Epidemiology of leptospirosis in North-Central Italy: Fifteen years of serological data (2002-2016)

Zoonoses and pet owners: A survey on risk perception in Northern Italy

Veterinary and human medicine are focused on the issue of emerging and re-emerging diseases, which are especially represented by zoonosis that could be a threat for public health. Zoonotic risk may come from pets: some canine and/or feline viral, bacterial, parasitic, protozoal or mycotic diseases can be transmitted directly to humans. There are several strategies to prevent the transmission of such zoonosis, and among them vaccination plays an important role. Through a survey carried out in Northern Italy aimed to collect information regarding owners' knowledge and perception of the zoonotic risks associated with three zoonoses (rabies, leptospirosis, and dermatophytosis), it was demonstrated that dog owners tend to adhere more consistently to their pets' vaccination schedules and are more receptive to changes in vaccination scheduling compared to cat owners. This study also suggests that cat owners predominantly visit veterinarians for vaccination purposes, whereas dog owners seek veterinary services for a variety of reasons. The survey highlighted the ongoing need to enhance owners' understanding of zoonoses affecting their pets and also the protective role of vaccines. Veterinarians should undertake the responsibility of educating, reassuring, and informing pet owners about the significance of vaccines for their pets and for public health.

Seroprevalence of leptospirosis among stray dogs in Bosnia and Herzegovina

Leptospirosis is a (re) emerging zoonosis that occurs worldwide. This study aimed to assess seroprevalence of leptospirosis and to identify the most common reactive serovars and risk factors for seropositivity in apparently healthy stray dogs of unknown vaccination status in the Sarajevo region of Bosnia and Herzegovina. Positive microscopic agglutination test titres (≥ 1:25) were detected in 3.87% (156/4028) of samples and most of the sera reacted against one serovar (85.9%). Dogs were most commonly reactive to Canicola (40.4%) and Hardjo (33.3%), followed by Pomona (15.4%) Tarassovi (14.7%), Icterohaemorrhagiae (8.3%), Grippotyphosa (5.8%), Bratislava (1.3%) and Saxkoebing (0.6%). Dogs older than one year had higher odds of seropositivity compared to younger dogs. The seropositivity was higher in spring and autumn than in summer. These results advocate for the need of a control strategy for this zoonosis in the country, which should include sero-surveillance, monitoring, and the inclusion of additional serovars in the testing.

Different Immune Control of Gram-Positive and Gram-Negative Mammary Infections in Dairy Cows

In the dairy industry, bovine mastitis represents a major concern due to substantial production losses and costs related to therapies and early culling. The mechanisms of susceptibility and effective response to intra-mammary infections are still poorly understood. Therefore, we investigated innate immunity in acellular bovine skim milk through cytofluorimetric analyses of bacterial killing activity against both Gram-positive and Gram-negative pathogens. Freshly cultured E. coli and S. aureus strains were incubated with colostrum and milk samples at different lactation time points from two groups of cows, purportedly representing mastitis-resistant and mastitis-susceptible breeds; bacterial cells were analyzed for vitality by flow cytometry following incorporation of vital dyes. N-acetyl-β-D-glucosaminidase (NAGase) activity was also investigated in milk and colostrum samples. Our findings revealed that colostrum and milk bacterial killing activity was greater against S. aureus compared to E. coli., with this activity correlated with milk NAGase levels. Furthermore, both killing of S. aureus and NAGase activity were negatively correlated to the elapsed time of lactation. Interestingly, samples from the allegedly mastitis-resistant breed displayed higher bacterial killing and NAGase activities. Our study suggests that diverse control mechanisms are exerted against Gram-positive and Gram-negative pathogens in the mammary glands of cows, probably beyond those already described in the literature.

Serological investigation of seven zoonotic pathogens in companion dogs in South Korea, 2018-2021

Based on the current situation of Korean culture and society, the population of companion animals in South Korea is growing rapidly along with zoonotic risks. The current data regarding zoonotic infections in companion dogs reported in Korea is sparse. This study aims to investigate the seroprevalence of seven potential zoonotic pathogens in companion dogs in South Korea: Anaplasma phagocytophilum, Borrelia burgdoferi, Ehrlichia canis, Coxiella burnetii, Brucella canis, Leptospira spp. and canine influenza A virus. A total of 284 serum samples were collected from 2018 to 2021, and the immunoglobulin G (IgG) antibodies against 7 zoonotic pathogens were detected using enzyme-linked immunosorbent assays. Samples were divided into five groups and analysed based on age. IgG antibodies against six of the seven pathogens were detected. The highest seropositivity rate was detected for canine influenza A virus exposure (59.1%) for which the rates were the highest in dogs under 1 year old and declined with age. Positivity rates of the other pathogens were relatively low: 1.76% for Leptospira spp., 1.40% for A. phagocytophilum and E. canis, 1.06% for B. canis and 0.35% for B. burgdoferi. No antibodies against C. burnetii were detected in this study. The exposure of dogs in South Korea to six zoonotic pathogens was serologically confirmed, highlighting a potential risk for human infection. The zoonotic risk of companion dogs cannot be neglected, and implementation of One Health approach should be advocated to establish effective preventive measures.

Acute human leptospirosis in a Caribbean region of Colombia: From classic to emerging risk factors

BACKGROUND

Leptospirosis is a zoonosis of worldwide incidence, with a broad spectrum of health risk factors.

AIM

The objective was to determine risk factors associated with acute human leptospirosis and to explore predictive variables of risk to human leptospirosis.

METHODS

The study was carried out in the Department of Córdoba, in the north of Colombia. We conducted a longitudinal prospective descriptive study with non-probabilistic sampling, which included 339 patients suspected of leptospirosis. Positive cases were confirmed by MAT and PCR. The determination of social and environmental risk factors was done with a survey on epidemiological and environmental variables to establish an association between cases of leptospirosis and risk factors as well as predictive variables.

RESULTS

We found 19.8% (67/339) cases of acute leptospirosis, and the seroprevalence was 27.1% (92/339). The most frequent serogroups were Sejroe, Australis, Pomona, Batavie, Pyrogenes and Grippotyphosa. We identified the following risk factors: age between 10 and 19 years (OR = 2.571; 95% CI); pig ownership (OR = 2.019; 95% CI); bathing or recreational activities in lake/lagoon (OR = 3.85; 95% CI) and in dams (OR = 3.0; 95% CI); floodings 30 days before the onset of symptoms (OR = 2.019; 95% CI), and a mean temperature of 28°C (p 0.044; 95%CI). As significant predictor variables, we identified age (10-19 years), bathing or recreational activities in the lake/lagoon, and flooding 30 days before symptoms were again evidenced. This region presents classic risk factors (pig ownership) and emerging environmental risk factors (recreational practice or bathing in a lake/lagoon and flooding 30 days before the onset of symptoms), and demographic factors such as young age (10-19 years).

CONCLUSIONS

These factors are also predictors of human cases of acute leptospirosis and provide contextual information on environmental and public health that should be considered for epidemiological surveillance in this endemic area.

