Determination of Leptospira borgpetersenii serovar Javanica and Leptospira interrogans serovar Bataviae as the persistent Leptospira serovars circulating in the urban rat populations in Peninsular Malaysia

Seroprevalence of pathogenic Leptospira serogroups in asymptomatic domestic dogs and cats: systematic review and meta-analysis

Leptospirosis is a neglected zoonotic disease transmitted by contact with the urine of animals infected with pathogenic species of the bacteria Leptospira or by contact with environments contaminated with the bacteria. Domestic dogs and cats may act as reservoirs or as sentinels of environmental contamination with leptospires, posing a public health concern. There is a great diversity of leptospires, and one common way to classify them is into serogroups that provide some information on the host species they are associated with. The aims of this study were: (1) to quantitatively summarize the overall prevalence and serogroup-specific prevalence of antibodies against pathogenic leptospires in asymptomatic dogs and cats and (2) to identify environmental and host characteristics that may affect the prevalence. Three electronic databases and the reference lists of eligible articles were screened, for epidemiological studies conducted between the years 2012-2022. We estimated overall and serogroup-specific prevalence using three-level meta-analysis models and assessed potential sources of heterogeneity by moderator analysis and meta-regression. Eighty-four studies met the inclusion criteria (dog studies 66.7%, cat studies 26.2%, and both species 7.1%). There were significant differences between dogs and cats in the overall prevalence model (P < 0.001), but not in the serogroup-specific model (P>0.05). In dogs, the prevalence of Leptospira interrogans serogroup Canicola was significantly higher than the other pathogenic serogroups (P < 0.001), while in cats there were no significant differences among serogroups (P = 0.373). Moderator analysis showed that the prevalence of L. kirschneri serogroup Grippotyphosa was significantly higher in stray/sheltered dogs than in domiciled dogs (P = 0.028). These results suggest that pathogenic serogroups associated with small mammals are circulating among asymptomatic pets and should be taken into account in the transmission cycle of leptospires, as well as in the standard MAT panel for diagnosis in dogs and cats. It also highlights the importance of including both dogs and cats as potential reservoirs when conducting eco-epidemiological studies in different geographical and ecological areas.

Leptospira infection and carrier survey on rats from wet market areas in Kuala Lumpur, Malaysia

BACKGROUND OBJECTIVES

Leptospirosis is an important zoonotic infection that has caused significant mortality and morbidity worldwide. This disease is endemic in Malaysia and as a developing tropical country, leptospirosis is concerning as it threatens Malaysian public health and the country's economic sectors. However, there is limited information on leptospirosis in Malaysia, especially regarding leptospiral seroepidemiology among carriers in Malaysia. Therefore, more epidemiological information on the source of the disease and reservoir are needed for better disease control and source intervention. The objectives of this study are to gather information on Leptospira infection and the carrier status of rats captured from selected wet markets of Kuala Lumpur metropolitan city in Malaysia.

METHODS

Live rat trappings were performed in four major wet markets in Kuala Lumpur, namely, Pudu, Chow Kit, Datuk Keramat, and Petaling Street. Animal samplings were performed for 12 months in 2017, where blood and kidney samples were collected and tested for anti-leptospiral antibodies via Microscopic Agglutination Test (MAT) and pathogenic Leptospira screening via Polymerase Chain Reaction (PCR) amplification offlaB gene.

RESULTS

MAT showed that 34.7% (n = 50/144) of the captured rats were positive for anti-leptospiral antibody of which the most prominent serovar was Malaya followed by a local strain, IMR LEP 175. In parallel, 50 rats were also positive for pathogenic Leptospira DNA.

INTERPRETATION CONCLUSION

This study showed that there are persistent Leptospira infections among rats in Kuala Lumpur wet markets and these rats are important reservoir hosts for the bacteria.

Application of Multilocus Sequence Typing for the Characterization of Leptospira Strains in Malaysia

Leptospirosis is a common zoonotic disease in tropical and subtropical countries. It is considered an emerging disease in Malaysia and is a notifiable disease. This study was conducted to characterize Malaysian isolates from human, animal and environmental samples via MLST and rrs2 sequencing in an attempt to develop a Malaysian genotypic database. An existing polymerase chain reaction (PCR)-based MLST scheme was performed to facilitate subsequent sequencing. Out of 46 extracted DNA, 36 had complete MLST profiles whereby all six genes were amplified and sequenced. Most of the pathogenic Leptospira genotypes with full MLST profiles were L. interrogans serogroup Bataviae (n = 17), followed by L. borgpetersenii serogroup Javanica (n = 9), L. interrogans serogroup Sejroe (n = 2), L. interrogans serogroup Australis (n = 2), L. kirschneri (n = 2), L. interrogans serogroup Grippotyphosa (n = 1) and L. interrogans serogroup Pyrogenes (n = 3). Two samples (R3_SER/17 and R4_SER/17) were not closely related with any of the reference strains. For the samples with incomplete MLST profiles, leptospiral speciation was conducted through rrs2 analysis, in which four samples were identified as L. borgpetersenii, five samples were closely related to L. kmetyi and one sample was known as L. yasudae. This study shows that molecular approaches that combine both MLST and rrs2 sequencing have great potential in the comprehensive characterization of pathogenic Leptospira because they can be performed directly from cultured and clinical samples.

