Cross-species surveillance of Leptospira in domestic and peri-domestic animals in Mahalla City, Gharbeya Governorate, Egypt

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.

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.

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.

Molecular and Serological Identification of Pathogenic Leptospira in Local and Imported Cattle from Lebanon

Leptospirosis is a worldwide bacterial zoonosis for which the risk increases in warm and wet climates. Despite the suitability of the local climate for the bacteria's persistence, Lebanon lacks a formal system of prophylaxis for the prevention of Leptospira infection in both humans and animals, and the disease's epidemiology is unknown so far. As a preliminary step, we focused on Leptospira infection in cattle, which is of public health and economic concern. We conducted a descriptive study in cattle from the governorate of Mount Lebanon (ML) and in imported cattle. A total of 187 blood and 135 serum samples were provided. Among the 187 blood samples, 135 were from randomly selected animals from 14 herds, while the remaining 52 were from imported livestock. Serum specimens (n = 135) were obtained exclusively from cattle in the ML governorate. DNA was extracted from all blood samples and subjected to real-time PCR targeting 16S rRNA. All Leptospira-positive DNA samples were then amplified using conventional PCR (cPCR), and Leptospira species were identified via Sanger sequencing. A microscopic agglutination test (MAT) was performed on the 135 serum samples from local cattle. The real-time PCR revealed Leptospira infection in 7 of 135 local animals and 1 of 52 imported animals. DNA from six of the seven local animals and the one imported animal were amplified by cPCR and successfully sequenced, identifying the pathogen as the species L. kirschneri. Seven animals located in five out of the 14 tested herds had MAT titers ≥1 : 100. Serogroup Grippotyphosa was predominant. This is the first study to provide epidemiological data on bovine Leptospira infection in Lebanon. Pathogenic Leptospira species and serogroups were identified in both local and imported cattle. These findings highlight the cattle associated risk of Leptospira infection in Lebanon, in the contexts of farming and trade. Summary. Leptospirosis is a severe zoonotic disease that can have critical consequences for people and animals. Within the country of Lebanon, this disease has been reported, but its epidemiology is unknown so far. The present study thus provides the first description of the existence of Leptospira in cattle in Lebanon (local and imported). It also highlights the existence of different pathogenic serogroups of Leptospira in local cattle. Our results should raise public health awareness of the threat posed by this underdiagnosed disease and serve as a starting point for control efforts in Lebanon.

First Molecular Detection of Pathogens Leptospira in Common Rodent Captured in North Algeria Urban Areas

Leptospirosis is an anthropozoonosis disease of worldwide distribution caused by mobile spirochetes of the genus Leptospira and rodents, mainly rats, are described as its primary reservoir. In Algeria, there is limited data about the prevalence of Leptospira spp. in humans and animals, as well as Leptospira carriage in wild rodents. The study aimed to highlight the importance of rodents as a reservoir of Leptospira bacterium in Blida city in Algeria by detecting and identifying circulating Leptospira species in the rodent population. A total of 101 rodents, 95 Rattus Norvegicus, 5 Rattus Rattus, and 1 Mus Musculus were captured and tested for pathogenic Leptospira spp. byreal-time PCR targeting the Leptospira 16S rRNA (rrs) gene, revealing a total prevalence of 40.6%, 95% IC [30.9-50.8%]. Positive samples were subjected to species-specific real-time PCR assays targeting L. interrogans, L. noguchii, L. borgpetersenii, and L. kirschneri for species identification. However, positive samples for which Leptospira-species could not be determined were subjected to conventional PCR targeting the partial 16S rRNA (rrs) gene, and amplified DNA was subjected to sequencing. Leptospira spp. was detected in 36 kidney, 16 urine, and three lung specimens. L. interrogans was identified in 39 rodents and L. borpetersenii in one rodent; however, one rodent with renal carriage could not be typed due to poor DNA quality. This study provides the first description of pathogenic Leptospira spp. in wild rodents in Algeria. These findings suggest a high potential risk of leptospirosis transmission from rodents to humans and animals in Algeria and therefore imply the adoption of prophylactic measures. In addition, further studies, including different animals and rodent species, should be conducted to clarify the epidemiology of this disease in Algeria.