Identification of zoonotic pathogenic bacteria from blood and ticks obtained from hares and long-eared hedgehogs (Hemiechinus megalofis) in eastern Iran

The role of wildlife in the complex balance of tick-borne diseases within ecosystems is crucial, as they serve as hosts for tick carriers and reservoirs for the pathogens carried by these ticks. This study aimed to investigate the presence of zoonotic pathogenic bacteria in wildlife, specifically in hares and long-eared hedgehogs (Hemiechinus megalofis), in the eastern region of Iran. The focus was on the detection of Borrelia spp., Coxiella burnetii, Anaplasma spp., Francisella spp., and Leptospira spp., using the Nested-PCR method. We analyzed a total of 124 blood samples, and 196 ticks collected from hares and long-eared hedgehogs were analyzed. The Nested-PCR method was employed to identify the presence of zoonotic pathogenic bacteria DNA. Our study revealed the presence of these zoonotic pathogenic bacteria in both wildlife species, indicating their potential role as hosts and reservoirs for the ticks carrying these pathogens. The specific presence and prevalence of Borrelia spp., Coxiella burnetii, Anaplasma spp., Francisella spp., and Leptospira spp. were determined through the Nested-PCR method. This study contributes to the limited knowledge about the involvement of wild animals in the transmission of tick-borne diseases. By using the Nested-PCR method, we successfully identified the presence of zoonotic pathogenic bacteria in hares and long-eared hedgehogs. This study emphasizes the need for further research to better understand the ecological process of tick-borne diseases, particularly the role of wildlife in their spread. Such knowledge is crucial for wildlife conservation efforts and the management of tick-borne diseases, ultimately benefiting both animal and human health.

A systematic review on leptospirosis in cattle: A European perspective

Leptospirosis is a zoonotic disease which is globally distributed and represents a classic One Health issue that demands a comprehensive understanding of the hosts, transmission paths, and risk factors of transmission. Bovine leptospirosis often results in economic losses through its severe impact on reproduction performance while it threatens human health at human-cattle-environment interfaces. However, a clear analysis of the disease characteristics in European cattle is currently lacking. The objective of this review was to summarise the current knowledge on the epidemiology of bovine leptospirosis in Europe. We conducted a systematic literature review, screening four electronic databases, and filtered articles published between 2001 and 2021, in English, German, and French. Sixty-two articles were ultimately included in the review. The seroprevalence of leptospirosis in cattle was remarkably variable among studies, probably reflecting local variations but also heterogeneity in the study designs, laboratory methods, and sample sizes. Risk factors positively associated with the disease were diverse, related to local, environmental, and climatic parameters as well as farming practices. The most reported circulating Leptospira serogroups in European cattle were Sejroe (58.5%), Australis (41.5%), Grippotyphosa (41.5%), Icterohaemorrhagiae (37.7%), and Pomona (26.4%), which have also been associated with human infections worldwide. Abortion (58.6%) and fertility disorders (24.1%) were the most frequently reported signs of leptospirosis in European cattle and were generally associated with chronic infections. This work highlights several research gaps, including a lack of harmonisation in diagnostic methods, a lack of large-scale studies, and a lack of molecular investigations. Given that predictions regarding the climatic suitability for leptospirosis in Europe suggest an increase of leptospirosis risk it is important to raise awareness among stakeholders and motivate an integrated One Health approach to the prevention and control of this zoonotic disease in cattle and humans.

Modelling the Unidentified Abortion Burden from Four Infectious Pathogenic Microorganisms (Leptospira interrogans, Brucella abortus, Brucella ovis, and Chlamydia abortus) in Ewes Based on Artificial Neural Networks Approach: The Epidemiological Basis for a Control Policy

Unidentified abortion, of which leptospirosis, brucellosis, and ovine enzootic abortion are important factors, is the main cause of disease spread between animals and humans in all agricultural systems in most developing countries. Although there are well-defined risk factors for these diseases, these characteristics do not represent the prevalence of the disease in different regions. This study predicts the unidentified abortion burden from multi-microorganisms in ewes based on an artificial neural networks approach and the GLM.

METHODS

A two-stage cluster survey design was conducted to estimate the seroprevalence of abortifacient microorganisms and to identify putative factors of infectious abortion.

RESULTS

The overall seroprevalence of Brucella was 70.7%, while Leptospira spp. was 55.2%, C. abortus was 21.9%, and B. ovis was 7.4%. Serological detection with four abortion-causing microorganisms was determined only in 0.87% of sheep sampled. The best GLM is integrated via serological detection of serovar Hardjo and Brucella ovis in animals of the slopes with elevation between 2600 and 2800 meters above sea level from the municipality of Xalatlaco. Other covariates included in the GLM, such as the sheep pen built with materials of metal grids and untreated wood, dirt and concrete floors, bed of straw, and the well water supply were also remained independently associated with infectious abortion. Approximately 80% of those respondents did not wear gloves or masks to prevent the transmission of the abortifacient zoonotic microorganisms.

CONCLUSIONS

Sensitizing stakeholders on good agricultural practices could improve public health surveillance. Further studies on the effect of animal-human transmission in such a setting is worthwhile to further support the One Health initiative.

Influence of landscape structure on previous exposure to Leptospira spp. and Brucella abortus in free-living neotropical primates from southern Brazil

The environments in which neotropical primates live have been undergoing an intense fragmentation process, constituting a major threat to the species' survival and causing resource scarcity, social isolation, and difficulty in dispersal, leaving populations increasingly vulnerable. Moreover, the proximity of wild environments to anthropized landscapes can change the dynamics of pathogens and the parasite-host-environment relationship, creating conditions that favor exposure to different pathogens. To investigate the previous exposure of free-living primates in Rio Grande do Sul State (RS), southern Brazil, to the bacterial agents Leptospira spp. and Brucella abortus, we investigated agglutinating antibodies against 23 serovars of Leptospira spp. using the microscopic agglutination test and B. abortus acidified antigen test in primate serum samples; 101 samples from primates captured between 2002 and 2016 in different forest fragments were used: 63 Alouatta caraya, 36 Alouatta guariba clamitans, and 02 Sapajus nigritus cucullatus. In addition, the forest remnants where the primates were sampled were characterized in a multiscale approach in radii ranging from 200 to 1400 m to investigate the potential relationship of previous exposure to the agent with the elements that make up the landscape structure. The serological investigation indicated the presence of antibodies for at least one of the 23 serovars of Leptospira spp. in 36.6% (37/101) of the samples analyzed, with titers ranging from 100 to 1600. The most observed serovars were Panama (17.8%), Ballum (5.9%), Butembo (5.9%), Canicola (5.9%), Hardjo (4.9%), and Tarassovi (3.9%); no samples were seropositive for Brucella abortus. Decreased forest cover and edge density were the landscape factors that had a significant relationship with Leptospira spp. exposure, indicating that habitat fragmentation may influence contact with the pathogen. The data generated in this study demonstrate the importance of understanding how changes in landscape structure affect exposure to pathogenic microorganisms of zoonotic relevance. Hence, improving epidemiological research and understanding primates' ecological role in these settings can help improve environmental surveillance and conservation strategies for primate populations in different landscapes.