Leptospira Infection in Rural Areas of Urabá Region, Colombia: A Prospective Study

The objective of this study was to analyze the eco-epidemiological aspects of Leptospira seroprevalence and seroincidence and its associated factors in two municipalities of northwest Colombia. A prospective study was performed in rural areas of Urabá, Antioquia, Colombia. The study enrolled 597 people between November 2015 and January 2016, of which 274 were followed up 1 year later. Serologic testing was performed by a microscopic agglutination. The outcomes were seroprevalent and seroincident cases, and the primary exposure was an outdoor occupation. A binary and mixed-effect multinomial logistic regression model was used to estimate factors associated with seroprevalent or seroincident cases of Leptospira infection. The overall Leptospira seroprevalence was 27.81% (95% confidence interval: 23.62-32.49), and the overall cumulative seroincidence for Leptospira was 14.60% (95% confidence interval: 10.33-20.23). Multivariable analysis showed that factors associated with L. interrogans serogroups seropositivity were outdoor occupation, male gender, older age, the presence of dirt floor in the household, and the presence of piglets and opossums. It also showed that factors associated with other Leptospira species serogroups were the presence of pit latrines and of turkeys. In addition, the multivariable model of seroincident cases of L. interrogans serogroups evidenced outdoor occupations, the presence of rats, and corn cultivation as risk factors. Likewise, the multivariable model for seroincident cases of other Leptospira species showed that the presence of hunting canines and cassava cultivation were risk factors. We found specific factors associated with the transmission of Leptospira serogroups contribute to the understanding of the epidemiology of Leptospira infection in rural areas of Urabá, Colombia.

Fine-scale prevalence and genetic diversity of urban small mammal-borne pathogenic Leptospira in Africa: A spatiotemporal survey within Cotonou, Benin

Leptospirosis is a zoonotic disease that is caused by spirochete bacteria of the genus Leptospira. Around the world, one million people each year are infected, leading to 60,000 deaths. Infection occurs through contact with environmental pathogens excreted by mammals (notably rodents). Data on Leptospira and leptospirosis in Africa are rather scarce, especially in urban habitats though these appear to be favourable environments for the pathogen circulation and human contamination. Using qPCR, DNA sequencing as well as MST/VNTR approaches, we examined Leptospira occurrence and genetic diversity in 779 commensal small mammals that were sampled over 2 years in the city centre of Cotonou, Benin, from three neighbourhoods with contrasting socio-environmental conditions. Overall prevalence reached 9.1%. However, very marked variations in both space and time were observed, with local peaks of high prevalence but no clear seasonal pattern. In most sites that could be regularly sampled, Leptospira-positive rodents were found at least once, thus confirming the widespread circulation of the pathogen within small mammal communities of Cotonou. Interestingly, an unusual diversity of small mammal-borne Leptospira species and genotypes was retrieved, with up to four species and three different genovars within the same neighbourhood, and even instances of two species and two genovars identified simultaneously within the same household. To our knowledge, such a high genetic diversity has never been described at such a fine scale, a fortiori in Africa and, more generally, within an urban environment. Altogether, our results underline that much remains unknown about leptospirosis as well as the associated infectious risk in African cities where the disease may be massively over-looked.

Serological and molecular characteristics of pathogenic Leptospira in rodent populations in Fujian Province, China, 2018-2020

Background

Leptospirosis is a significant emerging infectious disease worldwide. Rodents are considered to be the most critical hosts of Leptospira spp. Fujian Province is a region highly endemic for leptospirosis in China. However, the genetic diversity of leptospires circulating among rodents in Fujian is limited.

Results

The carrier status of rodents for Leptospira spp. was investigated by culture and serological detection in Fujian during 2018–2020. A total of 710 rodents, including 11 species, were trapped, with Rattus losea being the dominant trapped species (50.56%). Fourteen pathogenic Leptospira strains were obtained. Seven L. borgpetersenii serogroup Javanica strains belonging to ST143, 4 L. interrogans serogroup Icterohaemorrhagiae strains belonging to ST1 and ST17, 2 L. interrogans serogroup Bataviae strains belonging to ST96 and ST333, and 1 L. interrogans serogroup Pyrogenes strains belonging to ST332 were identified using 16S rDNA gene sequencing, microscopic agglutination test (MAT) and Multilocus sequence typing (MLST). L. borgpetersenii serogroup Javanica belonging to ST143 was the dominant type (50.00%). A total of 387 rodent serum samples were tested by MAT. Serum were considered positive for seroreactivity at a titer ≥ 1:160 against at least one serovar. A total of 90 (23.26%) serum samples tested positive, and four serogroups were identified, with Javanica being the dominant serogroup (87.78%), which was similar to the dominant serogroup isolated from rodents. This study demonstrates a high prevalence of leptospirosis in rodents and public health education among high-risk workers is highly recommended.

Conclusions

R. losea was the dominant trapped rodent, and L. borgpetersenii serogroup Javanica ST143 was widely distributed among rodents in Fujian from 2018 to 2020. Despite the low number of isolates obtained from rodents, this study suggests that continuous epidemiological surveillance of the aetiological characteristics of pathogenic Leptospira in wild animal reservoirs may help reduce the possible risk of disease transmission.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-022-02566-2.

Risk and Predictive Factors of Leptospirosis in Dogs Diagnosed with Kidney and/or Liver Disease in Selangor, Malaysia

Simple Summary

Canine leptospirosis is commonly associated with kidney and/or liver disease. The current study identified the potential risk and predictive factors of dogs diagnosed with kidney and/or liver disease due to leptospirosis. A total of 124 client-owned dogs were recruited and the samples collected were directly tested using polymerase chain reaction (PCR) and subsequently inoculated for bacterial isolation. Statistical analyses were descriptively analyzed, and risk analyses were performed using Pearson chi-square tests and logistic regression. The different breeds of dog with history of exposure to rats and those managed outdoors had a greater risk of leptospirosis (p < 0.05). The significant predictors for the dogs’ positivity were presence of rats and acute clinical illness (p < 0.05). Administration of antibiotics and detection of clinical illness at an early stage of the disease improved the survivability of the dogs (p < 0.05).

