Serologic and urinary PCR survey of leptospirosis in healthy cats and in cats with kidney disease

Molecular detection and phylogenetic analysis of Leptospira interrogans and Leptospira borgpetersenii in cats from Central region of Rio Grande do Sul state, Brazil

Leptospirosis is a zoonotic disease caused by the bacteria of the genus Leptospira, which is responsible for substantial impacts on the economy, animal health, and public health. This disease has a global distribution and is particularly prevalent in Brazil. While leptospirosis can affect different animal species, including domestic ones such as dogs and cats, the role of dogs in its epidemiology is established and well-understood. Conversely, the role of domestic cats in the epidemiology of leptospirosis remains unclear, with a significant lack of studies elucidating the roles they play in the transmission of Leptospira spp. and the bacterial species they can host. Therefore, this study aimed to evaluate the presence of Leptospira spp. DNA in domestic cats and to assess the phylogenetic relationships of the identified microorganisms in the Central region of Rio Grande do Sul State (RS) in southern Brazil. The samples were evaluated for the presence of the gene lipL32 by polymerase chain reaction and sequencing of the amplified fragment, followed by phylogenetic analysis. DNA from Leptospira spp. was extracted from the kidney tissue of domestic cats. Pathogenic Leptospira spp. DNA was detected in 22.1 % (67/303) of the samples. Molecular analyses revealed the presence of L. borgpetersenii and L. interrogans in these animals. This study is the first to identify L. borgpetersenii and L. interrogans in domestic cats in RS, highlighting their potential role as bacterial reservoirs. Our findings provide valuable insights into the epidemiology of leptospirosis and can contribute to sanitary measures aimed at controlling and preventing the disease, ultimately protecting public health.

Seroreactivity against Leptospira spp. differs between community cats and privately-owned cats in Hong Kong

Leptospirosis is a bacterial zoonotic disease of major One Health significance and public health impact globally, with a wide host range including mammals, cetaceans and herpetofauna. This study aimed to determine Leptospira seroprevalence, risk factors for seroreactivity and prevalence of urinary Leptospira shedding among domestic cats in Hong Kong. Microagglutination testing of 22 Leptospira serovars from 20 serogroups was performed on 738 sera from outdoor free-roaming "community" cats (n = 391) and privately-owned (n = 347) cats. Urine from 268 community cats was tested for pathogenic Leptospira DNA by qPCR targeting lipL32. Potential risk factors associated with exposure were assessed using logistic regression. Overall Leptospira seroprevalence was 9.35%. Of 14 serogroups detected, Javanica (4.3%), Djasiman (2.3%) and Australis (1.5%) were most common. Seroreactivity was significantly higher among community (13.3%) than privately-owned cats (4.9%; OR 2.98 [95% CI 1.68-5.25], P < 0.001), especially to Javanica (7.65% of community cats versus 0.58% of privately-owned cats (P < 0.001). Antibody titres to all serogroups ranged from 1:100 to 1:6400 (median 1:200) and were highest for Javanica (median 1:800). Leptospira DNA was detected in urine from 12/268 community cats (4.48%; median load 6.42 × 102 copies/mL urine; range 1.40 × 101-9.63 × 104). One in three seroreactive community cats with paired urine and blood samples had leptospiruria. After adjusting for source, none of breed, sex, neuter status, age, district rodent infestation rate, serum alanine transaminase or creatinine values were associated with seroreactivity. Cats in Hong Kong are exposed to a diversity of Leptospira serogroups and can shed Leptospira silently in urine. The higher seroprevalence among outdoor free-roaming community cats highlights the importance of environmental drivers in leptospirosis transmission and risks of exposure for sympatric human populations. Gloves should be worn when handling feline urine to minimise the risk of zoonotic transmission from subclinically infected cats.

Grenadian cats as potential reservoir for Leptospira

Leptospirosis is a spirochetal disease caused by Leptospira spp. bacteria with global distribution affecting multiple mammalian species, including humans. The disease is endemic in many geographic areas and is of particular concern in tropical regions with abundant rainfall, such as the Caribbean. Currently, there are no published reports on Leptospira exposure or infection in Grenadian cat populations, and the role of cats in the epidemiology of the disease is unknown. Our hypothesis is that Grenadian cat population may be a reservoir host for zoonotic Leptospira on the island. During 2019-2021, 160 feral cats were captured from three parishes in Grenada, and their urine and blood were tested for Leptospira. Urine from 4 of 148 (2.7%) cat samples tested PCR-positive for Leptospira. Serum from 6 of 136 (4.4%) cat samples tested PCR-positive for Leptospira. Sequence analysis of the Leptospira rpoB gene showed 86-100% similarity to known or presumed pathogenic Leptospira species. The findings of this study suggest that Grenadian cat populations are infected with and are shedding Leptospira genotypes that are phylogenetically related to known pathogenic Leptospira, including known zoonotic strains. These observations support the hypothesis that Grenadian cat populations may be a reservoir host for zoonotic Leptospira on the Island.

Insights into Leptospira spp. infection in pet cats in Croatia: Clinical, serological and molecular findings with emphasis on the potential important role of serogroup Pomona

Leptospirosis, a globally re-emerging zoonosis caused by pathogenic Leptospira spp., poses a significant threat to public health. Leptospirosis in cats is often neglected due to its high underdiagnosis. Therefore, the role of cats in disease transmission and bacterial maintenance in the environment remains unclear. For this study, 54 serum samples, 54 urine samples and 27 EDTA-anticoagulated blood samples from pet cats presenting to the Veterinary Teaching Hospital due to health problems were used. The serum samples were tested for antibodies against 12 pathogenic serovars of Leptospira spp. using the microscopic agglutination test (MAT). EDTA-anticoagulated blood and urine samples were tested for the lipL32 gene of pathogenic Leptospira spp. by conventional (PCR) and real-time (qPCR) polymerase chain reaction. Agglutinating antibodies were detected in 18.52% (10/54) of the sera with a titre range of 1:50 to 1:12800. The most common serogroup was Pomona, followed by Sejroe, Icterohaemorrhagiae, Australis and Javanica. Leptospira spp. DNA was found in 1.85% (1/54) of the urine samples, while all EDTA-anticoagulated blood samples were negative. A statistically significant difference in seropositivity regarding lifestyle was found between outdoor/indoor and indoor-only cats, while the presence of another cat in the household significantly increased the likelihood of seropositivity. Cats with immunocompromising conditions showed a significantly increased risk of seropositivity, especially those undergoing immunosuppressive treatment. In addition, respiratory signs and changes in lung structure associated with the presence of leptospiral antibodies, and these cats were more likely to be infected with the Pomona serogroup. Moreover, cats with anaemia, leucocytosis, and thrombocytopenia were significantly more likely to have antibodies against Leptospira spp., while seropositive cats had significantly lower urine-specific gravity compared to seronegative cats. The results underline the importance of raising awareness of feline leptospirosis in veterinary care and recognising pet cats as potential carriers of leptospires. Further research is needed to clarify the specific role of the Pomona serogroup as a potentially highly evolutionary drifting serogroup in terms of pathogenicity and to clarify the zoonotic potential of infected cats, which is crucial for the implementation of effective public health measures and veterinary interventions.

Investigation of anti-Leptospira spp. antibodies and leptospiruria in cats attended to a veterinary teaching hospital in southern Brazil

Leptospirosis is a bacterial zoonosis that affects both humans and animals worldwide. Currently, it is known that cats may be susceptible to infection. This study aims to investigate the presence of anti-Leptospira spp. antibodies and leptospiruria in cats, using Microscopic Agglutination Test (MAT) and Real-time Polymerase Chain Reaction (PCR) techniques, respectively. A total of 76 cats, undergoing comprehensive anamnesis, general physical examination, and complementary exams were included in the investigation. Among the 76 cats tested, 9.2% (7/76) exhibited the presence of anti-Leptospira spp. antibodies, while Leptospira spp. DNA was detected in at 1.3% (1/76) of the evaluated urine samples. No significant associations were observed between the serological and molecular diagnostic results and the assessed variables, including clinical data and laboratory results of cats testing positive. This study provides insight into the occurrence of Leptospira spp. infection and leptospiruria in cats treated at a veterinary teaching hospital in southern Brazil.

