ABSTRACTWeil's disease should be considered even in non‐endemic regions when compatible clinical findings are accompanied by relevant exposure history. This case is epidemiologically notable as the first documented report from South Khorasan Province, highlighting the diagnostic challenges of leptospirosis in non‐endemic settings and the potential risk of disease transmission associated with military deployment from endemic to non‐endemic regions.

Leptospirosis is a zoonotic infectious disease caused by pathogenic Leptospira species and is characterized by a broad spectrum of clinical manifestations. The disease ranges from a mild, self-limiting illness known as Akiyami to severe Weil's disease, which presents with high fever; jaundice; hemorrhagic tendencies involving the skin, nasal cavity, and lungs; and acute renal failure. Leptospirosis is endemic to many regions of Southeast Asia. In Japan, it occurs most frequently in Okinawa Prefecture. Human infections are primarily acquired through direct or indirect contact with water or soil contaminated with the urine of infected animals. Diagnosis is established using bacterial culture, polymerase chain reaction, and serological testing, which allow accurate detection across different stages of the disease. Treatment typically involves doxycycline for mild-to-moderate cases, whereas penicillin is recommended for severe diseases. Despite advances in its diagnosis and therapy, leptospirosis remains a major public health concern in endemic regions. Therefore, preventive strategies are essential, particularly during the rainy season and following floods or landslides when environmental contamination is more likely to occur. Avoiding unnecessary exposure to potentially contaminated water plays a critical role in reducing the risk of infection.

Leptospirosis is a globally prevalent zoonotic infection caused by pathogenic spirochaetes of the genus Leptospira Although typically associated with mild flu-like symptoms or Weil's disease (characterised by jaundice, renal failure and haemorrhagic manifestations), atypical and severe presentations can mimic other systemic disorders. A man in his 40s presented with fever, myalgia along with rapidly progressive jaundice, thrombocytopenia, microangiopathic haemolytic anaemia and acute kidney injury, preceded by a short episode of diarrhoea. The initial working diagnosis was haemolytic uraemic syndrome (HUS) secondary to Shiga toxin-producing Escherichia coli and he was treated with plasma exchange, transfusions and renal replacement therapy. However, stool examinations were negative for Shiga toxin and bacterial pathogens. Subsequent investigations confirmed leptospirosis. He improved significantly after treatment with doxycycline alongside supportive therapy. This case highlights the importance of considering leptospirosis as a differential diagnosis in patients with HUS, particularly in endemic regions, to avoid delays in targeted treatment.

Abstract Leptospirosis, a spirochetal zoonosis caused by pathogenic Leptospira species, may manifest as a mild illness but can progress to Weil’s disease – a severe form characterized by jaundice, acute kidney injury, hemorrhagic complications, and rhabdomyolysis. We report the case of a 31-year-old previously healthy male who presented with a 5-day history of 5 days of fever, malaise, body aches, difficulty walking, and jaundice. Laboratory studies showed marked leukocytosis, hyponatremia, elevated creatinine, marked hyperbilirubinemia with transaminitis, and evidence of rhabdomyolysis. Imaging revealed increased hepatic echogenicity. A positive Leptospira immunoglobulin M serology and urine PCR confirmed severe icteric leptospirosis (Weil’s disease). The patient’s clinical course was complicated by renal failure requiring hemodialysis, as well as hepatic dysfunction and rhabdomyolysis. With prompt antibiotic therapy using doxycycline and ceftriaxone, along with aggressive supportive care, his renal and hepatic parameters improved, and he was eventually discharged in stable condition. Severe leptospirosis remains extremely rare in high-income settings yet carries a substantial case fatality rate. This case highlights the importance of early recognition and treatment, particularly given its nonspecific presentation, potential for rapid deterioration, and public health relevance in the context of emerging zoonoses.