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.

AMYLOIDOSIS IN CAPTIVE EUROPEAN EASTERN BONGO (TRAGELAPHUS EURYCERUS ISAACI): PREVALENCE, PREDICTIVE FACTORS, ORGAN PREDILECTION, AND SERUM AMYLOID A CONCENTRATIONS

Amyloidosis is frequently identified during postmortem examination of captive eastern bongo (Tragelaphus eurycerus isaaci) in the European Endangered Species Programme (EEP). However, its significance and etiopathogenesis are poorly understood. The objective of this study was to investigate the prevalence of amyloidosis within this population and identify potential predictive factors for the presence of disease. Postmortem reports obtained from 24 EEP institutions were analyzed and assessed for evidence of amyloidosis. Seventy-two individuals had histopathological assessment performed after gross postmortem examination and were included in the study. Further histopathological analysis was performed on Congo red-stained slides from 26 individuals, and organ predilection sites were identified. Immunohistochemical analysis was performed in six individuals to identify the type of amyloid present. Serum amyloid A (SAA) analysis was performed on blood samples from 34 individuals, and concentrations in affected and unaffected individuals were compared. Amyloidosis was reported in 26 animals (36%). The association between the presence of amyloidosis and sex, age, or body condition was not statistically significant. However, amyloidosis was not identified in any individuals under the age of 6 yr. The presence of chronic inflammatory conditions was the only statistically significant predictive factor for the presence of amyloidosis (P = 0.03). Chronic inflammatory conditions present included nephritis, enteritis, and pneumonia. The majority of affected animals presented with amyloid deposition in multiple organs, with the liver and kidneys being most commonly affected. Immunohistochemistry confirmed the presence of AA amyloid. The association between the presence of amyloidosis and SAA values measured on a single occasion was not statistically significant. This study identified a high prevalence of amyloidosis within the captive European eastern bongo population associated with chronic inflammatory conditions. Antemortem diagnosis of amyloidosis remains challenging, and this study indicates that SAA protein concentrations are not a reliable indicator for the presence of amyloidosis.

An Overview of Anthropogenic Actions as Drivers for Emerging and Re-Emerging Zoonotic Diseases

Population growth and industrialization have led to a race for greater food and supply productivity. As a result, the occupation and population of forest areas, contact with wildlife and their respective parasites and vectors, the trafficking and consumption of wildlife, the pollution of water sources, and the accumulation of waste occur more frequently. Concurrently, the agricultural and livestock production for human consumption has accelerated, often in a disorderly way, leading to the deforestation of areas that are essential for the planet's climatic and ecological balance. The effects of human actions on other ecosystems such as the marine ecosystem cause equally serious damage, such as the pollution of this habitat, and the reduction of the supply of fish and other animals, causing the coastal population to move to the continent. The sum of these factors leads to an increase in the demands such as housing, basic sanitation, and medical assistance, making these populations underserved and vulnerable to the effects of global warming and to the emergence of emerging and re-emerging diseases. In this article, we discuss the anthropic actions such as climate changes, urbanization, deforestation, the trafficking and eating of wild animals, as well as unsustainable agricultural intensification which are drivers for emerging and re-emerging of zoonotic pathogens such as viral (Ebola virus, hantaviruses, Hendravirus, Nipah virus, rabies, and severe acute respiratory syndrome coronavirus disease-2), bacterial (leptospirosis, Lyme borreliosis, and tuberculosis), parasitic (leishmaniasis) and fungal pathogens, which pose a substantial threat to the global community. Finally, we shed light on the urgent demand for the implementation of the One Health concept as a collaborative global approach to raise awareness and educate people about the science behind and the battle against zoonotic pathogens to mitigate the threat for both humans and animals.

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.

Serological Investigation and Epidemiological Analysis of Bovine Leptospirosis in Egypt

Bovine leptospirosis is a bacterial zoonotic disease of worldwide distribution. Little information is available regarding the occurrence of the disease in the Nile Delta provinces, Egypt. The present study investigated the seroprevalence of leptospirosis among cattle from Dakahlia province, Northern Egypt, and identified the individual variables factors associated with infection. To this end, a total of 600 serum samples from cattle of small stakeholders with various clinical manifestations possibly associated with leptospirosis were collected from different localities across Dakahlia province, Egypt. Sera were examined serologically via ELISA to investigate the occurrence of the disease among animals. Chi-square test and multivariable logistic regression analyses were applied to determine the association between hypothesized risk factors and the disease. Interestingly, our findings showed that 39.33% of the examined sera were positive for Leptospira antibodies, with significant differences among different localities. In addition, statistical analysis showed significant differences among age groups. Notably, the highest prevalence rate (22%) was observed in those aged between 3 and 5 years (p < 0.0001), whereas the lowest prevalence (2.66%) was reported in cattle <1 year old (p < 0.0001). Moreover, females had a significantly higher prevalence rate (35.33%) than males (4%) (p < 0.0001). Furthermore, our results showed significant differences in the occurrence of infection and reported clinical signs (p < 0.0001). Multivariable logistic regression identified repeated breeder and drop milk yield as the best predictors for prediction of ELISA results and linear discriminant analysis (LDA) model showed that overall classification accuracy of ELISA result using clinical signs and demographic data as predictors was 70.7%. The current study concluded a relative high prevalence of leptospirosis among cows bred in movable herds and households in the studied area and that age, repeated breeder and drop milk yield can be considered major risk factors associated with infection.

Circulating serogroups of Leptospira in swine from a 7-year study in France (2011–2017)

Background

Leptospirosis is a widespread zoonotic disease caused by pathogenic Leptospira and is responsible for significant economic porcine livestock losses. Knowledge of Leptospira serogroups and their distributions is important for evaluation of the relevance of leptospirosis management measures, including use of the prophylactic vaccine that was recently made available in France. A retrospective study was conducted to determine the relationships between different circulating Leptospira serogroups. Pigs from across France presenting clinical signs suggestive of leptospirosis were tested with the microagglutination test (MAT) between 2011 and 2017. We used weighted averages to determine serogroup distributions according to MAT results and considering cross-reactions.

Results

A total of 19,395 pig sera, mostly from Brittany, were tested, and 22.7% were found to be positive for at least one Leptospira serogroup. Analysis of the 4,346 seropositive results for which the putative infective serogroup could be defined, revealed that two out of ten serogroups were much more frequent than the others: Australis (48.5%) and Icterohaemorrhagiae (38.2%). Other serogroups, including Autumnalis, Panama, Ballum, Tarassovi, Sejroe, Grippotyphosa, Bataviae, and Pomona, were less common.

Conclusions

Although diagnostic laboratory data cannot be extrapolated to infer the distribution of Leptospira serogroups at the nationwide scale in France, the analysis of such data can provide an overview of the relationship between circulating Leptospira serogroups in space and time. During the last decade, protection against the serogroups Australis and Icterohaemorrhagiae would have prevented most of the clinical porcine leptospirosis cases in the large number of farms that we studied. In the future, epidemiological information related to circulating Leptospira serogroups should be extracted from data with a standardized approach for use in nationwide or international surveillance and prophylactic strategy support.

