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.

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.

Emerging hantaviruses in Central Argentina: First case of Hantavirus Pulmonary Syndrome caused by Alto Paraguay virus, and a novel orthohantavirus in Scapteromys aquaticus rodent.

Orthohantaviruses are emerging rodent-borne pathogens that cause Hantavirus Pulmonary Syndrome in humans. They have a wide range of rodent reservoir hosts and are transmitted to humans through aerosolized viral particles generated by the excretions of infected individuals. Since the first description of HPS in Argentina, new hantaviruses have been reported throughout the country, most of which are pathogenic to humans. We present here the first HPS case infected with Alto Paraguay virus reported in Argentina. Until now, Alto Paraguay virus was considered a non-pathogenic orthohantavirus since it was identified in a rodent, Holochilus chacarius. In addition to this, with the goal of identifying potential hantavirus host species in the province of Santa Fe, we finally describe a novel orthohantavirus found in the native rodent Scapteromys aquaticus, which differed from other hantaviruses described in the country so far. Our findings implicate an epidemiological warning regarding these new orthohantaviruses circulating in Central Argentina as well as new rodent species that must be considered as hosts from now on.

Meta-analysis of risk factors for canine leptospirosis.

Leptospirosis is one of the most widespread zoonotic diseases, with more than one million human cases reported worldwide every year. Dogs could develop infections that range from asymptomatic to severe, and shed leptospires with their urine. Given their close contact with humans, dogs may act both as epidemiological links or as sentinels of pathogenic leptospires in the environment. The aims of our study were to quantitatively summarize the overall prevalence of leptospiral antibodies and to identify factors associated with the probabilities of infection. We searched the electronic databases Scopus, PubMed, PMC and ScienceDirect for observational studies on canine leptospirosis published between 1989 and December 2019 and written in English, Spanish or Portuguese. We fitted a series of multilevel random effects meta-analysis models to estimate the prevalence of antibodies against Leptospira for different types of dogs, health statuses, diagnostic tests, geographic regions and income categories of the countries. We also fitted a number of random effects meta-analysis models to estimate the pooled odds-ratio of factors associated with canine leptospirosis. After removing duplicates and articles not meeting selection criteria, a total of 130 studies in 91 articles were included in this work. We found lower seroprevalence estimates in North America countries (P<0.001) and other high income countries (P<0.001). We also found higher probabilities of leptospiral infection in adult (P=0.017), male dogs with access to the streets (P<0.001). Identifying the profile of dogs that are more exposed to leptospirosis could be useful in the design of public health strategies for the prevention and control of leptospirosis.

Seroprevalence of leptospiral antibodies in rodents from riverside communities of Santa Fe, Argentina.

BACKGROUND: Leptospirosis is a zoonotic disease that can be transmitted by contact with the urine of infected mammals. Rodents play a mayor role in the transmission of leptospires to humans. The province of Santa Fe reports the greatest number of cases in Argentina. Yet, in this region, there are still knowledge gaps regarding the diversity of rodent species that may be hosts of pathogenic leptospires. The aims of this study were to evaluate the presence of leptospiral antibodies in rodents from three riverside communities of Santa Fe, and to identify factors associated with leptospiral infection. METHODOLOGY/PRINCIPAL FINDINGS: Each community was divided into three environmental settings based on the level of human disturbance, and sampled during two springs (Sep-Oct 2014 and 2015) and one autumn (Mar-Apr 2015). Serum samples of captured sigmodontine and murine rodents were tested for leptospiral antibodies by enzyme-linked immunosorbent assay (ELISA), and microagglutination test (MAT) was used to assess the infecting serovar in seropositive individuals. Factors influencing seropositivity were analyzed using logistic regression models. We caught 119 rodents, of which 101 serums were suitable for analysis. Most frequently trapped species were Scapteromys aquaticus, Akodon azarae and Oligoryzomys spp., with seroprevalences of 41.3%, 42.9% and 55% respectively. Seropositivity was higher in individuals with an average body condition score and in those that were sexually mature, but in the latter the differences were marginally significant. CONCLUSIONS/SIGNIFICANCE: Our results suggest that native rodents may be playing a role in the environmental circulation of pathogenic leptospires and provide relevant information for public health policies in the area.

