First evidence of autochthonous cases of Leishmania (Leishmania) infantum in horse (Equus caballus) in the Americas and mixed infection of Leishmania infantum and Leishmania (Viannia) braziliensis

Cryptic Diversity in Sympatric Migonemyia migonei (Diptera: Psychodidae), Eventual Meaning for Leishmaniasis Transmission

Migonemyia migonei (Franҫa, 1920) (Diptera: Psychodidae) belongs to the subfamily Phlebotominae, of epidemiological importance due to its role as a vector in leishmaniasis transmission cycles and its broad geographic distribution in South America. Few morphometric and genetic studies have demonstrated the existence of variability among geographically distant populations in Brazil. The aim of the study was to estimate the genetic distance within the morphospecies Mg. migonei through the analysis of cytochrome C oxidase subunit I (COI) sequences of specimens captured in Argentina and those available in online databases. The COI sequences from specimens collected in different localities of Argentina and sequences available in online databases were utilized. Genetic distances were analyzed and a median-joining haplotype network was constructed. Finally, phylogenetic reconstruction was performed according to Bayesian inference. The analyses led to the identification of at least two haplogroups: haplogroup I with sequences of specimens from Colombia, Brazil and Argentina, and haplogroup II with sequences of specimens from Argentina. Interestingly, specimens from Argentina whose haplotypes corresponded to both haplogroups, were collected in sympatry. The results suggest that Mg. migonei could be a species complex with at least two distinct members. This hypothesis could explain the known characteristics of adaptability and vector permissiveness of the species, as the putative cryptic species of the complex could differ in traits of epidemiological importance.

Is leishmaniasis the new emerging zoonosis in the world?

Leishmania is a genus of parasitic protozoa that causes a disease called leishmaniasis. Leishmaniasis is transmitted to humans through the bites of infected female sandflies. There are several different species of Leishmania that can cause various forms of the disease, and the symptoms can range from mild to severe, depending on species of Leishmania involved and the immune response of the host. Leishmania parasites have a variety of reservoirs, including humans, domestic animals, horses, rodents, wild animals, birds, and reptiles. Leishmaniasis is endemic of 90 countries, mainly in South American, East and West Africa, Mediterranean region, Indian subcontinent, and Central Asia. In recent years, cases have been detected in other countries, and it is already an infection present throughout the world. The increase in temperatures due to climate change makes it possible for sandflies to appear in countries with traditionally colder regions, and the easy movement of people and animals today, facilitate the appearance of Leishmania species in new countries. These data mean that leishmaniasis will probably become an emerging zoonosis and a public health problem in the coming years, which we must consider controlling it from a One Health point of view. This review summarizes the prevalence of Leishmania spp. around the world and the current knowledge regarding the animals that could be reservoirs of the parasite.

Evidence of Horse Exposure to Anaplasma phagocytophilum, Borrelia burgdorferi, and Leishmania infantum in Greece through the Detection of IgG Antibodies in Serum and in an Alternative Diagnostic Sample-The Saliva

Among the various zoonotic pathogens that infect horses, Anaplasma phagocytophilum, Borrelia spp. and Leishmania spp. have gained scientific interest, and relevant molecular and serological studies in horses have been conducted worldwide. Moreover, human and veterinary medicine have extensively applied alternatives to serum diagnostic samples-such as saliva-for detecting pathogens or antibodies. In this study, we investigated the exposure of horses in Greece to A. phagocytophilum, B. burgdorferi, and L. infantum, and we assessed the diagnostic accuracy of saliva compared to serum in detecting IgG antibodies against the abovementioned pathogens. Paired saliva and serum samples were collected from 317 horses from different regions in Greece. The paired samples were examined using the indirect fluorescent antibody test (IFAT) for detecting IgG antibodies against A. phagocytophilum, B. burgdorferi, and L. infantum. Sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were determined to assess the validity of saliva as an alternative to serum. The receiver operating characteristic (ROC) curve revealed that the optimal cut-off value for detecting antibodies against all the examined pathogens in saliva was 1/10. Higher seropositivity rates were found for B. burgdorferi (15.14%) and A. phagocytophilum (14.19%) compared to L. infantum (1.26%). The detection of IgG antibodies using IFAT in saliva samples had a good test performance compared to serum. The two sample types had a substantial to almost perfect agreement. Although the sensitivity was moderate (70.83-75.56%) in all cases, the specificity was almost perfect to perfect (99.63-100%). This study provides the first evidence that horses in Greece are exposed to A. phagocytophilum and B. burgdorferi and confirms that the seroprevalence of L. infantum in horses in Greece remains low. Our findings suggest that saliva sampling coupled with IFAT could be successfully applied for detecting IgG antibodies against these important zoonotic pathogens in large-scale epidemiological studies in horses, at the population level, as an alternative to serum.

Prevalence and Factors Related to Leishmania infantum Infection in Healthy Horses (Equus caballus) from Eastern Spain

Leishmaniosis is a zoonosis caused by Leishmania spp., an intracellular protozoan parasite. This parasite is transmitted by sandflies, and the disease is endemic in the Mediterranean basin. In recent years, the number of species which could be a reservoir of the parasite is increased. One of the most relevant species is the horse, due to their contact with humans and ability to control the disease, thus being a possible silent reservoir. In this study, we have analyzed the prevalence and factors related to L. infantum infection in healthy horses in the Mediterranean region. Epidemiological data and serum samples were obtained from 167 apparently healthy horses, and the presence of L. infantum was evaluated via the ELISA method and real-time PCR. The results show 27.5% of prevalence and that the main factors related to infection are equine breed, morphotype, outdoor living, use, and season. In conclusion, the prevalence of L. infantum infection in apparently healthy horses from eastern Spain (Mediterranean basin) is elevated. To control this zoonosis, it would be advisable to carry out more studies on this and other species that could be silent reservoirs of the parasite, as well as carry out measures such as the use of repellents on a regular basis.