Abstract

Canine leptospirosis is commonly associated with kidney and/or liver disease. It has been widely reported and causes public health concerns due to its zoonotic potential and its re-emergence, resulting from close contact between humans and dogs. The current study identified potential risk and predictive factors for dogs diagnosed with kidney and/or liver disease due to leptospirosis. A total of 124 client-owned dogs were recruited, and information such as signalment, medical history, management, and clinical findings were documented. Samples collected from the recruited dogs were directly tested using polymerase chain reaction (PCR) and subsequently inoculated for bacterial isolation. Statistical analyses were descriptively analyzed, and risk analyses were performed using Pearson chi-square tests and logistic regression. A total of 53 dogs (42.7%) were positive for leptospiral infection based on PCR, and 10 leptospiral isolates were successfully recovered from eight dogs. The mortality rate of infected dogs was 34.0% (18/53). Medium and large dog breeds, with a history of exposure to rats, and managed outdoors had a greater risk for leptospirosis (p < 0.05). The significant predictors for the dogs’ positivity were the presence of rats and acute clinical illness (p < 0.05). Administration of antibiotics and the detection of clinical illness at an early stage of the disease improved the survivability of the dogs (p < 0.05). Identifying the profile of dogs that are at risk to leptospirosis could be useful in the design of diagnostic and treatment strategies, as well as to increase awareness for prevention of the disease.

Prevalence of anti-Leptospira antibodies and associated risk factors in the Malaysian refugee communities

Background

Refugees in Malaysia, who are afflicted by poverty, conflict and poor health, are vulnerable to a range of zoonotic infections in the deprived environmental and social conditions under which they live. Exposure to infections such as leptospirosis, for which rodents are primary hosts, is of particular concern.

Methods

A wellness program was conducted to determine the presence of antibodies against Leptospira (seroprevalence) in 11 refugee community schools and centers in the Klang Valley, Malaysia. A total of 433 samples were assessed for IgG and IgM antibodies against Leptospira, using enzyme-linked immunosorbent assays (ELISA).

Results

Overall Leptospira seroprevalence was 24.7%, with 3.0% being seropositive for anti-Leptospira IgG and 21.7% for anti-Leptospira IgM. Factors significantly associated with overall Leptospira seroprevalence included: age, ethnicity, pet ownership, knowledge of disease and awareness of disease fatality. For IgM seroprevalence, significant risk factors included sex, ethnicity, eating habits with hands, pet ownership, the presence of rats, walking in bare feet and water recreation visits.

Conclusions

These findings highlight the need for improvements in health and well-being among the refugee community through disease awareness programs and provision of healthy behavior programs, particularly in hygiene and sanitation through community engagement activities.

FREQUENT LEPTOSPIRA SPP. DETECTION BUT ABSENCE OF TULA ORTHOHANTAVIRUS IN MICROTUS SPP. VOLES, NORTHWESTERN SPAIN

The common vole (Microtus arvalis) is a major agricultural pest in Europe and is a reservoir for several zoonotic agents, such as Leptospira spp. and Tula orthohantavirus (TULV). However, little is known about the occurrence of those pathogens in voles from Spain, where the species has largely expanded its distribution range in the past decades, causing agricultural pests and zoonotic diseases. For a molecular survey, 580 common voles and six Lusitanian pine voles (Microtus lusitanicus) were collected in 26 localities from four provinces of northwestern Spain. We assessed the presence of Leptospira spp. DNA in kidney tissue by PCR targeting the lipL32 gene, detecting a prevalence of 7.9% (95% confidence interval, 5.9-10.4) for common voles and of 33.3% (95% confidence interval, 4.3-77.7) for Lusitanian pine voles. We identified Leptospira kirschneri in 24 animals and Leptospira borgpetersenii in two animals, using secY gene-specific PCR. We analyzed environmental and demographic factors (such as age class, weight, and sex) and population dynamics data for their potential effect on the Leptospira spp. prevalence in those voles. The Leptospira spp. DNA detection rate in common voles increased significantly with maximum air temperature, vole weight, and amount of accumulated rainfall during the 90 d before capture and within the peak phase of the population cycle. We assessed the presence of TULV in lung tissue of 389 voles by reverse-transcription PCR, with no positive results. The absence of TULV might be explained by the evolutionary isolation of the common vole in Spain. The detection of two Leptospira genomospecies underlines the necessity for further typing efforts to understand the epidemiology of leptospiral infection in the common vole and the potential risk for human health in Spain.

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

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

Detection and characterization of Leptospira spp. in dogs diagnosed with kidney and/or liver disease in Selangor, Malaysia

Leptospirosis is a serious bacterial disease that affects both humans and animals. A wide range of symptoms have been described in humans; the disease in dogs is commonly associated with kidney and/or liver disease. In Malaysia, information about the common serovars infecting dogs is limited. Therefore, we investigated the occurrences of leptospirosis in 124 pet dogs diagnosed with kidney and/or liver disease. Blood, urine, abdominal effusion, and/or kidney and liver were collected from the dogs. Based on microscopic agglutination testing, 53 of 124 (42.7%) dogs were seropositive for leptospiral exposure. Sera were frequently positive to serovars Bataviae (n = 12), Javanica (n = 10), and Icterohaemorrhagiae (n = 10). Direct detection using PCR showed that 42 of 124 (33.9%) of the whole blood and 36 of 113 (31.9%) urine samples were positive for pathogenic Leptospira spp. By PCR, 2 of 23 (9.1%) kidney and 2 of 23 (9.1%) liver were positive for pathogenic Leptospira spp. Abdominal effusion from 4 dogs were PCR-positive for pathogenic Leptospira spp. The species detected were L. interrogans, L. borgpetersenii, L. kirschneri, and L. kmetyi by partial 16S rRNA sequencing. We further identified and characterized 11 Leptospira spp. isolates from 8 dogs as serovars Bataviae, Javanica, and Australis. The mortality rate of the Leptospira-infected dogs was high (18 of 53; 34%).

Development of a Multiplex PCR Assay for Detection and Discrimination of Pathogenic and Saprophytic Leptospira in Water

Leptospirosis is a zoonosis prevalent in tropical countries and affects animals and humans alike. Leptospira interrogans, the causative organism for this waterborne infection, spreads through the urine of infected animals. There is a direct link between contaminated water and Leptospira outbreaks. This study reports a rapid assay to detect and differentiate pathogenic Leptospira from non-pathogenic in environmental water using multiplex PCR. The assay uses primers targeting the Lipl32 and Lipl21 gene. The multiplex PCR has been standardized using 11 pathogenic and one saprophytic serovar of Leptospira. The analytical sensitivity of the developed method was evaluated with different concentrations of template DNA. This method was used to screen water samples collected from 20 different sources from Chengalpattu town in Kancheepuram District, Tamil Nadu, India. Of the 20 water samples screened, 13 samples tested positive for pathogenic Leptospira, and seven samples tested negative. Four water samples were found to carry both pathogenic and saprophytic species. The developed multiplex PCR assay is highly useful for detecting and distinguishing pathogenic and saprophytic leptospires in water.