Feline leptospirosis prevalence worldwide: A systematic review and meta-analysis of diagnostic approaches

Background and Aim

Leptospirosis in felids (domestic and wild cats) presents an ongoing challenge in our understanding. Numerous studies have reported the detection of Leptospira spp. in these feline populations, highlighting their potential as zoonotic carriers. This systematic review and meta-analysis aimed to provide insight into the global prevalence of leptospirosis in domestic and wild cats.

Materials and Methods

We conducted extensive searches across five databases (PubMed, Scopus, Web of Science, Science Direct, and Google Scholar) following the Preferred Reporting Items for Systematic Reviews and Meta-analyses Protocols guidelines. Random-effect meta-analyses were performed using R software version 4.3.0 to estimate pooled prevalence rates. Subgroup meta-analyses were conducted based on continents, diagnostic methods, sample types, and wildcat genera.

Results

A total of 71 articles on leptospirosis in domestic cats and 23 articles on leptospirosis in wild cats met the eligibility criteria. Our findings indicated a significantly higher pooled seroprevalence of leptospirosis in domestic cats compared with infection prevalence (9.95% [95% confidence interval (CI), 7.60%-12.54%] vs. 4.62% [95% CI, 2.10%-7.83%], p = 0.01). In contrast, no significant difference was observed in pooled seroprevalence and infection prevalence among wild cats (13.38% [95% CI, 6.25%-21.93%] vs. 2.9% [95% CI, 0.00%-18.91%], p = 0.21). A subgroup meta-analysis of domestic cats revealed significant differences in seroprevalence across continents, sample types, and diagnostic methods. On the contrary, wild cats had no significant differences in any of the subgroups.

Conclusion

Leptospira spp. have evidently been exposed to both domestic and wild cats, highlighting their potential roles as reservoir hosts for leptospirosis. These findings highlight the importance of considering felids as a possible public health threat.

Acute phase proteins and total antioxidant capacity in free-roaming cats infected by pathogenic leptospires

BACKGROUND

Leptospirosis is a neglected but widespread zoonotic disease throughout the world. Most mammals are hosts of Leptospira spp., including domestic cats, species in which no consensus has been reached on the clinical presentation or diagnosis of the disease. The study of acute-phase proteins (APPs) and biomarkers of oxidative status would contribute to knowledge about the disease in cats. This report evaluated four APPs: Serum amyloid A-SAA, Haptoglobin-Hp, albumin and Paraoxonase 1-PON1 and the antioxidant response through Total Antioxidant Capacity-TAC, in 32 free-roaming cats. Cats were classified as seroreactive for anti-leptospiral antibodies (group 1, n = 8), infected with Leptospira spp (group 2, n = 5) and leptospires-free cats (group 3, n = 19).

RESULTS

SAA differences were observed between groups 1 and 2 (p-value = 0.01) and between groups 2 and 3 (p-value = 0.0001). Hp concentration differences were only detected between groups 2 and 3 (p-value = 0.001). Albumin concentrations only differed between groups 1 and 3 (p-value = 0.017) and 2 and 3 (p-value < 0.005). Cats in groups 1 (p-value < 0.005) and 2 (p-value < 0.005) had lower PON1 concentrations than group 3. No statistically significant differences between pairs of groups were detected for TAC concentrations. The principal component analysis (PCA) retained two principal components, (PC1 and PC2), explaining 60.1% of the observed variability of the inflammatory proteins and the antioxidant TAC.

CONCLUSIONS

Increases in Serum SAA, Hp, and decreases in PON1 activity may indicate an active inflammatory state in infected cats (currently or recently infected).

Evaluation of Leptospira infection and exposure in free-roaming cat populations in northern California and southern Texas

OBJECTIVES

Leptospirosis is a re-emergent zoonotic bacterial disease associated with renal and hepatic injury. In free-roaming cats in some regions, a high prevalence of Leptospira antibodies has been identified, and pathogenic leptospires have been detected in renal tissue, indicating that they may play a role in Leptospira epidemiology. The objective of this study was to determine the prevalence of Leptospira seroreactivity and urinary shedding of Leptospira DNA in free-roaming cats from northern California and southern Texas. A secondary objective was to compare the results of a point-of-care (POC) assay, designed to detect Leptospira antibodies, with the results of the microscopic agglutination test (MAT) when applied to serum samples from feral cats.

METHODS

Specimens were obtained from free-roaming cats from northern California (n = 52; 2020) and southern Texas (n = 75; 2017). Leptospira quantitative PCR was performed on blood and urine specimens from Californian cats. Serum samples from Californian and Texan cats were subjected to MAT to categorize them as Leptospira antibody-positive or antibody-negative. The performance of the POC assay was assessed using the MAT as the gold standard.

RESULTS

Leptospira DNA was not detected in the blood or urine of any cats tested. The results of the MAT were positive in 17.3% (n = 9) of Californian cats and 10.7% (n = 8) of Texan cats (P = 0.3). The median MAT titer was 1:100 (range 1:100-1:200) in Californian cats and 1:200 (range 1:100-1:800) in Texan cats. The POC assay was negative in all specimens.

CONCLUSIONS AND RELEVANCE

Free-roaming cats in California and Texas are exposed to Leptospira species and may have the potential to act as sentinel hosts. No cats had evidence of current infection, as determined using PCR on blood and urine specimens. The POC test did not reliably detect anti-Leptospira antibodies in these cats. The role of cats in the maintenance or shedding of pathogenic leptospires requires further investigation.

Leptospiral infection in domestic cats: Systematic review with meta-analysis

The role of domestic cats in the transmission of Leptospira is controversial, being considered either as a protective factor or a potential source of infection for humans. The aims of this study were to obtain an integrated estimate of the prevalence of leptospiral infection in domestic cats, and to characterize those individuals most susceptible to infection. For this systematic review and meta-analysis, five electronic databases, as well as the reference lists of eligible reports were screened for observational studies published during 1979-2022. The overall prevalence of leptospiral antibodies and of pathogenic Leptospira in kidney/urine was estimated using three-level meta-analysis models. To investigate potential sources of heterogeneity, moderator analyses was performed using the sampling year, health status, living environment, and origin of the cats. The odds-ratio (OR) of potential risk factors was estimated using random-effects meta-analysis models for binary outcomes. The literature search identified 61 eligible publications, containing 114 effect estimates. The overall seroprevalence was 11.7 % (95 % CI: 9.3-14.6 %), the prevalence of leptospires in urine was 3.7 % (95 % CI: 1.7-8.1 %), and the prevalence of leptospires in kidney tissue was 12.8 % (95 % CI: 3.2-39.9 %). There were no significant differences in the estimated prevalence after removing articles with medium risk of bias. Seroprevalence was higher in Europe when compared to Latin America and the Caribbean (P = 0.047) and showed a mild decrease over time (P = 0.023). Outdoor cats had almost three times greater probabilities of infection with Leptospira (OR: 2.74, 95 % CI: 1.10-6.84). No other significant effect was detected among the tested moderators or potential risk factors (P > 0.05). Results suggest that feline leptospirosis should receive particular attention in veterinary care, as exposure to leptospires can occur in approximately 1 in every 10 cats, and more frequently in cats with street access. Domestic cats should be considered as potential Leptospira carriers when designing public health strategies for the control and prevention of leptospirosis. Further investigation is required to improve knowledge of the role of these animals in the environmental transmission cycle.