Identification of infection by Leishmania spp. in wild and domestic animals in Brazil: a systematic review with meta-analysis (2001-2021)

Leishmaniasis is a zoonosis caused by protozoan species of the genus Leishmania. It generates different clinical manifestations in humans and animals, and it infects multiple hosts. Leishmania parasites are transmitted by sandfly vectors. The main objective of this systematic review was to identify the host, or reservoir animal species, of Leishmania spp., with the exception of domestic dogs, that were recorded in Brazil. This review included identification of diagnostic methods, and the species of protozoan circulating in the country. For this purpose, a literature search was conducted across index journals. This study covered the period from 2001 to 2021, and 124 studies were selected. Eleven orders possible hosts were identified, including 229 mammalian species. Perissodactyla had the highest number of infected individuals (30.69%, 925/3014), with the highest occurrence in horses. In Brazil, the most commonly infected species were found to be: horses, domestic cats, rodents, and marsupials. Bats, that were infected by one or more protozoan species, were identified as potential reservoirs of Leishmania spp. Molecular tests were the most commonly used diagnostic methods (94 studies). Many studies have detected Leishmania spp. (n = 1422): Leishmania (Leishmania) infantum (n = 705), Leishmania (Viannia) braziliensis (n = 319), and Leishmania (Leishmania) amazonensis (n = 141). Recognizing the species of animals involved in the epidemiology and biological cycle of the protozoan is important, as this allows for the identification of environmental biomarkers, knowledge of Leishmania species can improve the control zoonotic leishmaniasis.

Clinical evolution of equine leishmaniasis with self-limiting cutaneous disease caused by Leishmania infantum in northeastern Brazil: A case report

Leishmania infantum infections have long been described in humans and dogs worldwide, but characterization of equine cases remains scarce. We describe the clinical evolution of a natural L. infantum infection to contribute to the diagnostic knowledge and epidemiology of equine leishmaniasis (EL). An auction-acquired four-year-old Mangalarga Marchador mare from Pernambuco state, presented a few subcutaneous nodules on the head and neck upon arrival at the purchaser's stud at Bahia state, in November of 2019. They progressed to multiple ulcerated and non-ulcerated nodules and spread to both right limbs in seven weeks. Hematology revealed anemia, lymphocytosis, monocytosis, and elevated plasma fibrinogen. Histopathology of the biopsied nodules identified a granulomatous dermatitis with macrophages containing Leishmania amastigotes. PCR detected Leishmania in skin lesions, but not in blood or spleen aspirate samples; ITS1 PCR-RFLP and DNA sequencing confirmed L. infantum species. A topical antiseptic and insect-repellent therapy and a monthly follow-up were established. All lesions improved progressively, without specific anti-Leishmania treatment, and 14 months later there was a consistent resolution. This first description of EL by L. infantum in an endemic area is relevant to emphasize the need for epidemiological studies, and to enhance clinicians' awareness for differential diagnosis.

First report of Leishmania (Mundinia) martiniquensis in South American territory and confirmation of Leishbunyavirus infecting this parasite in a mare

BACKGROUND

Epidemiological data related to leishmaniases or Leishmania infection in horses are scarce. However, studies carried out in different regions in the world showed equids parasitised by Leishmania braziliensis, L. infantum and L. martiniquensis.

OBJECTIVES

Identify the Leishmania species causing cutaneous leishmaniasis in a mare, living in Rio de Janeiro State (Brazil), and search the presence of Leishmania viruses in the isolated parasite.

METHODS

Isoenzymes and polymerase chain reaction (PCR) targeting ITSrDNA region followed by sequencing were conducted for typing the isolated parasite. A search for Leishmania virus infection was also performed.

FINDINGS

The mare presented skin nodules and ulcers in the left pinna caused by Leishmania spp. that was detected by culture and PCR. The parasite was identified as Leishmania (Mundinia) martiniquensis, infected by Leishbunyavirus (LBV), representing the first description of this species in South America. The animal travelled to different Brazilian regions, but not to outside the country.

MAIN CONCLUSIONS

The worldwide distribution of L. martiniquensis and its infection by LBV were confirmed in this study, indicating the autochthonous transmission cycle in Brazil. The clinical profile of the disease in the mare, showing fast spontaneous healing of cutaneous lesions, may indicate that skin lesions related to L. martiniquensis infection in horses might be underdiagnosed.

Detection of Leishmania spp. in Chronic Dermatitis: Retrospective Study in Exposed Horse Populations

Leishmania infantum is a protozoan causing human zoonotic visceral leishmaniasis (ZVL) and visceral–cutaneous canine leishmaniosis (CanL) in the Mediterranean Basin. L. infantum is able to infect a large number of wild and domestic species, including cats, dogs, and horses. Since the 1990s, clinical cases of equine leishmaniasis (EL), typically characterized by cutaneous forms, have been increasingly diagnosed worldwide. The aim of the present study was to evaluate the presence of clinical forms of EL in CanL-endemic areas in Italy, where exposure of equine populations was ascertained from recent serological surveys. For this purpose, formalin-fixed and paraffin-embedded skin biopsies of 47 horses presenting chronic dermatitis compatible with EL were retrospectively selected for the study and subjected to conventional and q-PCR. A singular positivity for L. infantum was found; BLAST analysis of sequence amplicons revealed a 99–100% homology with L. infantum sequences. The histological examination revealed a nodular lymphoplasmacytic and histiocytic infiltrate; immunohistochemistry showed rare macrophages containing numerous positive amastigotes. The present retrospective study reports, for the first time, a case of a cutaneous lesion by L. infantum occurring in an Italian horse. Pathological and healthy skin samples should be investigated on a larger scale to provide information on the potential clinical impact of EL in the practice, and to define the role of horses in epidemiological ZVL and CanL scenarios.

Molecular detection of Leishmania infantum in donkeys and mules under semiarid conditions in Brazil

Visceral leishmaniasis is a parasitic zoonosis that mainly affects poorest and most vulnerable populations, and domestic dogs are considered to be the main source of infection to the vector and therefore humans. However, several studies have investigated the role of other vertebrate hosts in the disease cycle. In this context, the aim of the present study was to conduct a survey of Leishmania infantum infection in donkeys and mules living in a semiarid region of Brazil. Whole blood sampled from 72 equids (65 donkeys and 7 mules) was used to perform molecular diagnosis using the real-time polymerase chain reaction (qPCR) technique. A total of 25% of the samples (18/72) were positive through qPCR, but there were no significant differences between the species (donkeys or mules), sex (male or female) and abandonment situation of the animals (yes or no). Donkeys and mules living under semiarid conditions have high frequency of L. infantum infection. It is therefore worth assigning importance to these species in the epidemiological cycle of visceral leishmaniasis, either as potential reservoirs or just as an abundant food source for vectors.

