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PubMed2004

Serologic survey for selected disease agents in wolves (Canis lupus) from Alaska and the Yukon Territory, 1984-2000.

Wolves (Canis lupus) were captured in several geographic areas of Alaska (USA) and the Yukon Territory (Canada) during 1984-2000. Blood was collected from 1,122 animals. Sera were tested for antibodies against infectious canine hepatitis virus (ICH), canine distemper virus (CDV), canine parvovirus (CPV), Francisella tularensis, and serovars of Leptospira interrogans. Antibody prevalence for ICH was >84% for all areas. Area-specific prevalences of antibodies ranged from 12% to 70% for CPV, from 0% to 41% for CDV, and from 4% to 21% for F. tularensis. There was no evidence of CDV exposure at the two southernmost locations in Alaska. Prevalence of antibodies for ICH increased slightly during the 16-yr course of the survey. There was essentially no evidence of exposure to L. interrogans. Prevalences of antibodies for both CPV and CDV were age-specific, with higher values in the adult cohort compared with the pup cohort. There were no sex-specific differences in prevalence of antibodies for any of the five disease agents.

Alaska↗
PubMed1977

Bovine leptospirosis: experimental infection of pregnant heifers with a strain belonging to the Hebdomadis serogroup.

Twenty pregnant heifers were inoculated with a leptospire of the Hebdomadis serogroup. Leptospiraemia was accompanied by pyrexia which lasted from one to five days. Sixteen animals had relapses of fever. One of these aborted and two produced weak calves, one of which was premature. In the heifers, leptospires localised in the placentae, where they were demonstrable for 14-60 days after inoculation, and in the renal tubules for as long as 174 days. They were also demonstrated in liver, kidney and lung from the aborted fetus. Antibodies were detected in susceptible heifers six days after inoculation and maximum titres of up to 1:100,000 developed between 11 and 21 days. A titre of 1:10 was demonstrated in the serum of a premature live calf. These findings indicated that leptospires of the Hebdomadis group were capable of causing abortion in cattle.

Abortion, Veterinary↗
PubMed1999

Field evaluation of a one-step dipstick assay for the diagnosis of human leptospirosis in the Seychelles.

OBJECTIVE AND METHOD: To compare the response of a dipstick assay (DSA) detecting Leptospira-specific immunoglobulin M (IgM) antibodies with that of an enzyme-linked immunosorbent assay (ELISA), an indirect haemagglutination assay (IHA), the microagglutination test (MAT) and a polymerase chain reaction assay (PCR) in patients with leptospirosis confirmed by MAT alone or by MAT and/or PCR (MAT/PCR). RESULT: In 75 patients with acute leptospirosis diagnosed by MAT (respectively, 90 patients diagnosed by MAT/PCR), the response in paired early and convalescent sera was positive in 78.9% (67.9%) by DSA, 76.0% (67.8%) by ELISA, 58.7% (55.6%) by IHA, 44.0% (53.3%) by PCR, and 100% (90.0%) by MAT. In early serum only, the response in patients diagnosed by MAT (respectively by MAT/PCR) was positive in 36.0% (38.9%) by DSA, 36.0% (37.8%) by ELISA, 14.7% (18.9%) by IHA, 39.2% (48.3%) by PCR, and 53.3% (58.9%) by MAT titre > or =1:100. DSA detected the main serogroups implicated in human leptospirosis in Seychelles and demonstrated sensitivity comparable to ELISA. In 124 single sera from control subjects without overt disease, the response was positive in 4.8% by DSA, 3.2% by ELISA, 3.2% by IHA, 13.8% by PCR, 37.9% by MAT titre > or =1:100, and 2.4% by MAT titre > or =1:800, giving evidence of the frequency of both past and current subclinical infection in Seychelles and that DSA was less sensitive than MAT to detect moderate levels of leptospiral antibodies. CONCLUSION: DSA is a simple and reproducible assay well adapted to field conditions and could usefully contribute to the evaluation of leptospirosis in areas devoid of serological laboratory facilities.

Acute Disease↗
PubMed2006

Immunohistochemical identification and pathologic findings in natural cases of equine abortion caused by leptospiral infection.