Outbreak of Leptospira borgpetersenii Serogroup Sejroe Infection in Kennel: The Role of Dogs as Sentinel in Specific Environments

Kennels may represent high-risk environments for the diffusion of Leptospira infection in dogs and consequently a threat to public health. This study describes an outbreak of Leptospira infection in a kennel in Italy in 2020, both with clinically ill and asymptomatic dogs. Fifty-nine dogs, including three ill dogs, were tested for Leptospira spp. infection by the microscopic agglutination test (MAT) and real-time qPCR. Multi-locus sequence typing (MLST) analysis was used to genotype the identified leptospires. Thirty of the fifty-nine (50.9%) dogs had MAT titer and/or molecular positivity indicative of Leptospira infection. Twenty-two of the fifty-nine (37.3%) dogs exhibited seropositivity against at least one serovar belonging to the Sejroe serogroup, and MLST analysis identified L. borgpetersenii serogroup Sejroe (Leptospira ST155) as responsible for the outbreak. Up to now, Sejroe serogroup infection was sporadically reported in dogs. The extension of the MAT antigen panel to several serovars belonging to the serogroup Sejroe could be useful in the diagnosis of canine leptospirosis. Dogs may serve as sentinel of leptospires in specific environments, and surveillance of Leptospira infection in kennels is strongly recommended even when the correct vaccine prophylaxis is administered, because the vaccines currently available are not able to protect from all of the serogroups.

Leptospira in Slaughtered Fattening Pigs in Southern Italy: Serological Survey and Molecular Typing

Simple Summary

In this study, serological and molecular assays in 55 pigs in Sicily were conducted in order to investigate Leptospira spp. prevalence and to carry out strain characterization. A seropositivity rate of 16.4% was determined; 3.64% of kidney samples tested positive for pathogenic Leptospiral DNA. Obtained data showed that Leptospira infection is common among pigs in southern Italy, confirming the importance of Leptospiral infection in pigs and reaffirming the potential role of these animals as a source of infection for humans (occupational risk) and other animals. Our study delivers a comprehensive overview based on up-to-date data to deepen the knowledge of swine leptospiral infections, characterize new potential emerging strains, and reinforce control measures able to reduce the infection risk in swine herds.

Abstract

Leptospirosis is a re-emerging zoonosis of worldwide significance; a wide spectrum of wild and domestic animal species act as natural or accidental hosts. Swine can act as maintenance or accidental hosts of pathogenic Leptospira spp. This study aimed at investigation of Leptospira spp. prevalence and diversity in slaughtered pigs in southern Italy (Sicily). In total, 55 samples of kidneys and blood were collected. Microscopic agglutination test and real-time PCR were performed to detect pathogenic and intermediately pathogenic Leptospira. Partial rpoB gene sequencing and multi-locus sequence typing (MLST) were performed to characterize Leptospira species. The analysis showed a seropositivity rate of 16.4%, with Australis representing the most frequently identified serogroup (63.64%); Pomona and Sejroe were detected with a prevalence of 27.27% and 9.09%, respectively. Pathogenic Leptospiral DNA was detected in 2 kidney samples (3.64%). Leptospira were identified through MLST as L. borgpetersenii serovar Tarassovi (serogroup Tarassovi). Obtained data confirmed the presence of Leptospira infection among pigs in southern Italy, suggesting that management of these animals may be considered an occupational risk for humans.

Leptospira interrogans Serogroup Pomona in a Dairy Cattle Farm in a Multi-Host Zootechnical System

Bovine leptospirosis is an infectious zoonotic disease causing reproductive problems and economic losses in livestock. This work reports, for the first time in Sicily (South Italy), an outbreak of Leptospira interrogans serogroup Pomona that occurred in cattle farms within the Nebrodi Park and was mainly characterized by full-term abortion. Blood and urine samples were collected at different time points from animals of six different farms (Farms A–F) sharing the same grazing area. Research of antibodies against pathogenic Leptospira species in serum samples was carried out via Micro Agglutination Test (MAT). Urine samples were subjected to pathogen isolation and molecular analyses via TaqMan Real Time-PCR. Genotyping of Leptospira species was obtained by Multi-locus sequence typing. MAT detected antibodies against Leptospira interrogans serogroup Pomona in serum samples of all the farms. Pathogenic Leptospira spp. DNA and culture isolation was obtained from urine samples. Genotyping confirmed the excretion of L. interrogans serogroup Pomona. This study describes clinical manifestations, diagnostic implications and epidemiological characteristics of an outbreak in cattle due to L. interrogans Pomona in a protected multi-host area, where domestic and wild animals share the same habitat, suggesting a role of wild species in transmission and persistence of Pomona serogroup among cattle.

Pica (Allotriophagy): An Underestimated Risk Factor for Severe Leptospirosis (Weil's Diseases)? Report of a Leptospira Septic Shock Successfully Managed with ECMO

Leptospirosis is a zoonosis caused by infection with pathogenic strains of the bacterium Leptospira. The disease can be complicated by pulmonary hemorrhages and acute respiratory distress syndrome, with the mortality rate increasing to 51–100%. We report the case of a 37-year-old man who was admitted to the emergency department with a 6-day history of fever, weakness, vomiting and diarrhea, followed by jaundice. On admission, he presented leukocytosis, thrombocytopenia and acute liver and kidney injuries. His clinical course was critical, as it was immediately complicated by sepsis and severe respiratory failure, requiring haemodialysis, mechanical ventilation and broad-spectrum antibiotic therapy. In the following days, a veno-venous extracorporeal membrane oxygenation (VV-ECMO) was started due to a dramatic deterioration in respiratory function; 20 h later, it was switched to veno-arterial ECMO because of refractory cardiogenic shock. Hantavirus or Leptospira infection etiology was suspected, so penicillin G and methylprednisolone were initiated as an empirical therapy and subsequently confirmed after a laboratory diagnosis of leptospirosis. Although the clinical course was further complicated by hemorrhagic pneumonia, a gradual, full recovery occurred, and the patient was discharged from the hospital. After excluding other sources of contact with Leptospira-infected material, an unsuspected abnormal eating behavior was identified as the most probable cause of the patient’s Leptospira infection.

Influence of Selective Agents (EMJH-STAFF), Sample Filtration and pH on Leptospira interrogans Serovar Icterohaemorrhagiae Cultivation and Isolation from Swine Urine

Leptospira spp. cause the zoonotic disease leptospirosis, which occurs in numerous mammalians worldwide. Isolation is still important for serotyping and genotyping of Leptospira, which in turn is essential for epidemiological surveillance of leptospirosis and the development of diagnostic tests and vaccines. However, isolation of Leptospira from clinical specimens is inherently insensitive. This study was conducted to examine the influence of selective agents, sample filtration, sample pH and the use of phosphate buffered saline (PBS) buffer for sample storage to improve the success of cultivation and isolation of Leptospira interrogans serovar Icterohaemorrhagiae from swine urine. EMJH (Ellinghausen McCullough, Johnson and Harris) medium including the selective agents sulfamethoxazole, trimethoprim, amphotericin, fosfomycin and 5-fluorouracil (STAFF) increased the success of Leptospira isolation from spiked swine urine samples. Sample filtration yielded only negative results. Isolation in EMJH-STAFF was successful from swine urine with a density as low as 10⁴ Leptospira/mL, and urine with pH ≤ 7 impaired the cultivation rate. Cultivation and isolation were not improved by the addition of PBS to spiked urine samples prior to storage for 24 h at 4 °C. The results of the study demonstrate that cultivation and isolation of leptospires from swine urine can be improved by enhanced methods.