Feline Leishmaniasis Caused by Leishmania infantum: Parasite Sequencing, Seropositivity, and Clinical Characterization in an Endemic Area From Brazil

Zoonotic leishmaniasis caused by Leishmania infantum is a disease of One Health concern since human and animal cases and environmental damage are interconnected. L. infantum has a complex epidemiological cycle with multiple hosts, including mammals-humans, domestic, and wild animals-and arthropod vectors. Knowledge on mammal infections in endemic areas is crucial for developing control strategies. This work aimed to detect and characterize L. infantum infection in domestic cats from areas where human and canine leishmaniasis cases occur. No cases of feline leishmaniasis (FeL) had been previously reported in those areas. Five municipalities from Bahia state were chosen, comprising 2,480.8 km² with 1,103,866 inhabitants. Ninety domiciliated and/or sheltered cats underwent clinical examination and serology by a rapid reference test recommended by the Brazilian government. Cytology, PCR, and parasite DNA sequencing were performed in bone marrow samples. Rapid tests detected antibodies in 5.6% (5/90) of the cats. Leishmania infantum infection was confirmed in 7.8% (7/90) of the cats by PCR, sequencing, and parasite isolation. Three out of the five municipalities (60%) had infected cats, and PCR positivity varied from 6.9 to 29%. One cat was categorized as harboring active L. infantum infection with amastigote forms in bone marrow smears. No clinical signs were detected at the first clinical exam, but 1 month later the cat developed severe FeL. The cat isolate was grown in culture, typed and its DNA sequence was homologous to the L. infantum reference strain (PP75). In conclusion, cats are potential hosts and may acquire L. infantum in endemic areas where canine and human cases occur. For cats, the need for surveillance, differential diagnosis and clinical care is highly recommended since a fast clinical progression of FeL developed in a subclinical animal. An accurate standardized immunodiagnostic assay for FeL is warranted.

Equine infection with Leishmania spp. in Costa Rica: Study of five cases

BACKGROUND

Cutaneous forms of leishmaniosis due to Leishmania braziliensis have been reported in horses in the New World. Domestic animals play a role in the transmission of the disease. In Costa Rica, human cases of L. braziliensis, L. panamensis and L. infantum have been reported.

OBJECTIVES

The present report describes five cases of equine cutaneous leishmaniosis in Costa Rica. The aetiological diagnosis was based on the presence of the parasite within the lesions.

METHODS

Skin biopsies were used to perform histopathological analyses of the lesions. Immunohistochemistry was used to detect the presence of the Leishmania spp. antigens in tissue sections. Laser-capture micro-dissection and quantitative real-time PCR techniques were carried out to detect the pathogen nucleic acid within the microscopic lesions.

RESULTS

Histopathological analyses showed a granulomatous inflammation within the dermis, with multi-nucleated giant cells, macrophages, lymphocytes and few neutrophils and eosinophils. We detected the parasite by immunohistochemistry, using a rabbit polyclonal antibody raised against Leishmania spp. However, we could not identify Leishmania spp. by quantitative real-time PCR in formalin-fixed paraffin-embedded tissues, using specific primers for the conserved region in the minicircle of the Leishmania DNA kinetoplast.

CONCLUSIONS

Our results emphasise the importance of Leishmania spp. not only as a causative agent of equine cutaneous disease in the New World, but also as a possible emerging pathogen. Leishmaniosis is one of the most prevalent parasitic public health problems worldwide, and equines may have a role in the epidemiology of the disease.

Frequency and factors associated of potential zoonotic pathogens (Borrelia spp., Rickettsia spp., Leishmania spp., and Anaplasma phagocytophilum) in equids in the state of Bahia, Brazil

BACKGROUND

Currently, various zoonotic diseases are classified as emerging or reemerging. Because equids have a direct relationship with various vectors, they are possibly more frequently exposed to zoonotic agents than are humans. The undeniable importance of diseases such as human granulocytic anaplasmosis, spotted fever, and leishmaniasis for both public and animal health, as well as the possibility of equids acting as sources, reservoirs, or even sentinels for these pathogens, justifies the detection of their frequency and factors associated with infection in equids from northeastern Brazil.

METHODS

Blood samples were collected from 569 equids (528 horses, 33 donkeys, and 8 mules), 516 from a rural area and 53 from an urban area. Pathogen detection was carried out as follows: Borrelia spp. and Rickettsia spp., serological analysis; Leishmania spp., serological analysis and polymerase chain reaction (PCR); Anaplasma phagocytophilum, PCR. Determination of associated factors was carried out through generalized linear models.

RESULTS

The frequencies of positivity for the pathogens observed in equids were as follows: Borrelia spp., 13.9% (79/569); Leishmania spp., 3.5% (20/569); Rickettsia spp. 33.4% (190/569). Regarding factors associated with infection, male sex was associated with protection against Borrelia spp.; donkeys and mules were associated with protection against Rickettsia spp., while a younger age was a risk factor. The infection of A. phagocytophilum was not detected in the sampled population. Co-infection was detected in 5.1% (29/569) of the animals.

CONCLUSIONS

Most of the studied pathogenic agents are present in the prospected area, indicating a possible risk for both human and animal health. This demonstrates that equids can be considered important sentinels in the assessment of pathogens with zoonotic potential in the region.

