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Rodents are important reservoir hosts of pathogenic leptospires in the US Virgin Islands. Our previous work determined that trapped rodents were colonized with Leptospira borgpetersenii serogroup Ballum (n = 48) and/or Leptospira kirschneri serogroup Icterohaemorrhagiae (n = 3). In addition, nine rodents appeared to be colonized with a mixed population comprising more than one species/serogroup. The aim of this study was to validate this finding by characterizing clonal isolates derived from cultures of mixed species. Cultures of presumptive mixed species (designated LR1, LR5, LR37, LR57, LR60, LR61, LR68, LR70, and LR72) were propagated in different media including Hornsby-Alt-Nally (HAN) media, incubated at both 29â and 37â, and T80/40/LH incubated at 29â. Polyclonal reference antisera specific for serogroup Ballum and Icterohaemorrhagiae were used to enrich for different serogroups followed by subculture on agar plates. Individual colonies were then selected for genotyping and serotyping. Of the nine cultures of mixed species/serogroups, a single clonal isolate was separated in five of them: L. borgpetersenii serogroup Ballum in LR1, LR5, and LR37, and L. kirschneri serogroup Icterohaemorrhagiae in LR60 and LR72. In four of the cultures with mixed species (LR57, LR61, LR68, and LR70), clonal isolates of both L. borgpetersenii serogroup Ballum and L. kirschneri serogroup Icterohaemorrhagiae were recovered. Our results definitively establish that rodents can be colonized with more than one species/serogroup of Leptospira concurrently. The identification and characterization of multiple species/serogroups of Leptospira from individual reservoir hosts of infection are essential to understand the epidemiology and transmission of disease to both human and domestic animal populations.IMPORTANCEPathogenic Leptospira, the causative agent of human and animal leptospirosis, comprise a diverse genus of species/serogroups which are inherently difficult to isolate from mammalian hosts due to fastidious growth requirements. Molecular evidence has indicated that reservoir hosts of Leptospira may shed multiple species concurrently. However, evidence of this phenomena by culture has been lacking. Culture is definitive and is essential for comprehensive characterization of recovered isolates by high-resolution genome sequencing and serotyping. In this work, a protocol using recently developed novel media formulations, in conjunction with reference antisera, was developed and validated to demonstrate the recovery of multiple species/serogroups of pathogenic Leptospira from the same host. The identification and characterization of multiple species/serogroups of Leptospira from individual reservoir hosts of infection are essential to understand the epidemiology and transmission of disease to both human and domestic animal populations.
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Leptospira , Leptospirosis , Animales , Humanos , Serogrupo , Roedores , Leptospira/genética , Leptospirosis/veterinaria , Animales Domésticos , Riñón , Sueros Inmunes/genéticaRESUMEN
BACKGROUND: Leptospirosis is a neglected but widespread zoonotic disease throughout the world. Most mammals are hosts of Leptospira spp., including domestic cats, species in which no consensus has been reached on the clinical presentation or diagnosis of the disease. The study of acute-phase proteins (APPs) and biomarkers of oxidative status would contribute to knowledge about the disease in cats. This report evaluated four APPs: Serum amyloid A-SAA, Haptoglobin-Hp, albumin and Paraoxonase 1-PON1 and the antioxidant response through Total Antioxidant Capacity-TAC, in 32 free-roaming cats. Cats were classified as seroreactive for anti-leptospiral antibodies (group 1, n = 8), infected with Leptospira spp (group 2, n = 5) and leptospires-free cats (group 3, n = 19). RESULTS: SAA differences were observed between groups 1 and 2 (p-value = 0.01) and between groups 2 and 3 (p-value = 0.0001). Hp concentration differences were only detected between groups 2 and 3 (p-value = 0.001). Albumin concentrations only differed between groups 1 and 3 (p-value = 0.017) and 2 and 3 (p-value < 0.005). Cats in groups 1 (p-value < 0.005) and 2 (p-value < 0.005) had lower PON1 concentrations than group 3. No statistically significant differences between pairs of groups were detected for TAC concentrations. The principal component analysis (PCA) retained two principal components, (PC1 and PC2), explaining 60.1% of the observed variability of the inflammatory proteins and the antioxidant TAC. CONCLUSIONS: Increases in Serum SAA, Hp, and decreases in PON1 activity may indicate an active inflammatory state in infected cats (currently or recently infected).
