Effects of Accounting for Interval-Censored Antibody Titer Decay on Seroincidence in a Longitudinal Cohort Study of Leptospirosis.

Accurate measurements of seroincidence are critical for infections undercounted by reported cases, such as influenza, arboviral diseases, and leptospirosis. However, conventional methods of interpreting paired serological samples do not account for antibody titer decay, resulting in underestimated seroincidence rates. To improve interpretation of paired sera, we modeled exponential decay of interval-censored microscopic agglutination test titers using a historical data set of leptospirosis cases traced to a point source exposure in Italy in 1984. We then applied that decay rate to a longitudinal cohort study conducted in a high-transmission setting in Salvador, Brazil (2013-2015). We estimated a decay constant of 0.926 (95% confidence interval: 0.918, 0.934) titer dilutions per month. Accounting for decay in the cohort increased the mean infection rate to 1.21 times the conventionally defined rate over 6-month intervals (range, 1.10-1.36) and 1.82 times that rate over 12-month intervals (range, 1.65-2.07). Improved estimates of infection in longitudinal data have broad epidemiologic implications, including comparing studies with different sampling intervals, improving sample size estimation, and determining risk factors for infection and the role of acquired immunity. Our method of estimating and accounting for titer decay is generalizable to other infections defined using interval-censored serological assays.

Contributing role of TNF, IL-10, sTNFR1 and TNF gene polymorphisms in disease severity of leptospirosis.

The immune response is hypothesized as an important factor in the disease outcome of leptospirosis. Exaggerated immune response may promote tissue damage that lead to severe disease outcome. In this study TNF, IL-10, sTNFR1 levels were measured among sixty-two hospitalized leptospirosis confirmed patients in Sri Lanka. Thirty-one serum samples from healthy individuals were obtained as controls. PCR-RFLP method was used to identify TNF gene polymorphisms and to determine their association with TNF expression and disease severity in leptospirosis. TNF (p = 0.0022) and IL-10 (p < 0.0001) were found to be significantly elevated in leptospirosis patients, while sTNFR1 (p < 0.0001) was significantly suppressed. TNF was not significantly elevated in patients with complications while the anti-inflammatory cytokine IL-10 was significantly elevated among patients with complications (p = 0.0011) and with mortality (p = 0.0088). The ratio of IL-10 to TNF was higher among patients with complications (p = 0.0008) and in fatal cases (p = 0.0179). No association between TNF gene polymorphisms and TNF expression was detected due to the low frequency of heterozygous and mutated genes present in this study population. Thus the findings of the study show that elevated levels of IL-10 in the acute phase of disease could lead to severe outcomes and a high IL-10/TNF ratio is observed in patients with complications due to leptospirosis.

Evaluation of real-time PCR targeting the lipL32 gene for diagnosis of Leptospira infection.

BACKGROUND: Different diagnostic methods have been used for the laboratory confirmation of leptospirosis. Molecular diagnostic techniques are not only faster and more sensitive than culture analysis, but can also detect a Leptospira infection before the appearance of antibodies. The aim of the present study was to analyze and compare two different PCR approaches applied to blood and urine specimens obtained from patients with clinical manifestations that were suggestive of leptospirosis. Furthermore, the results of these different PCR approaches were compared with the results of culture and serology analyses. RESULTS: A total of 400 samples (234 blood or 58.5% and 166 urine of 41.5%) from 310 Slovenian patients with clinical manifestations suggestive of leptospirosis were tested using conventional PCR assays targeting the rrs gene and RT-PCR targeting the lipL32 gene. Additionally, culture, serology and sequence analysis were performed for the majority of these samples. The PCR and RT-PCR results were concordant in 376 out of 400 of these samples (94.0%). Conventional PCR was positive for 27 out of 400 samples (6.8%) and RT-PCR was positive for 47 out of 400 samples (11.8%). Culture and microscopic agglutination tests supported these diagnoses. CONCLUSIONS: A comparison of the two PCR methods indicated that the RT-PCR targeting of the lipL32 gene was faster, more sensitive and more specific for the determination of Leptospira DNA in these clinical samples.

The interplay between host haemostatic systems and Leptospira spp. infections.