Detection of Leishmania infantum DNA in blood samples of horses (Equus caballus) and donkeys (Equus asinus) by PCR

Visceral leishmaniasis (VL) is a neglected tropical disease caused by the Leishmania infantum parasite. The protozoan is able to infect several domestic and wild mammals. Since the first report on Leishmania spp. infection in horses in South America, leishmaniasis in equids has been highlighted in Brazil. A molecular epidemiological survey was carried out to verify the occurrence of Leishmania spp. DNA in horses and donkeys, in leishmaniases endemic areas in Sao Paulo State, Brazil. To this end, blood samples were obtained from 107 horses and 36 donkeys and subjected to DNA extraction followed by PCR targeting the ITS-1 region. Among the horses and donkeys, 1.87% (2/107) and 8.33% (3/36) were positive by PCR, respectively. The DNA sequencing of the ITS-1 amplification products confirmed L. infantum DNA in these animals. Our results suggest that horses and donkeys from non-VL and VL endemic areas of São Paulo State may be infected by the parasite.

Detecting antibodies to Leishmania infantum in horses from areas with different epizooticity levels of canine leishmaniosis and a retrospective revision of Italian data

Background

Leishmania infantum is a vector-borne pathogen endemic in countries in the Mediterranean basin, including Italy. Dogs act as the primary reservoir for this parasite, but other animal species may also be infected. Low-to-moderate seroprevalence levels of infection have been reported in apparent healthy equine populations in southern Europe, reinforcing the importance of exploring those species, including horses, that act as a food source for vectors and may thus participate in the epizoological scenario of canine leishmaniosis (CanL) and zoonotic visceral leishmaniosis (ZVL). Since little is known regarding the exposure to L. infantum in horses in Italy, we assessed the seroprevalence in healthy equine populations from different CanL endemic areas.

Methods

The survey was conducted on 660 apparently healthy horses distributed throughout central and northern regions of Italy between 2016 and 2019. Blood samples were collected and the presence of anti-Leishmania antibodies (IgG) was investigated by the immunofluorescence antibody test. Information on the location and altitude of the stables, along with the horses’ breed, age, sex, and reproductive status was obtained by filling in a questionnaire. This was then used for statistical analysis by generalized linear models to explore risk factors associated with seroreactivity to L. infantum.

Results

An average seroprevalence of 13.9% was detected for L. infantum in the equine populations investigated, with statistically significant associations between seroprevalence, geographical variables (northern vs central Italy, origin and altitude) and individual factors (i.e. age and breed morphotype).

Conclusions

Our results highlight that horses are frequently exposed to L. infantum. Further prevalence surveys in horses, also using direct methods (e.g. PCR), are warranted to clarify the role of these hosts in the epidemiology of Leishmania in Italy.

Complex ecological interactions across a focus of cutaneous leishmaniasis in Eastern Colombia: novel description of Leishmania species, hosts and phlebotomine fauna

This study aimed to analyse the patterns of diversity, blood sources and Leishmania species of phlebotomines in a focus of cutaneous leishmaniasis in Arboledas, Eastern Colombia. In total, 1729 phlebotomines were captured in two localities (62.3% Siravita and 37.7% Cinera) and five environments of Norte de Santander. We identified 18 species of phlebotomines: Pintomyia ovallesi (29.8%), Psychodopygus davisi (20.3%), Pi. spinicrassa (18.5%) and Lutzomyia gomezi (15.8%) showed the highest abundance. Species diversities were compared between Cinera (15.00) and Siravita (20.00) and among five microenvironments: forest remnants (19.49), coffee plantations (12.5), grassland (12.99), cane plantations (11.66) and citrus plantations (12.22). Leishmania DNA was detected in 5.8% (80/1380) of females, corresponding mainly to Pi. ovallesi (22/80; 27.2%), Lu. gomezi (17/80; 21.3%) and Pi. spinicrassa (11/80; 13.8%). Leishmania species were 63.1% L. braziliensis, 18.5% L. panamensis, 13.2% L. infantum and 6.1% L. amazonensis. The most frequent feeding sources were Homo sapiens (50%), Bos taurus (13.8%) and Canis lupus familiaris (10.3%). This focus of cutaneous leishmaniasis has a high diversity of Leishmania-carrying phlebotomines that feed on domestic animals. The transmission of leishmaniasis to human hosts was mainly associated with Lu. gomezi, Pi. ovallesi and L. braziliensis.

Clinical aspects and diagnosis of leishmaniasis in equids: a systematic review and meta-analysis

Leishmaniases are a group of diseases of zoonotic importance caused by over 20 species of protozoa of the genus Leishmania, in which domestic dogs are considered to be the main reservoir for the disease. However, the involvement of other vertebrates as reservoirs for these parasites has also been investigated. Therefore, the objective of the present study was to carry out a systematic review with meta-analysis on occurrences of leishmaniasis in equids. The case reports described animals with cutaneous symptoms of leishmaniasis (papules, nodules, ulcers or crusts) that regressed spontaneously, located mainly on the head and limbs, from which three species of protozoa were identified in the lesions: Leishmania braziliensis, Leishmania infantum and Leishmania siamensis. In turn, the meta-analysis showed a combined prevalence of 25%, although with high heterogeneity among the studies, which was attributed to the use of different methods for diagnosing the disease. Leishmaniasis in equids is a benign disease but it should be included in the differential diagnosis of cutaneous diseases among these species. Seroepidemiological studies are important in investigating and monitoring suspected exposure of these hosts to the parasite, especially in endemic areas. However, there is also a need to standardize diagnostic methods.

Genomes of Leishmania parasites directly sequenced from patients with visceral leishmaniasis in the Indian subcontinent

Whole genome sequencing (WGS) is increasingly used for molecular diagnosis and epidemiology of infectious diseases. Current Leishmania genomic studies rely on DNA extracted from cultured parasites, which might introduce sampling and biological biases into the subsequent analyses. Up to now, direct analysis of Leishmania genome in clinical samples is hampered by high levels of human DNA and large variation in parasite load in clinical samples. Here, we present a method, based on target enrichment of Leishmania donovani DNA with Agilent SureSelect technology, that allows the analysis of Leishmania genomes directly in clinical samples. We validated our protocol with a set of artificially mixed samples, followed by the analysis of 63 clinical samples (bone marrow or spleen aspirates) from visceral leishmaniasis patients in Nepal. We were able to identify genotypes using a set of diagnostic SNPs in almost all of these samples (97%) and access comprehensive genome-wide information in most (83%). This allowed us to perform phylogenomic analysis, assess chromosome copy number and identify large copy number variants (CNVs). Pairwise comparisons between the parasite genomes in clinical samples and derived in vitro cultured promastigotes showed a lower aneuploidy in amastigotes as well as genomic differences, suggesting polyclonal infections in patients. Altogether our results underline the need for sequencing parasite genomes directly in the host samples