The aim of this study was to examine the utility of immunohistochemistry (IHC) in the diagnosis of leptospiral equine abortion and to compare IHC to silver staining and serology of the aborted mares. Ninety-six fetuses from 57 farms were examined using all 3 diagnostic techniques, revealing evidence of leptospiral infection in 3 fetuses (3.1%) from 3 (5.3%) different farms. A new finding in 1 of these confirmed cases of leptospiral abortion was the presence of macroscopic pinpoint grayish-white nodules that had a histologic correlate of hepatic necrosis; other histologic findings were consistent with those previously reported. IHC performed using 2 different leptospiral antisera (multivalent whole-cell rabbit antiserum and rabbit antiserum against the major outer membrane protein LipL32) yielded similar results. IHC was more sensitive (19/21 [90.5%] tissue samples) than silver staining (8/21 [38.1%] tissue samples), and more specific than serology performed using the microscopic agglutination test. The primary advantage of IHC over silver staining was the ability of IHC to identify leptospiral antigen not only as morphologically intact spiral forms.

Aborted Fetus↗
PubMed1989

[Studies on enhancement of nonspecific resistance to infection by leptospiral lipopolysaccharide. II. The mechanisms of the nonspecific protective activity of the LPS].

Leptospiral lipopolysaccharide can enhance the nonspecific resistance of host to infection. By researching its mechanism, we found: (1) The phagocytic function of peritoneal macrophages of guinea pigs was strengthened by E-LPS and L-LPS; (2) L-LPS and E-LPS activated peritoneal macrophages of mice then enlarging the cell raji, and increase the quantity and activity of intracellular acid phosphatase. Relatively, the L-LPS might have a greater action in synthesis of the enzyme, while the E-LPS mainly enhanced the activity of the enzyme; (3) L-LPS and E-LPS appeared to be immunomodulant. When they were injected 3d after immunizing the mice with SRBC, immune adjuvant effect developed; however, if the injection of LPS was made 24h prior to the immunization, it would result in immunosuppression.

Acid Phosphatase↗
PubMed1999

Detection of leptospires in bovine semen by polymerase chain reaction.

OBJECTIVE: In view of the considerable importance of venereal transmission of bovine leptospirosis, the objective of the present study was to compare the polymerase chain reaction (PCR), culture/isolation and serology to detect leptospire infection in bovine semen. DESIGN: Blood for serologic examination and semen for bacterial culture and PCR were collected from 20 bulls at artificial insemination centres in Brazil. Each animal was sampled twice for serology. RESULT: Forty-five percent (9/20) of the serum samples collected showed agglutinin titers to serovar hardjo in the first sample and 25% (5/20) had agglutinin titers to serovar hardjo in the second sample. Eighty percent (16/20) of semen samples were positive by PCR. Leptospires could not be isolated from any of the semen samples examined. CONCLUSION: Polymerase chain reaction can be a method of great potential for the detection of leptospires at artificial insemination centres.

Animals↗
PubMedDate not supplied

Evaluation of a rapid slide agglutination test for the diagnosis of acute canine leptospirosis.

The standard method for the diagnostic of leptospirosis is the microscopic agglutination test (MAT). Nevertheless, it is time-consuming and presents risk of infection for laboratory personal. Several attempts to simplify and reduce the time, skill and expense required for serological testing were made. Rapid slide agglutination tests (RSAT) have been used nowadays as a reliable screening test for the detection of acute and recent infections by many laboratories. The purpose of that study was to evaluate a new antigen preparation for the rapid diagnoses of acute canine leptospirosis and to compare it with MAT results in clinically suspect serum samples. Two hundred and thirteen serum samples from dogs of both sexes and different ages were tested and 141 (66.2%) animals were considered as positive by MAT. The most frequent serovar was icterohaemorrhagiae, followed by canicola. RSAT results were very similar to those observed on MAT, with 139 (65.3%) reactive animals. Correlation between RSAT and MAT was positive (0.82) and significant (p < 0.01). Concordance of results was of 93.4% (199/ 213) of the animals correctly diagnosed by RSAT. Considering MAT as the standard test, sensitivity of RSAT was calculated on 94.3% (133/141) and specificity on 91.7% (66/72).

Agglutination Tests↗
PubMed2005

PCR screening for candidate etiological agents of canine hepatitis.

PROBLEM ASSESSED: Hepatitis, either acute or chronic, is a relatively common hepatic disease in dogs. Several forms of canine hepatitis can occur, some with a defined cause, most cases have an unknown etiology. The similarities between canine hepatitis and human viral hepatitis suggest that canine hepatitis may have a viral etiology too. OBJECTIVE: To test liver tissue of dogs with hepatitis for the presence of candidate agents based on their known association with hepatitis in other mammals. METHODS AND APPROACH: The following infectious agents were tested by PCR: Hepadnaviridae, Helicobacter spp., Leptospira spp., Borrelia spp., hepatitis A virus, hepatitis C virus and hepatitis E virus. Also canine adenovirus and parvovirus were included. Ninety-eight liver tissue samples of dogs with various histologically diagnoses forms of hepatitis were tested. Primers were designed on conserved regions in the genome of each of these agents, to increase the likelihood of detection by PCR. To further increase sensitivity, nested PCRs for all agents were designed. Finally, for each agent a nested short primer PCR (SPP) was performed. RESULTS: None of these agents were detected by nested PCR and nested SPP. However, in two acute hepatitis liver samples parvovirus was detected by nested PCR, and one of these was also detected by nested SPP. CONCLUSIONS: Hepatitis in dogs is not caused by agents with high homology to known infectious agents that cause hepatitis in other species.