Hemostasis is a defence mechanism that protects the integrity of the vascular system and is comprised of the coagulation cascade, fibrinolysis, platelet aggregation, and vascular endothelium. Besides the primary function in preserving the vascular integrity, the haemostatic system cooperates with immune and inflammatory processes to eliminate invading pathogens during microbial infections. Under pathological manifestations, hemostasis must therefore interact in a coordinated manner with inflammatory responses and immune reactions. Several pathogens can modulate these host-derived countermeasures by specifically targeting certain haemostatic components for their own benefit. Thus, the ability to modulate host defence systems has to be considered as an essential bacterial virulence mechanism. Complications that bacterial pathogens can induce are therefore often the consequence of evoked host responses. A comprehensive understanding of the molecular mechanisms triggered in infectious processes may help to develop prophylactic methods and novel therapies for the patients suffering from a particular infectious disease. This review aims to provide a critical updated compiling of recent studies on how the pathogenic Leptospira can interact with and manipulate the host haemostatic systems and the consequences for leptospirosis pathogenesis.

Cytokine response in human leptospirosis with different clinical outcomes: a systematic review.

BACKGROUND: Leptospirosis is a neglected zoonotic disease which is a major challenge for clinicians and public health professionals in tropical countries. The cytokine storm during the second (immune) phase is thought to be a major contributory factor for the leptospirosis disease severity. We aim to summarize evidence for cytokine response in leptospirosis at different clinical outcomes. METHODS: A systematic review was carried out to examine the cytokine response in leptospirosis patients using relevant scientific databases. Reference lists of the selected articles were also screened. Quality of the selected studies was assessed by using the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. RESULTS: Of the 239 articles retrieved in the initial search, 18 studies fulfilled the selection criteria. India and Thailand have produced the highest number of studies (17% each, n = 3). The majority were comparative cross-sectional studies (72%, n = 13). Overall the quality of the selected studies was fair regardless of few drawbacks such as reporting of sample size and the lack of adjustment for confounders. Microscopic agglutination test (67% - 12/18) and enzyme-linked immunosorbent assay (50% - 9/18) were commonly used for the confirmation of leptospirosis and the measurement of cytokines respectively. IL-1b, IL-2, IL-4, IL-6, IL-8, IL-10 and TNF-α levels were found to be significantly higher in severe than in mild leptospirosis. There were equivocal findings on the association between IL-1ß, TNF-α and IL-10/TNF-α ratio and disease severity. CONCLUSIONS: Leptospirosis had a wide-range of elevated cytokines. However, prospective studies in-relation to the onset of the symptom are required to better understand the pathophysiology of cytokine response in leptospirosis.

Heparin-Binding Protein Release Is Strongly Induced by Leptospira Species and Is a Candidate for an Early Diagnostic Marker of Human Leptospirosis.

BACKGROUND: Leptospirosis, caused by spirochetes of the genus Leptospira, is one of the most widespread zoonoses worldwide. Efficient diagnostic methods for early diagnosis of leptospirosis are still lacking, and acute disease presents with nonspecific symptomatology and is often misdiagnosed. The leptospires pathogenic processes and virulence mechanisms remain virtually unknown. In severe infections, hemostatic impairment is frequently observed, and pathophysiological complications often develop when the host response is modulated by the pathogen. The neutrophil heparin-binding protein (HBP) is an inflammatory mediator and potent inducer of vascular leakage. RESULTS: In this study, we found that leptospires and their secreted products induce the release of HBP from stimulated neutrophils through a controlled degranulation mechanism. We acknowledged 2 leptospiral proteins as able to induce HBP degranulation. These findings have clinical implications, as high levels of HBP were detected in serum from patients with leptospirosis, especially at the early phase of the disease. CONCLUSION: In conclusion, we describe a new mechanism by which the leptospirosis pathophysiological complications may arise, such as vascular leakage and edema formation. We also propose HBP as a new early screening biomarker for human leptospirosis.

Raised levels of Il-6, Il-17a, and Il-22 in fatal leptospirosis.