Primer informe de Leptospira interrogans en el roedor sigmodontino Scapteromys aquaticus

[RESUMEN]. La leptospirosis es una enfermedad zoonótica de distribución mundial que puede transmitirse por contacto directo o indirecto con orina o tejidos de animales infectados. En Argentina, la leptospirosis es endémica en la provincia de Santa Fe y presenta brotes epidémicos durante las inundaciones. Sin embargo, se sabe muy poco sobre el papel que cumplen los roedores silvestres en la diseminación de la enfermedad en el país. El objetivo de este estudio fue identificar las especies hospederas de leptospiras patógenas entre los roedores presentes en un asentamiento ribereño de la provincia de Santa Fe. Se realizó un muestreo de roedores durante octubre de 2015. Los riñones de los animales capturados se analizaron por real-time PCR para el gen LipL32 de leptospiras patógenas. En los animales que resultaron positivos, se realizó test de microaglutinación (MAT) y tipificación molecular por amplificación del gen 16S rRNA y dos esquemas de MLST. Se capturaron 37 roedores de las especies Akodon azarae, Cavia aperea, Oligoryzomys flavescens, Rattus rattus y Scapteromys aquaticus. En el análisis por real-time PCR resultó positivo un macho de Scapteromys aquaticus. El suero de este individuo y del resto de los S. aquaticus capturados (n = 18) se analizaron por test de microaglutinación (MAT), y fueron no reactivos para los 10 serovares probados. La amplificación del gen 16S rRNA identificó la especie infectante como Leptospira interrogans, mientras que no se obtuvo amplificación para los dos esquemas de MLST. El hallazgo de este estudio aporta nueva información acerca de presencia de leptospiras patógenas en roedores silvestres, que es relevante para la zona por tratarse de una especie ampliamente distribuida en ambientes pantanosos e inundables de América del Sur.

[ABSTRACT]. Leptospirosis is a globally distributed zoonosis that can be transmitted through direct or indirect contact with the urine or tissues of infected animals. In Argentina, leptospirosis is endemic in the province of Santa Fe and epidemic outbreaks occur during floods. However, very little is known about the role that wild rodents play in the spread of the disease in Argentina. The objective of this study was to identify the host species of pathogenic Leptospira among rodents in a riverine settlement in the province of Santa Fe. We conducted a trapping session in October 2015. Kidneys of the captured animals were analyzed by real-time PCR for the LipL32 gene of pathogenic Leptospira. Animals that were positive were subjected to microscopic agglutination test (MAT) and molecular typing by amplification of the 16S rRNA gene and two multilocus sequence typing (MLST) schemes. A total of 37 rodents of the species Akodon azarae, Cavia aperea, Oligoryzomys flavescens, Rattus rattus, and Scapteromys aquaticus were captured. Real-time PCR found one male Scapteromys aquaticus that was positive. The serum of this individual and of the rest of the S. aquaticus captured (n = 18) were analyzed by MAT and were non-reactive for the 10 serovars tested. Amplification of the 16S rRNA gene identified the infective species as Leptospira interrogans, while amplification could not be obtained for the two MLST schemes. The findings of this study contribute new information concerning the presence of pathogenic Leptospira in wild rodents, which is relevant in this region because the species is widely distributed in swampy and flood-prone environments of South America.