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Proteínas de Fase Aguda , Leptospira , Gatos , Animales , Antioxidantes , Proteína Amiloide A Sérica , Haptoglobinas , Albúminas , MamíferosRESUMEN
BACKGROUND: Rickettsial disease (RD) is a prevalent and underestimated cause of febrile illness worldwide, especially in the absence of an inoculation eschar. We attempted to quantify this underestimation at our clinic, by investigating past cases of febrile illness in travelers who had tested negative for leptospirosis, a disease that can initially present similarly to non-eschar RD, and which we routinely consider when other important causes of unspecified febrile illness have tested negative. METHODS: We performed a retrospective analysis in febrile returned travelers from Asia, Africa, or the Americas between 2010 and 2017, who had tested negative for leptospirosis. Serologic immunofluorescence assays were performed for Orientia tsutsugamushi (scrub typhus), typhus group, and spotted fever group RD. We performed a medical records review of all patients who tested positive. In case of a fitting medical history, cases were deemed either confirmed (based on convalescent serology) or suspected (based on single serology). RESULTS: Among 97 patients, convalescent serology was available in 16 (16.5%) patients, and a single serology in 81 (83.5%) patients. RD was the likely diagnosis in 8 of 16 (50.0%) patients with convalescent serology, and in 8 of 81 (9.9%) with single serology. Of the 16 confirmed/suspected cases, 11 (69%) had been missed and 7 (44%) had not received adequate empiric antibiotic therapy. CONCLUSIONS: This study shows that non-eschar RD is an important and poorly recognized cause of illness in travelers, even in a specialized travel clinic. A lower threshold to test and treat for RD is warranted in returning travelers with febrile illness.
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Infecciones por Rickettsia , Tifus por Ácaros , África , Asia , Humanos , Estudios Retrospectivos , Infecciones por Rickettsia/diagnóstico , Infecciones por Rickettsia/epidemiología , Tifus por Ácaros/diagnóstico , Tifus por Ácaros/epidemiologíaRESUMEN
BACKGROUND: Leptospirosis is a widespread zoonosis and has been recognized as a re-emerging infectious disease in humans and dogs, but prevalence of Leptospira shedding in dogs in Thailand is unknown. The aim of this study was to determine urinary shedding of Leptospira in dogs in Thailand, to evaluate antibody prevalence by microscopic agglutination test (MAT) and enzyme-linked immunosorbent assay (ELISA), and to assess risk factors for Leptospira infection. In Northern, Northeastern, and Central Thailand, 273 stray (n = 119) or client-owned (n = 154) dogs from rural (n = 139) or urban (n = 134) areas were randomly included. Dogs that had received antibiotics within 4 weeks prior to sampling were excluded. No dog had received vaccination against Leptospira. Urine was evaluated by real-time polymerase chain reaction (PCR) specific for lipL32 gene of pathogenic Leptospira. Additionally, urine was cultured for 6 months in Ellinghausen-McCullough-Johnson-Harris (EMJH) medium. Antibodies were measured by ELISA and MAT against 24 serovars belonging to 15 serogroups and 1 undesignated serogroup. Risk factor analysis was performed with backwards stepwise selection based on Wald. RESULTS: Twelve of 273 (4.4%; 95% confidence interval (CI): 2.0-6.8%) urine samples were PCR-positive. In 1/273 dogs (0.4%; 95% CI: 0.01-1.1%) Leptospira could be cultured from urine. MAT detected antibodies in 33/273 dogs (12.1%; 95% CI: 8.2-16.0%) against 19 different serovars (Anhoa, Australis, Ballum, Bataviae, Bratislava, Broomi, Canicola, Copenhageni, Coxi, Grippotyphosa, Haemolytica, Icterohaemorrhagiae, Khorat, Paidjan, Patoc, Pyrogenes, Rachmati, Saxkoebing, Sejroe). In 111/252 dogs (44.0%; 95% CI: 37.9-50.2%) immunoglobulin M (IgM) and/or immunoglobulin G (IgG) antibodies were found by ELISA. Female dogs had a significantly higher risk for Leptospira infection (p = 0.023). CONCLUSIONS: Leptospira shedding occurs in randomly sampled dogs in Thailand, with infection rates comparable to those of Europe and the USA. Therefore, the potential zoonotic risk should not be underestimated and use of Leptospira vaccines are recommended.