Clinical manifestations of leptospirosis range from mild, common cold-like illness, to a life-threatening condition. The host immune response has been hypothesized to play a major role in leptospirosis outcome. Increased levels of inflammatory mediators, such as cytokines, may promote tissue damage that lead to increased disease severity. The question is whether cytokines levels may predict the outcome of leptospirosis and guide patient management. This study aimed to assess the association between Th1-, Th2-, and Th17-related cytokines with the clinical outcome of patients with leptospirosis. Different cytokine levels were measured in fifty-two plasma samples of hospitalized patients diagnosed with leptospirosis in Malaysia (January 2016-December 2017). Patients were divided into two separate categories: survived (n = 40) and fatal outcome (n = 12). Nineteen plasma samples from healthy individuals were obtained as controls. Cytokine quantification was performed using Simple Plex™ assays from ProteinSimple (San Jose, CA, USA). Measurements were done in triplicate and statistical analysis was performed using GraphPad software and SPSS v20. IL-6 (p = 0.033), IL-17A (p = 0.022), and IL-22 (p = 0.046) were significantly elevated in fatal cases. IL-17A concentration (OR 1.115; 95% CI 1.010-1.231) appeared to be an independent predictor of fatality of leptospirosis. Significantly higher levels of TNF-α (p ≤ 0.0001), IL-6 (p ≤ 0.0001), IL-10 (p ≤ 0.0001), IL-12 (p ≤ 0.0001), IL17A (p ≤ 0.0001), and IL-18 (p ≤ 0.0001) were observed among leptospirosis patients in comparison with healthy controls. Our study shows that certain cytokine levels may serve as possible prognostic biomarkers in leptospirosis patients.

Leptospiral phosphatidylinositol-specific phospholipase C: a novel conserved antigen for the definitive diagnosis of Leptospirosis.

Identification and characterisation of novel antigenic proteins of Leptospira are necessary to unravel the secrets of the Leptospiral disease biology. Besides, the current scenario of Leptospirosis demands the development of advanced diagnostics with the potential of an early and specific diagnosis. This work reports the diagnostic efficacy of a PI-PLC (LA_1375) of Leptospira interrogans serovar Lai strain 56601. Phospholipases are enzymes that catalyse the degradation of membrane phospholipids, with the after effects of pathophysiological consequences through the impairment of cellular signalling mechanisms. The immunoblotting analysis allows to identify the Leptospirosis positive serum samples demonstrated the expression and exposure of the protein to the immune system and confirmed the antigenic nature of the protein. Furthermore, evaluation of diagnostic efficacy of an ELISA to detect antibodies against recombinant PI-PLC has tested in indirect IgM ELISA using the purified 50 kDa recombinant protein as the coating antigen. A cut-off value of 0.218 at mean + 2SD and a sensitivity value of 100% and a specificity value of 95.65% explored for the rPI-PLC IgM ELISA. The PPV and NPV of ELISA for the Leptospirosis confirmed acute phase samples were 95.87% and 100% respectively. Comparison of the ELISA assay with MAT for the detection of Leptospiral antibodies showed a positive correlation (r value 0.345, p < 0.05), and signified the diagnostic efficacy of rPI-PLC for the definitive diagnosis of the Leptospirosis. In addition, the revealed conservation nature of PI-PLC among different Leptospira species highlights the diagnostic and vaccine candidate potential. Thus, the study emphasises the Leptospiral PI-PLC as a potential antigen still the importance as a novel biomarker candidate for the serodiagnosis and pathogenesis of Leptospirosis have to be investigated.

Nucleic acid and antigen detection tests for leptospirosis.

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.

Seroprevalence of leptospirosis in human groups at risk due to environmental, labor or social conditions.

Leptospirosis is important in Uruguay due to the economic loss caused by the diseases of production animals, mainly bovines, and also due to frequent human infection. We decided to study anti-Leptospira antibodies in the sera of dairy workers, rice laborers, veterinarians, suburban slum dwellers and garbage recyclers. Our aims were to estimate the seroprevalence of infection by Leptospira spp. in these people at risk, the relative importance of the known risk factors associated with infection, and the impact of human infections in each setting. Groups at risk were identified and 35 visits to their locations were made, conducting field surveys and exchange talks for information and education. Simple epidemiological questionnaires were administered and sera samples were taken from 308 persons. The microagglutination Technique (MAT) and the IgM Indirect Immunofluorescence (IIF) assay were employed to detect antibodies. Environmental water samples, canine and equine sera were also examined. More than 45% of human sera were reactive and the studied groups were confirmed to be widely exposed to infection. Female sera were frequently reactive, though most illnesses occur in men, and the most severe cases in elderly males; the emergence and evolution of the disease may strongly depend on the host condition and functions. Animal contact and unsafe water usage were the main identified risk factors to be considered in prevention. Fifty per cent of the studied horses showed a positive MAT reaction. The underdiagnosis of the illness and its long-term symptoms require further study, as well as greater health and social attention efforts.

Effect of Antimicrobial Agents on Inflammatory Cytokines in Acute Leptospirosis.