[RESUMO]. A leptospirose é uma doença zoonótica de distribuição mundial transmitida pelo contato direto ou indireto com a urina ou os tecidos de animais infectados. Na Argentina, a leptospirose é endêmica na Província de Santa Fé com surtos epidêmicos ocorrendo com as enchentes. Sabe-se pouco sobre o papel dos roedores silvestres na propagação da doença no país. O objetivo deste estudo foi identificar as espécies hospedeiras de leptospiras patogênicas em roedores encontrados em um núcleo de povoamento ribeirinho na Província de Santa Fé. A amostragem dos roedores foi feita no mês de outubro de 2015. Os tecidos dos rins dos animais capturados foram analisados com a técnica de reação em cadeia da polimerase em tempo real (PCR-RT) quanto à presença do gene LipL32 de leptospiras patógenas. Para os animais com resultados positivos, foi realizado o teste de microaglutinação (MAT) e tipagem molecular baseada na amplificação do gene 16S rRNA e dois esquemas de tipagem por sequenciamento de locos múltiplos (MLST). Ao todo, foram capturados 37 roedores das espécies Akodon azarae, Cavia aperea, Oligoryzomys flavescens, Rattus e Scapteromys aquaticus. O ensaio de PCR-RT foi positivo em um roedor macho da espécie Scapteromys aquaticus. Os soros deste animal e dos outros S. aquaticus capturados (n = 18) foram analisados com o MAT e os resultados foram não reagentes para os 10 sorovares testados. A amplificação do gene 16S rRNA permitiu identificar a espécie infetante como sendo Leptospira interrogans e não houve amplificação nos dois esquemas de MLST. O achado deste estudo fornece um novo dado quanto à presença de leptospiras patogênicas em roedores silvestres, importante para esta área por se tratar de uma espécie de ampla distribuição em terras pantanosas e inundáveis da América do Sul.

Knowledge, attitudes and practices (KAP) regarding leptospirosis among residents of riverside settlements of Santa Fe, Argentina.

BACKGROUND: Leptospirosis is a global and re-emerging zoonotic disease caused by Leptospira spirochetes that are shed into the environment by infected animals. Humans can get infected via contact with animal hosts or contaminated environment. In Argentina, the highest annual incidences were reported in the province of Santa Fe, where epidemic outbreaks occurred during flooding events. This study examined the knowledge, attitudes and practices (KAP) regarding leptospirosis among residents of riverside slum settlements from Santa Fe after a major flood. METHODS AND FINDINGS: A cross-sectional questionnaire was administered to 113 residents of 3 riverside settlements from Santa Fe. The influence of knowledge and attitudes regarding leptospirosis on the likelihood that an individual will use preventive practices were evaluated using linear mixed-effects models. The majority of respondents (83.2%) had previously heard about leptospirosis; however specific knowledge about leptospirosis was limited. The results of the modeling efforts, show that the likelihood of using preventive practices was associated with having greater knowledge score, but not with more positive attitudes. We also found that females were more likely to use safer practices than males. CONCLUSIONS: Even though the majority of respondents had heard about leptospirosis, a high percentage of them had limited knowledge regarding the severity of the disease and its prevalence in the region. Our results suggest that public health interventions in these riverside communities should focus on educating the public on the multiple dimensions of leptospirosis in order to attain greater adherence to preventive practices instead of intending to change the perceptions or attitudes towards the disease, which did not have a significant influence. The key challenge lies in identifying effective strategies to reach the high risk group for leptospirosis here that is male fishermen, who spend most of the time in precarious campsites on the river islands.

[First report on Leptospira interrogans in the sigmodontine rodent Scapteromys aquaticusPrimeiro relato da presença de Leptospira interrogans em roedores sigmodontíneos Scapteromys aquaticus]. / Primer informe de Leptospira interrogans en el roedor sigmodontino Scapteromys aquaticus.