Presence and Characterization of Zoonotic Bacterial Pathogens in Wild Boar Hunting Dogs (Canis lupus familiaris) in Tuscany (Italy)

Domestic dogs (Canis lupus familiaris) used for wild boar (Sus scrofa) hunting may represent incidental hosts for several zoonotic pathogens. This investigation aimed to evaluate the presence of anti-Leptospira antibodies and the occurrence, antimicrobial resistance, and virulence of Salmonella spp., Yersinia enterocolitica, and Listeria monocytogenes in sera and rectal swabs collected from 42 domestic hunting dogs in the Tuscany region (Italy). Regarding Leptospira, 31 out of 42 serum samples (73.8%) were positive and serogroup Pomona was the most detected (71.4%) at titers between 1:100 and 1:400. Four Salmonella isolates (9.52%) were obtained, all belonging to serotype Infantis; two of them showed antimicrobial resistance to streptomycin, while pipB and sopE presence was assessed in all but one isolate. Concerning Yersinia enterocolitica, seven isolates (16.7%) were obtained, six belonging to biotype 1 and one to biotype 4. Resistance to amoxicillin-clavulanic acid, cephalothin, and ampicillin was detected. Biotype 4 presented three of the virulence genes searched (ystA, ystB, inv), while isolates of biotype 1 showed only one gene. No Listeria monocytogenes was isolated from dog rectal swabs. The results suggest that hunting dogs are exposed to different bacterial zoonotic agents, potentially linked to their work activity, and highlight the possible health risks for humans.

Genital Brucella suis Biovar 2 Infection of Wild Boar (Sus scrofa) Hunted in Tuscany (Italy)

Brucellosis is a zoonosis caused by different Brucella species. Wild boar (Sus scrofa) could be infected by some species and represents an important reservoir, especially for B. suis biovar 2. This study aimed to investigate the prevalence of Brucella spp. by serological and molecular assays in wild boar hunted in Tuscany (Italy) during two hunting seasons. From 287 animals, sera, lymph nodes, livers, spleens, and reproductive system organs were collected. Within sera, 16 (5.74%) were positive to both rose bengal test (RBT) and complement fixation test (CFT), with titres ranging from 1:4 to 1:16 (corresponding to 20 and 80 ICFTU/mL, respectively). Brucella spp. DNA was detected in four lymph nodes (1.40%), five epididymides (1.74%), and one fetus pool (2.22%). All positive PCR samples belonged to Brucella suis biovar 2. The results of this investigation confirmed that wild boar represents a host for B.suis biovar. 2 and plays an important role in the epidemiology of brucellosis in central Italy. Additionally, epididymis localization confirms the possible venereal transmission.

Leptospira fainei Detected in Testicles and Epididymis of Wild Boar (Sus scrofa)

Leptospirosis is a re-emerging and worldwide diffused zoonosis. Recently, the high importance of their epidemiology was explained by the intermediate Leptospira strains. Among these strains, Leptospira fainei was the first intermediate strain detected in domestic and wild swine. Wild boars (Sus scrofa) are well known as a reservoir, as well as all swine, for pathogenic Leptospira, but very little information is available concerning intermediate Leptospira infection. The investigation aim was to evaluate if intermediate Leptospira can infect the reproductive systems of wild boars hunted in the Tuscany region (Italy), as previously demonstrated for pathogenic ones. The reproductive system tissue (testicles, epididymides, uteri), and placentas and fetuses, were collected from 200 regularly hunted animals. Bacteriological examination and real-time PCR were performed to detect intermediate Leptospira DNA. Unfortunately, no isolates were obtained. Using real-time PCR, in six (3%) male organs (both testicles and epididymis), intermediate Leptospira DNA was found. The amplification of the 16S rRNA gene identified that all DNA obtained belong to Leptospira fainei. The results of this investigation highlighted for the first time the localization of Leptospira fainei in the male wild boar reproductive system, opening up a new avenue to further investigate.

Environmental Exposure of Wild Carnivores to Zoonotic Pathogens: Leptospira Infection in the First Free Living Wolf (Canis lupus Linnaeus, 1758) Found Dead in the Friuli Venezia Giulia Region

Leptospirosis is a worldwide-spread zoonosis causing disease and death in dogs and in humans. A Leptospiral infection has been recorded in several wild carnivore species in Europe, but tissue pathological changes were not commonly described. The Grey wolf (Canis lupus) has been expanding its distribution range in north-eastern Italy during the last decade. A young wolf, representing the first individual handled in the region, was found road-killed and then submitted to necropsy. Pathological changes included erosive lesions of gingival mucosa, mild liver enlargement, and multifocal degenerative-necrotic areas along with hyperemic reactive lesions; multifocal interstitial nephritis and multifocal lung hemorrhages were observed. A Polymerase Chain Reaction (PCR) able to detect pathogenic species of Leptospira performed on a kidney sample was positive. Serological reactions for serogroup Gryppotyphosa (1:6400), Pomona (1:800), and Icterohaemorrhagiae (1:200) were evidenced by MAT. Genotyping by Multilocus Sequence Typing (MLST) performed on detected Leptospira characterized it as belonging to Sequence Type (ST) 117, which refers to L. kirschneri, serogroup Pomona, serovar Mozdok. Regardless of the role of Leptospira infection as an eventual predisposing factor to the road killing of this wolf, to the best of the authors’ knowledge, this is the first report of Leptospira-induced pathology in a wolf in Europe. Surveys on Leptospira infection in free-ranging wildlife species should be pursued in order to achieve further epidemiological knowledge on the circulation of the Leptospira strain.

Serological Survey on the Occurrence of Anti-Leptospira spp. Antibodies in Red-Eared Terrapins (Trachemys scripta elegans) Living in a Natural Park of Northern Italy

Simple Summary

Although it has been supposed that reptiles, including chelonians, are involved in the epidemiology of Leptospira, data about leptospirosis in turtles are very scant. In the present survey, Trachemys scripta elegans terrapins living in a natural park were tested to verify the presence of antibodies against Leptospira spp., with 6% being positive. Infected turtles could be a source of infection for other animals and humans, shedding leptospirae into the environment. However, further studies are necessary to verify if Leptospira may cause disease in turtles or if these animals may serve as reservoirs.