Serological and Molecular Evidence of Pathogenic Leptospira spp. in Stray Dogs and Cats of Sicily (South Italy), 2017-2021

Leptospirosis is a zoonosis of public health concern. Its prevalence in stray animals in the South of Italy is unknown. This study aimed to investigate Leptospira spp. prevalence in 1009 stray animals. Out of them, 749 were alive animals, including 358 dogs (316 from Palermo and 42 from Ragusa) and 391 cats (359 from Palermo and 32 from Ragusa), and 260 were corpses (216 dogs and 44 cats) randomly collected in Sicily. Dogs and cats underwent a serological screening by Microscopic Agglutination Test and a molecular investigation by Real-Time PCR targeting lipL32. Corpses were subjected to Real-Time PCR. Serological analyses showed a prevalence of 1.12% (4/358) for dogs and 0.26% (1/391) for cats, with the only positive cat coming from Palermo. Serogroup Icterohaemorrhagiae serovar Icterohaemorrhagiae or Copenhageni, followed by Canicola and Bratislava, were the most spread among dogs, while the serological positive cat reacted with Hardjo serogroup. Two urine (2/32, 6.25%) and one blood (1/391, 0.26%) samples of cats, all from Ragusa, were positive at Real-Time PCR for pathogenic Leptospira spp. Sequencing analyses showed the presence of L. interrogans serogroup Icterohaemorrhagiae serovar Icterohaemorrhagiae or Copenhageni in one of the positive urine samples and in the positive blood sample. Analyses on corpses showed a prevalence of 1.85% (4/216) in Sicilian dog kidney samples, while all corpses of cats resulted in negative. Genotyping analysis showed a genetic relatedness between cat and human isolates. Results show Leptospira spp. circulation among Sicilian stray animals. The genetic relatedness between cat and human isolates suggests a possible common infection source.

Basic Aspects and Epidemiological Studies on Leptospirosis Carried Out in Animals in Chile: A Bibliographic Review

Leptospirosis is an important zoonosis worldwide. This disease affects numerous animal species, some of them are classified as "maintenance hosts", and others are categorized as "incidental hosts". Humans are at risk of becoming infected by having contact with domestic and wild animals. In this paper, general aspects of the etiology and transmission of leptospirosis are addressed, data regarding the clinical presentation of the pathology in humans and animals are also presented, and the results of some epidemiological studies on leptospirosis carried out in Chile in different animal species and humans are summarized through a bibliographic review of the literature. The research on domestic canines and horses stands out in terms of their number in the country, with prevalences between 12.0% and 59.1% in dogs and from 23.3% to 65.4% in equids. Studies have been performed on domestic felines in recent years with frequencies ranging from 3.0% to 25.2%, as well as on wild animals (mainly in mammals). In pigs, cattle, sheep, and goats, the information is scarce, with little updated research dating back several decades and variable prevalence rates, which are generally high, except for in sheep. Leptospirosis is a disease of varied etiology in terms of infecting species, serovars and serogroups, which influences its epidemiology, and its prevalence is variable in different animals. An increase in the awareness given to this pathology in human and veterinary public health is required, as well as more scientific studies in Chile, to update the existing knowledge.

Feline Susceptibility to Leptospirosis and Presence of Immunosuppressive Co-Morbidities: First European Report of L. interrogans Serogroup Australis Sequence Type 24 in a Cat and Survey of Leptospira Exposure in Outdoor Cats

Leptospirosis is one of the most widespread zoonotic diseases and can infect both humans and animals worldwide. The role of the cat as a susceptible host and potential environmental reservoir of Leptospira is still not well understood, due to the lack of obvious clinical signs associated with Leptospira spp. infection in this species. This study aims to describe the first European detection of Leptospira interrogans serogroup Australis ST 24 in a young outdoor cat with a severe comorbidity (feline panleukopenia virus). In addition, the results of a preliminary study conducted in 2014-2016 are presented (RC IZSVE 16/12), which reports an investigation of Leptospira exposure of outdoor cats in Northeast Italy by means of serological investigation and molecular evaluation of urine. The animals included in the survey are part of samples collected during active and passive surveillance (diagnostic samples). The study reported a seroprevalence of 10.5% among outdoor cats and the serogroups identified were Grippotyphosa, Icterohaemorrhagiae, Bratislava, Canicola and Ballum. Symptomatic cats reported high MAT titres (ranging from 1:800 to 1:1600) towards antigens belonging to the serovars Grippotyphosa (1:800), Bratislava (1:1600), Icterohaemorrhagiae (1:200) and Copenhageni (1:200-1:800). In one subject, urine tested positive for Leptospira PCR. Cats with high antibody titres for Leptospira and/or positivity on molecular test suffered from immunosuppressive comorbidities (feline immunodeficiency virus and feline leukaemia virus; feline herpesvirus and lymphoma; hyperthyroidism). The overall prevalence of serum antibodies against Leptospira found in free-ranging cats (10.53%, 95% CI: 4.35-16.70%) and the identification of L. interrogans ST 24 in a young cat with immunosuppressive disease (feline panleukopenia virus) suggest the possibility of natural resistance to clinical leptospirosis in healthy cats. In a One Health perspective, further studies are needed to better define the pathogenesis of leptospirosis in cats and their epidemiological role as environmental sentinels or possible carriers of pathogenic Leptospira.

Clinical characteristics and prognosis of patient with leptospirosis: A multicenter retrospective analysis in south of China

Purpose

Leptospirosis is a zoonotic disease caused by pathogenic spirochetes of the genus Leptospira. However, there is currently no consensual definition or diagnostic criteria for severe and different forms of leptospirosis. Therefore, more insight on clinical manifestations, risk factors, and outcomes of leptospirosis is warranted. The identification of leptospirosis with distinct clinical manifestations and prognosis in our population.

Methods

Multiple correspondence analysis and hierarchical classification on principal components were presented to identify different clinical types of leptospirosis. The outcomes were clinical phenotypes, laboratory and imaging findings, and prognosis.

Results

The 95 enrolled patients had median values of 54.0 years (39.0-65.0) for age, 9.0 (7.0-14.0) for total hospital stay lengths, of whom 86.3% was male and 40.0% was transferred to ICU. Three clinical types were distinguished: mild leptospirosis (n=43, 45.3%) with less organ dysfunction and shorter hospital stays; respiratory leptospirosis (n=28, 29.5%) with hemoptysis, and respiratory and circulatory failure; and hepato-renal leptospirosis (n=24, 25.3%) with worst liver and kidney dysfunction. Total hospital mortality was 15.8% and was associated with dyspnea and high levels of neutrophil counts.

Conclusions

The identification of leptospirosis with distinct clinical manifestations and prognosis in our population may assist clinicians to distinguish leptospirosis-like disease. Moreover, dyspnea and neutrophil count were found to be independent risk factors for severe leptospirosis progression.

Leptospira spp. Prevalence in Cats from Southern Italy with Evaluation of Risk Factors for Exposure and Clinical Findings in Infected Cats

Leptospirosis is a worldwide zoonotic disease, but feline leptospirosis is rarely reported. This study aimed at investigating Leptospira spp. prevalence in cats from southern Italy, evaluating risk factors, clinical findings and laboratory data associated with infection. The serum of 112 cats was investigated by microscopic agglutination test (MAT), detecting anti-Leptospira antibodies against 14 pathogenic serovars. Blood and urine samples were tested by a real-time polymerase chain reaction targeting the lipL32 gene of pathogenic Leptospira. Antibodies against serovars Poi, Bratislava, Arborea, Ballum, Pomona and Lora were detected in 15.3% (17/111) of cats (titers range: 20-320). Leptospira spp. DNA was found in 3% (4/109) of blood and 9% (10/111) of urine samples. The spring season was the only risk factor for urinary Leptospira DNA shedding. Laboratory abnormalities significantly associated and/or correlated with Leptospira spp. positivity were anemia, monocytosis, neutrophilia, eosinopenia, increased alanine aminotransferase activity, hypoalbuminemia and hyperglobulinemia. In the investigated areas, cats are frequently infected by Leptospira spp. and can represent an additional reservoir or sentinel for a risk of infection. Moreover, some laboratory changes could be compatible with a pathogenic effect of Leptospira spp. in the feline host.