Animals↗
PubMedDate not supplied

[Importance of the microbiological confirmation in an outbreak of human leptospirosis in the city of Villa Clara].

A multidisciplinary group was created to confirm the existance of human leptospirosis in the province of Villa Clara where by the end of June, 1977, there was a considerable increase of febrile cases with symptoms and signs consistent with diseases such as hemorrhagic dengue and human leptospirosis. The National Laboratory of Reference of Leptospires from "Pedro Kouri" Institute, organized a set of direct and indirect diagnostic techniques as a working strategy that would serve to confirm this health problem. As a final result, it was observed that the Ballum, Pomona, Canicola and icterohaemorrhagiae serogroups showed the highest percentage of appearance among the studied cases. A total of 7 cases had active infection, since they were positives by the passive hemoagglutination method. The four severe cases studied by passive hemoagglutination and microagglutination were positive. Sera from the 3 patients with febrile syndrome of unknown ethiology were negative by these 2 techniques. The 3 samples obtained from the autopsy of a dead were positive by direct exam in dark field and staining of immunoperoxidase. The monosera of the dead subjects were highly reactive by passive hemagglutination (titers from 1-10 and up to 1-640). 2 hemocultures were typified as Ballum; 2 urines and 1 hemoculture were positive by polymerase chain reaction. In this way, a fast answer was given to the health public authorities from the Viceministry of Hygiene and Epidemiology of Cuba on confirming microbiologically the existance of the disease. lt was sugggested to administer the Cuban vax SPIRAL vaccine in the affected area.

Cuba↗
PubMed1967

Antileptospiral activity of serum. II. Leptospiral virulence factor.

A definite relationship exists between the resistance of leptospires to the antibody-complement system and virulence. Leptospires capable of producing either lethal or renal infections in hamsters or guinea pigs were resistant to the leptospiricidal action of antibody and complement. Avirulent leptospires, in contrast to the virulent organisms, were rapidly immobilized and killed by these serum substances. The change of a virulent culture to the avirulent state as a result of growth in culture media was accompanied by the loss of resistance to antibody and complement. Virulent leptospires were phenotypically altered when grown in the presence of the purine analogue, 8-azaguanine. The cells became sensitive to antibody and complement without a corresponding decrease in virulence. The basis for a leptospiral virulence factor, the ability to multiply in vivo, appears to reside in their capacity to resist the leptospiricidal activity of the host antibody-complement system. The immune leptospiricidal assay provides a simple and rapid method of determining the virulence of a culture.

Animals↗
PubMed1993

Etiology and pathology of equine placentitis.

Placentas from aborted, stillborn, and premature foals were examined during the 1988 and 1989 foaling seasons, and 236 of 954 (24.7%) had placentitis. Microorganisms associated with placentitis were isolated or demonstrated from 162 of 236 (68.6%) placentitis cases. Leptospira spp. and a nocardioform actinomycete were 2 important, newly emerging bacteria associated with equine placentitis. Major pathogens identified in decreasing order were Streptococcus zooepidemicus, Leptospira spp., Escherichia coli, a nocardioform actinomycete, fungi, Pseudomonas aeruginosa, Streptococcus equisimilis, Enterobacter agglomerans, Klebsiella pneumoniae, and alpha-hemolytic Streptococcus. Pathogens were not recovered in 64 cases (27.1%) and overgrowth by saprophytic bacteria was recorded in 10 cases (4.2%). Twenty-seven cases (16.6%) had mixed bacterial growth and 93 cases (57.4%) had bacteria cultured from both placenta and fetal organs. The majority of the placentitis cases caused by bacteria, with the exception of Leptospira spp. and the nocardioform actinomycete, occurred in 2 forms. One was acute, focal or diffuse; had an infiltration of neutrophils in the intervillous spaces or necrosis of chorionic villi; was associated with bacteremia; and frequently occurred in the placenta from fetuses expelled before or at midgestation. The other was observed from foals expelled at late gestation, was mostly chronic and focal or focally extensive, and occurred mostly at the cervical star area. Chronic placentitis was characterized by the presence of 1 or a combination of the following lesions: necrosis of chorionic villi, presence of eosinophilic amorphous material on the chorion, and infiltration of mononuclear inflammatory cells in the intervillous spaces, villous stroma, chorionic stroma, vascular layer, and allantois.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Veterinary↗
PubMed2004

Role of nonesterified unsaturated fatty acids in the pathophysiological processes of leptospiral infection.