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Derrame de Bacterias , Enfermedades de los Perros/microbiología , Leptospira/fisiología , Leptospirosis/veterinaria , Animales , Anticuerpos Antibacterianos , Enfermedades de los Perros/epidemiología , Perros , Humanos , Leptospira/genética , Leptospirosis/epidemiología , Leptospirosis/microbiología , Leptospirosis/orina , Filogenia , Factores de Riesgo , Tailandia/epidemiología , ZoonosisRESUMEN
BACKGROUND: Early diagnosis of leptospirosis may contribute to the effectiveness of antimicrobial therapy and early outbreak recognition. Nucleic acid and antigen detection tests have the potential for early diagnosis of leptospirosis. With this systematic review, we assessed the sensitivity and specificity of nucleic acid and antigen detection tests. OBJECTIVES: To determine the diagnostic test accuracy of nucleic acid and antigen detection tests for the diagnosis of human symptomatic leptospirosis. SEARCH METHODS: We searched electronic databases including MEDLINE, Embase, the Cochrane Library, and regional databases from inception to 6 July 2018. We did not apply restrictions to language or time of publication. SELECTION CRITERIA: We included diagnostic cross-sectional studies and case-control studies of tests that made use of nucleic acid and antigen detection methods in people suspected of systemic leptospirosis. As reference standards, we considered the microscopic agglutination test alone (which detects antibodies against leptospirosis) or in a composite reference standard with culturing or other serological tests. Studies were excluded when the controls were healthy individuals or when there were insufficient data to calculate sensitivity and specificity. DATA COLLECTION AND ANALYSIS: At least two review authors independently extracted data from each study. We used the revised Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2) to assess risk of bias. We calculated study-specific values for sensitivity and specificity with 95% confidence intervals (CI) and pooled the results in a meta-analysis when appropriate. We used the bivariate model for index tests with one positivity threshold, and we used the hierarchical summary receiver operating characteristic model for index tests with multiple positivity thresholds. As possible sources of heterogeneity, we explored: timing of index test, disease prevalence, blood sample type, primers or target genes, and the real-time polymerase chain reaction (PCR) visualisation method. These were added as covariates to the meta-regression models. MAIN RESULTS: We included 41 studies evaluating nine index tests (conventional PCR (in short: PCR), real-time PCR, nested PCR, PCR performed twice, loop-mediated isothermal amplification, enzyme-linked immunosorbent assay (ELISA), dot-ELISA, immunochromatography-based lateral flow assay, and dipstick assay) with 5981 participants (1834 with and 4147 without leptospirosis). Methodological quality criteria were often not reported, and the risk of bias of the reference standard was generally considered high. The applicability of findings was limited by the frequent use of frozen samples. We conducted meta-analyses for the PCR and the real-time PCR on blood products.The pooled sensitivity of the PCR was 70% (95% CI 37% to 90%) and the pooled specificity was 95% (95% CI 75% to 99%). When studies with a high risk of bias in the reference standard domain were excluded, the pooled sensitivity was 87% (95% CI 44% to 98%) and the pooled specificity was 97% (95% CI 60% to 100%). For the real-time PCR, we estimated a summary receiver operating characteristic curve. To illustrate, a point on the curve with 85% specificity had a sensitivity of 49% (95% CI 30% to 68%). Likewise, at 90% specificity, sensitivity was 40% (95% CI 24% to 59%) and at 95% specificity, sensitivity was 29% (95% CI 15% to 49%). The median specificity of real-time PCR on blood products was 92%. We did not formally compare the diagnostic test accuracy of PCR and real-time PCR, as direct comparison studies were lacking. Three of 15 studies analysing PCR on blood products reported the timing of sample collection in the studies included in the meta-analyses (range 1 to 7 days postonset of symptoms), and nine out of 16 studies analysing real-time PCR on blood products (range 1 to 19 days postonset of symptoms). In PCR studies, specificity