Role of Diagnostics in Epidemiology, Management, Surveillance, and Control of Leptospirosis

A One Health approach to the epidemiology, management, surveillance, and control of leptospirosis relies on accessible and accurate diagnostics that can be applied to humans and companion animals and livestock. Diagnosis should be multifaceted and take into account exposure risk, clinical presentation, and multiple direct and/or indirect diagnostic approaches. Methods of direct detection of Leptospira spp. include culture, histopathology and immunostaining of tissues or clinical specimens, and nucleic acid amplification tests (NAATs). Indirect serologic methods to detect leptospiral antibodies include the microscopic agglutination test (MAT), the enzyme-linked immunosorbent assay (ELISA), and lateral flow methods. Rapid diagnostics that can be applied at the point-of-care; NAAT and lateral flow serologic tests are essential for management of acute infection and control of outbreaks. Culture is essential to an understanding of regional knowledge of circulating strains, and we discuss recent improvements in methods for cultivation, genomic sequencing, and serotyping. We review the limitations of NAATs, MAT, and other diagnostic approaches in the context of our expanding understanding of the diversity of pathogenic Leptospira spp. Novel approaches are needed, such as loop mediated isothermal amplification (LAMP) and clustered regularly interspaced short palindromic repeats (CRISPR)-based approaches to leptospiral nucleic acid detection.

Serologic and urinary survey of exposure to Leptospira species in a feral cat population of Prince Edward Island, Canada

OBJECTIVES

Recent studies show that cats could play an important role in the transmission of Leptospira species. There are few reports of leptospirosis on Prince Edward Island (PEI) and none in cats. The objective of this study was to determine the prevalence of serum antibodies against Leptospira serovars and of Leptospira DNA in the urine of a population of free-roaming cats.

METHODS

Paired blood and urine samples were collected from 200 cats brought to a trap-neuter-return program. Antibody titers against six Leptospira serovars (Bratislava, Canicola, Gryppotyphosa, Hardjo, Pomona, Icterohaemorrhagiae) were determined by microscopic agglutination test. PCR was performed on urine samples to identify urine shedding of Leptospira DNA.

RESULTS

Antibodies were detected in 20/200 cats (10%) for at least one serovar, with titers ranging from 1:50 to 1:6400 (all serovars tested, except Hardjo). Urine samples of 7/200 cats (3.5%) were PCR-positive.

CONCLUSIONS AND RELEVANCE

Feral cats in PEI had a higher than expected exposure to leptospirosis and can shed DNA from pathogenic Leptospira species in urine. Further studies are needed to determine the prevalence of exposure to leptospirosis in other species on PEI and the potential role of feral cats in transmission of the disease.

Shedding and Genetic Diversity of Leptospira spp. From Urban Stray Dogs in Klang Valley, Malaysia

Leptospirosis is an endemic zoonoses of global proportions. Stray dogs have been postulated to play a role in disease transmission; however, supporting information are still limited. Roaming behavior may not only predispose the dogs to infection, but could also contribute to disease spread. In this study, the susceptibility of urban stray dogs in shedding Leptospira spp. was determined. Blood, urine, and tissue samples of kidney and liver were collected from 100 dogs from 2 animal control facilities. Serological testing using microscopic agglutination test (MAT) were performed on blood against 20 leptospiral serovars with a cut-off titre of ≥ 1:100. Samples were cultured onto semi-solid Ellinghausen and McCullough modified by Johnson and Harris (EMJH) media. Isolates were identified using molecular polymerase chain reaction (PCR) using 2 primers (16s rRNA and LipL32) and hyperimmune serum (HIS) MAT. The seroprevalence for the dogs positive for leptospirosis was 32% (n=32/100) with the following detected serovars: Javanica (n=13), Bataviae (n=10), Icterohaemorrhagiae (n=3), Autumnalis (n=2), Canicola (n=1), Pyrogenes (n=1), Copenhageni (n=1), and Australis (n=1). Six Leptospira spp. isolated were procured from urine (n=2), kidney (n=2) and liver (n=2). All 6 isolates belonged to L. interrogans, a pathogenic variant of Leptospira spp. Serotyping and phylogenetic analysis suggested serovar Bataviae (n=5) and serovar Canicola (n=1). Presence of vaccinal serovars (Icterohaemorrhagiae and Canicola) suggested potential post-vaccination antibodies but the predominance of non-vaccinal serovars (Javanica and Bataviae) indicate the possibility of current infection or post-exposure. Isolation of Leptospira spp. directly from urine sample not only suggested an active infection but highlighted the potential shedding capability among these stray dogs. These findings further strengthen speculations that urban stray dogs could play a role in transmission and dissemination of leptospirosis through their constant movement. The urine of infected dogs may contaminate the environment, posing a major public health threat.

Molecular and serological epidemiology of Leptospira infection in cats in Okinawa Island, Japan

Leptospirosis is a zoonosis caused by pathogenic Leptospira spp. Cats have been reported to be infected with Leptospira spp. and shed the bacteria in the urine. However, the importance of cats as an infection source for humans remains unclear. In this study, Leptospira infection in cats in Okinawa Prefecture, Japan, where leptospirosis is endemic, was investigated by leptospiral antibody and DNA detection using microscopic agglutination test and nested PCR, respectively. Moreover, multilocus sequence typing (MLST) and whole genome sequencing (WGS) were conducted on the Leptospira borgpetersenii serogroup Javanica isolated from cats, black rats, a mongoose, and humans. Anti-Leptospira antibodies were detected in 16.6% (40/241) of the cats tested, and the predominant reactive serogroup was Javanica. The leptospiral flaB gene was detected in 7.1% (3/42) of cat urine samples, and their sequences were identical and identified as L. borgpetersenii. MLST and WGS revealed the genetic relatedness of L. borgpetersenii serogroup Javanica isolates. This study indicated that most seropositive cats had antibodies against the serogroup Javanica and that cats excreted L. borgpetersenii in the urine after infection. Further, genetic relatedness between cat and human isolates suggests that cats may be a maintenance host for L. borgpetersenii serogroup Javanica and a source for human infection.

Cats shedding pathogenic Leptospira spp.-An underestimated zoonotic risk?

Shedding of DNA of pathogenic Leptospira spp. has been documented in naturally infected cats in several countries, but urinary shedding of infectious Leptospira spp. has only recently been proven. The climate in Southern Chile is temperate rainy with high annual precipitations which represents ideal preconditions for survival of Leptospira spp., especially during spring and summer. The aims of this study were to investigate shedding of pathogenic Leptospira spp. in outdoor cats in Southern Chile, to perform molecular characterization of isolates growing in culture, and to assess potential risk factors associated with shedding. Urine samples of 231 outdoor cats from rural and urban areas in southern Chile were collected. Urine samples were investigated for pathogenic Leptospira spp. by 4 techniques: qPCR targeting the lipL32 gene, immunomagnetic separation (IMS)-coupled qPCR (IMS-qPCR), direct culture and IMS-coupled culture. Positive urine cultures were additionally confirmed by PCR. Multilocus sequence typing (MLST) was used to molecularly characterize isolates obtained from positive cultures. Overall, 36 urine samples (15.6%, 95% confidence interval (CI) 11.4-20.9) showed positive results. Eighteen (7.8%, 95% CI 4.9-12.1), 30 (13%, 95% CI 9.2-18), 3 (1.3%, 0.3-3.9) and 4 cats (1.7%; 95% CI 0.5-4.5) were positive in qPCR, IMS-qPCR, conventional culture, and IMS-coupled culture, respectively. MLST results of 7 culture-positive cats revealed sequences that could be assigned to sequence type 17 (6 cats) and sequence type 27 (1 cat) corresponding to L. interrogans (Pathogenic Leptospira Subgroup 1). Shedding of pathogenic Leptospira spp. by cats might be an underestimated source of infection for other species including humans. The present study is the first one reporting growth of leptospires from feline urine in culture in naturally infected cats in South-America and characterisation of culture-derived isolates. So far, very few cases of successful attempts to culture leptospires from naturally infected cats are described worldwide.

