Leptospirosis and the Environment: A Review and Future Directions

Scrub typhus-leptospirosis co-infection in India: a systematic review and meta-analysis

Scrub typhus and leptospirosis are re-emerging zoonotic infections with significant morbidity and mortality rates in India. Overlapping aetiological and epidemiological patterns indicate a high possibility of their co-infection in India, which can be a diagnostic challenge due to non-specific clinical features. A systematic search of the PubMed/MEDLINE, Scopus and Embase databases was conducted to identify relevant studies published through 31 August 2023. Studies reporting co-infection of scrub typhus and leptospirosis among the Indian population were included. Data extraction, quality assessment and statistical analysis were performed in accordance with established guidelines. Six studies met the inclusion criteria, comprising a total of 58 co-infection cases. Pooled prevalence of scrub typhus-leptospirosis co-infection among acute undifferentiated febrile illness patients was 3.7% (95% confidence interval [CI] 0.00 to 0.126). Among scrub typhus patients, the prevalence of co-infection with leptospirosis was 13.7% (95% CI 0.027 to 0.304). Significant heterogeneity was observed among the included studies, highlighting the need for cautious interpretation of prevalence estimates. This meta-analysis underscores the clinical importance of scrub typhus-leptospirosis co-infection in India and emphasizes the need for enhanced clinical awareness, improved diagnostic strategies and targeted research efforts to address this emerging infectious disease threat.

Prevalence of Leptospira spp. in Lithuanian Wild Boars (Sus scrofa)

Leptospira is a bacteria responsible for a widespread zoonosis that affects both humans and animals. Leptospirosis is a challenging pathology to diagnose and treat since its signs are unspecific and symptoms vary greatly. The disease seems to be highly prevalent in environments where reservoir animals such as rats and small mammals are common. Even though leptospirosis in humans in Lithuania is rare, it remains a disease of significance in Europe. Information on reservoir animals and prevalence of Leptospira in wild animals in Lithuania is lacking. The aim of this country-wide study was to evaluate the seroprevalence of Leptospira in wild boars in Lithuania. Hunted animals were collected from ten counties that represented the boar population of the country. The sera of 451 collected boars were evaluated for eight Leptospira serovars using the microscopic agglutination test. Seropositivity was observed in 102 (22.6%) boars. Overall, 194 positive reactions occurred. Boars older than 2 years were affected by more serovars and were more seropositive than younger boars (p < 0.05). The highest number of positive reactions was observed in Panevėžys (87.9%) and Vilnius (69.1%) counties. The results of this study might indicate that the wild boar is a reservoir animal of Leptospira and plays a role in its transmission in Lithuania.

Differential TLR2 and TLR4 mediated inflammatory and apoptotic responses in asymptomatic and symptomatic Leptospira interrogans infections in canine uterine tissue

Leptospirosis is major zoonotic disease with global implications, affecting both domestic animals and humans. It is caused by Leptospira interrogans (L. interrogans), which can damage multiple organs, including the kidneys, liver, testes, and uterus. Despite this, L. interrogans can also persist asymptomatically in tissues, akin to nonpathogenic strains. The mechanisms driving asymptomatic infections remain poorly understood. This study investigated the role of L. interrogans in asymptomatic infection within the uterine tissue of canines, focusing on the differential expression of Toll-like receptors (TLRs)2 and 4 and their roles in inflammatory and apoptotic pathways. We hypothesized that TLR2 and TLR4 coexpression is crucial for eliciting inflammation and apoptosis, whereas TLR4 alone might be insufficient. Our findings revealed that in symptomatic infections, both TLR2 and TLR4 are coexpressed, leading to markedly elevated levels of the proinflammatory cytokines IL-10, IL-1β, TNF-α, and IL-6. This enhanced inflammatory response is further evidenced by increased CD4 expression, indicating robust T helper cell activation. In contrast, asymptomatic infections are characterized by exclusive TLR4 expression, with inflammatory markers remaining at baseline levels. Additionally, we observed that L. interrogans induces apoptosis in symptomatic animals through TLR2 and TLR4 mediated activation of Caspase 8 and Caspase 3. These findings illustrate that L. interrogans drives both inflammation and apoptosis via the combination of TLR2 and TLR4 actions. When only TLR4 is activated, the immune response is insufficient, resulting in an asymptomatic disease course. This study provides novel insights into the differential roles of TLR receptors in leptospirosis, offering potential directions for targeted therapeutic strategies.