Case Report: Fatal Human Leptospirosis Caused by Leptospira interrogans Genotype ST149

Leptospirosis is an important zoonotic disease with worldwide distribution and nonspecific clinical manifestation. We report a case of fatal leptospirosis in a previously healthy woman with a causative agent. A young adult Indian woman was brought in dead to the forensic department. Ten days before, she developed fever, dizziness with headache, myalgia, diarrhea, and vomiting. Routine inquest and autopsy were performed on the deceased, revealing hemorrhagic lungs with extensive intra-alveolar hemorrhages, pale liver with dissociation and separation of hepatocyte plates, and edematous brain with histiocyte and lymphocyte infiltration in the parenchyma and meninges. Heart tissue depicts myocarditis and pericarditis inflammatory changes. Cerebrospinal fluid (CSF) was turbid in appearance with mildly elevated leukocytes, predominantly lymphocytes. Real-time PCR targeting lipL32 gene of pathogenic Leptospira was detected in the blood, CSF, brain, kidney, heart, and liver. The genetic profile of the causative agent was ST149 (multi-locus sequence typing Scheme 3). This study illustrates the usefulness of Leptospira PCR assay in postmortem diagnosis and addresses the need for further surveillance to identify the epidemiological link of the disease.

The interrelationship between meteorological parameters and leptospirosis incidence in Hambantota district, Sri Lanka 2008-2017 and practical implications

Background

Leptospirosis is a bacterial zoonosis. Leptospirosis incidence (LI) in Sri Lanka is high. Infected animals pass leptospires to the environment with their urine. Leprospires' survival in the environment to infect a new host depends on meteorological factors. El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) modulate the weather in Sri Lanka.

Objectives

The determination of interrelationship between the LI in the Hambantota District, and local meteorological parameters, ENSO and IOD.

Methods

We acquired notified leptospirosis cases in the Hambantota District and population data. We calculated weekly leptospirosis incidences for 2008 to 2017.Weather data from two weather stations was obtained, averaged and converted into weekly data. We plotted time series graphs and observed the correlation between seven aggregated weather parameters and LI. We estimated cross-correlations between those weather parameters and LI. As our principal analysis we determined correlation between LI and seven local weather parameters, Nino 3.4, Nino4 and Dipole Mode Index (DMI) indices using wavelet analysis.

Results

Our wavelet analysis results showed troughs of minimum, maximum, mean temperatures, soil temperature, the evaporation rate, the duration of sunshine were followed by peaks in LI and peaks of rainfall followed by peaks of LI, all after lag periods. Our time series graphs and cross-correlation determination results are generally in agreement with these results. However there was no significant correlation between rainfall and LI in the cross-correlation analysis. There were peaks of LI following both peaks and troughs of DMI. There was no clear correlation between both Nino indices and LI.

Discussion

This may be the first long-term study demonstrating soil temperature, evaporation rate and IOD are correlating with LI. The correlation pattern of LI with temperature parameters differs from similar past studies and we explain the reasons. We propose ways to control high LI we observed after periods of weather favorable for transmission of leptospirosis.

Seroprevalence and Distribution of Leptospiral Serovars in Livestock (cattle, Goats, and Sheep) in Flood-prone Kelantan, Malaysia

Introduction

Leptospirosis is a bacterial disease that affects both humans and animals, the occurrence of which increases markedly during and after heavy rainfall and flooding. The aim of this study was to determine the serological prevalence of leptospiral infection in livestock after a voluminous flood in 10 districts of the Malaysian state of Kelantan.

Material and Methods

In December 2014, Kelantan was hit by an extensive flood. A total of 1,728 serum samples were collected from livestock from the state, comprised of 1,024 from cattle, 366 from goats and 338 from sheep, and they were tested using the microscopic agglutination test (MAT).

Results

Altogether, 203 (11.75%; 203/1728; 95% CI: 10.20%–13.30%) of the tested sera were found to be positive serologically. Cattle had the highest prevalence of 14.16% (145/1024), while goats and sheep had 11.20% (41/366) and 5.03% (17/338) respectively. The most frequent serovars detected were Hardjo-bovis (3.70%; 64/1728), Hebdomadis (2.08%; 36/1728) and Pomona (1.04%; 18/1728). There was a statistically significant association (P < 0.05) between livestock that were exposed to the flood and seropositivity.

Conclusion

This study showed that flood is a risk factor that can play a role in the epidemiology of leptospiral infection in livestock.

Multi-locus sequence analyses reveal a clonal L. borgpetersenii genotype in a heterogeneous invasive Rattus spp. community across the City of Johannesburg, South Africa

BACKGROUND

Rattus spp. are frequently implicated as key reservoir hosts for leptospirosis, one of the most common, but neglected, bacterial zoonoses in the world. Although leptospirosis is predicted to be a significant public health threat in Africa, studies from the continent are limited.

METHODS

Rattus spp. (n = 171) were sampled (January-May 2016) across the City of Johannesburg, South Africa's largest inland metropole. Rattus spp. genetic diversity was evaluated by full length (1140 bp) cyt b sequencing of 42 samples. For comparison, a further 12 Rattus norvegicus samples collected in Cape Town, South Africa's largest coastal metropole, were also genotyped. Leptospira infections were identified and genotyped using real-time PCR and multi-locus (lfb1, secY and lipL41) DNA sequencing.

RESULTS

Five R. norvegicus haplotypes were identified across Johannesburg, four of which have not previously been detected in South Africa, and one in Cape Town. Across Johannesburg we identified a Leptospira spp. infection prevalence of 44% (75/171) and noted significant differences in the prevalence between administrative regions within the metropole. Multi-locus sequence analyses identified a clonal genotype consistent with L. borgpetersenii serogroup Javanica (serovar Ceylonica).