Detection and modeling of anti-Leptospira IgG prevalence in cats from Lisbon area and its correlation to retroviral infections, lifestyle, clinical and hematologic changes

Leptospirosis is a zoonosis of global importance caused by Leptospira species. Rodents are the main reservoirs, known to shed the bacteria in urine, thus contaminating water and soil and infecting other animals and people. Leptospirosis has been re-emerging in both developing and developed countries including Europe. It has been hypothesized that cats could be asymptomatic carriers of Leptospira. This study aims to evaluate cats' exposure to Leptospira in Lisbon, Portugal, by measuring IgG titres and correlating them with possible factors that may increase the risk of exposure in urban cats. Two hundred and forty-three samples were collected from the biobank. An ELISA test followed by a seroprevalence analysis using a finite mixture model was performed to detect and measure anti-Leptospira IgG antibodies titres. In parallel, a survey was conducted to identify possible risk factors for seropositivity. According to the ELISA test protocol, only twenty-three cats (9.5%; 95% CI =(6.1%;13.9%)) could be considered as seropositive to Leptospira antigens. However, when the same data were analysed by the best different mixture models, one hundred and forty-four cats (59.3%; 95%CI = (52.8%; 65.5%)) could be classified as intermediate and high antibody responders to Leptospira antigens. Seropositivity to Feline Immunodeficiency Virus infection (FIV) was found to be the only significant risk factor associated with anti-Leptospira IgG antibodies. In conclusion, the present studies raises the possibility of a higher exposure of cats to Leptospira than previously thought due to the identification of a subpopulation of cats with intermediate antibody levels.

Investigating the Immunological and Biological Equilibrium of Reservoir Hosts and Pathogenic Leptospira: Balancing the Solution to an Acute Problem?

Leptospirosis is a devastating zoonotic disease affecting people and animals across the globe. Pathogenic leptospires are excreted in urine of reservoir hosts which directly or indirectly leads to continued disease transmission, via contact with mucous membranes or a breach of the skin barrier of another host. Human fatalities approach 60,000 deaths per annum; though most vertebrates are susceptible to leptospirosis, complex interactions between host species and serovars of Leptospira can yield disease phenotypes that vary from asymptomatic shedding in reservoir hosts, to multi-organ failure in incidental hosts. Clinical symptoms of acute leptospirosis reflect the diverse range of pathogenic species and serovars that cause infection, the level of exposure, and the relationship of the pathogen with the given host. However, in all cases, pathogenic Leptospira are excreted into the environment via urine from reservoir hosts which are uniformly recognized as asymptomatic carriers. Therefore, the reservoir host serves as the cornerstone of persistent disease transmission. Although bacterin vaccines can be used to abate renal carriage and excretion in domestic animal species, there is an urgent need to advance our understanding of immune-mediated host–pathogen interactions that facilitate persistent asymptomatic carriage. This review summarizes the current understanding of host–pathogen interactions in the reservoir host and prioritizes research to unravel mechanisms that allow for colonization but not destruction of the host. This information is required to understand, and ultimately control, the transmission of pathogenic Leptospira.

Zoonotic and vector-borne pathogens in tigers from a wildlife safari park, Italy

Infectious diseases by pathogens, including those of zoonotic concern, may act as a primary or contributory cause of threat to wildlife conservation and may represent a risk for human health, mainly for people working at, or visiting the zoological parks. Given the paucity of data on pathogens infecting wild tigers, we investigated the occurrence of infectious agents in this animal species, with a special focus on those of zoonotic concern. Blood and serum samples from tigers (n = 20) living in a wildlife safari park of southern Italy were screened by serological and molecular tests. All animals scored positive for antibodies against Toxoplasma gondii (100%), whereas they displayed different prevalence of seropositivity for Rickettsia conorii (30%), Bartonella henselae (15%) and Leptospira interrogans sv Icterohaemorrhagiae and/or Leptospira kirschneri sv Grippotyphosa (15%). No antibodies against Coxiella burnetii were detected. In addition, 8 tigers (40%) tested molecularly positive to "Candidatus Mycoplasma haemominutum", and 3 (15%) to Hepatozoon canis. No DNA of R. conorii, Bartonella spp., Ehrlichia/Anaplasma spp. and piroplasmids was amplified. The occurrence of tiger infections by bacteria and parasites may represent a risk for morbidity and, in some circumstances, mortality in this endangered species and a source of infection for other animals, including humans. These findings indicate that the circulation of zoonotic pathogens such as T. gondii, R. conorii, L. interrogans sv Icterohaemorrhagiae, "Candidatus Mycoplasma haemominutum" and B. henselae in given environments may represent a relevant health issue considering the close association among animals and humans visiting, or working at, the wildlife safari park. Preventative measures are advocated in order to control ectoparasites and other sources of infection (e.g., small rodents), thus for minimizing the risk of infection for animals as well as for humans.

First report of pathogenic Leptospira spp. isolated from urine and kidneys of naturally infected cats

Leptospirosis is one of the most widespread zoonotic diseases and can infect both humans and animals worldwide. Healthy cat, as a potential source of exposure to humans, are likely underestimated owing to the lack of overt clinical signs associated with Leptospira spp. infection in this species. The aim of the study was to determine the exposure, shedding, and carrier status of leptospires in shelter cats in Malaysia by using serological, molecular, and bacteriological methods. For this study, 82 healthy cats from two shelters were sampled. The blood, urine, and kidneys were tested using the microscopic agglutination test (MAT), polymerase chain reaction (PCR), and bacterial culture. On the basis of serological, molecular, and/or culture techniques, the total detection of leptospiral infection was 29.3% (n = 24/82). Through culture techniques, 16.7% (n = 4/24) of the cats that tested positive were carriers with positive kidney cultures, and one cat was culture positive for both urine and kidney. The Leptospira spp. isolates were identified as pathogenic L. interrogans serovar Bataviae through serological and molecular methods. Through serological techniques, 87.5% (n = 21/24) had positive antibody titers (100-1600) and most of the Bataviae serogroup (n = 19/21). Using PCR, 16.7% (n = 4/24) of cats were shown to have pathogenic Leptospira spp. DNA in their urine. Furthermore, three out of four culture positive cats were serology negative. The present study reports the first retrieval of pathogenic leptospires from urine and kidneys obtained from naturally infected cats. The results provide evidence of the potential role of naturally infected cats in the transmission of leptospires. Additionally, leptospiral infection occurs sub-clinically in cats. The culture isolation provides evidence that healthy cats could be reservoirs of leptospiral infection, and this information may promote the development of disease prevention strategies for the cat population.

Leptospira Detection in Cats in Spain by Serology and Molecular Techniques

Leptospirosis is the most neglected widespread zoonosis worldwide. In Spain, leptospirosis reports in people and animals have increased lately. Cats can become infected with Leptospira, as well as be chronic carriers. The aim of this study was to determine serological antibody prevalence against Leptospira sp., blood DNA, and shedding of DNA from pathogenic Leptospira species in the urine of cats in Spain. Microagglutination tests (MAT) and blood and urine TaqMan real-time polymerase chain reaction (PCR) were performed. Leptospira antibodies were detected in 10/244 cats; with 4.1% positive results (95% confidence interval (CI): 2.1-7.18%). Titers ranged from 1:20 to 1:320 (serovars Ballum; Bataviae; Bratislava; Cynopteri; Grippotyphosa Mandemakers; Grippotyphosa Moskva; Pomona; and Proechimys). The most common serovar was Cynopteri. Blood samples from 1/89 cats amplified for Leptospira DNA (1.12%; 95% CI: 0.05-5.41%). Urine samples from 4/232 cats amplified for Leptospira DNA (1.72%; 95% CI: 0.55-4.10%). In conclusion free-roaming cats in Spain can shed pathogenic Leptospira DNA in their urine and may be a source of human infection. Serovars not previously described in cats in Spain were detected; suggesting the presence of at least 4 different species of pathogenic leptospires in the country (L. borgpetersenii; L. interrogans; L. kirschneri; and L. noguchii).