Visceral leishmaniasis (VL) is caused by parasitic protozoa of the Leishmania donovani complex and is lethal in the absence of treatment. Whole Genome Sequencing (WGS) of L. donovani clinical isolates revealed hitherto cryptic population structure in the Indian Sub-Continent and provided insights into the epidemiology and potential mechanisms of drug resistance. However, several biases are likely introduced during the culture step. We report here the development of a method that allows determination of parasite genomes directly in clinical samples, and validate it on bone marrow and splenic aspirates of VL patients in Nepal. Our study sheds a new light on the biology of Leishmania in the human host: we found that intracellular parasites of the patients had very low levels of aneuploidy, in sharp contrast to the situation in cultivated isolates. Moreover, the observed differences in genomes between intracellular amastigotes of the patient and the derived cultured parasites suggests polyclonality of infections, with different clones dominating in clinical samples and in culture, likely due to fitness differences. We believe this method is most suitable for clinical studies and for molecular tracking in the context of elimination programs.

Molecular identification of vector-borne organisms in Ehrlichia seropositive Nicaraguan horses and first report of Rickettsia felis infection in the horse

Certain vector-borne organisms serve as etiological agents of equine disease. After previously identifying a new Ehrlichia species in horses from Mérida, we aimed to determine the infection frequency and screen for a wide range of vector-borne organisms from 93 tick-exposed, Ehrlichia seropositive horses in this region. PCR assays were performed to identify infection by organisms within the following genera: Anaplasma, Babesia, Bartonella, Ehrlichia, Leishmania, Mycoplasma, Neorickettsia, Rickettsia and Theileria. Overall, 90/93 horses (96.8%) were infected with one or more vector-borne organisms. Ninety (96.8%) horses were infected with Theileria equi and 21 (26.8%) with Babesia caballi. Nine (9.7%) horses were infected with the novel Ehrlichia species previously designated H7, reported in horses from Nicaragua and Brazil. Two horses (2.2%) were infected with Rickettsia felis. Anaplasma, Bartonella, Leishmania, Mycoplasma, or Neorickettsia species DNA was not amplified from any horse. Ticks collected from horses infected with vector-borne organisms were identified as Amblyomma cajennense sensu lato and Dermacentor nitens. Horses in Mérida are infected by a range of vector-borne organisms, including B. caballi, T. equi, Ehrlichia species H7, and R. felis. To the authors' knowledge, this constitutes the first report of molecular detection of R. felis in horses.

Assessment of Leishmania infantum infection in equine populations in a canine visceral leishmaniosis transmission area

BACKGROUND

Leishmaniosis, zoonosis that produces significant public health impacts, is caused by Leishmania infantum. Canines are the main domestic reservoir and, besides humans, other species of mammals could be infected when living in endemic areas. In this study, we detected equine Leishmania infantum infections in a canine visceral leishmaniosis transmission area and evaluated the clinical, haematological, biochemical and oxidative stress disorders. This study was conducted in Uruguaiana, Rio Grande do Sul, south of Brazil. Peripheral blood samples were collected from 124 animals (98 horses and 26 dogs) of both genders and several breeds after they underwent general and dermatologic examinations.

RESULTS

Twenty five Leishmania infantum infected animals (20.16%), 14 horses and 11 dogs were detected by PCR (Polymerase Chain Reaction) amplification of kinetoplast DNA regions with 96% homology to Leishmania infantum (GenBank Accession No. L 19877.1). The clinical and haematological alterations of infected equines were skin lesions, nodules, lymphadenopathy, decreased levels in red blood cells and haematocrit (p < 0.05) and increase in urea serum concentration (p < 0.05), while CVL presented a decrease in red blood cells counts (p < 0.05), increase in lymphocytes (p < 0.05), and decrease in neutrophil-lymphocyte ratio (p < 0.05). Oxidative stress markers of plasma protein carbonyl and plasma lipid peroxidation were not statistically significant (p > 0.05) in both species.

CONCLUSIONS

To our knowledge, this has been the first leishmaniosis equine survey performed in south of Brazil, caused by Leishmania infantum that were able to initially identify haematological and biochemical changes in the species, even in asymptomatic animals. We present evidence supporting those findings of haematological and biochemical changes could be related to infection. Surprisingly, the clinical manifestations of equine infection were similar to those found in canine visceral leishmaniosis. The equine population could be play an important role in the cycle of leishmaniosis in south Brazil and consequently indicates a great risk of public health. This evaluation of infected animals is important to establish the clinical and laboratory parameters involved in the disease progression.

Molecular detection of Leishmania spp. in Brazilian cross-border south region mammalian hosts

Visceral leishmaniasis is an endemic zoonotic disease identified especially in developing territories. Brazil's northeast, southeast and midwest have been endemic for several years; currently, the infection is spreading to the south. Dogs are the main reservoirs; however, other mammal species have also been infected. Herein, we have identified the infecting Leishmania species in dogs and horses from the south of Brazil, a new outbreak of the infection. Blood samples were collected in the urban area of Uruguaiana city. DNA was extracted from peripheral blood, kinetoplast DNA (kDNA) and ribosomal DNA (rDNA) fragments were obtained by polymerase chain reaction (PCR) and sequenced. Out of 123 samples, 25 of them (14 dogs and 11 horses) were positive for Leishmania spp. Sequence alignment and phylogenetic analysis revealed that the kDNA in positive samples was similar to four species previously reported: L. infantum/L. chagasi, L. donovani, L. major. Despite kDNA minicircles regions are very useful due to high sensitivity to Leishmania spp. DNA detection, the sequence polymorphism among minicircles can be an obstacle to interspecific differentiation. Our results suggest that these strains are circulating in Brazil south region cross-border and indicate the susceptibility of new outbreak for visceral leishmaniasis infection in horses domiciled in endemic region for canine and human visceral leishmaniasis.