DISCUSSION

The prevalence of infection identified in this study is amongst the highest detected in Rattus spp. in similar contexts across Africa. Despite the complex invasion history suggested by the heterogeneity in R. norvegicus haplotypes identified in Johannesburg, a single L. borgpetersenii genotype was identified in all infected rodents. The lack of L. interrogans in a rodent community dominated by R. norvegicus is notable, given the widely recognised host-pathogen association between these species and evidence for L. interrogans infection in R. norvegicus in Cape Town. It is likely that environmental conditions (cold, dry winters) in Johannesburg may limit the transmission of L. interrogans. Spatial heterogeneity in prevalence suggest that local factors, such as land use, influence disease risk in the metropole.

CONCLUSIONS

In South Africa, as in other African countries, leptospirosis is likely underdiagnosed. The high prevalence of infection in urban rodents in Johannesburg suggest that further work is urgently needed to understand the potential public health risk posed by this neglected zoonotic pathogen.

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

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

Epidemiology and genetic diversity of zoonotic pathogens in urban rats (Rattus spp.) from a subtropical city, Guangzhou, southern China

Commensal rats (Rattus spp.), which are globally distributed, harbour many pathogens responsible for significant human diseases. Despite this, we have a poor understanding of the epidemiology and genetic diversity of some recently neglected zoonotic pathogens, such as Leptospira spp., Bartonella spp. and hepatitis E virus (HEV), which constitute a major public health threat. Thus, we surveyed the occurrences, co-infection and genetic diversity of these pathogens in 129 urban rats from China. For Rattus tanezumi, the prevalences of Leptospira spp., Bartonella spp. and HEV infection were 6.67%, 0% and 46.67%, respectively. The prevalences of Leptospira spp., Bartonella spp. and HEV infection were 57.89%, 9.65% and 57.89% for Rattus norvegicus respectively. Leptospira spp. and HEV infections were more likely to occur in mature R. norvegicus. Phylogenetic analyses showed that pathogenic Leptospira interrogans and Leptospira borgpetersenii might exist. We also found that Bartonella spp. showed high similarity to Bartonella elizabethae, Bartonella rochalimae and Bartonella tribocorum, which are implicated in human disease. Dual and triple infections were both detected. Moreover, dual infections with Leptospira spp. and HEV represented the most frequent co-infection, and there was a significantly positive association between them. High genetic diversity was observed in genes segments from Leptospira, Bartonella and HEV. Our results first discover the occurrence of multiple co-infections and genetic diversity of Leptospira, Bartonella and HEV in commensal rats from China. Altogether, the present study provides an insight into evaluating the risk of rat-borne zoonoses in urban China.

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.

Detection of Leptospira interrogans in Hedgehogs from Central China

Background: Leptospira is the causative agent of leptospirosis, a zoonotic disease of global importance. To have a better understanding on the host species of Leptospira, we investigated the prevalence of Leptospira species in hedgehogs in Central China. Materials and Methods: Hedgehogs were captured in Hubei Province, China in May and October, 2018. Total DNA was extracted from the kidney tissues of hedgehogs for determining the Leptospira species by PCR amplification of the rrs2, secY, and flaB genes with genus-specific primers. Results: PCR amplification indicated that the positive rate of hedgehogs to the rrs2, secY, and flaB genes were 19.5% (8/41), 12.2% (5/41), and 9.8% (4/41), respectively. The homology of the partial sequence of rrs2, secY, and flaB genes were 99.0-100% among the Leptospira strains from hedgehogs. Phylogenetic analysis revealed that Leptospira species detected in this study clustered together with Leptospira interrogans. Conclusions: We detected L. interrogans from hedgehogs in Central China, suggesting hedgehogs are the hosts of L. interrogans.

Leptospira infection in rats: A literature review of global prevalence and distribution

Background

The role of rodents in Leptospira epidemiology and transmission is well known worldwide. Rats are known to carry different pathogenic serovars of Leptospira spp. capable of causing disease in humans and animals. Wild rats (Rattus spp.), especially the Norway/brown rat (Rattus norvegicus) and the black rat (R. rattus), are the most important sources of Leptospira infection, as they are abundant in urban and peridomestic environments. In this study, we compiled and summarized available data in the literature on global prevalence of Leptospira exposure and infection in rats, as well as compared the global distribution of Leptospira spp. in rats with respect to prevalence, geographic location, method of detection, diversity of serogroups/serovars, and species of rat.

Methods

We conducted a thorough literature search using PubMed without restrictions on publication date as well as Google Scholar to manually search for other relevant articles. Abstracts were included if they described data pertaining to Leptospira spp. in rats (Rattus spp.) from any geographic region around the world, including reviews. The data extracted from the articles selected included the author(s), year of publication, geographic location, method(s) of detection used, species of rat(s), sample size, prevalence of Leptospira spp. (overall and within each rat species), and information on species, serogroups, and/or serovars of Leptospira spp. detected.

Findings

A thorough search on PubMed retrieved 303 titles. After screening the articles for duplicates and inclusion/exclusion criteria, as well as manual inclusion of relevant articles, 145 articles were included in this review. Leptospira prevalence in rats varied considerably based on geographic location, with some reporting zero prevalence in countries such as Madagascar, Tanzania, and the Faroe Islands, and others reporting as high as >80% prevalence in studies done in Brazil, India, and the Philippines. The top five countries that were reported based on number of articles include India (n = 13), Malaysia (n = 9), Brazil (n = 8), Thailand (n = 7), and France (n = 6). Methods of detecting or isolating Leptospira spp. also varied among studies. Studies among different Rattus species reported a higher Leptospira prevalence in R. norvegicus. The serovar Icterohaemorrhagiae was the most prevalent serovar reported in Rattus spp. worldwide. Additionally, this literature review provided evidence for Leptospira infection in laboratory rodent colonies within controlled environments, implicating the zoonotic potential to laboratory animal caretakers.