Leptospirosis in cats: Current literature review to guide diagnosis and management

GLOBAL IMPORTANCE

Leptospirosis is the most widespread zoonosis worldwide. Mammals (eg, rats, horses, cows, pigs, dogs, cats and aquatic species, such as sea lions and northern elephant seals) can all be infected by leptospires. Infection in animals occurs through contact with urine or water contaminated with the bacteria. In people, the disease is acquired mainly from animal sources or through recreational activities in contaminated water.

PRACTICAL RELEVANCE

Literature on the clinical presentation of leptospirosis in cats is scarce, although it has been demonstrated that cats are susceptible to infection and are capable of developing antibodies. The prevalence of antileptospiral antibodies in cats varies from 4% to 33.3% depending on the geographical location. Urinary shedding of leptospires in naturally infected cats has been reported, with a prevalence of up to 68%. Infection in cats has been associated with the consumption of infected prey, especially rodents. Thus, outdoor cats have a higher risk of becoming infected.

CLINICAL CHALLENGES

Clinical presentation of this disease in cats is rare and it is not known what role cats have in the transmission of leptospirosis. Ongoing work is needed to characterise feline leptospirosis.

AUDIENCE

This review is aimed at all veterinarians, both general practitioners who deal with cats on a daily basis in private practice, as well as feline practitioners, since both groups face the challenge of diagnosing and treating infectious and zoonotic diseases.

EVIDENCE BASE

The current literature on leptospirosis in cats is reviewed. To date, few case reports have been published in the field, and information has mostly been extrapolated from infections in people and dogs. This review is expected to serve as a guide for the diagnosis and management of the disease in cats.

Leptospirosis in an asplenic patient -case report

Background

The presentation of clinical leptospirosis has been historically associated with animal workers, slaughterhouse workers and medical veterinarians. This association has shifted to be related to flooding events and outdoor activities; few cases are related to high-risk factors found in immunosuppressed patients. Scarcely a handful of cases have serological evidence of immune response against Leptospira serovar Bratislava representing serogroup Australis, a serovar associated with poor reproductive performance in swine and horses, and recently with cats.

Case presentation

Herein, we describe a rare clinical presentation of disseminated Leptospira infection in an immunosuppressed 65-year-old woman. She was admitted to the emergency room with fever, bacteraemia, bilateral uveitis and pulmonary involvement. The patient denied outdoor activities; she only had wide exposure to faeces and urine from cats living in her home. Her medical history included idiopathic thrombocytopenic purpura (ITP) diagnosed at the age of 18. She did not respond to medical treatment, and a splenectomy was performed. At age 60, she was diagnosed with Chronic Myeloid Leukemia (CML), and was treated with a tyrosine kinase inhibitor (TKI) –Imatinib. The patient voluntarily discontinued the treatment for the last 6 months. After extensive workup, no microorganisms were identified by the commonly used stains in microbiology. The diagnosis was performed through dark-field microscopy, microagglutination test (MAT), Leptospira genus-specific PCR, the IS1500 PCR for identification of pathogenic species, and 16S based sequencing for the genus identification.

Conclusion

Immunosuppressed patients may acquire uncommon infections from ubiquitous microorganisms. In this case, serology evidence of exposure to Leptospira serovar Bratislava by MAT and the presence of the Leptospira genus were identified. It should be on mind for the diagnosis in otherwise healthy patients, and thoroughly search on splenectomised patients exposed to animals. Additionally, this report highlights the usefulness of PCR for diagnosis of this potentially life-threatening illness.

Leptospiral shedding and seropositivity in shelter dogs in the Cumberland Gap Region of Southeastern Appalachia

BACKGROUND

Leptospirosis, caused by pathogenic Leptospira spp., is a zoonotic infection that affects humans, dogs and many other mammalian species. Virtually any mammalian species can act as asymptomatic reservoir, characterized by chronic renal carriage and shedding of a host-adapted leptospiral serovar. Environmental contamination by chronic shedders results in acquisition of infection by humans and susceptible animals.

METHODS

In this study, we investigated if clinically normal shelter dogs and cats harbor leptospires in their kidneys by screening urine samples for the presence of leptospiral DNA by a TaqMan based-quantitative PCR (qPCR) that targets pathogen-associated lipl32 gene. To identify the infecting leptospiral species, a fragment of leptospiral rpoB gene was PCR amplified and sequenced. Additionally, we measured Leptospira-specific serum antibodies using the microscopic agglutination test (MAT), a gold standard in leptospiral serology.

RESULTS

A total of 269 shelter animals (219 dogs and 50 cats) from seven shelters located in the tri-state area of western Virginia, eastern Tennessee, and southeastern Kentucky were included in this study. All cats tested negative by both qPCR and MAT. Of the 219 dogs tested in the study, 26/198 (13.1%, 95% CI: 8.4-17.8%) were positive for leptospiral DNA in urine by qPCR and 38/211 (18.0%, 95% CI: 12.8-23.2%) were seropositive by MAT. Twelve dogs were positive for both qPCR and MAT. Fourteen dogs were positive by qPCR but not by MAT. Additionally, leptospiral rpoB gene sequencing from a sub-set of qPCR-positive urine samples (n = 21) revealed L. interrogans to be the leptospiral species shed by dogs.

CONCLUSIONS

These findings have significant implications regarding animal and public health in the Cumberland Gap Region and possibly outside where these animals may be adopted.

2019 AAFP Feline Zoonoses Guidelines

AIM

The overarching purpose of the 2019 AAFP Feline Zoonoses Guidelines (hereafter referred to as the 'Guidelines') is to provide accurate information about feline zoonotic diseases to owners, physicians and veterinarians to allow logical decisions to be made concerning cat ownership.

SCOPE AND ACCESSIBILITY

The Panelists are physicians and veterinarians who worked closely together in an attempt to make these Guidelines a document that can be used to support the International One Health movement. This version of the Guidelines builds upon the first feline zoonosis panel report, published in 2003 ( catvets.com/guidelines ), and provides an updated reference list and recommendations. Each of the recommendations received full support from every Panelist. Primary recommendations are highlighted in a series of 'Panelists' advice' boxes.

Serological detection of anti-leptospiral antibodies in outdoor cats in Switzerland

Leptospirosis is endemic in Switzerland affecting a broad range of hosts. The aim of this study was to estimate the exposure of cats to Leptospira in Switzerland. Plasma samples from 107 outdoor cats with an array of clinical problems were tested via microscopic agglutination test for the presence of anti-leptospiral antibodies against 12 serovars of 9 serogroups. Using a reciprocal cut-off titre of 1:100, an overall seroprevalence of 10.3% (95%CI 5.2-17.7) was observed. Seroreactivity against serovars Bratislava (n = 6), Australis (2), Pomona (3) and Copenhageni (1) was detected with reciprocal titres ranging from 1:100 to 1:800. The serologic status of the cats was independent of the disease group (p = 0.62). These results show that cats in Switzerland are commonly exposed to Leptospira and confirm the importance of serogroup Australis in this region.

Retrospective Biomolecular Investigation of Coxiella burnetii and Leptospira spp. DNA in Cases of Abortion, Stillbirth and Neonatal Mortality in Dogs and Cats

Abortion and neonatal mortality are events that can occur in breeding bitches and queens. It has been reported that up to 55% and 33% of these cases remain without a known cause, respectively, in canine and feline pregnancies. Unusual abortigenic and potentially zoonotic agents, including Coxiella burnetii and Leptospira spp., may be involved in these cases. C. burnetii is able to cause reproductive disorders in cattle, sheep and goats, and cases of abortion have been observed in dogs and cats. Moreover, several outbreaks of C. burnetii infection in humans have been caused by delivering bitches and queens, and some of these animals experienced abortion. Leptospira interrogans sensu lato is able to cause abortion or stillbirth in several animal species and its abortigenic role has occasionally been described in bitches and queens. The aim of this study was to search for C. burnetii and Leptospira spp. DNA in a retrospective series of 103 cases of canine and feline abortion, stillbirth, and neonatal mortality submitted for the identification of possible infectious agents. One hundred and fifty-one specimens were tested using PCR assays and found negative for C. burnetii and Leptospira DNA. However, in 49 samples (47.6%) other infectious causes of abortion, stillbirth, and neonatal mortality were identified. These results showed that C. burnetii and Leptospira spp. are probably not common abortigenic agents or causes of neonatal deaths in dogs. However, given the potential abortigentic and zoonotic role of these agents, surveillance of canine and feline abortion, stillbirth, and neonatal mortality could be advisable for a systematic investigation of these events.