Abstract

Turtles are suspected to be involved in the epidemiology of Leptospira; however, data about the dissemination of this zoonotic pathogen among chelonians are scant. In the present study, the serum samples collected from 49 Trachemys scripta elegans living in a natural park of northern Italy were tested by a microagglutination test to measure detectable antibodies against different Leptospira serovars. Three (6.12%) turtles had agglutinins to the serovar Tarassovi, suggesting that they were exposed to the spirochaetes. Currently, it is not clear if Leptospira can cause disease in chelonians or if these animals can serve as reservoirs of leptospirae. Considering that chelonians often share the same environment with other animals and humans, and considering the One Health perspective, investigations to better understand the role of chelonians as a source of Leptospira infection are necessary.

Human leptospirosis in the Marche region: Over 10 years of surveillance

We conducted a 10 years' retrospective study in 347 symptomatic individuals to assess the regional distribution of leptospirosis. A total of 173 individuals were diagnosed positive (49.8%): 11.5% were found positive to Leptospira by microscopic agglutination test positive, whereas 38.3% were found positive by microscopy analysis. The maximum peak of leptospirosis was reached in 2017 (n = 32). The most common serovars were Icterohaemorrhagiae and Poi.

Insight into the Epidemiology of Leptospirosis: A Review of Leptospira Isolations from "Unconventional" Hosts

Leptospirosis is a re-emerging worldwide zoonotic disease. Even though the primary serological test for diagnosis and surveying is the microscopic agglutination test (MAT), isolation remains the gold-standard test to detect Leptospira infections. The leptospirosis transmission is linked to maintenance and accidental hosts. In the epidemiology of Leptospira some serovar are strictly related to specific maintenance hosts; however, in recent years, the bacterium was isolated from an even wider spectrum of species. The aim of this review is to report the isolation of Leptospira strains in animals which could be recognized as "unconventional" hosts, analyzing studies from 1960 to 2020 that highlighted the Leptospira isolation. This scientific literature aimed to provide evidence of infection in several animal species including of the Carnivora, Didelphimorphia, Rodentia, Cetacea, Cingulata, Afrosoricida, Chiroptera and Primate orders, as well as in Reptilia and Amphibia classes. In conclusion, the spreading of Leptospira is attention-worthy because the infection could occur in all the animal species ranging in a specific area. Further screening and isolations are needed to collect all necessary data to gain a complete understanding of leptospirosis epidemiology and its modifications.

Presence of pathogenic Leptospira spp. in the reproductive system and fetuses of wild boars (Sus scrofa) in Italy

Leptospirosis is a re-emerging and globally spread zoonosis caused by pathogenic genomospecies of Leptospira. Wild boar (Sus scrofa) are an important Leptospira host and are increasing in population all over Europe. The aim of this investigation was to evaluate Leptospira spp. infection in the reproductive systems of wild boar hunted in two Italian regions: Tuscany and Sardinia. From 231 animals, reproductive system tissue samples (testicles, epididymides, uteri) as well as placentas and fetuses were collected. Bacteriological examination and Real-Time PCR were performed to detect pathogenic Leptospira (lipL32 gene). Leptospires were isolated from the testicles and epididymides of one adult and two subadult wild boar. Four isolates from the two subadult males were identified as Leptospira interrogans serogroup Australis by MLST, whereas Leptospira kirschneri serogroup Grippotyphosa was identified from the adult testicles and epididymis. Using Real-Time PCR, 70 samples were positive: 22 testicles (23.16%) and 22 epididymides (23.16%), 10 uteri (7.35%), 3 placentas (6.66%), and 13 fetuses (28.88%). Amplification of the rrs2 gene identified L. interrogans and L. kirschneri species. The results from this investigation confirmed that wild boar represent a potential source of pathogenic Leptospira spp. Isolation of Leptospira serogroups Australis and Grippotyphosa from the male reproductive system and the positive Real-Time PCR results from both male and female samples could suggest venereal transmission, as already demonstrated in pigs. Furthermore, placentas and fetuses were positive for the lipL32 target, and this finding may be related to a possible vertical transmission of pathogenic Leptospira.

Leptospirosis is an infectious zoonotic disease present worldwide and is caused by bacteria belonging to genus Leptospira. Several domestic and wild animals could serve as reservoir hosts of these bacteria and could transmit them to humans, directly or indirectly. Generally, in asymptomatic carriers the infection involves the urinary system, the kidneys in particular, and leptospires are eliminated via urine. In some animals, Leptospira could also colonize the reproductive system as consequence of a systemic infection or venereal transmission. In this work, the Authors describe, for the first time, the detection of Leptospira from male and female reproductive organs of hunted wild boar via culture-dependent and -independent methods. These findings could suggest a possible vertical transmission in wild boar, but also a possible venereal transmission cycle among wild swine, which could accidentally involve domestic pigs too. Manipulation of these organs by hunters during slaughtering could also expose them to Leptospira infection. Obtained data add information on Leptospira epidemiology and highlight the importance of wildlife monitoring programs.

Cross-sectional study of Leptospira spp. in commercial pig farms in the state of Goiás, Brazil

Leptospirosis is an infectious, contagious disease highly important to the world pig industry, which causes reproductive loss in breeding herds. Endemic infections in a herd may produce little evidence of clinical disease despite resulting in economic losses. However, some epidemiological features of leptospirosis in midwestern Brazil, such as risk factors and prevalence of the disease, remain unclear. Therefore, this study focused on assessing the prevalence of the Leptospira spp. in intensive pig herds and associating its risk factors. A set of 900 blood samples, equally distributed between nursery, growing, and finishing pigs of 30 intensive farrow-to-finish farms, were analyzed using the microagglutination test (MAT), in order to detect anti-Leptospira spp. antibodies for 24 different Leptospira spp. serovars. An occurrence of 4.67% (55/342) seropositive samples were detected in fattening pigs. The variables associated with the disease occurrence were animals per square meter at fattening (OR 0.006, CI 95% 0.004-0.42, p = 0.0105) and pen division between growing and fattening pigs (OR 3.56, CI 95% 0.563-22.541, p = 0.185). Thus, the variables semi-hollow floor in the maternity (OR 16.66; CI 95%: 2.17-128.2 and p = 0.006) and animals per trough at fattening (OR: 0.08, CI 95% 0.009-0.87 and p = 0.025), observed in this study, highlight the importance of the fattening phase in the epidemiology of the disease, bringing information on risk factors involved in the occurrence and dissemination of leptospirosis in intensive pig herds.

Isolation of Leptospira serovar Pomona from a crested porcupine (Hystrix cristata, L., 1758)

Pathogenic Leptospira is widespread in rodents, the most studied reservoir and the main hosts involved in its transmission. In Italy, among rodents, Hystrix cristata (crested porcupine) is the largest species and it is distributed all over the country. In this paper, the isolation and characterization of pathogenic Leptospira spp. from the kidney of H. cristata is reported for the first time. During Autumn 2018, Leptospira detection by real-time PCR and isolation were performed from kidneys of two died female porcupines (an adult and a porcupette). Only for porcupette kidney sample, real-time PCR for pathogenic Leptospira tested positive. The isolated strain was identified as Leptospira interrogans serogroup Pomona serovar Pomona, using the three schemes of multilocus sequence typing. The results show that H. cristata could be a Leptospira host. The infection of serovars Pomona could be related to the habitat shared with wild boar, a typical reservoir host for this serovar.

