Search Results (96)

Leptospirosis remains a public health concern in the Philippines. Conventional diagnostic methods, including the microscopic agglutination test (MAT) and qPCR, are routinely used for outbreak response and surveillance. However, these methods often yield discordant results due to cross-reactivity, limited sensitivity, or lack of species-level resolution. To address these diagnostic gaps, this study optimized the Boonsilp 16S rRNA PCR assay and applied Sanger sequencing for accurate species identification of Leptospira in 92 archived DNA samples collected between 2018 and 2020. The sensitivity and specificity of the optimized assay were compared with those of MAT and qPCR. Species-level identification was confirmed via sequencing, and a phylogenetic tree was constructed. Among the 92 samples, 46 (50.0%) tested positive by qPCR, 39 (42.4%) by MAT, and 67 (72.8%) by at least one of the two methods. The optimized Boonsilp assay detected Leptospira in 23 samples (25.0%), of which 22 were also qPCR positive. Twenty-one samples were confirmed as L. interrogans, one as L. borgpetersenii, and one as an unclassified Leptospira species. One sample undetected by both MAT and qPCR tested positive using the optimized assay. Compared to the composite reference, the Boonsilp assay showed 32.8% sensitivity and 96.0% specificity. Phylogenetic analysis revealed multiple L. interrogans strains, including those closely related to reference sequences of Copenhageni, Manilae, and Canicola. While the optimized Boonsilp PCR assay demonstrates diagnostic value as an adjunct molecular tool to qPCR and MAT supporting species-level identification during outbreak surveillance, this warrants further validation in freshly isolated DNA samples. Full article

Leptospirosis is an important zoonosis that can present as a self-limited influenza-like illness or progress to severe, including life-threatening multiorgan dysfunction. We report the epidemiology, clinical profile, and correlates of severity among adults hospitalized patients with leptospirosis diagnosed in central Romania over a period of 17 years. We conducted a retrospective, single-center cohort study of adults admitted between 1 January 2008 and 1 December 2025 with laboratory-confirmed leptospirosis. Confirmation was based on positive anti-Leptospira IgM serology, with repeat testing when the initial result was equivocal and confirmation with a microscopic agglutination test. We extracted demographic, exposure, clinical, laboratory, treatment, and outcome data from medical records. The modified Faine score was also calculated using admission data. Sixty-four patients were included in this analysis, of which 53 (82.8%) were male patients. Admissions peaked in 2023–2025 (34/64, 53.1%) and in the August–September months. Reported exposures were predominantly peri-domestic (46.9%), followed by rural/animal-related occupations (20.3%) and freshwater contact (17.2%). Severe disease occurred in 26/64 (40.6%), was more frequent in men (p = 0.021), and was more common pre-pandemic than during/after the pandemic (p < 0.001). Severe cases were associated with oliguria/anuria, hematuria, and jaundice, alongside higher urea/creatinine and bilirubin, lower hemoglobin and lymphocyte percentages, and a longer hospitalization period. One in-hospital death occurred (1.6%). Serogroup identification was available for 10 patients (15.6%) (pre-pandemic only). The mean modified Faine score was 27.5 ± 6.0. In this temperate-region cohort study, hospitalized leptospirosis showed a marked male predominance, a late-summer peak, and a substantial burden of severe disease. Early renal and hepatobiliary manifestations with concordant laboratory abnormalities may support timely risk stratification and escalation of care, while expanded molecular diagnostics and systematic typing are needed to clarify temporal trends and guide prevention. Full article

The microscopic agglutination test (MAT) is the diagnostic standard for canine leptospirosis. However, it is a time-consuming process and does not differentiate between infection- and vaccine-induced antibodies. Canine Leptospira spp.-specific antibody point-of-care (POC) tests provide the rapid detection of immunoglobulin M (IgM) and/or G (IgG). IgM POC tests are considered to become negative more rapidly after vaccination, making them more effective at diagnosing leptospirosis in not-recently vaccinated dogs. This study analysed 582 serum samples of 97 healthy dogs using five different POC tests and the MAT before vaccination and 2, 4, 12, 26, and 52 weeks afterwards. Among the POC tests, three detected IgM antibodies, one detected IgG antibodies, and one detected both IgM and IgG. The results were analysed using mixed-effects logistic regression. Before vaccination, only 2/291 IgM tests were positive (0.7%), compared to 45/194 IgG tests (23.2%). All the POC tests became positive after vaccination, but IgM positivity occurred significantly less frequently (59/1746), especially >4 weeks post-vaccination (7/59 positive results), with 94.5–99.6% specificity compared to 41.4–77.8% in IgG tests. These findings support the use of IgM POC tests in vaccinated dogs, while IgG POC tests are more difficult to interpret. Full article