One Health and sex and gender-related perspective in the ecosystem: Interactions among drivers involved in the risk of leptospirosis in Europe. A scoping review

Leptospirosis has a complex transmission, involving rodents and many species of domestic and wild animals. Carrier animals spread leptospires, contaminating soil and water, the main sources of human infection. The risk of infection is modulated by socio-economic factors, environment and host animals and has changed, historically linked to agriculture but now prevalent in recreational environments. Leptospirosis also reveal gender-specific exposure patterns that determine infection risks. Emphasizing the interconnectedness of humans, animals, and the environment, the One Health approach highlights the ecosystem dynamics through which leptospires interact with hosts and abiotic factors, ensuring their survival and transmission. We advocate for integrating gender considerations into the ecosystem dynamics of complex zoonoses, such as leptospirosis, through a One Health perspective. This approach, yet to be fully explored, may enhance our understanding of the infection and its modulating factors. A scoping review of the literature was conducted across Embase and Pubmed databases to collect information on sex and gender-specific drivers, sources of infections, environmental drivers, and related risks of leptospirosis. Quantitative data were extracted from the articles selected according to a list of criteria, and analyzed to discern sex and gender disparities and identify primary drivers of leptospirosis. We confirmed that the excess of male leptospirosis cases described in many parts of the world is also present in Europe. Furthermore, we identified environmental and sociocultural drivers and hypothesized their interactions between and within human, animal, and environmental sectors. These interactions modulate direct and indirect exposure to Leptospira, heightening infection risks across the ecosystem. Based on our findings, utilizing leptospirosis as a model, we advocate for integrating One Health and gender approaches in public health practices to better plan and implement more effective and timely intervention measures.

Uncovering latent infections in kidneys: A novel molecular approach for differential Leptospira detection

Leptospirosis, a re-emerging zoonotic disease caused by Leptospira spp., poses significant global health and veterinary challenges. Long-term colonization of renal tubules by Leptospira in asymptomatic hosts highlights the need for sensitive detection methods. This study evaluates the chronic or latent Leptospira infections in kidneys using a novel molecular approach to examine individual immune responses differences. Digital PCR strategies employing newly developed primer-probe sets targeting the flagellar fliG gene were used to assess the presence of trace Leptospira in infected murine kidneys and urine samples from laboratory-confirmed leptospirosis patients. RNA-based digital PCR detected leptospires in 58 % (targeting lipl32) and 83 % (targeting fliG) of infected kidneys, demonstrating that the digital PCR strategy targeting the fliG gene offers superior sensitivity. Notably, the newly developed fliG-targeting assay detected as low as 20 fg of Leptospira DNA, offering ten-fold greater sensitivity than traditional qPCR for trace detection. This allows for differential detection of Leptospira species and facilitates monitoring of extremely low bacterial loads with greater sensitivity than conventional methods. We also observed regenerating renal tubules with mitosis and elevated cytokine expression in kidneys with transcriptionally active Leptospira during chronic infection. This approach aids in identifying latent infections and offers insights into individual variations. Our research provides a powerful molecular tool for epidemiological studies and public health surveillance, contributing valuable insights into the prevalence and transmission dynamics of this pervasive zoonotic disease.

Atypical Cases of Leptospirosis: Insights From Georgia

Pathogenic Leptospira species are the source of leptospirosis, a common zoonotic infection that can cause a wide range of clinical manifestations, from minor flu-like symptoms to severe multiorgan failure. We present two peculiar cases of leptospirosis; they highlight the need for clinical awareness to improve patient outcomes and further knowledge of leptospirosis epidemiology and therapy by illuminating the difficulties in diagnosis and treatment. The first case involved a 30-year-old male presented with jaundice. Although he had no history of chronic illnesses, an exhaustive investigation was warranted due to his recent travel history and occupational contact. Laboratory tests revealed significantly increased levels of AST and ALT and positive Leptospira IgM serology. Remarkably, the patient refuted the traditional theory of leptospirosis transmission by denying direct animal interaction. After starting therapy with dexamethasone initially and adding doxycycline later, the patient's condition significantly improved; his jaundice resolved and his liver enzyme levels returned to normal. An outpatient follow-up after discharge was advised to assess liver and kidney function. The second case involved an 87-year-old woman with a fever, weakness and hypertension. Investigations revealed hepatosplenomegaly, raising the possibility of hypersplenism. She reported exposure to animals, particularly her dogs in her urban house. Surprisingly, her AST and ALT levels were normal. Lab tests also revealed thrombocytopoenia with normal APTT and prolonged PT. Serological tests indicated positive Leptospira IgM. Along with intravenous infusions, the patient's treatment plan comprised dexamethasone, enalapril and ceftriaxone to treat inflammation, hypertension and bacterial infection, respectively. Following a 20-day hospital stay, the patient's laboratory results and symptoms improved, leading to her discharge. Continuous follow-up recommended to monitor her recovery and prevent recurrence. These case studies emphasise the significance of taking leptospirosis into account when treating patients who do not have normal exposure histories yet present with unusual symptoms.