Epidemiology of Leptospirosis: The First Literature Review of the Neglected Disease in the Middle East

Leptospirosis is a major zoonotic disease that has emerged worldwide, and numerous studies performed in affected countries have provided epidemiological knowledge of the disease. However, currently, there is inadequate knowledge of leptospirosis in the Middle East. Therefore, we grouped publications from various Middle Eastern countries to acquire a general knowledge of the epidemiological situation of leptospirosis and provide an initial description of the leptospiral relative risk and circulating serogroups. We conducted a detailed literature search of existing studies describing Leptospira prevalence and seroprevalence in Middle Eastern countries. The search was performed using online PubMed and ScienceDirect databases. One hundred and one articles were included in this review. Some countries, including Iran, Turkey, and Egypt, reported more publications compared to others, such as Lebanon, Kuwait, and Saudi Arabia. Frequently, the seroprevalence of leptospirosis varied considerably between and within countries. The prevalence of leptospirosis was comparable in most Middle Eastern countries; however, it varied between some countries. The methods of detection also varied among studies, with the microscopic agglutination test used most commonly. Some hosts were more recurrent compared with others. This review summarizes the epidemiological situation of Leptospira infection in the Middle East, reporting predominant serogroups-Sejroe, Grippotyphosa, Icterohaemorrhagiae, Autumnalis, and Pomona-that were identified in the most commonly tested hosts. Our findings emphasize the need to develop a deeper understanding of the epidemiology of Leptospira spp. and prioritize the disease as a public health problem in this region. To achieve this goal, increased awareness is critical, and more publications related to the topic and following a standardized approach are needed.

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.

Sero-prevalence of anti-Leptospira antibodies and associated risk factors in rural Rwanda: A cross-sectional study

Background

Leptospirosis is a zoonotic disease transmitted through the urine of wild and domestic animals, and is responsible for over 50,000 deaths each year. In East Africa, prevalence varies greatly, from as low as 7% in Kenya to 37% in Somalia. Transmission epidemiology also varies around the world, with research in Nicaragua showing that rodents are the most clinically important, while studies in Egypt and Chile suggest that dogs may play a more important role. There are no published studies of leptospirosis in Rwanda.

Methods & findings

We performed a cross-sectional survey of asymptomatic adults recruited from five occupational categories. Serum samples were tested using ELISA and Microscopic Agglutination Test (MAT). We found that 40.1% (151/377) of asymptomatic adults had been exposed to Leptospira spp. Almost 36.3% of positive subjects reported contact with rats (137/377) which represent 90.7% among positive leptospira serology compared with 48.2% of negative subjects (182/377) which represent 80.5% among negative leptospira serology (OR 2.37, CI 1.25–4.49) and 1.7 fold on prevalence ratio and 2.37 of odd ratio. Furthermore, being a crop farmer was significantly associated with leptospirosis (OR 2.06, CI 1.29–3.28). We identified 6 asymptomatic subjects (1.6%) who met criteria for acute infection.

Conclusions

This study demonstrates a high prevalence of leptospiral antibodies infection among asymptomatic adults in rural Rwanda, particularly relative to neighboring countries. Although positive subjects were more likely to report rat contact, we found no independent association between rats and leptospirosis infection. Nonetheless, exposure was high among crop farmers, which is supportive of the hypothesis that rats together with domestic livestock might contribute to the transmission.

Further studies are needed to understand infecting Leptospira servers and elucidate the transmission epidemiology in Rwanda and identify means of host transmitters.

Leptospirosis is the most widespread zoonosis in the world, and infections are underappreciated in regions of the world where it may be mistaken for malaria and other tropical illnesses. We performed a seroprevalence study of leptospirosis in healthy asymptomatic adults in Rwanda. Among 377 subjects, we found evidence of infection in 40.1% (151 / 377), which is higher than in neighboring countries such as Kenya (7 to 16%), Tanzania (10 to 15.8%) and Uganda (15%). Our data suggest that leptospirosis may be a common cause of febrile illness in Rwanda, but further studies are needed to differentiate active from asymptomatic.