Background: A fever in a returned traveller broadens the possible differential diagnosis for clinicians and can include unfamiliar diseases, making a diagnosis more challenging. Leptospirosis is a worldwide tropical zoonotic infection caused by the bacteria Leptospira. Most cases are mild but can progress to life-threatening infections without appropriate treatment. The severe form of the illness, sometimes called Weil's disease, can cause multiorgan dysfunction with high mortality rates. Methods: This case describes the presentation of a 16-year-old male patient with febrile illness upon returning to Canada from Jamaica. He was managed in an ICU setting for sepsis with severe pain and signs of rhabdomyolysis, hyperbilirubinemia, and renal dysfunction. He was empirically treated with broad-spectrum antibiotics, and a comprehensive infectious workup was sent to identify the responsible pathogen. Results: A polymerase chain reaction (PCR) assay was used to confirm the diagnosis of leptospirosis, and the patient recovered with appropriate antibiotic treatment. Incidentally, the patient was seropositive for prior arbovirus infection. Conclusions: This report documents the first PCR-confirmed case of human leptospirosis in the province of Nova Scotia, Canada, and highlights the potentially severe nature of the disease. Early suspicion is crucial for a positive clinical outcome, and leptospirosis should be on the differential for any febrile traveller returning from an endemic area.

Weil's disease following exposure to flooding in the Valencia region, Spain

Vaccination is implicated in development of human immune-mediated diseases, but studies in dogs yielded conflicting results for immune-mediated hemolytic anemia (IMHA) and thrombocytopenia (ITP). To investigate temporal relationships between onset of IMHA or ITP and vaccination in dogs. Client-owned dogs with nonassociative IMHA (n=295) and ITP (n=163) at 4 referral hospitals, alongside control dogs (n=1180 for IMHA, 652 for ITP) presented contemporaneously. Multicenter retrospective case-control study, with meta-analysis of published studies. Proportions vaccinated ≤ 30days before disease onset were compared to controls, along with times since last vaccine. Proportion of dogs vaccinated ≤ 30days of disease onset was significantly higher in the IMHA group (35/295, 11.9%) compared with controls (72/1180, 6.1%; P=.0015). Dogs with IMHA vaccinated ≤ 30days of disease onset were more likely to have received a L2 vaccine (Leptospira serovars Canicola and Icterohemorrhagiae) in their last dose than those vaccinated > 30days before onset (P=.04). Meta-analysis indicated dogs with IMHA were 2.48 times (95% CI, 1.69-3.63) more likely to have been vaccinated in the past month than controls, but with high heterogeneity across this and 2 other studies. There was no difference in proportion of ITP dogs and controls vaccinated ≤ 30days of disease onset, and meta-analysis with 1 other study showed no temporal association, though both analyses were likely underpowered. These results support a possible temporal association between vaccination and onset of IMHA in dogs. Our results do not establish a causal relationship between vaccination and IMHA.

Introduction: Weil disease, characterized by jaundice, renal failure and hemorrhage, is caused by the pathogenic Leptospira spirochete. Transmission to humans occurs via exposure to animals or contaminated urine. Most United States cases occur in tropical states, such as Puerto Rico and Hawaii. However, recent literature suggests that climate change may impact our previous understanding of Leptospira’s geographic predilection. We present a rare case of Leptospirosis in Baltimore, Maryland, in a patient presenting with pulmonary-renal syndrome who lacked obvious risk factors. Description: A 44-year-old man with no medical history presented for 3 days of vomiting, diarrhea, myalgias and anuria. The family noted rodent sightings in their Baltimore suburb. He was admitted for abnormal blood work: acute kidney injury, thrombocytopenia, mild transaminitis and direct hyperbilirubinemia. Initially stable, he had rapid clinical deterioration requiring intubation, vasopressors and continued renal replacement therapy. Evidence of urine red blood cell casts and diffuse alveolar hemorrhage (DAH) on bronchoalveolar lavage led to high-suspicion of autoimmune pulmonary-renal syndrome. He was treated with early pulse-dose methylprednisolone and empiric antibiotics. Workup for immunodeficiency and autoimmune disease was unrevealing. Renal biopsy showed acute tubular necrosis without vasculitis; steroids were discontinued. Leptospirosis IgM was positive. His clinical status improved with treatment for Leptospirosis, ultimately leading to liberation from the ventilator and vasopressors. Discussion: Our patient had classic symptoms for Weil disease but no clear exposure history. Testing and treatment for Leptospirosis should be promptly considered in the presence of possible pulmonary-renal syndrome even without a clear exposure history on thorough exploration. In our literature search, this is the first case of Leptospirosis in Baltimore since 2020. Although the exact source of our patient’s infection is unclear, heavy rainfall in July 2025 may have increased the risk of transmission from rats in the patient’s neighborhood. Since Leptospirosis has not been a reportable CDC disease since 1994, we must remain vigilant and aware of evolving disease incidence as our external environment changes.