Unveiling the impact of Leptospira TolC efflux protein on host tissue adherence, complement evasion, and diagnostic potential

The TolC family protein of Leptospira is a type I outer membrane efflux protein. Phylogenetic analysis revealed significant sequence conservation among pathogenic Leptospira species (83%-98% identity) compared with intermediate and saprophytic species. Structural modeling indicated a composition of six β-strands and 10 α-helices arranged in two repeats, resembling bacterial outer membrane efflux proteins. Recombinant TolC (rTolC), expressed in a heterologous host and purified via Ni-NTA chromatography, maintained its secondary structural integrity, as verified by circular dichroism spectroscopy. Polyclonal antibodies against rTolC detected native TolC expression in pathogenic Leptospira but not in nonpathogenic ones. Immunoassays and detergent fractionation assays indicated surface localization of TolC. The rTolC's recognition by sera from leptospirosis-infected hosts across species suggests its utility as a diagnostic marker. Notably, rTolC demonstrated binding affinity for various extracellular matrix components, including collagen and chondroitin sulfate A, as well as plasma proteins such as factor H, C3b, and plasminogen, indicating potential roles in tissue adhesion and immune evasion. Functional assays demonstrated that rTolC-bound FH retained cofactor activity for C3b cleavage, highlighting TolC's role in complement regulation. The rTolC protein inhibited both the alternative and the classical pathway-mediated membrane attack complex (MAC) deposition in vitro. Blocking surface-expressed TolC on leptospires using specific antibodies reduced FH acquisition by Leptospira and increased MAC deposition on the spirochete. These findings indicate that TolC contributes to leptospiral virulence by promoting host tissue colonization and evading the immune response, presenting it as a potential target for diagnostic and therapeutic strategies.

Monitoring of pathogenic Leptospira infection in wolves (Canis lupus) from Spain and Italy

Leptospirosis is a bacterial disease of worldwide distribution with relevant implications for animal and human health. Different large wild carnivore species can act as reservoirs of this zoonotic pathogen. This study aimed to evaluate the circulation of Leptospira spp. in free-ranging wolves (Canis lupus) from southern Europe. A total of 281 kidney samples of wolves from Spain and Italy were collected between 2017 and 2023. The presence of Leptospira DNA was analysed by real-time PCR and phylogenetic analyses were carried out using a Bayesian approach. The overall prevalence was 3.2 % (9/281; 95 %CI: 1.1-5.3). Leptospira DNA was detected in nine of the 180 wolves from Spain (5.0 %; 95 %CI: 1.8-8.2), but not in the Italian wolf population (0 %; 0/101). Molecular analyses revealed high homology between the sequences obtained in the present study and isolates of Leptospira interrogans and Leptospira borgpetersenii from different rodent and domestic ungulate species. Our results provide evidence of a low and spatially heterogeneous circulation of this pathogen in wolf populations of southern Europe. The detection of zoonotic Leptospira species in this survey supports the need to consider wolf populations in monitoring programs for leptospirosis with a One Health approach.

Chemokine profile in the serum of patients with leptospirosis

Introduction

Leptospirosis is a global zoonosis that affects more than one million people per year, with a lethality rate of approximately 15%. Chemokines are crucial in the immune response against Leptospira, recruiting leukocytes to the site of infection and regulating immune activity. In previous studies, we have shown that CCL2, CXCL5, and CCL8 are involved in the leptospirosis process, although the mechanisms are not understood.

Methods

In this study, we present the frequency of Leptospira serovars in human samples. We then evaluated the profile of various chemokines in sera from patients diagnosed with leptospirosis, assessing the possible correlation between them. Moreover, we evaluated the changes in the chemokine profile on different days after the first symptoms. The frequency of the Leptospira serovars in human samples is presented.