Evaluation of LAMP for detection and/or screening of Leptospira spp. infection among domestic animals in the Philippines

Objective:

This study assessed the applicability of loop-mediated isothermal amplification (LAMP) for the detection of leptospirosis among domesticated animals and sewage rats. Specifically, it evaluated the ability of LAMP to amplify Leptospira spp. targeting the 16s rRNA gene in boiled urine samples.

Materials and methods:

A total of 140 samples from different domestic animals were tested for the presence of the antigen. A nested-polymerase chain reaction (nPCR) protocol was used to compare and determine the sensitivity of LAMP in detecting Leptospira spp. The LAMP was also evaluated by comparing its amplification result using agarose gel electrophoresis and color change using dye.

Results:

Positivity rate of Leptospira spp. antigen was 29.0% (40/140) for LAMP and 9.3% (13/140) for nPCR. Also, LAMP results for gel electrophoresis and dye color change varied in some samples that may be due to the interpretation of the result in dye color change.

Conclusion:

Overall, LAMP is a rapid, sensitive, and cost-effective diagnostic method compared with nPCR. Also, LAMP has a potential application as pen-side screening, surveillance, and clinical diagnostic kits of infectious diseases without requiring advance equipment and skilled personnel.

Evidence of interspecies transmission of pathogenic Leptospira between livestock and a domestic cat dwelling in a dairy cattle farm

A domestic cat dwelling in a dairy cattle farm with haematuria was referred for a physical examination. The examination showed no abnormalities therefore complementary exams were performed. Leukocytosis with neutrophilia, monocytosis and hyperproteinaemia were detected. The urine analysis showed a bacterial infection without ultrasound findings. Serological titers to Leptospira interrogans serovar Pomona and Autumnalis were detected. Molecular analysis demonstrated the presence of Leptospira spp. in urine. The findings were consistent with subclinical leptospirosis. The cattle herd had evidence of Leptospira infection. The microbiological exams confirmed the presence of the Leptospira spp. in urine and serum. According to the evidence presented in this study, cats that dwell within a dairy farm could play a role in the Leptospira infection epidemiologically. The importance of feline leptospirosis must be evaluated with leptospirosis control in livestock.

Prevalence of Renal Lesions in the Small Indian Mongoose ( Herpestes auropunctatus) Inhabiting the Caribbean Island of Saint Kitts

We describe histopathologic abnormalities in the kidneys of small Indian mongoose ( Herpestes auropunctatus) on the Caribbean island of Saint Kitts. The lesions observed in moderate to severe cases were suggestive of a chronic nephropathy. Further investigation is needed to explore the magnitude of the problem, potential causes, and predisposing factors.

Urinary shedding of pathogenic Leptospira in stray dogs and cats, Algiers: A prospective study

Background

Leptospirosis is an important worldwide zoonosis. This disease is caused by pathogenic species of the genus Leptospira which are maintained in the environment via chronic renal infection of carrier animals which can be asymptomatic excretors of the organisms in their urines and become a source of infection for humans and other hosts. The prevalence of animal leptospirosis in Algiers, Algeria, is unknown.

Methodology/principal findings

Real-time PCR and standard PCR and sequencing were used to detect pathogenic Leptospira organisms in the urines of stray dogs and cats in Algiers. In the presence of appropriate controls, none of the 107 cat urine samples were positive while 5/104 (4.8%) canine urine samples (asymptomatic mixed-breed dogs, three females and two males) were positive in two real-time PCR assays targeting the rrs and hsp genes. The positivity of these samples was confirmed by partial PCR-sequencing of the rpoB gene which yielded 100% sequence similarity with Leptospira interrogans reference sequence. In this study, L. interrogans prevalence was significantly higher in dogs aged < one year (16.46% - 29.41%) than in adults (0%) (P value = 0.0001) and then in the overall dog population (2.68% - 4.8%) (P = 0.0007).

Conclusions/significance

These results suggest that dogs are maintenance hosts for zoonotic leptospirosis in Algiers, Algeria. To face this situation, effective canine vaccination strategies and raising public health awareness are mandatory. Further investigations incorporating a larger sample in more localities will be undertaken to document the epidemiology of urban animal leptospirosis in Algeria at large.

Leptospira Seroprevalence in Domestic Dogs and Cats on the Caribbean Island of Saint Kitts

Leptospirosis is an important bacterial zoonotic disease that affects humans and many animal species. Knowledge of prevalence of Leptospira in a given geographic region supports the implementation of effective control/prevention programmes and thus reduces the transmission risks. This study provides Leptospira seroprevalence and serovar distribution in dogs and cats on the Caribbean island of Saint Kitts. Convenient serum samples from domestic dogs (n = 101) and cats (n = 50) were tested by the microscopic agglutination test (MAT) using 21 Leptospira serovars belonging to 17 serogroups. Seroprevalence was recorded at 73.2% in dogs (95% confidence interval CI: 62.5–80.1%). Agglutinating antibodies to Leptospira were present against 13 of the 21 serovars tested by MAT. The highest seroprevalence was observed for serovar Autumnalis (56.4%) followed by Icterohaemorrhagiae (27.7%), Canicola (17.8%), Djasiman (14.9%), Bratislava (11.9%), Pyrogenes (11.9%), and Pomona (7.9%). A very low seroprevalence (4%, 95% CI: 0.5–14%) was observed in cats. This data confirms that dogs in Saint Kitts have a high-level exposure to a diverse set of Leptospira serovars.

[Epidemiology and prevention of leptospirosis in dogs]

Leptospirosis is a zoonotic disease with increasing prevalence in dogs and humans. The various Leptospira serovars display different pathogenicity. Even healthy infected dogs can shed leptospires with their urine and thus, represent a risk for humans and other animals. Vaccination is the most important measure for prevention; it not only prevents disease in dogs, but also reduces shedding of leptospires in urine. For comprehensive protection through vaccination, tetravalent vaccines containing serovars of the serogroups relevant in the corresponding region should be used. The spread of the pathogen can be reduced by a wide application of these vaccines. A detailed owner education about the zoonotic potential of the infection and appropriate hygiene measures when handling the infected dog and its urine are essential.

Risk and protective factors for cats with naturally occurring chronic kidney disease

Objectives Chronic kidney disease (CKD) is a significant disease in cats. Identifying risk and protective factors may help to prevent this significant disease. Methods An age-matched case-control study was performed to determine the risk factors in cats with naturally occurring CKD. Twenty-nine clinically normal cats aged ⩾5 years and 101 cats with naturally occurring CKD were studied. Risk factors were determined by interviewing cat owners from the Small Animal Hospital, Faculty of Veterinary Science, Chulalongkorn University, and veterinary hospitals in the Bangkok Metropolitan area, through questionnaires completed between June 2004 and November 2014. Univariable and multivariable analyses were performed using two independent proportional test methods and logistic regression analysis with backward elimination. Results Male sex (odd ratios [OR] 2.80, 95% confidence interval [CI] 1.02-8.87; P = 0.02), tap water (OR 3.43, 95% CI 1.08-11.45; P = 0.03) and an outdoor lifestyle (OR 3.77, 95% CI 1.03-17.99; P = 0.04) were associated with an increased risk for CKD. Commercial dry cat food (OR 0.06, 95% CI 0.02-0.17; P = 0.00), filtered water (OR 0.13, 95% CI 0.03-0.52; P = 0.01) and an indoor lifestyle (OR 0.28, 95% CI 0.07-0.98; P = 0.02) were associated with a decreased risk. Logistic regression analysis using backward elimination demonstrated that cats fed commercial dry cat food (OR 0.042, 95% CI 0.01-0.17; P = 0.00) had a decreased risk for CKD compared with cats on other types of diet. Conclusions and relevance Multivariable analysis found only feeding commercial dry cat food to be significant, suggesting that commercial dry cat food may be a potential protective factor for CKD in cats.