was lower in settings with high leptospirosis prevalence. Other investigations of heterogeneity did not identify statistically significant associations. Two studies suggested that PCR and real-time PCR may be more sensitive on blood samples collected early in the disease stage. Results of other index tests were described narratively. AUTHORS' CONCLUSIONS: The validity of review findings are limited and should be interpreted with caution. There is a substantial between-study variability in the accuracy of PCR and real-time PCR, as well as a substantial variability in the prevalence of leptospirosis. Consequently, the position of PCR and real-time PCR in the clinical pathway depends on regional considerations such as disease prevalence, factors that are likely to influence accuracy, and downstream consequences of test results. There is insufficient evidence to conclude which of the nucleic acid and antigen detection tests is the most accurate. There is preliminary evidence that PCR and real-time PCR are more sensitive on blood samples collected early in the disease stage, but this needs to be confirmed in future studies.
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Anticuerpos Antibacterianos/inmunología , Leptospira/inmunología , Leptospirosis/diagnóstico , Ácidos Nucleicos/sangre , Reacción en Cadena de la Polimerasa/métodos , Ensayo de Inmunoadsorción Enzimática/métodos , Humanos , Leptospirosis/sangre , Curva ROC , Sensibilidad y EspecificidadRESUMEN
In the Netherlands, 97 human leptospirosis cases were notified in 2014. This represents a 4.6-fold increase in autochthonous cases (n = 60) compared with the annual average between 2010 and 2013. Most cases had symptom onset between June and November. This marked increase in humans coincided with an increase of leptospirosis in dogs. In 2014, 13 dogs with leptospirosis were reported, compared with two to six dogs annually from 2010 to 2013. The majority of the autochthonous cases (n = 20) were linked to recreational exposure, e.g. swimming or fishing, followed by occupational exposure (n = 15). About sixty per cent (n = 37) of the autochthonous cases were most likely attributable to surface water contact, and 13 cases to direct contact with animals, mainly rats. A possible explanation for this increase is the preceding mild winter of 2013-2014 followed by the warmest year in three centuries, possibly enabling rodents and Leptospira spp. to survive better. A slight increase in imported leptospirosis was also observed in Dutch tourists (n = 33) most of whom acquired their infection in Thailand (n = 18). More awareness and early recognition of this mainly rodent-borne zoonosis by medical and veterinary specialists is warranted.
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Enfermedades de los Perros/epidemiología , Exposición a Riesgos Ambientales/estadística & datos numéricos , Leptospirosis/epidemiología , Leptospirosis/veterinaria , Estaciones del Año , Viaje/estadística & datos numéricos , Adolescente , Adulto , Distribución por Edad , Anciano , Animales , Brotes de Enfermedades/estadística & datos numéricos , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/microbiología , Perros , Femenino , Humanos , Incidencia , Leptospirosis/microbiología , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Vigilancia de la Población , Factores de Riesgo , Distribución por Sexo , Adulto JovenRESUMEN
To increase knowledge of leptospirosis in the Netherlands and identify changing trends of this disease over time, we analyzed historical passive surveillance reports for an 84-year period (1925-2008). We found that 2,553 mainly severe leptospirosis cases were diagnosed (average annual incidence rate 0.25 cases/100,000 population). The overall case-fatality rate for patients with reported leptospirosis was 6.5% but decreased over the period, probably because of improved treatment. Ninety percent of reported leptospirosis cases were in male patients. Most autochthonous leptospirosis infections were associated with recreational exposures, but 15.5% of the cases were attributed to accidents that resulted in injury and to concomitant water contact. Since the end of the 1950s, the proportion of imported infections gradually increased, reaching 53.1% of the total during 2005-2008. Most (80.1%) imported infections were associated with sporting and adventurous vacation activities.