The generalization of long-term data (1961-2023) on the epidemiological and epizootic situation with leptospirosis in the Mykolaiv region reveals a steady trend. Although the epidemic situation is being kept at a controlled level, the long-term intensity indicators are 3.2-4.5 cases per 100,000 people, exceeding the average Ukrainian level of 3.1-3.6 cases per 100,000 people. The current (2019-2023) epidemic intensity of leptospirosis is 4.2-4.6 cases per 100,000 people, which is close to the long-term average. The tensest situation is characteristic of the hydromorphic areas of Pervomaisk, Domanivka, and Kryvoozersk districts, with a maximum in Pervomaisk district - 9.6 cases per 100,000 people. Epidemiological analysis of the situation with leptospirosis in livestock in the region demonstrates a direct correlation between the number of farm animals and the proportion of seropositive (infected) animals among them, indicating that the epidemiological process depends on the density of the affected object. The current manifestation of human and animal leptospirosis in the Nyzhnie Pobuzhzhia region is categorized into two ecologically distinct forms based on the sources of infection. These forms are associated with synanthropic and natural sources of Leptospira. Leptospira Icterohaemorrhagiae, from both sources, plays a significant role in epidemics, accounting for 78.12% of laboratory-confirmed cases during the study period. The fluctuations in the activity of leptospira foci lead to their periodic spread in the Western Black Sea region, extending to the coastal areas of Romania and Bulgaria. This research is practically valuable as it provides detailed insights into the ecological differentiation of various types of foci that serve as reservoirs of infection. This understanding enables targeted and environmentally rational strategies to mitigate the threat posed to humans and animals.

Background: Leptospirosis is a zoonotic disease endemic in tropical regions with a high burden among low-income populations. Its clinical spectrum ranges from mild illness to severe Weil’s disease, which may involve multiple organs with common and severe complication is acute kidney injury (AKI) with no specific therapy exists. In this report, we describe how early hemodialysis may improve outcomes. Case Presentation: A 60-year-old man presented with a 10-day history of fever. He also reported calf pain and jaundice that had appeared one week prior to admission. Over the past week, the patient experienced decreased urinary frequency, with urine becoming more concentrated in color. Laboratory tests revealed thrombocytopenia, leukocytosis, elevated SGOT and SGPT levels, hyperbilirubinemia, and azotemia. Leptospira IgM was positive. Urinalysis demonstrated proteinuria and bilirubinuria. The patient’s Modified Faine’s Criteria score was 34, and his SOFA score was 11. Results: Patient was diagnosed with Weil's disease with AKI III complicated by sepsis. The furosemide stress test was administered to the patient but the results was not favorable therefore hemodialysis was initiated leading to an improvement in the patient’s condition. Conclusion: Early initiation of hemodialysis in patients with leptospirosis induced AKI provides favorable immediate outcome and prevents them from falling into uremic syndrome leading to mortality.

Ictero-hemorrhagic leptospirosis -Weil's disease.