The aim of this study was to assess the inflammatory cytokine response and possible association with antimicrobial treatment with penicillin, ceftriaxone, and doxycycline in acute leptospirosis. In the early acute stage, interleukin-10 (IL-10) levels were higher in mild cases than in severe cases (P = 0.01). IL-6 and IL-8 levels were low in patients who received >5 antimicrobial doses (P < 0.01). IL-8 levels were negatively correlated with the number of ceftriaxone doses administered (r = -0.315; P = 0.031). Further studies are needed to evaluate the possible downregulation of proinflammatory cytokines by ceftriaxone in leptospirosis.

Thrombocytopenia and Platelet Dysfunction in Acute Tropical Infectious Diseases.

Thrombocytopenia is a well-known manifestation of acute tropical infectious diseases. The role of platelets in infections has received much attention recently because of their emerging activities in modulation of inflammatory responses, host defense, and vascular integrity. However, while many studies have addressed thrombocytopenia in tropical infections, abnormalities in platelet function have been largely overlooked. This is an important research gap, as platelet dysfunction may contribute to the bleeding tendency that characterizes some tropical infections. The development of novel platelet function assays that can be used in thrombocytopenic conditions (e.g., flow cytometry assays) has contributed to important new insights in recent years. In this review, the importance of platelets in tropical infections is discussed with special emphasis on the underlying mechanisms and consequences of thrombocytopenia and platelet dysfunction in these infections. Special attention is paid to malaria, a disease characterized by microvascular obstruction in which bleeding is rare, and to infections in which bleeding is common, such as dengue, other viral hemorrhagic fevers, and the bacterial infection leptospirosis. Given the importance of platelet function abnormalities in these infections, the development of affordable assays for monitoring of platelet function in low-resource countries, as well as pharmacologic interventions to prevent or reverse platelet function abnormalities, might improve clinical care and the prognosis of these infections.

Geographic distribution of anti-Leptospira antibodies in humans in Côte d'Ivoire, West Africa.

Leptospirosis is a zoonotic bacterial disease with a worldwide importance, mostly frequent in tropical and subtropical countries. In Côte d'Ivoire, little is known about leptospirosis and human data are sparse. This disease is usually misdiagnosed with other febrile illnesses, and determining high-risk areas could allow better management of this disease, leading to policies. This study aims to map leptospirosis exposure areas by determining geographic distribution of anti-Leptospira antibodies in humans in Côte d'Ivoire. A total of 384 serum samples were randomly selected in the national surveillance system for communicable diseases in 2014. All the 82 health districts were include in the study. Serums were screened by ELISA at Institut Pasteur de Côte d'Ivoire and confirmed by MAT in the National Reference Centre for leptospirosis in Institut Pasteur in Paris. In these samples, ELISA screened 90 specimens showing anti-Leptospira antibodies and 36 specimens were confirmed by MAT (9.4%). Observed cases were mostly located in health districts of the western and the southern parts of the country. People with anti-Leptospira antibodies had a mean age of 34.5 years old and a sex ratio of 2. This pattern corresponds to active low-income farmers working into agricultural fields. This study reveals circulation of leptospirosis in human population in Côte d'Ivoire. The disease seems to be more frequent in the western and the southern parts of the country. Active low-income farmers working into agricultural fields without personal protective gear could be one of the most at-risk populations.

Seroprevalence and distribution of leptospirosis serovars among wet market workers in northeastern, Malaysia: a cross sectional study.

BACKGROUND: Leptospirosis is a zoonotic disease associated with occupations which exposed workers to environments contaminated with urine of infected animals. The objective of this study was to determine the seroprevalence of leptospirosis among wet market workers in Kelantan. METHODS: A cross sectional study was conducted in two main wet markets in Kelantan and 232 wet market workers were randomly selected. Blood samples were analysed for microscopic agglutination test (MAT) against 20 live leptospirosis reference serovars. MAT titres of 1:100 or more were considered as seropositive. RESULTS: It was found that the overall seroprevalence for leptospirosis among the respondents was 33.6% (95% CI = 27.5, 39.7). The samples were tested positive against serovars Melaka (IMR LEP 1), Terengganu (IMR LEP 115), Sarawak (IMR LEP 175), Copenhageni (IMR LEP 803/11), Hardjobovis (IMR LEP 27), Australis, Autumnalis, Bataviae, Canicola, Grippotyphosa, Hardjoprajitno, Icterohaemorrhagiae, Javanica, Pyrogenes, Terrasovi, Djasiman, Patoc and Pomona. The predominant serovars was Autumnalis (18.2%). CONCLUSION: Wet markets workers were at risk for leptospirosis infection evidenced by high seroprevalence of leptospirosis in this study. Further research need to be conducted to determine factors that favours infection in this groups.