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Leptospirosis/mortalidad , Adulto , Femenino , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Incidencia , Leptospirosis/historia , Masculino , Países Bajos/epidemiología , Distribución por SexoRESUMEN
This review presents an overview of the most important rodent-borne hemorrhagic fever pathogens directly transmitted from rodents to humans, namely Leptospira and hantaviruses, together with the New- and Old-World arenaviruses. These zoonotic diseases frequently share clinical symptoms, transmission routes and other epidemiological features and often have an emerging pattern. Differential diagnostics could benefit from a syndrome-based approach grouping these pathogens. In this review extensive descriptions of the epidemiology, clinical symptoms, diagnostics and treatment are provided including a practical overview, listing clinical features, diagnostics and risk factors for each selected rodent-borne hemorrhagic fever pathogen.
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Fiebres Hemorrágicas Virales/diagnóstico , Fiebres Hemorrágicas Virales/terapia , Animales , Fiebres Hemorrágicas Virales/epidemiología , Fiebres Hemorrágicas Virales/microbiología , Humanos , Leptospirosis/diagnóstico , Leptospirosis/epidemiología , Leptospirosis/terapia , Zoonosis/epidemiologíaRESUMEN
The MAT test is of great importance in the diagnosis of leptospiral infections. Based on various differences, the serovar Grippotyphosa has been divided into two types, Moskva V and Duyster. Differences or similarities of the two type strains in the context of leptospiral diagnostics have not yet been elucidated in more detail; therefore both strains were analysed in MAT diagnostics for the detection of leptospiral infections in pigs, dogs and horses. Serum samples from 2996 pigs, 55 dogs and 35 horses, as well as vitreous and/or aqueous fluid samples from these and 13 additional horses were analysed by MAT; available supplementary samples were tested for leptospires by PCR. In pigs, 92.6% of the samples with both strains received an identical titre result in the MAT test, whereas in dogs and horses only 53.0% and 43.6% had concordant results. Since infections with the serovar Grippotyphosa occur more frequently in dogs and horses overall, more differences were observed here. In the case of discrepant serological results, supplementary samples and PCR examinations were not able to add information on the true status. Further analyses of follow-up studies or at least serum pairs from dogs and horses infected with the serovar Grippotyphosa are necessary.
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Leptospirosis is a worldwide zoonotic disease, but feline leptospirosis is rarely reported. This study aimed at investigating Leptospira spp. prevalence in cats from southern Italy, evaluating risk factors, clinical findings and laboratory data associated with infection. The serum of 112 cats was investigated by microscopic agglutination test (MAT), detecting anti-Leptospira antibodies against 14 pathogenic serovars. Blood and urine samples were tested by a real-time polymerase chain reaction targeting the lipL32 gene of pathogenic Leptospira. Antibodies against serovars Poi, Bratislava, Arborea, Ballum, Pomona and Lora were detected in 15.3% (17/111) of cats (titers range: 20-320). Leptospira spp. DNA was found in 3% (4/109) of blood and 9% (10/111) of urine samples. The spring season was the only risk factor for urinary Leptospira DNA shedding. Laboratory abnormalities significantly associated and/or correlated with Leptospira spp. positivity were anemia, monocytosis, neutrophilia, eosinopenia, increased alanine aminotransferase activity, hypoalbuminemia and hyperglobulinemia. In the investigated areas, cats are frequently infected by Leptospira spp. and can represent an additional reservoir or sentinel for a risk of infection. Moreover, some laboratory changes could be compatible with a pathogenic effect of Leptospira spp. in the feline host.