Seroprevalence and risk factors of Leptospira sp. among different groups in the Jordanian population: first study

BACKGROUND

Leptospirosis is re-emerging as a major public health problem worldwide. However, there are limited data on the disease from the Middle East, including from Jordan, despite recent outbreaks occurring in Jordan's neighbouring countries.

METHODS

Sera samples from 809 participants in 11 governorates were tested for Leptospira sp. seropositivity to determine the seroprevalence and risk factors of Leptospira sp. in Jordan.

RESULTS

Overall, 3.3% (95% confidence interval [CI] 2.2 to 4.8) of individuals tested were seropositive for Leptospira antibodies. Individuals who drink surface water (spring or rain water) had 5.69 (95% CI 2.57 to 12.60) higher odds of seropositivity compared with individuals who used municipal or filtered water, after controlling for age and practicing horticulture.

CONCLUSIONS

This is the first seroprevalence study of Leptospira sp. in Jordan and included important data on environmental and animal exposures.

Leptospira infection among human-close-contact animals in different geographical areas in Vietnam

Leptospirosis is a neglected disease in Vietnam. Only a few studies have evaluated the status of Leptospira infection in both humans and animals. To our knowledge, this is the first serological survey of Leptospira in both domestic and wild animals, which may act as reservoirs of this agent. This study aimed to evaluate the seroprevalence of Leptospira in animals that are in close contact with humans in different geographical areas in Vietnam. Sera were collected from 1205 individual animals of six species, including buffaloes, cattle, cats, dogs, swine, and rats. The microscopic agglutination test (MAT) against 25 serovars of Leptospira spp. has been employed to detect serovars of Leptospira among the studied population. Overall, 44.2% of buffaloes, 24.9% of cattle, 10.2% of swine, 32.9% of dogs, 12.2% of cats, and 16% of rats were seropositive. A total of 17 different serovars were detected, of which serovars Hebdomadis and Canicola circulated in all the studied animal species. Variability of the predominant serovars circulating in animal species and in different geographical areas of Vietnam has been noted. We conclude that this study showed a high prevalence of Leptospira circulating in animals that are in close contact with humans, raising an alert of the important sources of pathogenic leptospires transmission to humans in Vietnam. These findings prove an imperative need for effective measures for disease prevention.

Feline-Human Zoonosis Transmission in North Africa: A Systematic Review

Throughout human history, domestic animal species have represented a unique zoonotic disease risk for the transmission of pathogens ranging from viral, bacterial, parasitic, and fungal. In North Africa, cats have a particularly long record and occupy a specialized niche within many communities. This systematic review was conducted to analyze the current and historical literature documenting the breadth and variety of zoonoses in North Africa, specifically relating to the domesticated feline. Multiple electronic databases were searched on January 16, 2019, for published reports on feline zoonoses in North Africa. A total of 76 studies met the inclusion criteria for a full assessment. Articles selected for the review ranged in publication dates from 1939 to 2019 and included a case study, cross-sectional surveys, genomic analyses, and a book chapter. The most commonly studied pathogen was Toxoplasma gondii (n = 17) followed by a variety of helminths (n = 10). Of the countries in the target region, most publications were of studies conducted in Egypt (n = 53) followed by Tunisia (n = 12), Algeria (n = 11), Morocco (n = 5), and Libya (n = 3). The results of this review identify a variety of viral, bacterial, fungal, and parasitic zoonotic diseases associated with cats in North Africa, ranging from historically endemic diseases in both human and animal populations in the region, to emerging infections with recent confirmatory diagnoses. This review describes reported feline zoonoses in North Africa and provides recommendations for their prevention and control. In addition to vaccination campaigns for domesticated felines and postexposure prophylaxis for humans, prompt veterinary and medical care of exposure risks and subsequent infections are essential in limiting the zoonotic disease burden in North African communities of humans and cats.

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.