Detection of Leptospira DNA in urine and presence of specific antibodies in outdoor cats in Germany

Objectives Clinical manifestation of infection with Leptospira species in cats is rare. Nevertheless, cats can develop specific antibodies against the spirochetes after infection. In Canada, Taiwan and the USA it was recently demonstrated that naturally infected cats can also shed DNA from pathogenic Leptospira species in their urine, but the zoonotic potential of infected cats is still unclear. The objective of this study was to demonstrate if outdoor cats in Germany shed DNA from pathogenic Leptospira species in their urine. As a second aim, antibody prevalence was determined. Methods Two hundred and fifteen outdoor cats were prospectively recruited. Urine samples were tested by real-time PCR targeting the lipL32 gene of pathogenic Leptospira species. Antibody titres against eight serovars (Australis, Autumnalis, Bratislava, Canicola, Copenhageni, Grippotyphosa, Pomona, Saxkoebing) belonging to seven serogroups (Australis, Autumnalis, Canicola, Grippotyphosa, Icterohaemorrhagiae, Pomona, Sejroe) were determined by microscopic agglutination test. Results Urine samples from 7/215 cats (3.3%; 95% confidence interval [CI] 0.9-5.7) were PCR-positive. Specific antibodies were detected in 35/195 cats (17.9%; 95% CI: 12.5-23.3) with titres ranging from 1:100 to 1:6400. Australis, Bratislava and Grippotyphosa were the most common serovars. Conclusions and relevance Outdoor cats in Germany can shed DNA from pathogenic Leptospira species. Therefore, outdoor cats should be considered as a possible source of infection for dogs or humans. Further studies are needed to determine the role of Leptospira species as a cause of disease in cats.

[Leptospira infections in cats]

Leptospirosis is a widespread zoonosis found in over 150 mammalian species. Subclinically infected rodents and farm animals serve as reservoir hosts. Cats are exposed to leptospires regularly, particularly through hunting infected rodents. However, clinical leptospirosis is rare in cats. Nevertheless, infected cats can shed the pathogen through urine and thus, cats could play an important role in the epidemiology of leptospires.

Serological survey of Leptospira interrogans, Toxoplasma gondii and Trypanosoma cruzi in free roaming domestic dogs and cats from a marginated rural area of Yucatan Mexico

To evaluate the serological status for Trypanosoma cruzi, Toxoplasma gondii and Leptospira interrogans antibodies in free roaming dogs and cats from a marginated rural community in Yucatan Mexico, 100 households were visited and animals sampled. From the 106 samples, 93 were from dogs and 13 were from cats. Frequency of positive results for T. gondii, T. cruzi and Leptospira spp was 97.8%, 9.7% and 45.2% for dogs and 92.3%, 0.0% and 15.2% for cats, respectively. No associations with age, sex and body condition was found for T. gondii and Leptospira spp neither for the place where pets sleep, fumigation or presence of triatomes in the household in the case of T. cruzi. For leptospirosis the most common serovars found were Canicola, Autralis and Bratislava in dogs and cats with titres of 100 or 200 with exception of one dog with a titre of 400. The high frequency of seropositive dogs suggests a high circulation of the agents in the population of free roaming owned dogs and cats probably due to the lack of control of the reservoirs and vectors involved. Domestic animals in those rural communities can be sentinels to assess the risk of human exposure in the rural communities.

Evaluation of the Leptospira species microscopic agglutination test in experimentally vaccinated cats and Leptospira species seropositivity in aged azotemic client-owned cats

OBJECTIVES

The objectives of this study were to validate the microscopic agglutination test (MAT) using feline sera, determine cross-reactivity of Borrelia burgdorferi antibodies in the MAT, and evaluate if there is an association between Leptospira species seropositivity in aged (⩾10 years) client-owned cats with and without azotemia (creatinine >2 g/dl).

METHODS

A four-serovar canine leptospiral vaccine was administered to two specific pathogen-free (SPF) cats on days 0 and 14. The MAT was performed intermittently until day 42 for the serovars Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, Pomona and Bratislava, with a cut-off value of ⩾1:100. Five purpose-bred cats were infested with wild-caught Ixodes scapularis adults with an average B burgdorferi infection rate of 50%, and tested for antibodies against B burgdorferi C6 peptide and DNA in skin biopsies, as well as by MAT. Sera from 66 azotemic and 75 non-azotemic cats ⩾10 years of age were tested for Leptospira species antibodies using the MAT and results were compared by the χ(2) test.

RESULTS

Both SPF cats seroconverted by week 3 and formed antibodies against at least one serovar. There was no cross-reactivity in the MAT using samples from cats with antibodies to B burgdorferi. MAT results were positive for 4/66 azotemic cats and 8/75 non-azotemic cats; these results were not statistically different.

CONCLUSIONS AND RELEVANCE

The MAT can be interpreted using feline serum and does not appear to cross-react in cats with B burgdorferi antibodies. There was no association between Leptospira species MAT results and azotemia in this group of aged client-owned cats but further studies are needed to determine if leptospirosis contributes to feline chronic kidney disease.

Current Understanding of the Pathogenesis of Progressive Chronic Kidney Disease in Cats

In cats with chronic kidney disease (CKD), the most common histopathologic finding is tubulointerstitial inflammation and fibrosis. However, these changes reflect a nonspecific response of the kidney to any inciting injury. The risk of developing CKD is likely to reflect the composite effects of genetic predisposition, aging, and environmental and individual factors that affect renal function over the course of a cat's life. However, there is still little information available to determine exactly which individual risk factors predispose a cat to develop CKD. Although many cats diagnosed with CKD have stable disease for years, some cats show overtly progressive disease.

European consensus statement on leptospirosis in dogs and cats

Leptospirosis is a zoonotic disease with a worldwide distribution affecting most mammalian species. Clinical leptospirosis is common in dogs but appears to be rare in cats. Both dogs and cats, however, can shed leptospires in the urine. This is problematic as it can lead to exposure of humans. The control of leptospirosis, therefore, is important not only from an animal but also from a public health perspective. The aim of this consensus statement is to raise awareness of leptospirosis and to outline the current knowledge on the epidemiology, clinical features, diagnostic tools, prevention and treatment measures relevant to canine and feline leptospirosis in Europe.

Leptospira Exposure and Gardeners: A Case-Control Seroprevalence Study

Background

Leptospira can be found in soil. However, it is unclear whether occupational exposure to soil may represent a risk for Leptospira infection in humans. Therefore, we sought to determine the association of Leptospira IgG seroprevalence with the occupation of gardener, and to determine the epidemiological characteristics of gardeners associated with Leptospira exposure.

Methods

We performed a case-control study in 168 gardeners and 168 age- and gender-matched control subjects without gardening occupation in Durango City, Mexico. The seroprevalence of anti-Leptospira IgG antibodies in cases and controls was determined using an enzyme immunoassay. Bivariate and multivariate analyses were used to assess the association of Leptospira exposure and the characteristics of the gardeners.

Results

Anti-Leptospira IgG antibodies were found in 10 (6%) of 168 gardeners and in 15 (8.9%) of 168 control subjects (odds ratio (OR): 0.64; 95% confidence interval (CI): 0.28 - 1.48; P = 0.40). Multivariate analysis showed that Leptospira seropositivity was positively associated with female gender (OR: 5.82; 95% CI: 1.11 - 30.46; P = 0.03), and negatively associated with eating while working (OR: 0.21; 95% CI: 0.05 - 0.87; P = 0.03). In addition, multivariate analysis showed that high anti-Leptospira levels were associated with consumption of boar meat (OR: 28.00; 95% CI: 1.20 - 648.80; P = 0.03).

Conclusions

This is the first case-control study of Leptospira exposure in gardeners. Results do not support an association of Leptospira exposure with the occupation of gardener. However, further studies to confirm the lack of this association are needed. The potential role of consumption of boar meat in Leptospira infection deserves further investigation.