Conclusions

Reports on global distribution of Leptospira infection in rats varies widely, with considerably high prevalence reported in many countries. This literature review emphasizes the need for enhanced surveillance programs using standardized methods for assessing Leptospira exposure or infection in rats. This review also demonstrated several weaknesses to the current methods of reporting the prevalence of Leptospira spp. in rats worldwide. As such, this necessitates a call for standardized protocols for the testing and reporting of such studies, especially pertaining to the diagnostic methods used. A deeper understanding of the ecology and epidemiology of Leptospira spp. in rats in urban environments is warranted. It is also pertinent for rat control programs to be proposed in conjunction with increased efforts for public awareness and education regarding leptospirosis transmission and prevention.

The role of rodents in the transmission of many diseases, including leptospirosis, is widely known. Rats abundant in urban and peridomestic environments are the most important reservoirs and sources of Leptospira infection in humans and animals. Leptospirosis is a significant but neglected disease of humans and animals that is increasing in incidence in regions affected by natural disasters. This paper summarizes the global prevalence and distribution of Leptospira infection in rats and will add to the literature that supports research, education, and public awareness regarding leptospirosis transmission and prevention.

Genetic characteristics of pathogenic Leptospira in wild small animals and livestock in Jiangxi Province, China, 2002-2015

Background

Leptospirosis is one of the most important neglected tropical bacterial diseases worldwide. However, there is limited information on the genetic diversity and host selectivity of pathogenic Leptospira in wild small mammal populations.

Methodology/Principal findings

Jiangxi Province, located in southern China, is a region highly endemic for leptospirosis. In this study, among a total of 3,531 trapped rodents dominated by Apodemus agrarius (59.7%), 330 Leptospira strains were successfully isolated from six different sites in Jiangxi between 2002 and 2015. Adding 71 local strains from humans, various kinds of livestock and wild animals in Jiangxi, a total of 401 epidemic strains were characterized using 16S rRNA gene senquencing, multilocus sequence typing (MLST) and the microscopic agglutination test (MAT). Among them, the most prevalent serogroup was Icterohaemorrhagiae (61.10%), followed by Javanica (19.20%) and Australis (9.73%); the remaining five serogroups, Canicola, Autumnalis, Grippotyphosa, Hebdomadis and Pomona, accounted for 9.97%. Species identification revealed that 325 were L. interrogans and 76 were L. borgpetersenii. Moreover, L. interrogans was the only pathogenic species in Fuliang and Shanggao and was predominant in Shangrao (95.0%); L. borgpetersenii was the most common in the remaining three sites. Twenty-one sequence types (STs) were identified. Similarly, ST1 and serogroup Icterohaemorrhagiae were most prevalent in Shangrao (86.0% and 86.4%) and Fuliang (90.4% and 90.4%), ST143 and serogroup Javanica in Shangyou (88.5% and 90.4%) and Longnan (73.1% and 73.1%), and ST105 and serogroup Australis in Shanggao (46.3% and 56.1%). Serogroup Icterohaemorhagiae primarily linked to A. agrarius (86.9%), serogroup Canicola to dogs (83.3%). There were significant differences in the distribution of leptospiral species/serogroups/STs prevalence across host species/collected locations among the 394 animal-associated strains (Fisher’s exact test, p<0.001).

Conclusions/Significance

Our study demonstrated high genetic diversity of pathogenic Leptospira strains from wild small animals in Jiangxi from 2002 to 2015. A. agrarius was the most abundantly trapped animal reservoir, and serogroup Icterohaemorrhagiae and ST1 were the most dominant in Jiangxi. Significant geographic variation and host diversity in the distribution of dominant species, STs and serogroups were observed. Moreover, rat-to-human transmission might play a crucial role in the circulation of Leptospirosis in Jiangxi. Details of the serological and molecular characteristics circulating in this region will be essential in implementing prevention and intervention measures to reduce the risk of disease transmission in China. However, phylogenetic analysis of more Leptospira isolates should explore the impact of ecological change on leptospirosis transmission dynamics and investigate how such new knowledge might better impact environmental monitoring for disease control and prevention at a public health level.

Leptospirosis, caused by pathogenic Leptospira spp, is one of the most widespread zoonoses. In recent years, human leptospirosis with occasionally fatal infections has been frequently reported in Jiangxi Province, a highly endemic region located in the south of China. However, there is a lack of information on circulating Leptospira strains in this province. To identify the etiological characteristics, 401 Leptospira from Jiangxi were characterized using serological and molecular typing methods. Serological typing revealed that 61.10% of the isolates belonged to serogroup Icterohaemorrhagiae. Two species, L. interrogans and L. borgpetersenii, were identified using 16S rRNA gene sequencing. A. agrarius may be the main carrier of leptospirosis in this endemic region. Furthermore, the diversity of leptospiral isolates was demonstrated using MLST analysis. ST1, as the most prevalent ST of pathogenic leptospires, was widely dispersed in China. Significant geographic variation and host diversity in the distribution of dominant species, serogroups and STs were found in Jiangxi. This study is the first to demonstrate the distribution of Leptospira in domestic and wildlife animals in Jiangxi. This retrospective study represents the longest and largest field epidemiological investigation on the etiological characteristics and genetic diversity of pathogenic Leptospira among large wild animal reservoirs and human populations in Jiangxi. A better understanding of the circulating etiological agents and epidemiology of leptospirosis will provide a good starting point for efforts to control and prevent this disease.