Prevalence of Leptospira serogroups in buffaloes from the Brazilian Amazon

Although Brazil has one of the largest buffalo populations in the Americas, buffalo leptospirosis is still poorly explored when compared to that in bovines; thus, the aim of this research was to carry out a large serological study for leptospirosis in this species in the Brazilian Amazon. For this, we collected 1,405 serum samples from buffaloes raised in the Amazon delta region, which is considered a major area of buffalo production in Brazil. The test used was a microscopic agglutination test (MAT) adopting 34 Leptospira antigens, some of which have never been tested for buffaloes in Brazil, including autochthonous strains; in total, 20 serogroups were evaluated. From the total of 1,405 serum samples, 894 (63.6%) reacted in the MAT to at least one of the 20 serogroups, and 511 (36.4%) did not react. The serogroups Sejroe, Autumnalis and Pomona were the most prevalent, with titres ranging from 100 to 12,800, and the autochthonous strains used were not significant in relation to the reference serovars. Leptospirosis in buffaloes seems to have a serological profile similar to leptospirosis in cattle, mainly due to the prevalence of the Sejroe serogroup; however, the results of this study suggested that in the Brazilian Amazon, Leptospira strains that are serologically distinct from the autochthonous strains isolated in the southeastern region of Brazil may be circulating in these animals. Other serovars could also be inserted into the panel of antigens used in MAT for serological studies on buffaloes.

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.

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.

Prevalence and renal pathology of pathogenic Leptospira spp. in wildlife in Abeokuta, Ogun State, Nigeria

There is paucity of information on the prevalence of leptospirosis in wildlife in Nigeria. This study investigated the prevalence and renal pathology of leptospirosis in wild animals in Southwest Nigeria. One hundred and five kidney samples were examined from 10 different wildlife species (antelope) greater cane rat (GCR), hare, African giant rat (AGR), tree hyrax, civet cat, monitor lizard, python, bushbuck and partridge) using a combination of Ellinghausen McCullough Johnson Harris (EMJH) medium, microscopic agglutination test (MAT), Warthin- Starry silver stain (WSss) and immunohistochemistry. Chi-square test was used with confidence level set at 0.05 to ascertain associations between positive cases and sex and species. Eightytwo (78.1%) samples were culturally positive, while 67.7% (63/93), 57.0% (16/28) and 66.7% (8/12) were WSss, MAT and immunohistochemically positive, respectively. Interstitial nephritis (41.0%) and tubular nephrosis (81.0%) were the most prominent histopathological changes. Pathogenic Leptospira organisms were highest in GCR (32.1%) and antelope (14.3%). Serovars hardjo (11.54%), bratislava (3.9%), canicola (3.9%), icterohaemorrhagiae (15.4%), pomona (7.14%) gripptotyphosa (19.2%) and undetermined isolates were also detected in other animals. The result showed high prevalence of Leptospira infection in the wild and the possibility of domestic animals and humans contracting the disease. This study is the first documentation of evidence of pathogenic Leptospira species in wildlife in Nigeria.

Identification of cattle, buffaloes and rodents as reservoir animals of Leptospira in the District of Gampaha, Sri Lanka

Background

Leptospirosis is an important emerging infectious disease in Sri Lanka. Rats are the most important reservoir of Leptospira but domestic and wild mammals may also act as important maintenance or accidental hosts. In Sri Lanka, knowledge of reservoir animals of leptospires is poor. The objective of this study was to identify potential reservoir animals of Leptospira in the District of Gampaha, Sri Lanka.

Findings

Blood and kidney samples were collected from 38 rodents and mid-stream urine samples were randomly collected from 45 cattle and five buffaloes in the District of Gampaha. Kidney and urine samples were tested by real-time polymerase chain reaction (PCR) and serum samples were tested by the microscopic agglutination test (MAT). Of the 38 rodent kidney samples, 11% (4/38) were positive by real-time PCR. The prevalence of leptospiral carriage was 11% (3/26) and 8% (1/12) in female and male rodents, respectively. Three rodent serum samples were positive by MAT. Of the 50 cattle/buffalo urine samples tested, 10% (5/50) were positive by real-time PCR. The prevalence of leptospiral carriage was 9% (4/45) and 20% (1/5) in cattle and buffaloes, respectively.

Conclusion

Results of PCR and MAT showed that Leptospira were present in a significant proportion of the rodents and farm animals tested in this study and suggest that these (semi-) domestic animals form an infection reservoir for Leptospira. Therefore, there is a potential zoonotic risk to public health, most notably to farmers in this area.