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Leptospirosis is a global zoonotic disease that causes significant morbidity and mortality in human and animal populations. Leptospira interrogans is a leading cause of human disease, and L. borgpetersenii is a leading cause of animal disease. Cattle are reservoir hosts of L. borgpetersenii serovar Hardjo, which is transmitted via urine, semen, and uterine discharges resulting in abortion and poor reproductive performance. Bovine bacterin vaccines can only protect against those serovars included in vaccine formulations and typically include serovar Hardjo among others. Genotyping and serotyping represent two different and unique methods for classifying leptospires that do not always correlate well; comprehensive characterization using either method requires recovery of isolates from infected animals. In this study, we report for the first time, isolation of L. borgpetersenii serovar Tarassovi from the urine of a dairy cow in the U.S. The classification of the isolate, designated strain MN900, was confirmed by whole-genome sequencing, serotyping with reference antisera and monoclonal antibodies, Matrix Assisted Laser Desorption/Ionization (MALDI), and immunoblotting with reference antisera. Strain MN900 was excreted in urine samples for 18 weeks even as the cow was seronegative for serovar Tarassovi. Strain MN900 has an unusual morphology since it is not as motile as other leptospires and lacks hooked ends. Serovar Tarassovi is not included in U.S. bacterin vaccines. These results demonstrate the importance of culture and concomitant genotyping and serotyping to accurately classify leptospires, and as required to design efficacious vaccine and diagnostic strategies to not only limit animal disease but reduce zoonotic risk.
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Leptospirosis is one of the most common zoonotic diseases in the world and endemic in the Caribbean Islands. Bovine leptospirosis is an important reproductive disease. Globally, cattle are recognized as a reservoir host for L. borgpetersenii serovar Hardjo, which is transmitted via urine, semen, and uterine discharges, and can result in abortion and poor reproductive performance. The dairy industry in Puerto Rico comprises up to 25% of agriculture-related income and is historically the most financially important agricultural commodity on the island. In this study, we report the isolation of two different pathogenic Leptospira species, from two different serogroups, from urine samples collected from dairy cows in Puerto Rico: L. borgpetersenii serogroup Sejroe serovar Hardjo and L. santarosai serogroup Pyrogenes. Recovered isolates were classified using whole-genome sequencing, serotyping with reference antisera and monoclonal antibodies, and immunoblotting. These results demonstrate that dairy herds in Puerto Rico can be concurrently infected with more than one species and serovar of Leptospira, and that bacterin vaccines and serologic diagnostics should account for this when applying intervention and diagnostic strategies.
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Leptospirosis is among the most important zoonotic diseases in (sub-)tropical countries. The research objective was to evaluate the accuracy of the Serion IgM ELISA EST125M against the Microscopic Agglutination Test (MAT = imperfect reference test); to assess its ability to diagnose acute leptospirosis infections and to detect previous exposure to leptospires in an endemic setting. In addition, to estimate the overall Leptospira spp. seroprevalence in the Wiwa indigenous population in North-East Colombia. We analysed serum samples from confirmed leptospirosis patients from the Netherlands (N = 14), blood donor sera from Switzerland (N = 20), and sera from a cross-sectional study in Colombia (N = 321). All leptospirosis ELISA-positive, and a random of negative samples from Colombia were tested by the MAT for confirmation. The ELISA performed with a sensitivity of 100% (95% CI 77% - 100%) and a specificity of 100% (95% CI 83% - 100%) based on MAT confirmed Leptospira spp. positive and negative samples. In the cross-sectional study in Colombia, the ELISA performed with a sensitivity of 100% (95% CI 2-100%) and a specificity of 21% (95% CI 15-28%). Assuming a 5% Leptospira spp. seroprevalence in this population, the positive predictive value was 6% and the negative predictive value 100%. The Leptospira spp. seroprevalence in the Wiwas tested by the ELISA was 39%; however, by MAT only 0.3%. The ELISA is suitable to diagnose leptospirosis in acutely ill patients in Europe several days after onset of disease. For cross-sectional studies it is not recommended due to its low specificity. Despite the evidence of a high leptospirosis prevalence in other study areas and populations in Colombia, the Wiwa do not seem to be highly exposed to Leptospira spp.. Nevertheless, leptospirosis should be considered and tested in patients presenting with febrile illness.