Results and discussion

The main findings were that CCL5, CXCL5, and CXCL9 are highly expressed during leptospirosis, indicating a special role of these molecules in the immunity and pathogenesis of the disease. The correlation analysis of detected chemokines CXCL11, CXCL9, CCL3, and CCL2 helps to clarify the role of each cytokine in leptospirosis. The possible use of CCL5 as a biomarker for complementary diagnosis of the disease is suggested.

Leptospirosis Incidence Post-Flooding Following Storm Daniel: The First Case Series in Greece

The present study investigates the public health impact of flooding on leptospirosis incidence after Storm Daniel in Thessaly, Greece, in September 2023. A notable increase in cases was observed, with seven cases of female patients and a mean age of 40.2 years, indicating a significant risk among working-age adults. From the end of September to the beginning of November 2023, a total of 35 patients from flood-prone areas presented to the Emergency Department of the Tertiary University Hospital of Larissa. Diagnosis of leptospirosis was established by meeting the criteria suggested by the national public health organisation (EODY)-compatible clinical course, epidemiological exposure, molecular and serologic confirmation by the detection of immunoglobulin M antibodies to leptospira spp. using a commercially available enzyme-linked immunosorbent assay and real-time quantitative PCR for the molecular detection of leptospira. The larger part (84.6%) of leptospirosis cases were associated with contact with floodwater. The majority of these patients (71.4%) were from the prefecture of Larissa, followed by 14.3% from the prefecture of Karditsa, 8.6% from the prefecture of Trikala, and 5.7% from the prefecture of Magnesia. Occupational exposure and urbanisation were key risk factors. The most prevalent clinical feature was rash (69.2%), followed by fever (61.5%) and myalgia (30.7%). The findings emphasise the need for robust public health strategies, improved sanitation, rodent control, and protective measures for sanitation workers. The data highlight the broader implications of climate change on public health and the necessity for ongoing surveillance and community education to mitigate future outbreaks.

Survival outcomes, low awareness, and the challenge of neglected leptospirosis in dogs

Background

Leptospirosis is a globally neglected zoonotic disease with significant morbidity and mortality in dogs, particularly in resource-limited settings.

Aim

This study aimed to characterize prognostic factors and survival outcomes in dogs with suspected leptospirosis, emphasizing the potential underestimation of disease burden.

Methods

This retrospective study was conducted using medical records of dogs diagnosed with urinary Leptospira polymerase chain reaction (PCR).

Results

Urinary Leptospira PCR was positive in 22 dogs and negative in 62. Azotemia was present in approximately two-thirds of both groups, with no predictive value identified between PCR-positive and PCR-negative dogs. However, PCR-positive dogs exhibited significantly shorter survival times for both all-cause mortality (median 60 days, range: 8-601 days) and leptospirosis-related death (median 27 days, range: 8-67 days) compared to PCR-negative dogs (median 402 days, range: 7-812 days) (p < 0.01). The neutrophil-to-lymphocyte ratio (NLR) in-dependently predicted leptospirosis-related death (HR = 1.073, 95%CI: 1.02-1.13, p = 0.01), while the BUN-to-creatinine ratio predicted all-cause mortality (HR = 1.02, 95% CI: 1.003-1.03, p = 0.02).

Conclusion

Our findings underscore the severity of leptospirosis in older dogs, particularly those with azotemia or positive PCR results. NLR and BUN to creatinine ratios could be valuable tools for risk assessment and guiding treatment strategies in this vulnerable population.

Identifying the Drivers Related to Animal Reservoirs, Environment, and Socio-Demography of Human Leptospirosis in Different Community Types of Southern Chile: An Application of Machine Learning Algorithm in One Health Perspective

Leptospirosis is a zoonosis with global public health impact, particularly in poor socio-economic settings in tropical regions. Transmitted through urine-contaminated water or soil from rodents, dogs, and livestock, leptospirosis causes over a million clinical cases annually. Risk factors include outdoor activities, livestock production, and substandard housing that foster high densities of animal reservoirs. This One Health study in southern Chile examined Leptospira serological evidence of exposure in people from urban slums, semi-rural settings, and farm settings, using the Extreme Gradient Boosting algorithm to identify key influencing factors. In urban slums, age, shrub terrain, distance to Leptospira-positive households, and neighborhood housing density were contributing factors. Human exposure in semi-rural communities was linked to environmental factors (trees, shrubs, and lower vegetation terrain) and animal variables (Leptospira-positive dogs and rodents and proximity to Leptospira-positive households). On farms, dog counts, animal Leptospira prevalence, and proximity to Leptospira-contaminated water samples were significant drivers. The study underscores that disease dynamics vary across landscapes, with distinct drivers in each community setting. This case study demonstrates how the integration of machine learning with comprehensive cross-sectional epidemiological and geospatial data provides valuable insights into leptospirosis eco-epidemiology. These insights are crucial for informing targeted public health strategies and generating hypotheses for future research.