Leptospirosis is a common zoonotic disease with a 10-fold higher incidence in tropical regions compared to temperate zones. The disease is endemic to the Indian subcontinent, particularly prevalent in the southern states. It has a wide spectrum of presentations, most commonly high-grade fever, myalgia, conjunctivitis, haematuria, jaundice, abdominal pain, and vomiting. Severe infection manifests as multisystemic vasculitis and Weil's disease. Here we describe an atypical presentation which posed a diagnostic dilemma. Considering the age of the patient and the presenting symptoms, colonic malignancy with hepatic metastasis was suspected, and further investigations were conducted, which indeed revealed a colonic growth in the descending colon, consistent with the clinical suspicion. However, the colonic growth was found to be an inflammatory mass caused by leptospiral infection, confirmed by various investigation modalities and response to antibiotic therapy. Few publications have reported cases of leptospirosis presenting with episodes of bleeding per rectum with colonic growth.

Endometritis is defined as the inflammation of the endometrium and myometrium. Social factors can predispose to concomitant tropical infections, and diseases such as leptospirosis can have overlapping symptoms. We present the case of a 19-year-old female who had an urgent cesarean section, had a poor clinical course with jaundice, acute kidney injury, and coagulopathy requiring a second surgical time, and underwent an urgent hysterectomy for severe and irreversible endometritis. Additionally, leptospirosis-induced Weil’s syndrome was confirmed by serology (positive IgM) due to the presence of systemic alterations that could not be explained by a gynecologic condition alone. Endometritis has identifiable risk factors, and a typical antibiotic regimen is usually sufficient to prevent complications. However, severe cases can still occur despite treatment. This case highlights the diagnostic challenge of differentiating severe sepsis due to obstetric syndromes and zoonotic diseases such as leptospirosis, which can mimic gynecologic diseases and delay diagnosis and treatment. Analyzing each case is crucial to identifying unusual pathologies in pregnant patients and preventing adverse outcomes.

Leptospirosis is a widespread zoonotic infection caused by pathogenic spirochetes of the genus Leptospira. The disease is prevalent in tropical and subtropical regions, but sporadic cases are increasingly reported in Europe and the United States. It presents in two major clinical forms: anicteric leptospirosis — a mild, self-limiting febrile illness—and icteric leptospirosis (Weil’s disease), which may progress to multiorgan involvement, including acute hepatic and renal failure. In Georgia, multiple Leptospira serovars have been identified, such as L. icterohemorrhagica, L. automualis, L. mankarsto, L. wolffii, and L. canicola. Since 2011, the incidence of leptospirosis has increased significantly, reaching 1.81 per 100,000 population, with icteric and anicteric forms occurring at nearly equal rates (44.6% and 55.4%, respectively). Icteric forms were frequently associated with hepatic and renal failure in approximately one-third of patients, while hemorrhagic manifestations and pneumonia occurred in 5.3% and 3.6% of cases, respectively. In 2023, a clinical study at the First University Clinic of TSMU investigated patients with prolonged fever exceeding five days and no catarrhal symptoms. Serological testing (IgM ELISA) confirmed leptospiral infection in 40 patients (64.5%), aged 17–80 years, from both urban (51.6%) and rural (48.3%) areas. The most common presentation was pneumonia (35.5%), whereas icteric forms were less frequent (12.9%). These findings indicate that the epidemiological and clinical characteristics of leptospirosis have changed in recent years. The disease now more frequently affects urban populations and often manifests as prolonged febrile illness with lower respiratory involvement and intoxication syndrome. Severe cases are mainly complicated by acute respiratory failure, typically without multiorgan dysfunction. Early recognition and timely etiological diagnosis through serological testing are essential for appropriate management and prevention of complications.

Leptospirosis is a zoonosis caused by the pathogenic Leptospira, having an estimated global epidemiology of 1.03 million cases. Early diagnosis of leptospirosis is crucial to prevent its progression into more severe form known as Weil's syndrome. A pragmatic approach for early diagnosis of leptospirosis necessitates the direct detection pathogenic Leptospira itself by a specific molecular recognition element. To achieve this, we have isolated two aptamers against the target LipL32 protein of the pathogenic Leptospira, LepDapt-9149 and LepDapt-5561 by a modified SELEX strategy known as the Tripartite-hybrid-HT SELEX. These two aptamers have Kd values of 64.59 ± 11.25nM and 48.36 ± 8.03nM, respectively, estimated by direct ELASA. On the other hand, the Kd values obtained using filter binding assay-qPCR analysis were 39.35 ± 0.12 and 18.03 ± 0.23nM for LepDapt-9149 and LepDapt-5561, respectively. Integrating these aptamer pair into sandwich ELASA, the developed assay is highly specific against the pathogenic Leptospira without displaying any cross-reactivity against the non-pathogenic Leptospira and NS1 protein of dengue virus. The assay also reached a LOD of 55CFU/ mL in 1% serum, which is sensitive enough to reach the clinical range of leptospirosis, which is between 104 to 106CFU/ mL. The sandwich ELASA assay integrated with the isolated aptamer pair has an enormous potential for the diagnosis of leptospirosis.