Leptospirosis is a zoonotic disease caused by Leptospira spp., with over 250 serovars classified into 24 serogroups. Control measures depend on understanding serovar-specific epidemiology, yet the microscopic agglutination test (MAT) is only serogroup specific, and classification is complicated by cross-reactivity. While MAT is the reference standard for leptospirosis serodiagnosis and seroepidemiological studies, factors influencing serogroup cross-reactivity remain poorly characterized. We investigated the relationship between age, antibody titer, and serogroup diversity among seropositive individuals in a population-based serosurvey in the Dominican Republic. Between June and October 2021, we conducted a multistage national serosurvey, enrolling 6683 participants across 134 clusters. MAT was performed on sera from 2091 participants in two provinces using a 20-serovar panel. MAT positivity was defined as titers ≥ 1:100. Generalized Additive Models were used to assess associations between age, maximum titer, and serogroup diversity. Of 2091 tested samples, 237 (11.3%) were seropositive. Older individuals and those with higher titers reacted to a greater number of serogroups (p = 0.005 and p < 0.0001, respectively). However, mean maximum titer decreased with age, suggesting that broader serogroup reactivity in older individuals reflects cumulative exposure rather than higher titers. Maximum titer was the strongest predictor of serogroup breadth, while gender, study region, and urban/rural setting were not significant. Overall, our findings demonstrate that serogroup cross-reactivity in MAT was significantly influenced by antibody titer and prior exposure, with older individuals displaying broader serogroup reactivity despite lower titers. These findings highlight key considerations for interpreting MAT results in seroepidemiological studies and underscore the limitations of MAT in serogroup-level classification. Full article

In order to investigate the occurrence and epidemiology of leptospirosis in the wild boar (Sus scrofa) population of Saxony-Anhalt, Germany, blood samples were collected from 2616 wild boar regularly hunted in 2023 and 2024. The diagnostic investigations were performed using the microscopic agglutination test (MAT) using a panel of fifteen pathogenic and one intermediate serovar of Leptospira spp. Overall, 12.4% (325/2616) (CI 95% 11.2–13.7) of wild boar were seropositive, with Australis being the most prevalent serovar (22.8%), followed by Pomona (13.2%) and Pyrogenes (12.3%). Specific antibodies against the intermediate Leptospira fainei serovar Hurstbridge were also detected in 8% of the positive samples. Based on these results, we conclude that wild boar are regularly infected with different zoonotic Leptospira serovars. As these hunted animals are tested for other notifiable diseases, additional screening for specific antibodies against Leptospira spp. could be easily implemented. This would be an important tool for detecting human and domestic animals’ risk of exposure and may provide insight into which Leptospira serovars might be currently of clinical relevance. Full article

Background: Leptospirosis is a potentially fatal infectious disease. Therefore, annual revaccination of dogs is recommended, but this can lead to diagnostic interference due to vaccine-induced antibodies. This study determined the prevalence of Leptospira spp.-specific antibodies in 97 healthy adult dogs revaccinated with a 4-serovar vaccine (Nobivac^® L4). Methods: Antibodies were measured with a microscopic agglutination test against 12 serovars before (week 0) and 2, 4, 12, 26, and 52 weeks after revaccination. Logistic regression analysis was performed to determine the presence of pre-revaccination antibodies. Mixed-effect logistic regression analyses and chi-squared tests were used to compare differences between antibodies against vaccine serovars and between vaccine and non-vaccine serovars at different time points. Results: Overall, 63/97 dogs (64.9%) had antibodies against vaccine serovars before revaccination. During the study period, antibodies against $\ge$1 vaccine serovars were detected in all 97 dogs (100.0%). The highest likelihood of detectable antibodies was present in weeks 2 and 4, but 71/97 dogs (73.2%) had antibodies persisting 52 weeks after revaccination. Of 97 dogs, 75 dogs (78.4%) even had antibodies against $\ge$1 non-vaccine serovars. Among those, 19/75 (25.0%) had a fourfold titre increase. Conclusions: These findings suggest that high levels of antibody titres against Leptospira spp. occur frequently and cross-reactivity against non-vaccine serovars is likely. The detection of vaccine-induced antibodies can therefore complicate the diagnosis of leptospirosis. Full article