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Leptospira , Leptospirosis , Pruebas de Aglutinación , Anticuerpos Antibacterianos , Colombia/epidemiología , Estudios Transversales , Ensayo de Inmunoadsorción Enzimática , Humanos , Inmunoglobulina M , Pueblos Indígenas , Leptospirosis/diagnóstico , Leptospirosis/epidemiología , Sensibilidad y Especificidad , Estudios SeroepidemiológicosRESUMEN
INTRODUCTION: Clinical presentations of leptospirosis are diverse, with meningitis easily confused with other microbial causes. We aimed to investigate the involvement of pathogenic leptospira in the cerebrospinal fluid (CSF) of meningitis-suspected children in Sudan. METHODS: A total of 153 CSF specimens were collected over 5 months from patients attending a reference pediatric hospital in Omdurman, Sudan. All patients had provisionally been diagnosed with meningitis on admission. Demographic, clinical, and conventional laboratory findings were obtained. DNA was extracted using a QIAamp mini kit, and the secY gene investigated using real-time PCR. RESULTS: Nine of 153 (6%) CSF specimens were positive for pathogenic leptospiral DNA. All these patients were male (seven infants and two toddlers aged Ë4 years). Typical conventional laboratory findings for aseptic meningitis (ie, CSF turbidity/pleocytosis, normal or reduced CSF glucose, normal or elevated proteins) were seen in five (56%). All patients presented with fever and seizures, 56% vomiting and stiff neck, and 29% bulging fontanel. Most (67%) patients presented in summer (March to May). Polymicrobial infections were identified in three patients (33%). CONCLUSION: We conclude that pathogenic leptospira are probably a common cause of meningitis in children in Sudan; therefore, we recommend including leptospirosis in the differential diagnosis of CNS infections and other undifferentiated febrile illnesses in this country.
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The ability of Leptospirae to persist in environments and animal hosts but to cause clinically highly variable disease in humans has made leptospirosis the most common zoonotic disease. Considering the paucity of data on variation in complete genomes of human pathogenic Leptospirae, we have used a combination of Single Molecule Real-Time (SMRT) and Illumina sequencing to obtain complete genome sequences of six human clinical L. interrogans isolates from Malaysia. All six contained the larger (4.28-4.56 Mb) and smaller (0.34-0.395 Mb) chromosome typical of human pathogenic Leptospirae and 0-7 plasmids. Only 24% of the plasmid sequences could be matched to databases. We identified a chromosomal core genome of 3318 coding sequences and strain-specific accessory genomes of 49-179 coding sequences. These sequences enabled detailed genomic strain typing (Genome BLAST Distance Phylogeny, DNA-DNA hybridization, and multi locus sequence typing) and phylogenetic classification (whole-genome SNP genotyping). Even though there was some shared synteny and collinearity across the six genomes, there was evidence of major genome rearrangement, likely driven by horizontal gene transfer and homologous recombination. Mobile genetic elements were identified in all strains in highly varying numbers, including in the rfb locus, which defines serogroups and contributes to immune escape and pathogenesis. On the other hand, there was high conservation of virulence-associated genes including those relating to sialic acid, alginate, and lipid A biosynthesis. These findings suggest (i) that the antigenic variation, adaption to various host environments, and broad spectrum of virulence of L. interrogans are in part due to a high degree of genomic plasticity and (ii) that human pathogenic strains maintain a core set of genes required for virulence.
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Leptospira kirschneri is an agent causing leptospirosis in animals and humans. We report the draft genome sequence of Leptospira kirschneri serovar Mozdok type 2 strain Horse 112, comprising 485 contigs and having a genome size of 4,301,784 bp. This genome will facilitate studying important mechanisms for clinical outcomes.
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At least two real-time PCRs for the early diagnosis of leptospirosis have been described, evaluated and validated. However, at least one other report suggested adaptation and modification of primers and probes used in these assays since additional Leptospira species have been described and the primers and probe in use possess a serious mismatch to corresponding target sequence. In this study we developed a real-time PCR for detection of pathogenic Leptospira based on the lipL32 gene. The present method consists of generic primers and probes based on target sequence of 10 pathogenic Leptospira species including Leptospira interrogans. The hybridization, annealing and extension temperature (60°C) were optimized as the optimal temperature of the DNA polymerase enzyme which is used in the amplification reaction. The present assay has a high analytical sensitivity and specificity; the calculated diagnostic sensitivity and specificity were 93.0% and 98.3% respectively. Moreover, the present method includes an internal control which enables easy detection of false negative results and an optional extraction control which enables the estimation of the DNA extraction efficiency.