Leptospirosis is a zoonotic infection caused by slow-growing spirochetes of the genus Leptospira. The clinical picture varies from asymptomatic disease and mild flu-like symptoms to severe infection with jaundice, renal failure and pulmonary haemorrhage (Weil's disease). Brown rats are the most important reservoir for human infection, and the animals excrete the bacteria in their urine. Humans are infected either through direct contact with infected animals or indirectly through contaminated fresh water and soil via wounds, damaged skin or mucous membranes. Here we present two cases of indigenous leptospirosis in Sweden, one of whom developed Weil's disease.

To carry out a retrospective analysis of Leptospira microscopic agglutination test (MAT) results performed at Tifton Veterinary Diagnostic and Investigational Laboratory in Georgia from June 2015 to December 2023. Test records for MAT against 7 Leptospira interrogans serovars (Autumnalis, Bratislava, Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, and Pomona) were retrieved from submissions among cattle, dogs, goats, equids, pigs, and wildlife/exotic species. Further categorization was performed by state and health conditions for seropositive animals, including by breed purpose for cattle (beef, dairy, and dual purpose) and body weight groups for dogs (large, medium, and small). Across all species, the seropositivity rate was 52.3% (552 of 1,055), and the most frequently detected MAT antibodies were against serovar Autumnalis (60.3%; 95% CI, 56.1% to 64.4%), followed by Icterohaemorrhagiae (52.7%; 95% CI, 48.5% to 57.0%). Equids had the highest seropositivity rate (82.5% [47 of 57]) followed by pigs (80.0% [16 of 20]), cattle (54.1% [351 of 649]), dogs (45.6% [131 of 287]), goats (23.3% [7 of 30]), and exotic species (0% [0 of 12]). The highest MAT titer (1:12,800) was detected in a Florida dairy cow against Pomona; a Georgia dog against Autumnalis, Grippotyphosa, and Pomona; and a South Carolina Paint Horse against Pomona. In the southeastern region of the US, the most frequently detected MAT titers were against serovar Autumnalis in dogs, equids, goats, and pigs, while in cattle, Autumnalis was the second most frequent serovar after Icterohaemorrhagiae. The frequent and/or exclusive detection of Autumnalis and Bratislava MAT titers supports the inclusion of these 2 serovars in leptospirosis vaccines and MAT panels used in veterinary diagnostic laboratories across the US.

Leptospirosis is a zoonotic disease caused by bacteria that can infect both humans and other animals. This disease is caused by an infection of Leptospira bacteria, which can be transmitted through the nose, mouth, eyes, or through open wounds on the skin when a person is exposed to water contaminated with the urine of infected animals. In this case report, a 45-year-old woman came to the emergency department with complaints of shortness of breath, abdominal discomfort, high fever, and generalized body pain, especially in her calves. The patient reported that her urine output had been significantly reduced for three days prior to hospital admission. The patient was hospitalized in the high care unit for 12 days. Following the administration of third-generation cephalosporin antibiotics and two sessions of hemodialysis during the course of treatment, the patient showed clinical improvement, with decreased serum concentrations of urea and creatinine, as well as increased urine output without the use of diuretics. The prognosis of acute kidney injury in patients with severe leptospirosis depends on the clinical condition of the patient, the accuracy of the diagnosis, and the timeliness of initiating treatment. In patients with significantly impaired renal function and declining clinical status, prompt initiation of renal replacement therapy such as hemodialysis is recommended.