Infection of the equine population by Leishmania parasites

Infection of equids by Leishmania (L.) parasites was previously described in both the Old and New World, particularly in Central and South America. Equine cutaneous leishmaniasis (CL) is caused by the Leishmania species, L. Viannia (V.) braziliensis and L. infantum, previously identified in humans and other parasite hosts living in the same geographic endemic areas. Sporadic autochthonous clinical cases, with no travel history, were documented in several countries including Germany, Portugal, Spain, Texas and Brazil; L. infantum and L. (Mundinia) martiniquensis were the infectious species. Prevalence of subclinical infections is extremely low and CL is observed in only a small proportion of infected animals with the appearance of single or multiple cutaneous lesions located on the head, external ear, scrotum, legs and the neck. To date, there has been no report of visceral abnormalities. However, the mild clinical profile of the disease and its spontaneous regression may indicate that skin lesions related to Leishmania infection is underdiagnosed. Importantly, although the prevalence of Leishmania infections in the equine population is low, a risk may rise from its potential involvement in the parasite transmission cycles as a source of infection for phlebotomine vectors and susceptible mammalian hosts. This review article summarises our current knowledge of the epidemiology, clinical presentation and diagnosis of Leishmania-infected equids.

Serological and Molecular Findings of Leishmania Infection in Healthy Donkeys (Equus asinus) from a Canine Leishmaniosis Endemic Focus in Tuscany, Italy: A Preliminary Report

Leishmania parasites are considered to be emergent zoonotic pathogens, which is a new concept regarding their epidemiology and the identification of novel animal hosts. The present study is the first in Italy to evaluate anti Leishmania seroprevalence, and the first in Europe to detect parasite DNA in donkeys' blood. The study was performed on jennies living in a Leishmania infantum endemic area of Central Italy. One hundred and ten blood samples were obtained from 67 healthy lactating Amiatina jennies that were semi-extensively reared in Tuscany. When possible, more than one sample was subsequently obtained from the same subject. All samples were processed by immunofluorescence antibody test (IFAT) and by polymerase chain reaction (PCR). For the results, 11 out of 30 animals (36.7%) showed positive scores under IFAT. In addition, 22 out of the other 37 jennies had positive scores, also. The animals showed titers ranging from 40 to 320. Furthermore, 2 subjects that were submitted for 2 and 3 blood samplings, both had more than one positive score. Moreover, 2 seropositive animals were positive for Leishmania DNA. Donkeys are considered to be a preferred source for a sandfly blood meal, even if clinical leishmaniosis has never been reported in Europe for this animal species. In the view of these facts, our preliminary findings would suggest the role of donkey as a potential reservoir for this protozoan agent. Additional studies would be welcome to elucidate the role of the donkey in Leishmania epidemiology of CanL endemic areas and to confirm the preliminary findings and the hypothesis proposed here.

Molecular detection of Leishmania spp. in cattle from Brazil by means of PCR using internal transcribed spacer 1

Leishmania spp. are important agents of human and animal leishmaniases that have an important impact on public health. In this study, we aimed to detect the circulation of Leishmania spp. in cattle from a visceral leishmaniasis non-endemic area of the state of São Paulo, Brazil. DNA was extracted from blood samples from 100 heifers in the municipality of Pirassununga and was amplified using primers specific for the first internal transcriber spacer (ITS1), to assess the presence of trypanosomatids. The assays revealed that one sample presented bands of between 300 and 350 base pairs. In GenBank, this sample matched 100% with Leishmania infantum (314 base pairs). The results suggest that cattle can be infected by Leishmania infantum in Brazil.

Molecular detection of Leishmania infantum DNA according to clinical stages of leishmaniasis in dog

The aim of this study was to compare molecular tests used to diagnose Leishmania spp. in dogs with different stages of infection. Blood and conjunctival swab (CS) samples from dogs classified in four clinical stages were subjected to different PCR protocols (13A/13B, MC1/MC2, LITSR/L5.8S and LEISH-1/LEISH-2 primers). To the study, 22.3% (48/215) of dogs were classified as without clinical signs, 67.5% (145/215) stage I (mild disease), 7.0% (15/215) stage II (moderate disease) and 3.2% (7/215) stage III (severe disease). The results showed that in blood samples, 13A/13B detected a significant higher number of positive dogs in stage I (25/145) and in total (42/215) (p≤0.05). However, when CS samples were tested, no difference was observed (p>0.05). On the other hand, in blood samples, MC1/MC2 detected significantly fewer positive dogs classified as without clinical signs (0/48), in stage I (0/145) and in total (1/215) (p≤0.05). Likewise, in CS samples, this primers showed also lower detection (1/215) (p≤0.05). So than, we can conclude that PCR on blood samples with 13A/13B primers has greater capacity to detect positive dogs, mainly at the initial of clinical disease than do other primers and MC1/MC2 are not a good choice to detect Leishmania infantum infection in dogs.

Evaluation of Serum Biochemical Parameters, Structural Changes, Immunohistochemistry and Parasite Load in the Urinary System of Dogs Infected Naturally by Leishmania infantum

The aim of this study was to evaluate the histopathological changes in the urinary system and their correlation with serum biochemical parameters, parasite load and immunodetection of amastigotes in 30 dogs infected naturally by Leishmania infantum. The major histological changes were glomerulonephritis and interstitial nephritis. Serum biochemistry demonstrated that the dogs had progressive loss of renal function. L. infantum amastigotes were detected immunohistochemically in all parts of the urinary system, except the ureters. There was a correlation between parasite load, severity of histopathological changes and immunodetection of the parasites, but parasite load was not correlated with the serum biochemical parameters evaluated.