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Proteínas de la Membrana Bacteriana Externa/genética , ADN Bacteriano/aislamiento & purificación , Leptospira interrogans/aislamiento & purificación , Leptospirosis/diagnóstico , Lipoproteínas/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , ADN Bacteriano/sangre , ADN Bacteriano/orina , Diagnóstico Precoz , Humanos , Leptospira interrogans/genética , Leptospirosis/sangre , Leptospirosis/microbiología , Leptospirosis/orina , Sensibilidad y EspecificidadRESUMEN
GLOBAL IMPORTANCE: Leptospirosis is the most widespread zoonosis worldwide. Mammals (eg, rats, horses, cows, pigs, dogs, cats and aquatic species, such as sea lions and northern elephant seals) can all be infected by leptospires. Infection in animals occurs through contact with urine or water contaminated with the bacteria. In people, the disease is acquired mainly from animal sources or through recreational activities in contaminated water. PRACTICAL RELEVANCE: Literature on the clinical presentation of leptospirosis in cats is scarce, although it has been demonstrated that cats are susceptible to infection and are capable of developing antibodies. The prevalence of antileptospiral antibodies in cats varies from 4% to 33.3% depending on the geographical location. Urinary shedding of leptospires in naturally infected cats has been reported, with a prevalence of up to 68%. Infection in cats has been associated with the consumption of infected prey, especially rodents. Thus, outdoor cats have a higher risk of becoming infected. CLINICAL CHALLENGES: Clinical presentation of this disease in cats is rare and it is not known what role cats have in the transmission of leptospirosis. Ongoing work is needed to characterise feline leptospirosis. AUDIENCE: This review is aimed at all veterinarians, both general practitioners who deal with cats on a daily basis in private practice, as well as feline practitioners, since both groups face the challenge of diagnosing and treating infectious and zoonotic diseases. EVIDENCE BASE: The current literature on leptospirosis in cats is reviewed. To date, few case reports have been published in the field, and information has mostly been extrapolated from infections in people and dogs. This review is expected to serve as a guide for the diagnosis and management of the disease in cats.
Asunto(s)
Enfermedades de los Gatos/diagnóstico , Enfermedades de los Gatos/terapia , Leptospirosis/veterinaria , Animales , Gatos , Leptospirosis/diagnóstico , Leptospirosis/terapiaRESUMEN
Cattle are susceptible to infection with multiple serovars of pathogenic leptospires, resulting in abortion, stillbirth, premature birth, reproductive failure and milk drop syndrome. Cattle also act as a reservoir host for L. borgpetersenii serovar Hardjo which is excreted from renal tubules via urine into the environment where it persists in suitable moist conditions. Our previous work demonstrated that 7% of urine samples from beef cattle were positive for L. borgpetersenii serovar Hardjo by culture and/or the fluorescent antibody test (FAT). In this study, a real-time PCR (rtPCR) assay was applied to determine the relative performance of rtPCR based detection of L. borgpetersenii serovar Hardjo compared to previously reported culture and FAT techniques. Of 42 bovine urine samples positive for leptospires by culture and/or FAT, 60% (25/42) were positive by rtPCR. Of 22 culture-positive samples, 91% (20/22) were rtPCR-positive. Of 32 FAT-positive samples, 50% (16/32) were rtPCR-positive. For 10 samples that were culture-positive but FAT-negative, 90% (9/10) were rtPCR-positive. For 20 samples that were FAT-positive but culture-negative, 25% (5/20) were rtPCR-positive. Collectively, these results indicate that no single assay is optimal, and the use of more than one assay to detect leptospires in urine from naturally infected cattle is recommended.