Preliminary Evaluation of In Vitro Bacteriostatic and Bactericidal Effect of Salt on Leptospira spp

Environmental resistance is an important factor for understanding the epidemiology of leptospirosis. Recently, new Leptospira hosts were identified, including also marine mammals. Moreover, halotolerant Leptospira strain, isolated from the environment and animals, highlighted the capability of this microorganism to persist in the seawater. The aim of this research was to investigate the bacteriostatic and bactericidal effect of salt on Leptospira strains belonging to 16 different serovars. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were verified through the microdilutions method starting from a 20% sodium chloride concentration. MIC values obtained were between 0.3125% and 10% of salt, while MBC values between 0.625% and >20%. Icterohaemorrhagiae (MIC: 0.3125%; MBC: 0.625%) resulted the most inhibited serovar, while the most resistant was Tarassovi (MIC: 10%; MBC: >20%). Interestingly, trends were reported for Pomona (MIC: 1.25%; MBC: >20%) and Bratislava (MIC: 0.625%; MBC: 20%), highlighting low MIC values but high MBC values. This is the first investigation aimed at the in vitro effect of salt on the growth of Leptospira spp. reference strains.

Bacteriostatic and Bactericidal Effect of Tigecycline on Leptospira spp

Tigecycline is a relatively new antimicrobial, belonging to glycylcyclines with antimicrobial activity against a large spectrum of bacteria. Very few data are available on its effect on Leptospira spp., which consist in a bacteriostatic mechanism. The aim of this investigation was to evaluate the bacteriostatic and bactericidal effect of tigecycline on reference Leptospira strains belonging to 16 serovars. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined through the microdilutions method, and tetracycline was used as the control. Results showed that tigecycline had higher MIC and MBC values than tetracycline. Obtained MIC values were between 4 and 32 µg/mL, while MBC values between 16 and >128 µg/mL. Patoc (MIC: 4 µg/mL; MBC: 16 µg/mL) resulted in the most susceptible serovar, while the most resistant were Bataviae (MIC: 32 µg/mL; MBC: 64 µg/mL), Bratislava (MIC: 8 µg/mL; MBC 128 µg/mL), and Tarassovi (MIC: 8 µg/mL; MBC: >128 µg/mL). This is the first investigation focused on the effect of tigecycline against Leptospira spp. reference strains. Since tigecycline is used as a treatment for bacteremia and urinary tract disease, and these symptoms could be linked to Leptospira infection, the possibility of using this antibiotic as a treatment for leptospirosis should be evaluated. Further studies are needed to explore the possibility to use tigecycline for in vivo application against Leptospira.

Leptospira Infections in Domestic and Wild Animals

Leptospirosis is a worldwide-distributed, re-emerging zoonosis due to the large variety of wild and domestic animal species that can play the role of natural or accidental host. Currently, specific animal species play an important role as the reservoir for particular Leptospira serovars, although recent investigations have highlighted new host–pathogen interactions involved in Leptospira epidemiology. Furthermore, the constant modification of ecosystems and wildlife habitats and the constantly increasing number of animal species moving towards urban or peri-urban areas are increasing the possibility of direct or indirect contacts between wildlife and domestic animals; furthermore, the constant modification of animal leptospirosis also causes problems for human health. The studies published in this Special Issue have evidenced and confirmed the hidden role of a large variety of animal species, domestic and wild, in the leptospirosis epidemiology. They highlighted the necessity for continuous monitoring and large-scale surveillance studies to better understand this neglected and re-emerging zoonosis.

Detection of New Leptospira Genotypes Infecting Symptomatic Dogs: Is a New Vaccine Formulation Needed?

Leptospirosis in dogs has been largely described worldwide, and epidemiological studies have been mainly based on serological data. This study aims to detect and genotype leptospires affecting symptomatic dogs in Northeast Italy between 2013 and 2019. Overall, 1631 dogs were tested using real-time PCR, and leptospires from 193 dogs were subjected to Multilocus Sequence Typing and a Multiple Loci Variable-number Tandem Repeat Analysis. Leptospires were successfully isolated from 15 symptomatic dogs. Six distinct Sequence Types (STs) were found for 135 leptospires, with 3 STs characterizing Leptospira interrogans (ST17, ST198 and ST24), 2 STs characterizing Leptospira kirschneri (ST117 and ST289) and 1 ST characterizing Leptospira borgpetersenii (ST155), revealing the circulation of the serogroups Icterohaemorrhagiae, Australis, Sejroe and Pomona. The Multiple Loci Variable-number Tandem Repeat Analysis of 17 samples did not result in any additional discrimination. Genotypes were compared with those of strains present in the historical internal database, and possible transmission chains were identified from rat, mouse, hedgehog and pig. This work highlights the importance of molecular methods in revealing and identifying circulating Leptospira strains, and it also encourages the evaluation of the ability of commercially available vaccines to reduce the disease burden among dogs.

Leptospira Survey in Wild Boar (Sus scrofa) Hunted in Tuscany, Central Italy

Leptospirosis is a re-emerging, worldwide zoonosis, and wild boar (Sus scrofa) are involved in its epidemiology as the reservoir. The aim of this study was to investigate the prevalence of Leptospira with serological, bacteriological, and molecular assays in wild boar hunted in Tuscany (Italy) during two hunting seasons. In total, 287 specimens of sera, kidneys, and liver were collected to perform microscopic agglutination tests (MATs), isolation, and RealTime PCR to detect pathogenic (lipL32 gene), intermediate (16S rRNA gene), and saprophytic (23S rRNA gene) Leptospira. Within sera, 39 (13.59%) were positive to the MAT, and Australis was the most represented serogroup (4.88%), followed by Pomona (4.18%), and Tarassovi (3.14%). Moreover, four Leptospira cultures were positive, and once isolates were identified, one was identified as L. borgpetersenii serovar Tarassovi, and three as L. interrogans serovar Bratislava. Pathogenic Leptospira DNA were detected in 32 wild boar kidneys (11.15%). The characterization through the amplification of the rrs2 gene highlighted their belonging to L. interrogans (23 kidneys), L. borgpetersenii (four), and L. kirschneri (one), while nine kidneys (3.14%) were positive for intermediate Leptospira, all belonging to L. fainei. The results of this study confirmed the importance of wild boar in the epidemiology of leptospirosis among wildlife in Central Italy.

Identification of Serogroups Australis and Icterohaemorrhagiae in Two Dogs with a Severe Form of Acute Leptospirosis in Italy

Leptospirosis is an infectious disease that causes serious illness in dogs. For this reason, epidemiological and clinical studies focusing on disease characterization are widely advocated. The aim of this study was to characterize the leptospires identified in dogs with confirmed symptomatic acute leptospirosis. Leptospira spp. DNA detected in urine, blood, or both samples from nine infected dogs was analyzed using the multi-locus sequence typing (MLST) technique. Leptospires from two dogs were successfully typed: one was identified as belonging to Sequence Type (ST) 17 and one to ST198, both within the L. interrogans species, serogroups Icterohaemorrhagiae and Australis, respectively. Based on the results of routine serologic tests, antibodies reactive toward these serogroups are commonly revealed in dogs in Italy. This study provides the first molecular analysis that identifies infecting Leptospira directly on DNA from biological samples of dogs, showing that serogroup Australis can lead to a severe clinical presentation of leptospirosis in infected dogs.