At a veterinary hospital in southern Chile, we conducted an epidemiological study involving domestic dogs, cats, and horses to determine the seropositivity for pathogenic Leptospira spp., identify the infecting serogroups, measure antibody titers, and characterize seropositive animals by sex and age. None of the sampled animals showed clinical signs of leptospirosis. The microscopic agglutination test, using a panel of eight serogroups, was used for diagnosis. The seropositivity was 36.5% (95% confidence interval [CI] = 24.5–48.4) in dogs, 12.9% (95% CI = 2.6–23.1) in cats, and 45.2% (95% CI = 30.1–60.2) in horses. Serological reactions were detected for the Tarassovi and Canicola serogroups in dogs, Sejroe, Canicola, Icterohaemorrhagiae, and Grippotyphosa in horses, and Tarassovi in cats. The most frequent antibody titers were 1:200 and 1:400 in dogs, 1:400 in cats, and 1:800 in horses. The distribution of seropositivity varied by sex and age across different animal species. The seropositivity for pathogenic Leptospira in dogs, cats, and horses attending a veterinary hospital underscores the role of domestic animals as sentinels for zoonotic diseases. This finding has implications for epidemiological surveillance systems in increasing awareness of seropositivity and establishing specific prevention measures to mitigate the risk of leptospirosis transmission. Full article

Leptospirosis is a globally significant zoonosis affecting animal health, productivity, and the environment. While typically associated with tropical climates, its persistence in semi-arid regions such as La Laguna, Mexico—characterized by low humidity, high temperatures, and limited water sources—remains poorly understood. Although these adverse environmental conditions theoretically limit the survival of Leptospira, high livestock density and synanthropic reservoirs (e.g., rodents) may compensate, facilitating transmission. In this cross-sectional study, blood sera from 445 dairy cows (28 herds: 12 intensive [MI], 16 semi-intensive [MSI] systems) were analyzed via microscopic agglutination testing (MAT) against 10 pathogenic serovars. Urine samples were cultured for active Leptospira detection. Risk factors were assessed through epidemiological surveys and multivariable analysis. This study revealed an overall apparent seroprevalence of 27.0% (95% CI: 22.8–31.1), with significantly higher rates in MSI (54.1%) versus MI (12.2%) herds (p < 0.001) and an estimated true seroprevalence of 56.3% (95% CI: 50.2–62.1) in MSI and 13.1% (95% CI: 8.5–18.7) in MI herds (p < 0.001). The Sejroe serogroup was isolated from urine in both systems, confirming active circulation. In MI herds, rodent presence (OR: 3.6; 95% CI: 1.6–7.9) was identified as a risk factor for Leptospira seropositivity, while first-trimester abortions (OR:10.1; 95% CI: 4.2–24.2) were significantly associated with infection. In MSI herds, risk factors associated with Leptospira seropositivity included co-occurrence with hens (OR: 2.8; 95% CI: 1.5–5.3) and natural breeding (OR: 2.0; 95% CI: 1.1–3.9), whereas mastitis/agalactiae (OR: 2.8; 95% CI: 1.5–5.2) represented a clinical outcome associated with seropositivity. Despite semi-arid conditions, Leptospira maintains transmission in La Laguna, particularly in semi-intensive systems. The coexistence of adapted (Sejroe) and incidental serogroups underscores the need for targeted interventions, such as rodent control in MI systems and poultry management in MSI systems, to mitigate both zoonotic and economic impacts. Full article