High frequency of seropositivity of Leptospira in cattle in North Tunisia

The authors report a survey carried out in a cattle farm between January and April 2009 in Mateur region (Northern Tunisia). Seroprevalence by Microscopic Agglutination Test (MAT) was estimated to 81.4 ± 6% and 35 ± 2% in cows and calves, respectively. Seropositivity to more than one serovar was noticed in 91% (81/89) of infected animals. The examination of the distribution pattern of Leptospira serovars involved in this outbreak indicates that serovar Pomona was the predominant one (75.3%), followed by Autumnalis (59.5%), Bim (58.4%) and Munchen (55%). High titres (between 400 and 6400) were found in 68.7% of the tested animals and were correlated with clinical onset of leptospirosis. Leptospirosis is an underestimated pathogen in Tunisia; further investigations are needed to study the epidemiology both in man and animals and to implement effective control measures.

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.

Leptospirosis in animals and human contacts in Egypt: broad range surveillance

INTRODUCTION

Leptospirosis is a re-emerging zoonotic disease of humans and animals worldwide. The disease is caused by pathogenic species of the genus Leptospira. These organisms are maintained in nature via chronic renal infection of carrier animals, which excrete the organisms in their urine. Humans become infected through direct or indirect exposure to infected animals and their urine or through contact with contaminated water and soil. This study was conducted to investigate Leptospira infections as a re-emerging zoonosis that has been neglected in Egypt.

METHODS

Samples from 1,250 animals (270 rats, 168 dogs, 625 cows, 26 buffaloes, 99 sheep, 14 horses, 26 donkeys and 22 camels), 175 human contacts and 45 water sources were collected from different governorates in Egypt. The samples were collected from different body sites and prepared for culture, PCR and the microscopic agglutination test (MAT).

RESULTS

The isolation rates of Leptospira serovars were 6.9%, 11.3% and 1.1% for rats, dogs and cows, respectively, whereas the PCR results revealed respective detection rates of 24%, 11.3% and 1.1% for rats, dogs and cows. Neither the other examined animal species nor humans yielded positive results via these two techniques. Only six Leptospira serovars (Icterohaemorrhagiae, Pomona, Canicola, Grippotyphosa, Celledoni and Pyrogenes) could be isolated from rats, dogs and cows. Moreover, the seroprevalence of leptospiral antibodies among the examined humans determined using MAT was 49.7%.

CONCLUSIONS

The obtained results revealed that rats, dogs and cows were the most important animal reservoirs for leptospirosis in Egypt, and the high seroprevalence among human contacts highlights the public health implications of this neglected zoonosis.

Leptospira Serovars for Diagnosis of Leptospirosis in Humans and Animals in Africa: Common Leptospira Isolates and Reservoir Hosts

The burden of leptospirosis in humans and animals in Africa is higher than that reported from other parts of the world. However, the disease is not routinely diagnosed in the continent. One of major factors limiting diagnosis is the poor availability of live isolates of locally circulating Leptospira serovars for inclusion in the antigen panel of the gold standard microscopic agglutination test (MAT) for detecting antibodies against leptospirosis. To gain insight in Leptospira serovars and their natural hosts occurring in Tanzania, concomitantly enabling the improvement of the MAT by inclusion of fresh local isolates, a total of 52 Leptospira isolates were obtained from fresh urine and kidney homogenates, collected between 1996 and 2006 from small mammals, cattle and pigs. Isolates were identified by serogrouping, cross agglutination absorption test (CAAT), and molecular typing. Common Leptospira serovars with their respective animal hosts were: Sokoine (cattle and rodents); Kenya (rodents and shrews); Mwogolo (rodents); Lora (rodents); Qunjian (rodent); serogroup Grippotyphosa (cattle); and an unknown serogroup from pigs. Inclusion of local serovars particularly serovar Sokoine in MAT revealed a 10-fold increase in leptospirosis prevalence in Tanzania from 1.9% to 16.9% in rodents and 0.26% to 10.75% in humans. This indicates that local serovars are useful for diagnosis of human and animal leptospirosis in Tanzania and other African countries.