Leptospirosis transmitted from a pet dog

Leptospirosis is a widespread zoonosis in tropical regions and it is not frequently recognised in developed countries. We report a case of leptospirosis transmitted from a pet dog. A middle-aged woman was referred to our emergency department with a 7-day history of fever and diarrhoea. She presented with hypotension, tachycardia, grasping pain in the entire muscle and petechiae. A detailed medical interview revealed that her pet dog had been to the veterinarian 1 month earlier with similar symptoms. We treated her with intravenous antibiotics. The patient's diagnosis of leptospirosis was confirmed by serological testing and the detection of DNA in her urine. We contacted the veterinarian and shared the information. We found that the dog had suffered from leptospirosis based on serological testing. We emphasise the possibility of leptospirosis being transmitted from pet dogs. Persistent suspicion of leptospirosis will contribute to its diagnosis and improved public health.

Immunoinformatic approaches for ErpY-LemA chimeric protein design for use in leptospirosis control

AIMS

Currently, immunoinformatic approaches have shown promise in rapidly and cost-effectively identifying new antigens from the Leptospira proteome. Chimeric multiepitope proteins offer a strategy with significant potential for implementation in diagnosis and vaccines development.

METHODS AND RESULTS

In this study, we detail the immunoinformatic analyses and design of a new recombinant chimeric protein constructed with epitopes identified from the sequences of ErpY-like and LemA proteins, previously identified as potential antigens for controlling leptospirosis. We expressed the chimeric protein using Escherichia coli heterologous systems, evaluated its antigenicity using serum from naturally infected patients, and its immunogenicity in mice as an animal model, with Freund as an adjuvant. The resulting recombinant chimeric protein, named rErpY-LemA, was successfully expressed and purified using a prokaryotic system, with an expected mass of 35 kDa. Serologic assays using serum samples from naturally infected patients demonstrated recognition of the chimera protein by antibodies present in sera. Animals immunized with the chimera exhibited a significant IgG antibody response from the 7th day (P < 0.001), persisting until day 49 of experimentation, with a titer of 1:12,800 (P < 0.05). Notably, significant production of IgA, IgM, and IgG subclasses was observed in animals immunized with the chimera.

CONCLUSIONS

These results highlight the promising role of immunoinformatics in rapidly identifying antigens and the potential of chimeric multiepitope proteins in developing effective strategies for leptospirosis control.

Evaluation of Rat Density and the Associated Factors in Leptospirosis Endemic Areas: The First Report on the Use of BI-Index

Introduction: Leptospirosis is a health problem in tropical countries where rats serve as the reservoir of Leptospira contamination. Previous investigations implementing the Bi-index to assess rat density in Leptospirosis endemic areas are highly limited. This study aimed to use the Bi-index in monitoring rat density and the associated factors in urban Leptospirosis endemic areas. Methods: Four endemic areas in Semarang City were selected as the study sites based on Leptospirosis data in Puskesmas Gayamsari. Live traps were positioned in one case house and 39-49 neighboring houses in a 100m radius, on three consecutive days. Trapped rats were collected for species identification, morphometrics evaluation, and calculation of Bi-index and rat indices, while environmental parameters were obtained through observation. Results and Discussion: 67.1% of participants were women, private employees, and aged 17-55, while trap success ranged from 2.5-26.5% with the Bi, diversity, dominance, and evenness indices of 0.02-0.32, 0.94-1.09, 0.36-0.44, and 0.79-0.96, respectively. Trapped species included Rattus norvegicus, Rattus tanezumi, and Mus musculus with proportions of 61.3%, 34.1%, and 4.7%, respectively. The presence of rats was associated with closeness to the river containing stagnant water, frequent flooding, water entering houses during floods, open trash bins, and rubbish bins around the houses. The high rat density, dominant species, and correlated environmental conditions are strategic targets in controlling Leptospirosis in Semarang City. Conclusion: The rat density (dominated by R. norvegicus) in Semarang City was correlated with water drainage and garbage management, hence further investigation was recommended to determine Leptospira bacterial infection in rodents.