"BAIXADEIROS" HORSES: PREVALENCE OF ANTI-Trypanosoma spp. AND ANTI-Leishmania spp. ANTIBODIES

Abstract A total of 138 horse blood samples were collected from 2012 to 2013 for the subsequent separation of serum collection. For detection of anti-Leishmania spp. and anti-Trypanosoma spp. antibodies, indirect immunofluorescence reactions and immunoenzymatic assays were performed. Samples with titers ≥40 were considered positive in the indirect immunofluorescence (IFAT), and the cut off for the enzyme immunoassay (ELISA) was calculated with three standard deviations. When tested for Trypanosoma spp., 50.37% (68/135) of the samples were ELISA reagents, 18.84% (8/136) were positive for IFAT and 2.89% (4/138) for both tests. A significant statistical association was observed for the municipality (p = 0.013) and collection period (p = 0.042) in the ELISA. When tested for Leishmania spp., 25.4% (35/138) of the samples were ELISA reagents, 13.00% (18/138) were positive for the IFAT and 4.34% (6/138) were positive for two tests, there were no variables associated with seropositivity. A statistical association (p = 0.0034) was observed between the presence of anti-Trypanosoma spp. and anti-Leishmania spp. antibodies when the ELISA was used. The results suggest that this horse breed is in contact with leishmaniasis and trypanosomiasis, which demonstrates the need for a more accurate investigation into the real role of horses in these diseases to assist in disease control measures.

Molecular diagnosis of Trypanosoma cruzi/Leishmania spp. coinfection in domestic, peridomestic and wild mammals of Venezuelan co-endemic areas

American trypanosomiasis and leishmaniases are diseases caused by protozoans of the Trypanosomatidae family. In Venezuela, although several endemic foci of both diseases coincide, there are no reports of coinfection in mammals. The molecular diagnosis of the coinfection T. cruzi-Leishmania spp. was done in 527 blood samples collected on filter paper of several species of mammals (Canis familiaris, Equus asinus, Didelphis marsupialis, Equus mulus, Rattus rattus, Equus caballus, Artibeus fraterculus, Felis catus, Sus scrofa, Bos taurus, Capra hircus and Sciurus granatensis) from the states Cojedes, Aragua, Anzoátegui, Guárico, Miranda and Capital District. The T. cruzi infection was determined through PCR amplification of DNA of kinetoplast minicircles (kDNA) and satellite DNA (sDNA). The Leishmania spp. infection was detected by Leishmania nested PCR (Ln-PCR), and ribosomal DNA internal transcribed spacer 1 PCR (ITS1-PCR). The percentage of infection by T. cruzi was 23.5%, by Leishmania spp. 12.9% and coinfection was 5.7%. D. marsupialis was the species with the highest percentage of infection for each parasitosis (T. cruzi 34.3%, Leishmania spp. 20.0%) and coinfection (14.3%). Anzoátegui was the state with the highest percentage of infection for each parasitosis (T. cruzi 64.9%, Leishmania spp. 64.9%) and coinfection (43.2%). Infections were determined in species not reported as natural reservoirs of T. cruzi (E. asinus and E. mulus) and of Leishmania spp. (E. mulus and S. scrofa). Coinfection was a frequent phenomenon in mammals in several co-endemic zones evaluated.

Molecular and serological detection of Leishmania spp. in horses from an endemic area for canine visceral leishmaniasis in southeastern Brazil

ABSTRACT: This study aimed to verify the occurrence of Leishmania spp. and Leishmania (Leishmania) infantum in horses from a visceral leishmaniasis endemic area in Brazil. DNA samples from blood and conjunctival swab (CS) were tested by PCR and Indirect Immunofluorescence Antibody Test (IFAT). Although none of the horses was clinically sick, animals infected by Leishmania spp. were found and some could be characterized as infected by L. (L.) infantum. From 40 horses, 100% of the animals were positive by blood PCR, 90% (36/40) by CS PCR, and 2.5% (01/40) in serodiagnosis, by IFAT. Six from these 40 horses were L. (L.) infantum positive by blood PCR. Direct sequencing and analysis of amplicons resulted in a sequence to evolutionary analysis. Results indicate the presence of Leishmania spp. and L. (L.) infantum infecting healthy horses in Brazil. The presence of Leishmania spp. and L. (L.) infantum DNA in asymptomatic horses suggests that they can be important reservoirs of these parasites, a highly relevant finding for the epidemiological surveillance of the diseases they cause.

Canine Leishmaniasis: An Overview of the Current Status and Strategies for Control

Canine leishmaniasis (CanL) is a vector-borne disease caused by Leishmania infantum and is transmitted by female phlebotomine sand flies primarily between animals and secondarily to humans. The course of infection may be different from one individual dog to another, ranging from spontaneous cure to acute evolution that leads to death, if proper management and therapy are not adopted. A parasitological cure is rarely achieved and clinical recurrences in CanL are frequent. Vaccination associated with the use of topical insecticides is undoubtedly the most effective form of prevention and control of the disease. In order to integrate the most important scientific knowledge of the literature in one objective publication, this review proposes a short overview of the main points of CanL.

Detection of Leishmania DNA and Blood Meal Identification in Sand Flies (Diptera: Psychodidae) From Lençois Maranhenses National Park Region, Brazil

To elucidate portions of the transmission cycles of American tegumentary leishmaniasis (TL) and visceral leishmaniasis (VL) occurring in the region surrounding the Lençóis Maranhenses National Park, an important tourist center in Brazil, the present study objectives were to determine the rate of natural infection by Leishmania spp. and the blood meal in caught sand flies species in the region. Sand flies were captured over 36 mo in 62 locations of the municipality of Barreirinhas, Maranhão with notifications of disease incidence. Species identification of parasites was performed with internal transcribed spacer 1 (ITS1) PCR-RFLP using HaeIII enzyme. Blood meal identification was performed with cytochrome b (cytb) gene PCR-RFLP using HaeIII and MboI enzyme. The species Lutzomyia longipalpis (Lutz and Neiva 1912) presented a positivity rate of 3.7% for Leishmania infantum. Species not considered vectors of this parasite such as Lu. lenti (Mangabeira 1938) and Lu. whitmani (Antunes & Coutinho 1939) showed infection rates of 0.6% and 0.9%, respectively. Among the vectors of Leishmania spp. was Lu. whitmani with detection rate of 0.3% for Le. braziliensis and Lu. flaviscutellata (Mangabeira 1942) with a detection rate of 8% for Le. amazonensis. After restriction of amplification product encoding a 359bp sequence of the cytb recognized in as follows: pigs (37.9%); dogs (27.4%); chickens (20.9%); horses (9%), rodents (3.3%), and humans (1.4%). The presence of Leishmania DNA in sand flies fed with human blood and domestic animals in villages with transmission of VL and TL suggests that transmission could be occurring in the locations of the infected patients.