Epidemiology of Leptospirosis in Africa: A Systematic Review of a Neglected Zoonosis and a Paradigm for 'One Health' in Africa

BACKGROUND

Leptospirosis is an important but neglected bacterial zoonosis that has been largely overlooked in Africa. In this systematic review, we aimed to summarise and compare current knowledge of: (1) the geographic distribution, prevalence, incidence and diversity of acute human leptospirosis in Africa; and (2) the geographic distribution, host range, prevalence and diversity of Leptospira spp. infection in animal hosts in Africa.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, we searched for studies that described (1) acute human leptospirosis and (2) pathogenic Leptospira spp. infection in animals. We performed a literature search using eight international and regional databases for English and non-English articles published between January 1930 to October 2014 that met out pre-defined inclusion criteria and strict case definitions.

RESULTS AND DISCUSSION

We identified 97 studies that described acute human leptospirosis (n = 46) or animal Leptospira infection (n = 51) in 26 African countries. The prevalence of acute human leptospirosis ranged from 2 3% to 19 8% (n = 11) in hospital patients with febrile illness. Incidence estimates were largely restricted to the Indian Ocean islands (3 to 101 cases per 100,000 per year (n = 6)). Data from Tanzania indicate that human disease incidence is also high in mainland Africa (75 to 102 cases per 100,000 per year). Three major species (Leptospira borgpetersenii, L. interrogans and L. kirschneri) are predominant in reports from Africa and isolates from a diverse range of serogroups have been reported in human and animal infections. Cattle appear to be important hosts of a large number of Leptospira serogroups in Africa, but few data are available to allow comparison of Leptospira infection in linked human and animal populations. We advocate a 'One Health' approach to promote multidisciplinary research efforts to improve understanding of the animal to human transmission of leptospirosis on the African continent.

Predominant leptospiral serogroups circulating among humans, livestock and wildlife in Katavi-Rukwa ecosystem, Tanzania

Background

Leptospirosis is a worldwide zoonotic disease and a serious, under-reported public health problem, particularly in rural areas of Tanzania. In the Katavi-Rukwa ecosystem, humans, livestock and wildlife live in close proximity, which exposes them to the risk of a number of zoonotic infectious diseases, including leptospirosis.

Methodology/Principal Findings

A cross-sectional epidemiological study was carried out in the Katavi region, South-west Tanzania, to determine the seroprevalence of Leptospira spp in humans, domestic ruminants and wildlife. Blood samples were collected from humans (n = 267), cattle (n = 1,103), goats (n = 248), buffaloes (n = 38), zebra (n = 2), lions (n = 2), rodents (n = 207) and shrews (n = 11). Decanted sera were tested using the Microscopic Agglutination Test (MAT) for antibodies against six live serogroups belonging to the Leptospira spp, with a cutoff point of ≥ 1:160. The prevalence of leptospiral antibodies was 29.96% in humans, 30.37% in cattle, 8.47% in goats, 28.95% in buffaloes, 20.29% in rodents and 9.09% in shrews. Additionally, one of the two samples in lions was seropositive. A significant difference in the prevalence P<0.05 was observed between cattle and goats. No significant difference in prevalence was observed with respect to age and sex in humans or any of the sampled animal species. The most prevalent serogroups with antibodies of Leptospira spp were Sejroe, Hebdomadis, Grippotyphosa, Icterohaemorrhagie and Australis, which were detected in humans, cattle, goats and buffaloes; Sejroe and Grippotyphosa, which were detected in a lion; Australis, Icterohaemorrhagie and Grippotyphosa, which were detected in rodents; and Australis, which was detected in shrews. Antibodies to serogroup Ballum were detected only in humans.

Conclusions

The results of this study demonstrate that leptospiral antibodies are widely prevalent in humans, livestock and wildlife from the Katavi-Rukwa ecosystem. The disease poses a serious economic and public health threat in the study area. This epidemiological study provides information on circulating serogroups, which will be essential in designing intervention measures to reduce the risk of disease transmission.