Serological evidence of Leptospira sp. in humans from Fernando de Noronha Island, Brazil

The prevalence of leptospirosis in humans is highly variable, being influenced by climatic factors, the presence of reservoirs, occupational exposure, recreational activity, and socioeconomic conditions. The objective of this study was to estimate the prevalence of Leptospira sp. and identify the predominant human serovars on the island of Fernando de Noronha, Brazil, based on a microscopic agglutination test. The prevalence of anti-Leptospira antibodies was 1.17% (4/341; I.C. 0.46%-2.98%), with the predominance of serovars Icterohaemorrhagiae, Javanica, Mini and Louisiana. This is the first study on the occurrence of antibodies against Leptospira sp. in humans in Fernando de Noronha and highlights the need to implement control and prevention strategies in this island environment.

Crested Porcupine (Hystrix cristata L.): A New Potential Host for Pathogenic Leptospira Among Semi-Fossorial Mammals

Wildlife plays a pivot role in the epidemiology of leptospirosis and rodents have a reservoir function for several Leptospira serogroups. The crested porcupine is the largest rodent of the Italian fauna and shares the same environment with red foxes, badgers, coypus and wild boars that are known to be infected by Leptospira. Between 2018 and 2019 the seroprevalence of Leptospira in crested porcupine was investigated for the first time. Overall 7 out of 14 sera (50 %) were found positive to Leptospira. Icterohaemorrhagiae resulted as the most detected serogroup (57 %) followed by Pomona, Australis and Sejroe. The highest titer (1:1600) was detected for the serogroup Australis. These results indicate that porcupines could be infected by several serogroup of Leptospira and the role of reservoir or accidental host need to be addressed. Further investigations are necessary in order to clarify the leptospirosis - epidemiology - wildlife framework in light of its potential zoonotic source.

Leptospira Seroprevalence in Bardigiano Horses in Northern Italy

A cross-sectional study was carried out in Bardigiano horses in the Province of Parma, Northern Italy, to assess the seroprevalence of Leptospira spp. and to investigate risk factors associated with the infection. A representative sample of 134 horses from 43 farms was selected by stratified systematic randomization. Blood sera were examined by MAT for the presence of antibodies against seven Leptospira serovars. Ninety animals (67.2%; 95% Confidence Interval 63.2-71.1) and 41 farms (95.3%; 95% CI 92.2-98.5%) were found positive to at least one of the serovars. The most frequently detected reactions were against serovar Bratislava (41.8%), followed by Canicola (36.6%), Tarassovi (28.4%), Copenhageni (17.9%), Pomona (10.4%) and Hardjo (2.2%). None of the sera reacted against serovar Grippothyphosa. Forty-eight horses (53.3% of the seropositives) were positive for more than one serovar and 21 (15.7% of the seropositives) had serum titres ≥ 1000. Bratislava was the serovar providing the highest antibody titres. Prevalence was significantly higher between adult horses and in farms lacking rodent control (p = 0.006 and p = 0.025, respectively). No significant gender or housing-related difference in seroprevalence was found. The anamnestic data suggest that the infection in Bardigiano horses is subclinical in most of the cases. The high seroprevalence indicates that Bardigiano horses living in the investigated area are at high risk of exposure and infection by Leptospira spp.

Molecular detection of Leptospira spp. in wild boar (Sus scrofa) hunted in Liguria region (Italy)

Leptospirosis is a re-emerging and widespread zoonosis, worldwide distributed, due to a wide variety of wild and domestic animal species able to act as natural or accidental hosts. During last years, in Europe, as in Italy, wild boar (Sus scrofa) population is increased. This animal represents a reservoir for different etiological agents, such as Leptospira. The aim of this investigation was to evaluate the prevalence of Leptospira spp. in wild boar hunted in Liguria region (Italy) during two-year hunting seasons. From 611 hunted wild boar, kidneys were collected. DNA was extracted from each organ and different targets were used to detect pathogenic (lipL32 gene), intermediate (16S rRNA gene) and saprophytic (23S rRNA gene) Leptospira by Taqman-based RealTime-PCR assays. Overall, kidneys were sampled from 282 adults, 155 sub-adults and 174 young wild boar (in total 314 males and 298 females). By RealTime PCR 77 kidneys were positive and, among these, 74 resulted positive for pathogenic (96.10%) and 3 (3.90%) for intermediate Leptospira. No significant differences in pathogenic Leptospira infection ratio were detected between male (11.50%) and female (12.75%). Only 13 sub-adult animals (8.39%) resulted infected by pathogenic Leptospira; 23 young animals (13.22%) and 38 adult animals (13.47%) were positive. The results of this study confirmed the importance of wild boar in the epidemiology of leptospirosis, which is able to infect other animal species (domestic and wild) including humans. Rarely, intermediate Leptospira could be able to infect wild boar with a renal localization that can contribute to their shedding and circulation.

Seroprevalence and associated risk factors of leptospirosis in slaughter pigs; a neglected public health risk, western Kenya

BACKGROUND

Leptospirosis is a neglected zoonosis of public health importance transmitted through contact with contaminated soil, water or urine of infected animals. In pigs the disease is characterized by abortion, still births and weak piglets. A cross-sectional study was conducted in May to July 2018 to estimate the sero-prevalence of leptospirosis and factors associated with seropositivity in slaughter pigs. A questionnaire was used to collect information on animal demographics. Serum was tested for anti-leptospiral antibodies using microscopic agglutination test (MAT) with a panel of 8 serovars. Sera were considered positive for sero-reactivity at a MAT titre ≥1:40 against at least one serovar. Chi-square tests were used to measure the strength of association between the MAT test result and exploratory variables.

RESULTS

A total of 252 pig serum samples from seven slaughterhouses were tested for Leptospira antibodies by MAT. Of the 252 pigs sampled, 88.8% (244/252) were indigenous breeds; 55.6% (140/252) were female and 88.7% (220/252) were reared in extensive production systems. Eighty-three (32.9%; 83/252) sera samples tested positive on MAT against at least one serovar. Of the 8 serovars, the highest prevalence was recorded for serovar Lora 21.4% followed by Kenya 5.2%, Sokoine 3.6% and Grippotyphosa at 3.2%. Risk factors for leptospirosis seropositivity in pigs were: originating from farms with other types of livestock (OR 2.3; 95% CI 1.0-4.5) and mature pigs (OR 1.9; 95% CI 1.1-3.3).

CONCLUSION

This study demonstrates that there is a high prevalence of leptospirosis positive pigs at slaughter in a small-holder livestock keeping region of the Lake Victoria basin. The potential for cross species transmission of pathogenic serovars is highlighted as well as the potential for occupational exposure to slaughterhouse personnel. Improvements in husbandry practices (confinement and rodent control) and public health education among slaughterhouse workers and other high-risk groups is recommended.