Leptospirosis presenting as haemolytic uraemic syndrome: a case report.

BACKGROUND: Leptospirosis is a rare infectious disease especially in Western Countries. Renal involvement is a recognised complication of leptospirosis but leptospirosis-associated haemolytic uraemic syndrome is extremely rare and to our knowledge has only been reported once, in 1985. CASE PRESENTATION: A 29-year-old male was transferred to our Renal Unit with fevers, myalgia and diarrhoeal illness. Laboratory investigations revealed an acute kidney injury, acute liver injury, significantly raised lactate dehydrogenase with marked anaemia, thrombocytopenia and schistocytes on a blood film. A diagnosis of haemolytic uraemic syndrome was made. Surprisingly, the stool culture was negative which led to a suspicion of leptospirosis as one of the differential diagnoses. This was subsequently confirmed by enzyme-linked immunosorbent assay and microscopic agglutination test. He received plasma exchange and antibiotics and made a complete recovery on discharge. CONCLUSION: Leptospirosis presenting as haemolytic uraemic syndrome is rare but should be considered in the differential diagnosis especially in the presence of significant liver injury, as current evidence suggests that the disease is re-emerging.

Evaluation of a Commercial Immuno-Chromatographic Assay Kit for Rapid Detection of IgM Antibodies against Leptospira Antigen in Human Serum.

Leptospirosis is a febrile zoonotic disease. Routine diagnosis of leptospirosis is based on the detection of specific antibodies with serological tests. The aim of our study was to determine the usefulness of immunochromatographic assay (ICA), ImmuneMed Leptospira IgM Duo Rapid test kit from Korea, in rapid screening of acute leptospirosis in emergency cases with limited expertise. A total of 197 serum samples (93 positive, 104 negative) were selected randomly. The test has good diagnostic sensitivity 73% and specificity 90%. With positive predictive value of 87% and negative predictive value of 79%, this reassures patients have higher chance of correct diagnosis. This ICA is acceptable for screening of leptospirosis but confirmation with microscopic agglutination test should follow.

Seroprevalence and herd-level risk factors for seroprevalence of Leptospira spp. in sheep, beef cattle and deer in New Zealand.

AIMS To determine seroprevalence of Leptospira borgpetersenii serovar Hardjo and L. interrogans serovar Pomona in beef cattle, sheep and deer in New Zealand and the association between farm-level risk factors and seroprevalence. METHODS Between June 2009 and July 2010, 20 serum samples per flock or herd were collected from 162 sheep flocks, and 116 beef cattle and 99 deer herds from 238 farms, along with farm data by interview. Samples were tested for antibodies to serovars Hardjo and Pomona by microscopic agglutination testing, with a titre ≥48 being positive. Species-specific associations between herd-level seroprevalence (number of seropositive animals, for each serovar, divided by the number of animals tested) and herd-level risk factors were determined by multivariable logistic regression analysis. Vaccinated animals were excluded from seroprevalence estimates but included in multivariable analyses. RESULTS For sheep (n=3,339), animal-level seroprevalence was 43.6 (95% CI=41.9-45.3)% for serovar Hardjo and 14.1 (95% CI=12.9-15.3)% for serovar Pomona; for beef cattle(n=1,886), it was 45.6 (95% CI=43.3-47.9)% for Hardjo and 19.6 (95% CI=17.9-21.5)% for Pomona; and for deer (n=1,870), it was 26.3 (95% CI=24.3-28.4)% for Hardjo, 8.8 (95% CI=7.6-10.2)% for Pomona. In sheep flocks (n=161), flock-level prevalence for Hardjo varied from 77.9-91.3%, and for Pomona from 40.4-73.9%, when ≥1, ≥2 or ≥3 animals were seropositive. In beef herds (n=95), herd-level prevalence for Hardjo varied from 79.0-90.5%, and for Pomona from 42.1-68.4%. In deer herds (n=93), herd-level prevalence for Hardjo varied from 45.2-59.1%, and for Pomona from 22.6-48.4%. For sheep flocks, herd-level seroprevalence for Hardjo was associated with flock size (OR=1.56) and number of dogs (OR=0.75), and for Pomona, seroprevalence varied with region. For beef cattle, herd-level seroprevalence for Hardjo was associated with herd size (OR=1.4), presence of dams (OR=0.6) and vaccination (OR=2.9), and for Pomona, co-grazing with deer (OR=0.4), vaccination (OR=3.22), presence of dams (OR=0.2) and streams (OR=2.7). For deer herds, seroprevalence for Hardjo or Pomona was associated with herd size (OR=1.6 and 1.8) and varied with region, and for Pomona seroprevalence varied with season (summer vs. winter: OR=4.8). CONCLUSIONS Serovars Hardjo and Pomona were highly prevalent at herd and animal levels, with serovar Hardjo highest in all species. Larger herd size was the common risk factor for seroprevalence in all livestock species.