Leptospirosis is a disease of worldwide significance, and it is also an important zoonotic disease, particularly in developing countries. Subclinically infected rodents maintain leptospires in nature, and some that recover from the primary leptospiral infection may release the bacterium in their urine for the rest of their lives. These rodents serve as a potential source of leptospiral infection to animals and humans. Non-rodent mammals can also be reservoirs of leptospiral infection to animals and humans. Globally, animal and human leptospirosis has been attributed to rodents. There is limited knowledge on the occurrence of the disease in domestic animals, humans, wildlife and rodents in many parts of Tanzania, including the Katavi-Rukwa ecosystem. Serological examination of cattle, goats, humans, buffaloes, zebra, lions, rodents and shrews in the ecosystem revealed the presence of antibodies to serogroups Sejroe, Hebdomadis, Grippotyphosa, Icterohaemorrhagie, Australis and Ballum. These serogroups infect not only their usual hosts but also other animal species, which can in turn act as reservoirs of these serogroups to other animals and humans. This study demonstrates the distribution of leptospiral serogroups in domestic animals, humans, wildlife, rodents and shrews in the Katavi-Rukwa ecosystem. The results of the current study will help in developing appropriate interventions for preventing or mitigating the impacts of infections in domestic animals, humans, wildlife, rodents and shrews. Our results also suggest that human and animal populations are at risk of contracting the infection.

Serosurvey for zoonotic viral and bacterial pathogens among slaughtered livestock in Egypt

INTRODUCTION

Zoonotic diseases are an important cause of human morbidity and mortality. Animal populations at locations with high risk of transmission of zoonotic pathogens offer an opportunity to study viral and bacterial pathogens of veterinary and public health concern.

METHODS

Blood samples were collected from domestic and imported livestock slaughtered at the Muneeb abattoir in central Egypt in 2009. Samples were collected from cattle (n=161), buffalo (n=153), sheep (n=174), and camels (n=10). Samples were tested for antibodies against Leptospira spp. by a microscopy agglutination test, Coxiella burnetii by enzyme immunoassay, Brucella spp. by standard tube agglutination, and Rift Valley Fever virus (RVFV), Crimean-Congo hemorrhagic fever virus (CCHFV), sandfly fever Sicilian virus (SFSV), and sandfly fever Naples virus (SFNV) by enzyme-linked immunosorbent assay.

RESULTS

Antibodies against Leptospira spp. were identified in 64 (40%) cattle, 45 (29%) buffalo, 71 (41%) sheep, and five (50%) camels; antibodies against C. burnetii in six (4%) buffalo, 14 (8%) sheep, and seven (70%) camels; and antibodies against Brucella spp. in 12 (8%) cattle, one (1%) buffalo, seven (4%) sheep, and one (10%) camel. Antibodies against RVFV were detected in two (1%) cattle and five (3%) buffalo, and antibodies against CCHFV in one (1%) cow. No antibodies against SFSV or SFNV were detected in any species.

DISCUSSION

RESULTS indicate that livestock have been exposed to a number of pathogens, although care must be taken with interpretation. It is not possible to determine whether antibodies against Leptospira spp. and RVFV in cattle and buffalo are due to prior vaccination or natural exposure. Similarly, antibodies identified in animals less than 6 months of age may be maternal antibodies transferred through colostrum rather than evidence of prior exposure. RESULTS provide baseline evidence to indicate that surveillance within animal populations may be a useful tool to monitor the circulation of pathogens of veterinary and public health concern in Egypt.

Health impact evaluation of alternative management systems in vicuña (Vicugna vicugna mensalis) populations in Peru

To determine the impact of farming over vicuña population in Peru, serum samples were collected from 207 vicuñas (126 captive vicuñas and 81 free-ranging vicuñas) and 614 domestic South American camelids (571 alpacas and 43 llamas), in ten Andean communities at the Salinas y Aguada Blanca reserve, province of Arequipa, southern Peru. Samples were tested for the presence of leptospirosis, foot and mouth disease (FMD), bovine viral diarrhea (BVD), bovine herpesvirus type 1 (BHV-1), brucellosis, bluetongue disease (BT), paratuberculosis, and neosporosis. Serological results showed that 1.9% (4/207) of vicuñas, 18.6% (106/571) of alpacas, and 23.3% (10/43) of llamas were positive to one or more Leptospira serovars. One percent of vicuñas (2/207) and 2.4% of domestic camelids (15/614) had Neospora caninum antibodies tested by ELISA, but only two vicuñas and two alpacas were confirmed by Western blot. Epidemiological evaluation found an association of leptospirosis to sex and age (p < 0.001), with female subjects older than 2.5 years at higher risk of infection. Interestingly, antibodies against Leptospira serovars were only found in captive vicuñas. This is the first study where health status of free-ranging and captive vicuñas has been compared. Results indicate minimal to nil presence of FMD, BVD, BHV-1, brucellosis, BT, paratuberculosis, and neosporosis allied to health disorders in our sample. The detection of seropositive animals against Leptospira, however, unveils the likely significance of leptospirosis in wild and domestic South American camelids, the impact of mixed husbandry over vicuña population and the risk to human health.