Anti-Leptospira Seroprevalence and Associated Risk Factors among Forestry Workers in Lower Saxony, North-West Germany

As leptospirosis is re-emerging, a seroprevalence study was conducted, assessing the prevalence of anti-Leptospira IgG antibodies and infection-associated risk factors among forestry workers (FWs) in Lower Saxony, Germany, to develop targeted public health measures. Sera of 877 FWs, sampled in 2016, were tested for anti-Leptospira seropositivity by commercial IgG-ELISA. Data on demographics and Leptospira-specific exposures, knowledge, sources of information, and preventive measures were collected by standardized, self-administered questionnaire. A subset of 244 sera was retested via in-house IgG-ELISA. Risk factors were assessed from the subset using multivariable logistic regression analysis. The commercial IgG-ELISA revealed a seroprevalence of 4.8% (95% confidence interval CI95 = 3.5-6.4). Of the 601 FWs who completed the questionnaire, 67.9% had been informed about leptospirosis and Leptospira spp., mainly by employers (55.2%) and peers (38.9%). Positive associations with seropositivity were observed for canoeing (adjusted odds ratio (aOR) = 2.35, p = 0.044), touching rodents (aOR = 2.4, p = 0.021), and living close to beech trees (aOR = 2.18, p = 0.075). Frequently cleaning animal stables was negatively associated (aOR = 0.20, p = 0.002). The unexpected positive association with wearing gloves when handling plants and soil (aOR = 2.16, p = 0.011) needs further discussion. Overall, seroprevalence was in the range of other studies in Germany. The identified factors will be used to develop targeted information reaching out to at-risk groups tapping various communication channels.

Leptospirosis in India: insights on circulating serovars, research lacunae and proposed strategies to control through one health approach

Leptospirosis is one of the most neglected zoonotic infections of public health concern worldwide and a remerging infection in tropical countries such as India. The infection least explored disease and the epidemiological and other critical data are scarce for the disease rate reported and to control the infection. Leptospirosis as sapronosis is as underrated as the infection itself, and this article aims to explore the significance of this aspect of the disease. The research review aimed at the epidemiological understanding of the infection to control the negative impact of the disease. A mixed review and analysis were carried out to understand the knowledge published on the critical and understudied areas like epidemiology, transmission, diagnosis, treatment, and control of infection. A systematic analysis was carried out to extract information about the reported circulating strains, and research lacunae in India with the published data available in PubMed. The article elaborately discusses crucial inference areas of infection transmission and addresses lacunae in critically unacclaimed areas of infection to control the spread of infection using one health approach (OHA), and strategies to control leptospiral infection are proposed. The article also reviewed how and why Leptospirosis can be best studied and controlled by "One health approach" in India.

Accuracy of rapid lateral flow immunoassays for human leptospirosis diagnosis: A systematic review and meta-analysis

BACKGROUND

In the last two decades, several rapid lateral flow immunoassays (LFIs) for the diagnosis of human leptospirosis were developed and commercialized. However, the accuracy and reliability of these LFIs are not well understood. In this study, we aimed to evaluate the accuracy of leptospirosis LFIs as well as the factors affecting the test efficiency using systematic review and meta-analysis.

METHODS AND RESULTS

Original articles reporting the accuracy of human leptospirosis LFIs against microagglutination tests (MAT) or immunofluorescent assays (IFA) were searched from PubMed, Embase, and Scopus, and selected as per pre-set inclusion and exclusion criteria. A total of 49 data entries extracted from 24 eligible records published between 2003 and 2023 were included for meta-analysis. A meta-analysis was performed using STATA. The quality of the included studies was assessed according to the revised QUADAS-2. Only nine studies (32.1%) were considered to have a low risk of bias and no concern for applicability. Pooled sensitivity and specificity were calculated to be 68% (95% confidence interval, CI: 57-78) and 93% (95% CI: 90-95), respectively. However, the ranges of sensitivity (3.6 - 100%) and specificity (53.5 - 100%) of individual entries are dramatically broad, possibly due to the heterogeneity found in both study designs and LFIs themselves. Subgroup analysis demonstrated that IgM detection has better sensitivity than detection of IgG alone. Moreover, the test performance seems to be unaffected by samples from different phases of infection.