Prevalence of Leptospira Infection in Rodents from Bangladesh

Worldwide, Leptospira infection poses an increasing public health problem. In 2008, leptospirosis was recognised as a re-emerging zoonosis of global importance with South-East Asia being one of the most significant centres of the disease. Rodents are thought to be the most important host for a variety of Leptospira serovars. Because Bangladesh offers a suitable humid climate for the survival of these pathogenic bacteria, the presence of rodents could be a serious risk for human infection, especially in peri-urban areas or locations where food is stored. In order to gain more understanding of the multi-host epidemiology, a prevalence study was conducted in Comilla, Bangladesh to determine the presence of pathogenic Leptospira species in rodents. Real-time Polymerase Chain Reaction (qPCR) and sequencing showed that 13.1% (61/465) of the trapped rodents were infected with pathogenic Leptospira. Sequencing of the qPCR products identified the presence of three species: Leptospira interrogans, Leptospira borgpetersenii, and Leptospira kirschneri. Rodents of the genus, Bandicota, were significantly more likely to be positive than those of the genus, Rattus and Mus. Our results confirm the importance of rodents as hosts of pathogenic Leptospira and indicate that human exposure to pathogenic Leptospira may be considerable, also in places where food (rice) is stored for longer times. This study emphasizes the need to improve rodent management at such locations and to further quantify the public health impacts of this neglected emerging zoonosis in Bangladesh.

The prevalence of Leptospira among invasive small mammals on Puerto Rican cattle farms

Leptospirosis, an emerging infectious disease caused by bacteria of the genus Leptospira, is thought to be the most widespread zoonotic disease in the world. A first step in preventing the spread of Leptospira is delineating the animal reservoirs that maintain and disperse the bacteria. Quantitative PCR (qPCR) methods targeting the LipL32 gene were used to analyze kidney samples from 124 House mice (Mus musculus), 94 Black rats (Rattus rattus), 5 Norway rats (R. norvegicus), and 89 small Indian mongooses (Herpestes auropunctatus) from five cattle farms in Puerto Rico. Renal carriage of Leptospira was found in 38% of the sampled individuals, with 59% of the sampled mice, 34% of Black rats, 20% of Norway rats, and 13% of the mongooses. A heterogeneous distribution of prevalence was also found among sites, with the highest prevalence of Leptospira-positive samples at 52% and the lowest at 30%. Comparative sequence analysis of the LipL32 gene from positive samples revealed the presence of two species of Leptospira, L. borgpetersenii and L. interrogans in mice, detected in similar percentages in samples from four farms, while samples from the fifth farm almost exclusively harbored L. interrogans. In rats, both Leptospira species were found, while mongooses only harbored L. interrogans. Numbers tested for both animals, however, were too small (n = 7 each) to relate prevalence of Leptospira species to location. Significant associations of Leptospira prevalence with anthropogenic landscape features were observed at farms in Naguabo and Sabana Grande, where infected individuals were closer to human dwellings, milking barns, and ponds than were uninfected individuals. These results show that rural areas of Puerto Rico are in need of management and longitudinal surveillance of Leptospira in order to prevent continued infection of focal susceptible species (i.e. humans and cattle).

Association of rodent-borne Leptospira spp. with urban environments in Malaysian Borneo

Although leptospirosis is traditionally considered a disease of rural, agricultural and flooded environments, Leptospira spp. are found in a range of habitats and infect numerous host species, with rodents among the most significant reservoirs and vectors. To explore the local ecology of Leptospira spp. in a city experiencing rapid urbanization, we assessed Leptospira prevalence in rodents from three locations in Malaysian Borneo with differing levels of anthropogenic influence: 1) high but stable influence (urban); 2) moderate yet increasing (developing); and 3) low (rural). A total of 116 urban, 122 developing and 78 rural rodents were sampled, with the majority of individuals assigned to either the Rattus rattus lineage R3 (n = 165) or Sundamys muelleri (n = 100). Leptospira spp. DNA was detected in 31.6% of all rodents, with more urban rodents positive (44.8%), than developing (32.0%) or rural rodents (28.1%), and these differences were statistically significant. The majority of positive samples were identified by sequence comparison to belong to known human pathogens L. interrogans (n = 57) and L. borgpetersenii (n = 38). Statistical analyses revealed that both Leptospira species occurred more commonly at sites with higher anthropogenic influence, particularly those with a combination of commercial and residential activity, while L. interrogans infection was also associated with low forest cover, and L. borgpetersenii was more likely to be identified at sites without natural bodies of water. This study suggests that some features associated with urbanization may promote the circulation of Leptospira spp., resulting in a potential public health risk in cities that may be substantially underestimated.

Leptospirosis is a significant zoonotic disease that is found in a range of environments worldwide, most notably tropical regions prone to flooding. The bacterial agents of this disease, Leptospira spp., are most often associated with rodents, including species frequently found in urban areas. In cities, rodent populations are often larger and denser than those found in natural environments, which can lead to higher rates of contact with people and impact human disease risk. To investigate the impacts of urbanization on Leptospira spp., we sampled rodents at locations with differing levels of human influence, from highly urbanized to rural, surrounding a city in Malaysian Borneo. We found that 31.6% of all rodents were positive for Leptospira spp. DNA, and that two primary species were present, L. interrogans and L. borgpetersenii, both of which are known human pathogens. Statistical analyses revealed that infected animals were more common in areas with higher levels of human influence, and were more likely to occur at sites with limited forest cover, and mixed commercial and residential activity. Our study adds to a growing body of evidence suggesting that there is a significant yet underappreciated risk of leptospirosis for people living in urban environments.

An outbreak of leptospirosis among reserve military recruits, Hulu Perdik, Malaysia

Here, we investigated an outbreak of leptospirosis among reserve military recruits that occurred following a survival exercise in the Hulu Perdik forest within the Hulu Langat district, Kuala Lumpur, Malaysia. Blood samples from the 12 patients that presented symptoms for febrile illness on clinical examination were subjected to laboratory investigation, comprising Lepto IgM rapid test, IgM ELISA, and microscopic agglutination test (MAT). All these patients were interviewed for possible risk factors for leptospirosis. Rodent trapping and environmental sampling for possible isolation of leptospires in the outbreak site was performed. The isolated leptospires were genetically characterized and investigated for the potential epidemiological link with human leptospirosis. Among the 12 patients, two (2/12; 16.6%) were confirmed positive for leptospirosis by microscopic agglutination test (MAT with titers 400-800; serovar autumnalis and hardjobovis). Two Leptospira species from rodents (L. interrogans and L. borgpetersenii) and two from the environment (L. kmetyi and L. wolffii) were identified. The possible epidemiological link between human serovars and animal Leptospira species indicates rodents as the potential reservoir while the environment (soil and water) serves as a transmission route. This investigation highlights the robust presence of pathogenic leptospires on Malaysian environment and rodents which may present the risk of infection, especially among high-risk individuals. Hence, occupational risk individuals are cautioned to observe appropriate preventive measures including prophylaxis and seek immediate medical attention for any illness following similar activities.