[Diagnostic procedure after abortions in sows after simultaneous infection with leptospira and chlamydia]. / Diagnostische Abklärung von Aborten bei Zuchtsauen nach Leptospiren- und Chlamydieninfektion.

INTRODUCTION: In a farrowing farm 2 first parity sows aborted on day 95 and day 110 of gestation due to an infection with leptospira and chlamydia. The double infection was diagnosed by PCR examination of abortion material. Serum samples of both sows and additional 8 sows taken three weeks after abortions were sent to two different labs for serological examination for antibodies against leptospira and chlamydia using a microagglutination test and a complement fixation test, respectively. In both labs the tests for antibodies against chlamydia were negative. Titers against diverse leptospira serovars varied between both labs and were low, so that they were not indicative for the involvement of the two pathogens regarding abortion. This case report indicates the diagnostic difficulties of direct and indirect detection methods for leptospira and chlamydia to assess the impact of these pathogens on observed reproductive failure.

Cytokine profile of patients with leptospirosis in Sabah, Malaysia.

BACKGROUND: Leptospirosis is a zoonotic disease with symptoms ranging from a mild, febrile illness to a severe form with multiorgan failure. Severe leptospirosis may require medical interventions in the form of dialysis and/or mechanical ventilation and often leads to mortality. An exaggerated host immune response-in particular, a "cytokine storm"-that causes endothelial and organ damage is associated with the disease severity and mortality. METHODS: Microscopic agglutination test (MAT)-positive and MAT-negative human serum samples (n=30) from patients with leptospirosis were obtained from the Public Health Laboratory, Kota Kinabalu, Sabah, Malaysia and control serum samples (n=10) were obtained from healthy student volunteers. We estimated the levels of IL-1ß, IL-6, IL-8, IL-10, and TNF-α in serum samples by a Luminex assay. RESULTS: The levels of IL-6, IL-8, and IL1-ß were significantly higher in 13% of the patients with leptospirosis compared to the healthy controls, while the levels of IL-10 and TNF-α were not elevated in either group. CONCLUSION: Our data suggest that elevated levels of IL-6, IL- 8, and IL1-ß may be associated with leptospirosis disease severity, which requires patient follow-up for confirmation.

Leptospirosis in Poland in the years 2014-2017 ­ characteristics of infections and epidemiological surveillance data

OBJECTIVES: The aim of the study was the analysis of current Leptospira spp. infections in Poland on the basis of blood serum samples tests results and clinical data collected from clinicians in the Laboratory NIPH-NIH. METHODS: Clinical materials from 48 patients with clinical symptoms suggesting Leptospira spp suspected of leptospirosis from the years 2014-2017 were included to the study. Blood serum samples collected from patients were tested in Laboratory of Rickettsiae, Chlamydiae and Spirochaetes (currently Laboratory of Vector-borne Diseases) of NIPH-NIH. Levels of specific IgM and IgG antibodies to Leptospira spp. antigens were detected with the enzyme-linked immunosorbent assay (ELISA). RESULTS: Specific antibodies to Leptospira spp. were detected in 18 patients (37.5%). IgM antibodies were found in 6 patients (12.5%) and IgG antibodies were identified in 7 patients (14.6%). Both classes of antibodies of were detected in 5 patients (10.4%). The most samples for study were sent to laboratory from Masovian (13 samples) and Kuyavian-Pomeranian (11 samples) Voivodeships. Not any samples from the Lower Silesia, Lublin, Lódz, Podlaskie and Warmian-Masurian Voivodeships were received. In these patients the most common symptoms of disease were: fever, hepatitis with jaundice and renal failure. CONCLUSIONS: The number of diagnosed human leptospirosis in Poland is low in comparison to the number of cases in other countries, although the Leptospira spp. spirochetes occur in animals in the environment.