Organ malfunctions in patients with leptospirosis have been associated with the bacterial glycolipoprotein endotoxin and with its nonesterified unsaturated fatty acid (NEUFA) components. We examined the involvement of NEUFAs in the pathophysiological processes of leptospirosis. Patients showed a moderate increase in serum concentrations of oleic and linoleic acids but an important decrease in serum concentrations of albumin. A highly significant correlation between serum concentrations of creatinine or total bilirubin and the oleic-plus-linoleic acid : albumin ratio was revealed. We used the Na(+),K(+)-ATPase inhibitory property of NEUFAs to test the capacity of serum to prevent the cytotoxic effects of NEUFAs in vitro. Albumin solutions and serum samples from healthy volunteers, but not serum samples from severely affected patients, were able to revert the Na(+),K(+)-ATPase inhibition by oleic acid. On the basis of these data, we defined a "serum protection factor" that can be helpful in predicting NEUFA toxicity. Our data support the concept that the administration of human albumin to patients may be helpful in severe leptospirosis cases.

Adult↗
PubMed2006

Isolation and characterization of the emerging foodborn pathogen Arcobacter from human stool.

At present, isolation of arcobacters from human specimens is performed by slightly of not modified Campylobacter, Yersinia or Leptospira isolation techniques, and knowledge if arcobacters are part of the human commensal flora is lacking. Therefore, an Arcobacter selective isolation procedure was validated for the examination of human fecal specimens, and the presence and characteristics of Arcobacter in feces of asymptomatic humans was examined in order to assess the clinical relevance of arcobacters in diarrheal stool. With this method, Arcobacter was isolated from seven of 500 (1.4%) stool samples of healthy people with Arcobacter cryaerophilus as the only species present. Seven A. cryaerophilus genotypes were detected and only one genotype was found per person. Neither A. butzleri nor A. skirrowii were isolated, therefore the presence of those latter species in clinical samples requires further attention. Though the pathogenic role and potential virulence factors of arcobacters have to be further examined, the current status of arcobacters as emerging pathogens remains justified.

Adult↗
PubMed1997

Leptospirosis in Kolenchery, Kerala, India: epidemiology, prevalent local serogroups and serovars and a new serovar.

Leptospirosis is the most widespread zoonosis in the world. It is mostly an occupational disease especially in rural areas. Kolenchery is in the midlands of Kerala. The landscape consists of marshy land and dry land interspersed by rivulets and ponds. Irrigation of dry lands for cultivation during the summer months started in mid 1980s after the irrigation projects were commissioned. Cases of leptospirosis were rarely diagnosed in Kolenchery before 1987. Since then a yearly increase in incidence is observed. No major study on either epidemiology or clinical picture has been done on human leptospirosis in Kerala so far. The aim of this study was to define the major clinical presentations, epidemiology of the infection and demonstrate the predominant serogroups and serovars causing the illness in this limited geographical area. The study involves 976 cases of leptospirosis confirmed by culture and/or serological tests. Serogroups Autumnalis, Australis and Icterohaemorrhagiae were the commonest. Mortality rate was 5.32%. The increase in incidence is probably due to the geographical characteristics, continuous moisture of the soil due to irrigation in summer and year-round cultivation making food and cover available to host rodents. Close interaction of humans, animals, soil and water in this region make the spread of leptospirosis to humans easy. Confirmation of cases has been done by enzyme linked immunosorbent assay (ELISA) and/or microscopic agglutination test (MAT) and/or by culture. Serovar identification has been done in 21 cultures isolated from patients. One new serovar belonging to serogroup Australis has been identified from a patient and named serovar Australis bharathy.

Adolescent↗
PubMed1981

Serological and bacteriological survey of leptospiral infection in pigs in southern England.

A total of 597 pigs were examined for serological and bacteriological evidence of leptospiral infection. The sample comprised 189 porkers, 205 baconers and 203 sows. Sera were tested against 17 antigens from 16 serogroups and the overall prevalence of titres was 15.7 per cent. The lowest prevalence of titres was found in porkers (10.0 per cent). The highest prevalence of titres to an individual antigen was recorded with bratislava, a member of the Australis serogroup, with 12.2 per cent of pigs positive. Copenhageni titres were present in 1.8 per cent of the sera and sporadic titres were recorded to various other antigens. Leptospires were isolated from five pigs. Four isolates were identified as belonging to the Icterohaemorrhagiae serogroup and one to the Hebdomadis serogroup. The serological to bacteriological ratio for the Icterohaemorrhagiae serogroup was 11:4. The virtual absence of titres to pomona and tarassovi, the two serovars most commonly maintained by porcine populations in other countries, confirms the results of earlier serological surveys.