A killed, whole-cell vaccine was produced to induce immunity in dogs against leptospirosis. The vaccine, containing serovar Copenhageni, was produced and administered to 12 beagle dogs at both 8 and 12 weeks of age. Ten unvaccinated dogs of the same age group served as the control group. A live, virulent inoculum of Leptospira (1.52 × 10⁹–4.40 × 10⁹ leptospires per dog) was used to challenge the dogs at 2 weeks (Study 1) and 14 months (Study 2) post-booster vaccination. At regular intervals, pre- and post-challenge (PC), the microscopic agglutination test (MAT) was performed to measure antibody titers. Leptospiremia and leptospiruria were determined via culture, and the cytokine, biochemical, and pathological profiles of vaccinates and controls were also assessed. A high antibody response was measurable after booster administration. In Study 1 (onset of immunity), acute leptospirosis was observed in five (100%) out of five unvaccinated dogs. In contrast, no acute clinical leptospirosis developed in vaccinated dogs, except in one (20%) dog with mild clinical signs. In Study 2 (duration of immunity), mild clinical signs were observed in two (40%) of the control dogs, while all vaccinated dogs remained clinically normal. The incidence of leptospiruria and leptospiremia PC was lower in the vaccinated dogs compared to the unvaccinated group. Severe thrombocytopenia occurred in 100% (5/5) of the unvaccinated dogs in Study 1 that exhibited acute severe leptospirosis, whereas 80% (4/5) of the unvaccinated dogs in Study 2 showed mild to moderate thrombocytopenia 3 days after challenge. Four out of five unvaccinated dogs (80%) in Study 1 exhibited icteric tissues and hemorrhages in the lungs and mucosal surfaces of the stomach and intestines. A high IL-10 to TNF-α ratio, observed in the control group of both studies, and severe thrombocytopenia observed in the control group of Study 1, indicative of acute leptospiral disease, were detected. The vaccine prevented acute clinical leptospirosis and reduced the renal carrier state in beagle dogs, and further investigation is required using a larger sample size. Full article

Laboratory confirmation of human leptospirosis relies on serological tests, with the microscopic agglutination test (MAT) as the reference. However, due to its complexity, there is a need for a simpler and more accessible diagnostic method. This study aimed to standardise and develop an IgM dot-blot test with a whole-cell antigen from saprophytic Leptospira biflexa serovar Patoc for diagnosing human leptospirosis. After checkerboard titration standardisation, IgM dot-blot was performed with paired serum samples from 124 MAT-confirmed leptospirosis cases and 143 serum samples from healthy and diseased individuals as the control group. Repeatability and reproducibility were also evaluated. An IgM dot-blot kit was then developed and compared to the Panbio^TM Leptospira IgM ELISA using 144 serum samples from patients with suspected leptospirosis. The IgM dot-blot showed a sensitivity of 58.1% and 96.0% when performed on acute and convalescent samples, respectively. Specificity was 94.4%. The repeatability and reproducibility of the IgM dot-blot showed 100% consistency. Comparison of IgM dot-blot and IgM ELISA showed almost perfect agreement, with a Kappa index of 0.81. The developed IgM dot-blot offers a robust alternative to existing methods, requiring minimal specialised equipment and fewer reagents than IgM ELISA. The good performance of this IgM dot-blot immunoassay makes it a promising tool for diagnosing human leptospirosis, potentially increasing diagnostic capacity, especially in places with limited resources. Full article

Background/Objectives: FimH adhesin, located at the tips of type 1 pili in Escherichia coli (E. coli), plays a crucial role in bacterial adhesion to the surface urothelial cells—a key step in the pathogenesis of urinary tract infections (UTIs). Given the rising concern over antimicrobial resistance (AMR), and considering that E. coli is one of the pathogens with the largest AMR burdens on a global scale, alternative strategies targeting bacterial adhesion are gaining increasing attention. Products that contain D-mannose and cranberry-derived phenolic compounds have shown promise in preventing E. coli colonization and infection. The aim of this study was to investigate the antiadhesive effects of cranberry-related phenolic compounds on FimH-mediated E. coli adhesion using a cellular hemagglutination inhibition assay, as well as to assess the synergistic effects of mannose and phenolic compounds on biofilm formation. Methods: A range of phenolic acids (benzoic, chlorogenic, hippuric, p-coumaric, ferulic and caffeic), resveratrol, (+)-catechin and procyanidin A, as well as a Vaccinium macrocarpon extract, were evaluated for their ability to inhibit FimH-mediated adhesion. A binocular microscope was used to observe agglutination, and we also evaluated the biofilm inhibition potential of the phenolic compounds in the presence of D-mannose. Results: Our results demonstrated that these compounds significantly reduced hemagglutination, with benzoic acid, chlorogenic acid, caffeic acid and resveratrol exhibiting strong inhibitory effects at concentrations as low as 0.25 mM. Furthermore, the addition of 1 mM solutions of these phenolic compounds to D-mannose resulted in a twofold reduction in the inhibition titer, suggesting synergistic interactions. In addition to their antiadhesive properties, the tested phenolic compounds contributed slightly to the inhibition of FimH-mediated biofilm formation, further supporting their potential roles in UTI prevention. Conclusions: These findings highlight the potential of cranberry-derived phenolics as natural antiadhesive agents against E. coli and warrant further investigation into their mechanisms of action and possible applications in infection control. Full article