CONCLUSIONS

The pooled specificity of LFIs observed is somewhat acceptable, but the pooled sensitivity is low. These results, however, must be interpreted with caution because of substantial heterogeneity. Further evaluations of the LFIs with well-standardized design and reference test will be needed for a greater understanding of the test performance. Additionally, IgM detection type should be employed when leptospirosis LFIs are developed in the future.

Current treatment options for leptospirosis: a mini-review

Leptospirosis, one of the most common global zoonotic infections, significantly impacts global human health, infecting more than a million people and causing approximately 60,000 deaths annually. This mini-review explores effective treatment strategies for leptospirosis, considering its epidemiology, clinical manifestations, and current therapeutic approaches. Emphasis is placed on antibiotic therapy, including recommendations for mild and severe cases, as well as the role of probiotics in modulating the gut microbiota. Furthermore, novel treatment options, such as bacteriophages and newly synthesized/natural compounds, are discussed, and the findings are expected to provide insights into promising approaches for combating leptospirosis.

Exploring the complex interplay: gut microbiome, stress, and leptospirosis

Leptospirosis, a re-emerging zoonotic disease, remains a significant global health concern, especially amid floods and disasters such as the Kakhovka Dam destruction. As is known, the stress that occurs in the conditions of military conflicts among civilian and military personnel significantly affects susceptibility to infectious diseases and possibly even influences their course. This review aims to explore how the gut microbiome and stress mediators (such as catecholamines and corticosteroids) might impact the leptospirosis disease course. The review opens new horizons for research by elucidating the connections between the gut microbiome, stress, and leptospirosis.

Landscape, Socioeconomic, and Meteorological Risk Factors for Canine Leptospirosis in Urban Sydney (2017-2023): A Spatial and Temporal Study

Leptospirosis is a potentially fatal zoonotic disease caused by infection with pathogenic Leptospira spp. We described reported clinical cases of canine leptospirosis in the council areas of the Inner West and the City of Sydney, Australia, from December 2017 to January 2023 and tested the association with urban spatial (landscape and socioeconomic factors, community seroprevalence, and urban heat island effect) and temporal (precipitation and minimum and maximum temperature) factors and the cases using log-transformed Poisson models, spatially stratified population-adjusted conditional logistic models, General Additive Models (GAMs), and Autoregressive Integrated Moving Average (ARIMA) models. The results suggested that canine leptospirosis is now endemic in the study area. A longer distance to the nearest veterinary hospital (RR 0.118, 95% CI -4.205--0.065, p < 0.05) and a mildly compromised Index of Economic Resources (IER) (RR 0.202, 95% CI -3.124--0.079, p < 0.05) were significant protective factors against leptospirosis. In areas proximal to the clinical cases and seropositive samples, the presence of tree cover was a strong risk factor for higher odds of canine leptospirosis (OR 5.80, 95% CI 1.12-30.11, p < 0.05). As the first study exploring risk factors associated with canine leptospirosis in urban Sydney, our findings indicate a potential transmission from urban green spaces and the possibility of higher exposure to Leptospira-or increased case detection and reporting-in areas adjacent to veterinary hospitals.

First Report on Leptospira Species Isolated from Patients in Slovenia

Leptospirosis is an important worldwide zoonosis, and it has also been reported in Slovenia. The cultivation of Leptospira from human material is difficult. Despite that, we successfully isolated 12 human Leptospira strains isolated from patients between 2002 and 2020 and used various methods for the phenotypic and genotypic characterization of the strains, including matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) using our own MALDI-TOF data library, melting temperature analysis of the amplified lfb1 gene, determination of Leptospira serogroups using rabbit immune sera, NotI-RFLP of the whole Leptospira genome, multilocus sequence typing (MLST) of seven housekeeping genes, and whole-genome sequencing (WGS)-based typing. We confirmed the presence of four pathogenic Leptospira species (L. kirschneri, L. interrogans, L. borgpetersenii, and L. santarosai) and three serogroups: Grippotyphosa, Icterohaemorrhagiae, and Sejroe. MALDI-TOF identified three of seven isolates at the species level and four isolates at the genus level. Serovars of 8 of the 10 strains were determined using NotI-RFLP. MLST showed that the clinical isolates belonged to sequence types ST17, ST110, and ST155. WGS confirmed the analysis of Leptospira strains using conventional methods. In addition, WGS provided better taxonomic resolution for isolate DDA 10944/10.