The aim of the study was to determine the species affiliation and genetic diversity of pathogens of bacterial natural focal infections in order to refine the spectrum of circulating agents in certain areas of the Kherson and Zaporozhe Regions. Materials and methods. An epizootiological survey of the territory of Verkhnerogachik, Genichesk, Novotroitsk districts of the Kherson Region, Akimov, Berdyansk, Vasilievsk, Veselovsky, Melitopol, Pologovsky districts of the Zaporozhe Region was conducted. The study of field material was carried out by molecular-genetic, serological, and biological methods. Sequencing of Borrelia DNA isolates by a fragment of the 16S rRNA gene, fragments of genes (gltA, ompB) of Rickettsia spp. DNA isolates, MLVA-25 typing of Francisella tularensis strains were performed. Statistical analysis of the laboratory test results was performed using Microsoft Excel 2010. The data were analyzed using the cartographic method applying ArcGIS 10.3. Results and discussion. The circulation of pathogens of tularemia, leptospirosis (Leptospira icterohaemorrhagiae, L. grippotyphosa), rickettsiosis (Rickettsia aeschlimannii, R. heilongjiangensis, R. conorii, R. slovaca, R. vini), Ixodidae tick-borne borreliosis (Borrelia afzelii, B. miyamotoii) in individual areas of the Kherson and Zaporozhe Regions has been established. Markers of Anaplasma phagocytophilum have been identified in the Zaporozhe Region. The data obtained indicate a possible joint circulation of pathogens of leptospirosis, tick-borne rickettsiosis, Ixodidae tick-borne borreliosis in the Genichesky district of the Kherson Region; tularemia, leptospirosis, tick-borne rickettsiosis, Ixodidae tick-borne borreliosis, human granulocytic anaplasmosis in the Melitopol district of the Zaporozhe Region; leptospirosis, tick-borne rickettsiosis, Ixodidae tick-borne borreliosis, human granulocytic anaplasmosis in the Berdyansk district of the Zaporozhe Region. Based on the results of the conducted studies, information on the circulation of pathogens of tularemia, leptospirosis, rickettsiosis, Ixodidae tick-borne borreliosis in certain areas of the Kherson and Zaporozhe Regions has been obtained, which suggests the presence of foci of combined infections. Outbreak and sporadic incidence of natural focal infections is possible in the surveyed area. To assess the epidemic potential of territories, further epizootiological examination, assessment of the number and species composition of carriers and vectors of pathogens of natural focal infections, and an analysis of morbidity are required.

The incidence of leptospirosis is increasing globally, and developing countries are no exception. Leptospirosis cases are called the tip of the iceberg phenomenon, even though misdiagnosis, underdiagnosis, and underreporting still occur in health services. Thus, it leads to delays in leptospirosis treatment and may result in increased mortality rate from severe leptospirosis infection (Weil's disease). This study was to establish an accurate diagnosis by optimizing the Faine criteria. This study used an analytical observational design with a cross-sectional approach to examine faine criteria and laboratory examinations. We collected data from medical records from the Karanganyar General Hospital and the PKU Muhammadiyah Surakarta Hospital. We processed the data using SPSS version 25. The total number of samples was 42. They were divided into women (19%) and men (81%). Based on the definition category of leptospirosis cases, there were 2.4% probable group (score criteria faine part A 20-25) and 97.6% not-probable group (score criteria faine part A <20). Bivariate analysis (Chi-Square test) showed that there was no significant correlation between Faine Part A criteria and serological tests in both groups (p=0.874) as well as Hb (p=0.522), thrombocytopenia (p=0.265), leukocytosis (p=0.197), and neutrophilia (p=0.710). Loss of sodium and potassium didn’t show significant data (hyponatremia p=0.174; hypokalemia p=0.311; hypocalcemia p=0.131) not as in tropical diseases. The approach to diagnosis of leptospirosis cannot be performed using only Part A criteria, Faine, even though the patient was included in the probable definition category, even though the Faine Part A criteria score is 20-25 or ≥26.