Leptospirosis is one of the world’s major neglected tropical zoonotic diseases (NTZDs), implicated in animal health and welfare with economic consequences for livestock production. This study aims to estimate the seroprevalence of Leptospira spp. and identify potential risk factors in small ruminant herds. This epidemiological cross-sectional study was conducted in Nuevo León, a semi-arid region of Mexico. A total of 389 blood samples from goats and 385 from sheep older than eight months were randomly collected from 128 herds. Anti-Leptospira antibodies were detected using the microscopic agglutination test (MAT), and univariate and multivariate logistic regression analyses were performed to determine their association with leptospirosis infection. The overall prevalence was 13.5% (105/774), with 14.4% (56/389) in goats and 12.7% (49/385) in sheep. Sejroe was the most predominant serogroup. The main risk factors in sheep were contact with domestic cattle, ≥100 animals per herd, congenital abnormalities, contact with feral pigs, meat production system, absence of veterinary care, and abortions with odds ratios (OR) between 1.7 and 4.1. In goats, the main risk factors included lack of quarantine measures, contact with feral pigs, absence of veterinary care, and abortions where the OR ranged from 1.7 to 3.3. These findings indicate that Leptospira spp. is present in small ruminant herds. This is the first study aimed at understanding leptospirosis epidemiology in the northeastern region of Mexico, as goats and sheep may act as potential reservoirs. Continuous monitoring of Leptospira infections is imperative, as well as developing educational initiatives for farmers to implement biosecurity and prevention measures to prevent infections within herds and protect public health. Full article

Leptospirosis is a zoonotic disease with a varied clinical presentation that can mimic other infectious diseases, posing diagnostic challenges. While the Microscopic Agglutination Test (MAT) remains the gold standard for serological diagnosis, its limitations have led to increasing interest in polymerase chain reaction (PCR) as a rapid and sensitive diagnostic tool. This systematic review evaluates the role and clinical applications of PCR for diagnosing human leptospirosis. We analyzed the sensitivity and specificity of PCR, compared its performance with other diagnostic tests, and assessed the comparative utility of blood and urine samples for PCR testing. Our findings demonstrate that PCR has a high sensitivity and specificity, particularly in the early stages of the disease. Combining PCR with serological tests like MAT can maximize the diagnostic accuracy across different stages of illness. We recommend that PCR be considered a first-line diagnostic test for suspected leptospirosis, especially when rapid diagnosis is crucial. Further research is needed to standardize PCR protocols and explore its potential in differentiating Leptospira species and serotypes. By leveraging the strengths of PCR and combining it with other diagnostic methods, we can significantly improve the diagnosis and management of leptospirosis. Full article

Bovine genital leptospirosis (BGL) is a chronic reproductive disease in cattle, often causing significant economic losses, and is commonly associated with leptospiral strains belonging to the Sejroe serogroup. A two-step protocol was recommended, based on serological screening of the herds followed by an individual diagnosis with PCR of a genital sample. Although proposed, it has not been commonly applied under field conditions, leading to frustrating outcomes in disease control. In that context, the present study aimed to demonstrate the viability of that two-step protocol under field conditions for diagnosing BGL in eight herds with reproductive disorders. Blood samples were collected from 440 cows for serology. In addition, 304 cervicovaginal mucus (CVM) samples were collected for lipL32-PCR and 11 samples were sequenced of the secY gene. All herds showed high seroreactivity, mainly against the serogroup Sejroe. In addition, 113 of the 304 CVM samples (37.2%) were PCR-positive. DNA sequencing of 11 positive samples based on the secY gene revealed maximum identity (100%) with L. interrogans species. This study found CVM sampling quick and easy, making it practical for field use. Overall, the results support the two-step protocol serological screening followed by CVM-PCR testing as an efficient and reliable method for diagnosing BGL in herds with reproductive disorders in field conditions. Full article

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. Full article