Evaluation of BOX-PCR and ERIC-PCR as Molecular Typing Tools for Pathogenic Leptospira

In the last decades, leptospirosis had gained public health concern due to morbidity and mortality rates caused by pathogenic Leptospira. The need for rapid and robust molecular typing methods to differentiate this zoonotic pathogen is of utmost importance. Various studies had been conducted to determine the genetic relatedness of Leptospira isolates using molecular typing methods. In this study, 29 pathogenic Leptospira isolates from rat, soil, and water samples in Sarawak, Malaysia, were characterized using BOX-PCR and ERIC-PCR. The effectiveness of these two methods with regard to the ease of interpretation, reproducibility, typeability, and discriminatory power was also being evaluated. Using BOX-PCR, six clusters and 3 single isolates were defined at a genetic distance percentage of 11.2%. ERIC-PCR clustered the isolates into 6 clusters and 2 single isolates at a genetic distance percentage of 6.8%. Both BOX-PCR and ERIC-PCR produced comparable results though the discriminatory index for ERIC-PCR (0.826) was higher than that for BOX-PCR (0.809). From the constructed dendrogram, it could be summarized that the isolates in this study were highly heterogeneous and genetically diverse. The findings from this study indicated that there is no genetic relatedness among the pathogenic Leptospira isolates in relation to the locality, source, and identity, with some exceptions. Out of the 29 pathogenic Leptospira isolates studied, BOX-PCR and ERIC-PCR successfully discriminated 4 isolates (2 isolates each) into the same cluster in relation to sample sources, as well as 2 isolates into the same cluster in association with the sample locality. Future studies shall incorporate the use of other molecular typing methods to make a more thorough comparison on the genetic relatedness of pathogenic Leptospira.

High Leptospira seroprevalence in captive and wild-caught vervet monkeys (Chlorocebus sabeus) on the Caribbean island of Saint Kitts

Leptospirosis is a zoonotic disease of global importance. Very little information is available on Leptospira infection in nonhuman primates. We report herein a high seroprevalence (49.4%; 95% confidence interval: 41.6–57.2%) to Leptospira serovars in vervet monkeys ( Chlorocebus sabeus) on the Caribbean island of Saint Kitts. Monkeys bred in captivity ( n = 81) had a significantly higher seroprevalence compared to wild-caught monkeys ( n = 81; p < 0.05). Seroprevalence to serovar Bataviae was significantly higher in monkeys bred in captivity and was higher to serovar Bratislava in wild-caught monkeys ( p < 0.05). Our data confirm that exposure to various Leptospira serovars and seroconversion occurs in wild and captive vervet monkeys on the Caribbean island of Saint Kitts. Further studies are warranted to better understand epidemiology, transmission, pathology, and possible reservoir status in this species.

A duplex endpoint PCR assay for rapid detection and differentiation of Leptospira strains

INTRODUCTION:

This study aimed to develop a duplex endpoint PCR assay for rapid detection and differentiation of Leptospira strains.

METHODS:

Primers were designed to target the rrs (LG1/LG2) and ligB (LP1/LP2) genes to confirm the presence of the Leptospira genus and the pathogenic species, respectively.

RESULTS:

The assay showed 100% specificity against 17 Leptospira strains with a limit of detection of 23.1pg/µl of leptospiral DNA and sensitivity of 103 leptospires/ml in both spiked urine and water.

CONCLUSIONS:

Our duplex endpoint PCR assay is suitable for rapid early detection of Leptospira with high sensitivity and specificity.

Survey for zoonotic pathogens in Norway rat populations from Europe

BACKGROUND

The Norway rat Rattus norvegicus is an important reservoir of various zoonotic pathogens, such as cowpox virus and Leptospira, but also for agents of no or unknown zoonotic potential. We describe a survey of 426 Norway rats originating from five European countries and different habitats for Leptospira spp., rickettsiae, orthopoxvirus (OPV), avian metapneumovirus subtypes A and B (aMPV) and rat polyomavirus (rat PyV).

RESULTS

Leptospira DNA was detected in 60 out of 420 (14.3%) rats, and Rickettsia DNA was found in three out of 369 (0.8%) rats investigated. PCR-based typing resulted in the identification of L. interrogans sequence type 17, which corresponds to the serogroup Icterohaemorrhagiae, and Rickettsia helvetica respectively. Rat PyV DNA was detected in 103 out of 421 (24.5%) rats. OPV DNA and aMPV RNA were detected in none of the rats, but OPV-specific antibodies were detected in three out of 388 (0.8%) rats. The frequency of single Leptospira and rat PyV infections and coinfections was, independent of sex, greater for adults compared with juveniles/subadults and greater at rural sites compared with urban areas.

CONCLUSIONS

Study results indicate a broad geographical distribution of Leptospira DNA in rats within Europe, underlining the need to investigate further the potential mechanisms leading to increased prevalence in rural habitats and to assess the relevance to public health. In contrast, rickettsia and OPV infections rarely occurred in wild rat populations. The potential influence of rat PyV on the susceptibility to infections with other pathogens should be investigated in future studies. © 2016 Society of Chemical Industry.

Draft Genome Sequence of Leptospira interrogans Serovar Bataviae Strain LepIMR 22 Isolated from a Rodent in Johor, Malaysia

Leptospira interrogans serovar Bataviae was recently identified as one of the persistent Leptospira serovars in Malaysia. Here, we report the draft genome sequence of the L. interrogans serovar Bataviae strain LepIMR 22 isolated from kidney of a rodent in Johor, Malaysia.