Serological and PCR detection of feline leptospira in southern Taiwan

Taiwan is in the subtropical zone and has typhoons every year. Leptospirosis is an endemic disease in Taiwan, and feline leptospirosis in Taiwan remains unknown so far. From January, 2010, to September, 2011, 233 cats in south Taiwan (159 stray cats and 74 household cats) were sampled in this research. Leptospira antibody titer was detected by the serology gold standard, the microscopic agglutination test (MAT). Both serum and urine were examined for Leptospira DNA by polymerase chain reaction (PCR) with two sets of primers. In this study, the serological survey showed 21 (9.3%) examined sera contained antibodies specific for pathogenic Leptospira serogroups. The results of PCR revealed that 25 (19.1%) serum and 80 (67.8%) urine samples were found positive for leptospiral DNA sequences. All products amplified from PCR reactions were sequenced by an automated method for further confirmation. This is the first study concerning the epidemiology of pathogenic Leptospira in stray and household cats' urine, and the results demonstrate that some of the cats are susceptible to pathogenic Leptospira and have the potential to shed pathogenic Leptospira into the environment. This could be an issue of public health.

Endemicity of leptospirosis in domestic and wild animal species from Reunion Island (Indian Ocean)

Leptospirosis is the major infectious disease on Reunion Island but little is known about the animal reservoir. We conducted a wide-ranging survey that included samples from 574 animals belonging to 12 species. The seroprevalence and prevalence of renal carriage varied greatly depending on the species, with the highest seroprevalence (79·5%) found in Norway rats, and the lowest (13·2%) in tenrecs. The renal carriage rate ranged from 84·6% in mice to 0% in tenrecs. Our results suggest that rodents are the most important reservoirs of leptospirosis on Reunion Island. The epidemiological role that animals play in human infection is discussed. For the first time, we quantified the renal concentration of leptospires in ten naturally infected mammals. The history of Reunion Island colonization probably explains why the circulating Leptospira serogroups were similar to those found in Europe. Our study provides evidence that will help implement preventive measures against this zoonosis.

Leptospira spp. Prevalence in Small Mammal Populations in Cotonou, Benin

The aim of this study was to assess the Leptospira prevalence in small animals in Cotonou, the capital of Benin. Rodents and shrews were captured in urban and periurban settings and determined as species of the genera Rattus, Mastomys, and Crocidura. Kidney specimens of 90 animals were examined using a real-time PCR assay specific for leptospires that belong to pathogenic species. Leptospiral DNA was amplified from kidney tissues ranging from 13.3% (8/60) in Rattus rattus to 100.0% (1/1) in Crocidura spp. with an average of 18.9% (17/90) of the animals caught at 15 locations. Clade-specific Taqman PCR on 10 samples placed six of these within clade 1 comprising the species L. kirschneri, L. interrogans, L. meyeri, and L. noguchii and four within clade 2 consisting of species L. weilii, L. alexanderi, L. borgpetersenii, and L. santarosai. Phylogenetic analysis of partial sequences of the amplicons of seven samples of these 10 samples revealed that four of the clade 1 samples could equally be assigned to L. interrogans and L. kirschneri and three samples from clade 2 belonged to L. borgpetersenii. Results presented in the paper indicate that small mammals present a major public health risk for acquiring leptospirosis in Cotonou, Benin and will contribute to a raised awareness amongst health care workers and decision makers and hence promote appropriate clinical management of cases.