Leptospirosis is a globally distributed zoonosis that can be transmitted through direct or indirect contact with the urine or tissues of infected animals. In Argentina, leptospirosis is endemic in the province of Santa Fe and epidemic outbreaks occur during floods. However, very little is known about the role that wild rodents play in the spread of the disease in Argentina. The objective of this study was to identify the host species of pathogenic Leptospira among rodents in a riverine settlement in the province of Santa Fe.We conducted a trapping session in October 2015. Kidneys of the captured animals were analyzed by real-time PCR for the LipL32 gene of pathogenic Leptospira. Animals that were positive were subjected to microscopic agglutination test (MAT) and molecular typing by amplification of the 16S rRNA gene and two multilocus sequence typing (MLST) schemes.A total of 37 rodents of the species Akodon azarae, Cavia aperea, Oligoryzomys flavescens, Rattus rattus, and Scapteromys aquaticus were captured. Real-time PCR found one male Scapteromys aquaticus that was positive. The serum of this individual and of the rest of the S. aquaticus captured (n = 18) were analyzed by MAT and were non-reactive for the 10 serovars tested. Amplification of the 16S rRNA gene identified the infective species as Leptospira interrogans, while amplification could not be obtained for the two MLST schemes.The findings of this study contribute new information concerning the presence of pathogenic Leptospira in wild rodents, which is relevant in this region because the species is widely distributed in swampy and flood-prone environments of South America.

A leptospirose é uma doença zoonótica de distribuição mundial transmitida pelo contato direto ou indireto com a urina ou os tecidos de animais infectados. Na Argentina, a leptospirose é endêmica na Província de Santa Fé com surtos epidêmicos ocorrendo com as enchentes. Sabe-se pouco sobre o papel dos roedores silvestres na propagação da doença no país. O objetivo deste estudo foi identificar as espécies hospedeiras de leptospiras patogênicas em roedores encontrados em um núcleo de povoamento ribeirinho na Província de Santa Fé.A amostragem dos roedores foi feita no mês de outubro de 2015. Os tecidos dos rins dos animais capturados foram analisados com a técnica de reação em cadeia da polimerase em tempo real (PCR-RT) quanto à presença do gene LipL32 de leptospiras patógenas. Para os animais com resultados positivos, foi realizado o teste de microaglutinação (MAT) e tipagem molecular baseada na amplificação do gene 16S rRNA e dois esquemas de tipagem por sequenciamento de locos múltiplos (MLST).Ao todo, foram capturados 37 roedores das espécies Akodon azarae, Cavia aperea, Oligoryzomys flavescens, Rattus e Scapteromys aquaticus. O ensaio de PCR-RT foi positivo em um roedor macho da espécie Scapteromys aquaticus. Os soros deste animal e dos outros S. aquaticus capturados (n = 18) foram analisados com o MAT e os resultados foram não reagentes para os 10 sorovares testados. A amplificação do gene 16S rRNA permitiu identificar a espécie infetante como sendo Leptospira interrogans e não houve amplificação nos dois esquemas de MLST.O achado deste estudo fornece um novo dado quanto à presença de leptospiras patogênicas em roedores silvestres, importante para esta área por se tratar de uma espécie de ampla distribuição em terras pantanosas e inundáveis da América do Sul.

Primer informe de Leptospira interrogans en el roedor sigmodontino Scapteromys aquaticus / First report on Leptospira interrogans in the sigmodontine rodent Scapteromys aquaticus / Primeiro relato da presença de Leptospira interrogans em roedores sigmodontíneos Scapteromys aquaticus

RESUMEN La leptospirosis es una enfermedad zoonótica de distribución mundial que puede transmitirse por contacto directo o indirecto con orina o tejidos de animales infectados. En Argentina, la leptospirosis es endémica en la provincia de Santa Fe y presenta brotes epidémicos durante las inundaciones. Sin embargo, se sabe muy poco sobre el papel que cumplen los roedores silvestres en la diseminación de la enfermedad en el país. El objetivo de este estudio fue identificar las especies hospederas de leptospiras patógenas entre los roedores presentes en un asentamiento ribereño de la provincia de Santa Fe. Se realizó un muestreo de roedores durante octubre de 2015. Los riñones de los animales capturados se analizaron por real-time PCR para el gen LipL32 de leptospiras patógenas. En los animales que resultaron positivos, se realizó test de microaglutinación (MAT) y tipificación molecular por amplificación del gen 16S rRNA y dos esquemas de MLST. Se capturaron 37 roedores de las especies Akodon azarae, Cavia aperea, Oligoryzomys flavescens, Rattus rattus y Scapteromys aquaticus. En el análisis por real-time PCR resultó positivo un macho de Scapteromys aquaticus. El suero de este individuo y del resto de los S. aquaticus capturados (n = 18) se analizaron por test de microaglutinación (MAT), y fueron no reactivos para los 10 serovares probados. La amplificación del gen 16S rRNA identificó la especie infectante como Leptospira interrogans, mientras que no se obtuvo amplificación para los dos esquemas de MLST. El hallazgo de este estudio aporta nueva información acerca de presencia de leptospiras patógenas en roedores silvestres, que es relevante para la zona por tratarse de una especie ampliamente distribuida en ambientes pantanosos e inundables de América del Sur.(AU)