Animals↗
PubMed2006

Evaluation of a commercial latex agglutination assay for serological diagnosis of leptospirosis.

Leptospirosis is a febrile zoonosis of worldwide distribution. A latex agglutination assay was evaluated in two studies, the first using a panel of well-characterized sera from patients with leptospirosis and from patients with other disease states and the second, a prospective hospital-based study, evaluating sera from 186 consecutive patients admitted to hospital with acute febrile illness. The confirmed leptospirosis serum panel included paired acute- and convalescent-phase specimens from 40 cases, of which 34 gave positive latex tests (case sensitivity, 85%; 95% confidence interval [95% CI], 70 to 94%). The other diseases represented in the panel of 112 specimens from nonleptospirosis patients included autoimmune diseases, brucellosis, dengue, melioidosis, malaria, syphilis, toxoplasmosis, viral hepatitis, and a number of other viral infections. The specificity of latex agglutination using this panel was 81% (95% CI, 73 to 87%). Among the patients with acute febrile illness, there were 25 cases of leptospirosis and 161 patients with other diagnoses. The sensitivity and specificity of latex agglutination in this group were 88% (95% CI, 72 to 97%) and 98% (95% CI, 95 to 100%), respectively. In this evaluation, the two distinct groups of specimens gave similar results for sensitivity, but specificity was different in each study. The sensitivity and specificity observed for the hospital study were similar to those obtained in evaluations of other rapid tests in the same population. The results of this study suggest that multiple evaluations of new diagnostic assays should be performed, because performance characteristics may vary in different populations.

Antibodies, Bacterial↗
PubMed1994

[The role of the kallikrein-kinin system in the pathogenesis of leptospirosis].

The author studied the clinical and biochemical characteristic of leptospirosis in 101 patients and the changes of the components of the kallikrein-kinin system during the dynamics of the disease and the valuation of its prognosticated importance. In 26 patients she determined the level of prekallikrein and kallikrein in serum. Furthermore author measured level of components of kallikrein-kinin system in 16 guinea-pigs, infected with different virulence L. icterohaemorrhagie. She determined the serum prekallikrein and kallikrein in 20 control persons and 10 healthy guinea-pigs. At the peak of the disease the decreased level of prekallikrein with increased kallikrein activity at the same time was evaluated as in one respect its reduced synthesis in the liver, on the other hand by change of proenzyme into active form. In the phase of reconvalescence the normalization of the level of prekallikrein was missing. In these patients who got over the illness of icteric leptospirosis with acute renal failure at the controlled examination increased prekallikrein were found that supposed the absence of normalization of metabolism of kinins. On the basis of these data and experimental results author can establish that the components of kallikrein-kinin system in the high degree reflect the functional condition of liver and kidney at different phase of the disease.

Adult↗
PubMed2003

"Probable" versus "confirmed" leptospirosis: an epidemiologic and clinical comparison utilizing a surveillance case classification.

PURPOSE: For surveillance purposes, the Centers for Disease Control and Prevention and Council of State and Territorial Epidemiologists (CDC/CSTE) have defined two case classifications for leptospirosis: "confirmed" and "probable." The objective of this study was to provide data to refine the current surveillance case classifications. METHODS: All reported leptospirosis infections from exposures within the State of Hawaii, 1974 to 1998 meeting CDC/CSTE "confirmed" and "probable" case classifications were compared on a number of clinical and epidemiologic parameters. RESULTS: Confirmed cases (n = 276) had more severe clinical manifestations than probable cases (n = 180); however, probable cases with higher peak microscopic agglutination test (MAT) titers (> or =1:800) were clinically and epidemiologically comparable to confirmed cases. In addition, 77 cases demonstrating fourfold or greater MAT titer increases in paired serum collected less than two weeks apart (currently excluded from the "confirmed" case classification) were also comparable to confirmed cases. CONCLUSIONS: Our findings support amending the current CDC/CSTE surveillance confirmed case classification to include demonstration of a fourfold or greater MAT titer increase in paired serum, irrespective of the interval between specimen collection. Consideration should also be given to including single MAT titer > or =1:800 as a criterion for "confirmation." These changes would both simplify and expedite the surveillance confirmation of leptospirosis.

Diagnosis, Differential↗