Leishmania infection and blood food sources of phlebotomines in an area of Brazil endemic for visceral and tegumentary leishmaniasis

The aims of the study were to determine the blood feeding preferences of sandflies and to identify species of Leishmania that infected phlebotomines in Caxias, Maranhão, Brazil, an area that is highly endemic for leishmaniasis. Sandflies were captured in light traps located in the peridomiciliary environments of randomly selected houses in urban and rural settings between 1800 and 0600 hours on new moon days between March 2013 and February 2015. DNA extracts from 982 engorged female sandflies were submitted to fragment length polymorphism analysis to identify infecting species of Leishmania, and blood sources were identified for 778 of these specimens. Infection by Leishmania infantum was detected in Lutzomyia longipalpis, Lu. whitmani and Lu. termitophila; L. infantum/L. braziliensis in Lu. longipalpis, Lu. whitmani and Lu. trinidadensis; L. shawi in Lu. longipalpis; L. mexicana in Lu. longipalpis; L. braziliensis in Lu. longipalpis and Lu. whitmani; L. guyanensis in Lu. longipalpis and Lu. termitophila; L. amazonensis in Lu. longipalpis and L. lainsoni or L. naiffi in Lu. longipalpis, while Lu. longipalpis and Lu. trinidadensis were infected with unidentified Leishmania sp. Blood sources were identified in 573 individual phlebotomines and the preferred hosts were, in decreasing order, chicken, dog, rodent and human with lower preferences for pig, horse, opossum and cattle. Lu. longipalpis and Lu. whitmani performed mixed feeding on man, dog and rodent, while Lu. longipalpis was the most opportunistic species, feeding on the blood of all hosts surveyed, but preferably on dog/chicken, dog/rodent and rodent/chicken. Our findings reveal the concomitant circulation of Leishmania species that cause visceral leishmaniasis and tegumentary leishmaniasis in the study area, and explain the occurrence of autochthonous human cases of both clinical forms of leishmaniasis in Caxias, Maranhão. The results support our hypothesis that, in the municipality of Caxias, transmission of Leishmania occurs in close proximity to humans.

Leishmania (V.) braziliensis infecting bats from Pantanal wetland, Brazil: First records for Platyrrhinus lineatus and Artibeus planirostris

In the New World genus Leishmania parasites are etiological agents of neglected zoonoses known as leishmaniasis. Its epidemiology is very complex due to the participation of several species of sand fly vectors and mammalian hosts, and man is an accidental host. Control is very difficult because of the different epidemiological patterns of transmission observed. Studies about Leishmania spp. infection in bats are so scarce, which represents a large gap in knowledge about the role of these animals in the transmission cycle of these pathogens, especially when considering that Chiroptera is one of the most abundant and diverse orders among mammals. Leishmaniasis in Mato Grosso do Sul, Brazil are remarkably frequent, probably due to the abundance of its regional mastofauna. The recent record of L. braziliensis in bats from this state indicates the need to clarify the role of these mammals in the transmission cycle. In this study we evaluated the presence of Leishmania parasites in the skin of different species of bats, using PCR directed to Leishmania spp. kDNA for screening followed by PCR/RFLP analysis of the hsp70 gene for the identification of parasite species. Leishmania species identification was confirmed by PCR directed to the G6PD gene of L. braziliensis, followed by sequencing of the PCR product. Samples from 47 bats were processed, of which in three specimens (6.38%) was detected the presence of Leishmania sp. kDNA. PCR/RFLP and sequencing identified the species involved in the infection as L. braziliensis in all of them. This is the first report of Leishmania braziliensis in bats from Pantanal ecosystem and the first record of this species in Platyrrhinus lineatus and Artibeus planirostris, bats with a wide distribution in South America. These results reinforce the need to deepen the knowledge about the possibility of bats act as reservoirs of Leishmania spp. especially considering their ability of dispersion and occupation of anthropic environments.

Seroepidemiology ofLeishmaniaspp. in equids from Uberlândia, Minas Gerais, Brazil

ABSTRACT: This study evaluated the occurrence of Leishmania spp. in equids from Uberlândia, Minas Gerais, Southeastern Brazil. Serum samples from 257 healthy equids of Uberlândia were assessed for the presence of antibodies against Leishmania spp. by using the indirect fluorescent-antibody test. Additionally, an epidemiological survey was done to evaluate the possible risk factors (species of equids, age, gender, economic activity, and contact with domestic and wild animals) associated with the presence of antibodies against Leishmania spp. The total seroprevalence against Leishmania spp. was 24.1% (62/257); representing seroprevalence levels of 22.7% (55/242) in horses, 50% (4/8) in mules, and 42.9% (3/7) in ponies from all regions evaluated. The species of equid was the only factor that contributed to an elevated seroprevalence of Leishmania spp.

Can equids be a reservoir of Leishmania braziliensis in endemic areas?

In this study, we detected Leishmania (Viannia) braziliensis infection in equids living in endemic regions of cutaneous leishmaniasis. To determine the role of these animals in the Leishmania cycle, we used two approaches: serological and molecular methods. Antibodies to the parasite were assayed using the Enzyme Linked Immunosorbent Assay (ELISA). Blood samples were collected and tested by polymerase chain reaction (PCR), and the positive products were sequenced. The results showed that 11.0% (25/227) of the equids were seropositive for Leishmania sp, and 16.3% (37/227) were PCR positive. Antibodies were detected in 20 horses, 3 donkeys, and 2 mules, and the parasite DNA was detected in 30 horses, 5 donkeys, and 2 mules. Sequencing the amplified DNA revealed 100% similarity with sequences for Viannia complex, corroborating the results of PCR for L. braziliensis. Our results show that equids are infected with L. braziliensis, which could be food sources for phlebotomines in the peridomiciliary environment and consequently play a role in the cutaneous leishmaniasis cycle.