ABSTRACT Leptospirosis is a globally distributed zoonosis that can be transmitted through direct or indirect contact with the urine or tissues of infected animals. In Argentina, leptospirosis is endemic in the province of Santa Fe and epidemic outbreaks occur during floods. However, very little is known about the role that wild rodents play in the spread of the disease in Argentina. The objective of this study was to identify the host species of pathogenic Leptospira among rodents in a riverine settlement in the province of Santa Fe. We conducted a trapping session in October 2015. Kidneys of the captured animals were analyzed by real-time PCR for the LipL32 gene of pathogenic Leptospira. Animals that were positive were subjected to microscopic agglutination test (MAT) and molecular typing by amplification of the 16S rRNA gene and two multilocus sequence typing (MLST) schemes. A total of 37 rodents of the species Akodon azarae, Cavia aperea, Oligoryzomys flavescens, Rattus rattus, and Scapteromys aquaticus were captured. Real-time PCR found one male Scapteromys aquaticus that was positive. The serum of this individual and of the rest of the S. aquaticus captured (n = 18) were analyzed by MAT and were non-reactive for the 10 serovars tested. Amplification of the 16S rRNA gene identified the infective species as Leptospira interrogans, while amplification could not be obtained for the two MLST schemes. The findings of this study contribute new information concerning the presence of pathogenic Leptospira in wild rodents, which is relevant in this region because the species is widely distributed in swampy and flood-prone environments of South America.(AU)

RESUMO A leptospirose é uma doença zoonótica de distribuição mundial transmitida pelo contato direto ou indireto com a urina ou os tecidos de animais infectados. Na Argentina, a leptospirose é endêmica na Província de Santa Fé com surtos epidêmicos ocorrendo com as enchentes. Sabe-se pouco sobre o papel dos roedores silvestres na propagação da doença no país. O objetivo deste estudo foi identificar as espécies hospedeiras de leptospiras patogênicas em roedores encontrados em um núcleo de povoamento ribeirinho na Província de Santa Fé. A amostragem dos roedores foi feita no mês de outubro de 2015. Os tecidos dos rins dos animais capturados foram analisados com a técnica de reação em cadeia da polimerase em tempo real (PCR-RT) quanto à presença do gene LipL32 de leptospiras patógenas. Para os animais com resultados positivos, foi realizado o teste de microaglutinação (MAT) e tipagem molecular baseada na amplificação do gene 16S rRNA e dois esquemas de tipagem por sequenciamento de locos múltiplos (MLST). Ao todo, foram capturados 37 roedores das espécies Akodon azarae, Cavia aperea, Oligoryzomys flavescens, Rattus e Scapteromys aquaticus. O ensaio de PCR-RT foi positivo em um roedor macho da espécie Scapteromys aquaticus. Os soros deste animal e dos outros S. aquaticus capturados (n = 18) foram analisados com o MAT e os resultados foram não reagentes para os 10 sorovares testados. A amplificação do gene 16S rRNA permitiu identificar a espécie infetante como sendo Leptospira interrogans e não houve amplificação nos dois esquemas de MLST. O achado deste estudo fornece um novo dado quanto à presença de leptospiras patogênicas em roedores silvestres, importante para esta área por se tratar de uma espécie de ampla distribuição em terras pantanosas e inundáveis da América do Sul.(AU)