarrhea (2), jaundice (1), and an unsteady gait (1). Morphological characteristics of the disease were massive pulmonary haemorrhage and haemorrhagicthrombotic or extracapillary glomerulonephritis with tubulonephrosis and interstitial oedema. In most foals high or increasing MAT titres to serovar bratislava were found; from one foal Leptospira interrogans serovar lora was isolated.

Serological examination of all 56 mares at the farm (August 1986) revealed antibodies to serovar bratislava in 64 per cent of the animals. These findings support the idea that Leptospira interrogans serovar bratislava and closely related strains (in this study serovar lora) may be adapted to and maintained by the horse population.     

Prevalence of Leptospira infection in aborted pigs in Northern Ireland

During an investigation of pig abortions and stillbirths in Northern Ireland, leptospires were isolated from 55 of the 78 litters examined. Strains belonging to four serogroups (Australis, Icterohaemorrhagiae, Hebdomadis and Autumnalis) were recovered but leptospires of the Australis serogroup accounted for 91 per cent of the isolates. Two serovars of the Australis group bratislava and muenchen, were identified.     

Leptospirosis in raccoons in Quebec: 2 case reports and seroprevalence in a recreational area.

Raccoons may represent a source of leptospires for humans and domestic animals. We describe a case of severe interstitial nephritis associated with the serovar bratislava of Leptospira interrogans (1st report in wildlife), and the seroprevalence to 4 leptospire serovars in a recreational area in Quebec.     

Leptospira interrogans infection in domestic and wild animals in Fiji

Clinical and serological evidence has indicated that human leptospirosis in Fiji is an important disease, and the prevalence of antibody is exceptionally high. A serological survey of the rural population showed that only 12% of the people studied did not have complement fixing (CF) leptospiral antibody. As the origin of this infection could not be explained by the known distribution of leptospiral infection in domestic and wild animals, a serological survey using the complement fixation test (CFT) was undertaken as the first stage of an epidemiological investigation into human and animal leptospirosis. Sera from domestic and wild animals were tested for CF antibody to 12 leptospiral serovars, namely: pomona, copenhageni, grippotyphosa, hardjo, ballum, tarassovi, canicola, australis, bratislava, autumnalis, pyrogenes and bataviae. Antibody was detected in 27.5% of 480 cattle, 17.1% of 70 sheep, 10.3% of 252 goats, 10.0% of 480 pigs, 57.0% of 100 dogs, 55.8% of 34 rats (Rattus rattus, R. frugivorus, R. exulans and R. norvegicus), 53.1% of 32 mongooses (Herpestes auropunctatus) and 40.0% of 10 mice (species unknown.) Cross-reactivity precluded the identification of infecting serogroups with the exception of pomona in pigs and icterohaemorrhagiae, ballum and australis in dogs. Infection of dogs with a serovar of the australis serogroup may explain the predominance of serological reactions to bratislava in man. The survey revealed a significant level of leptospiral antibody in the animal populations of Fiji and indicated that cattle, dogs, rats, mongooses and mice are probably the most important maintenance hosts. Consequently, further investigation will concentrate on the attempted isolation of leptospires from these species.     

Animal- and herd-level risk factors for leptospiral seropositivity among sows in the Mekong delta, Vietnam

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.     

Experimental canine leptospirosis caused by Leptospira interrogans serovars pomona and bratislava

OBJECTIVE: To evaluate gross, histopathologic, and serum biochemical findings caused by Leptospira interrogans serovars pomona and bratislava inoculated in dogs. ANIMALS: Twenty-seven 8-week-old female Beagles. PROCEDURE: Dogs were randomly assigned to challenge or control groups. Challenge groups were conjunctivally inoculated on 3 successive days with 5 x 10(7) L interrogans serovar pomona (n = 12) or serovar bratislava (11). Clinical signs were recorded throughout the experiment, and clinical pathology assays, bacteriologic culture, and necropsies (6 or 7 dogs necropsied at each time point) were done on postinoculation day (PID) 7, 10, 14, and 20. RESULTS: Infection could not be confirmed in any serovar bratislava-inoculated dog, and control dogs remained healthy throughout the experiment. Positive culture and fluorescent antibody test results were confirmed in 11 of 12 serovar pomona-inoculated dogs. Fever and lethargy starting at PID 7 were the most common clinical signs in serovar pomona-infected dogs. On day 10, gross lesions included multifocal renal and pulmonary hemorrhage and perirenal edema. Serovar pomona-inoculated dogs had histopathologic lesions including hepatitis, interstitial nephritis, and pneumonia at PID 7, 10, 14, and 20. Increases in BUN, anion gap, and bilirubin concentration occurred on PID 10, 14, and 20. Platelet counts in dogs with positive results of bacteriologic culture were decreased from baseline values on PID 10, 12, and 14. CONCLUSIONS AND CLINICAL RELEVANCE: Conjunctival inoculation with L interrogans serovar pomona resulted in a high rate of infection with concomitant hemorrhagic and inflammatory lesions of the kidneys, liver, and lungs.     

Etiologic studies on late-term swine abortions

One hundred thirty-eight swine abortions were studied in detail in an effort to identify an etiologic agent. A viral agent was implicated in 7 cases. Bacteria were isolated in less than half of the examined cases: however, in 61% of the cases, motile, filamentous organisms were observed in tissues and fluids. Although swine sera from farms experiencing reproductive problems had a high reactor rate to Leptospira bratislava antigen, electron microscopy of the observed organism revealed a wall-free prokaryote morphologically typical of the class Mollicutes.