Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 925
Filtrar
1.
Mem Inst Oswaldo Cruz ; 116: e200428, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33729396

RESUMO

BACKGROUND: Dogs are the main peridomiciliary reservoir of Leishmania infantum thus the correct diagnosis of infection is essential for the control of the transmission and treatment as well. However, the diagnosis is based on serological assays that are not fully effective. OBJECTIVE: We aimed to establish an effective serological assay for the diagnosis of L. infantum infected dogs using Leishmania-derived recombinant antigens. METHODS: Leishmania derived rK39-, rK28-, rKR95-based enzyme-linked immunosorbent assay (ELISA) was standardized using symptomatic and asymptomatic L. infantum-infected dogs. Then 2,530 samples from inquiry in endemic areas for VL were evaluated and the results compared with recommended assays by the Brazilian Ministry of Health (MH algorithm). Further samples from a cohort of 30 dogs were searched. FINDINGS: For rK39-, rK28- and rKR95-ELISA the sensitivity was around 97% and specificity 100%. The positivity of these three ELISA in the inquiry samples was 27-28%, around 10% higher than the assays currently in use. When cohort samples were searched, we observed likely false-negative results (> 65%) with supposedly negative samples that turned positive six months later with the assays in use (MH algorithm). MAIN CONCLUSIONS: For the diagnosis of L. infantum-infected dogs, rK39-based ELISA showed better diagnostic performance than other assays in use in Brazil and worldwide.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças do Cão/diagnóstico , Ensaio de Imunoadsorção Enzimática/normas , Ensaio de Imunoadsorção Enzimática/veterinária , Leishmania infantum/imunologia , Leishmaniose Visceral/diagnóstico , Animais , Antígenos de Protozoários/biossíntese , Brasil , Cães , Ensaio de Imunoadsorção Enzimática/métodos , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/sangue , Leishmaniose Visceral/veterinária , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade , Testes Sorológicos
2.
Am J Trop Med Hyg ; 103(5): 1930-1933, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32959759

RESUMO

There has been increased interest in using metagenomic next-generation sequencing as an unbiased approach for diagnosing infectious diseases. We describe a 61-year-old man on fingolimod therapy for multiple sclerosis with an extensive travel history who presented with 7 months of fevers, night sweats, and weight loss. Peripheral blood tests showed pancytopenia and abnormal acute phase reactants. A bone marrow aspirate showed the presence of numerous intracellular and extracellular amastigotes consistent with visceral leishmaniasis (VL). Metagenomic sequencing of the bone marrow aspirate confirmed Leishmania infantum, a species widely reported in the Mediterranean region. This correlated with acquisition of VL infection during the patient's most recent epidemiological exposure in southern Italy 12 months prior. This case demonstrates the potential application of metagenomic sequencing for identification and speciation of Leishmania in cases of VL; however, further assessment is required using other more readily obtained clinical samples such as blood.


Assuntos
Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/diagnóstico , Metagenômica , Medula Óssea/parasitologia , Humanos , Hospedeiro Imunocomprometido , Itália , Leishmania infantum/genética , Leishmaniose Visceral/parasitologia , Masculino , Pessoa de Meia-Idade , Viagem
3.
Parasitol Res ; 119(10): 3541-3548, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32803333

RESUMO

The aim of this study was to evaluate, through qPCR, the prevalence of parasitemia in sick kennel dogs naturally infected by canine leishmaniasis. An evaluation of daily changes of the parasitic load in peripheral blood was also performed. A comprehensive clinical examination and the collection of several samples (blood, lymph node, skin, and conjunctiva) were performed in 140 dogs living in an endemic area. Among these, only the dogs with clinically evident leishmaniasis were enrolled (39/140; 27.9%). Twelve (30.8%) out of 39 showed parasitemia, with a low load (median: 4 Leishmania/ml) despite a high lymph node parasite load (median: 4000 Leishmania/ml) and high IFAT titers (≥ 1:640). Seven sick dogs were sampled every 4 h for 6 times during a 24-h period, in order to obtain light- and dark-span samples. Only one (14.3%) out of the seven serial sampled dogs showed Leishmania DNA in the peripheral blood in two samples (2/42; 4.8%). Surprisingly, Leishmania DNA was also detected in the peripheral blood of asymptomatic dogs, negative to both serology and PCR performed on samples other than blood (6/101; 5.9%). The present study confirms that in canine leishmaniasis parasitemia is uncommon and even transitory. Even if recommended, microscopic examination is confirmed as a low sensitivity method with a lower diagnostic utility in canine leishmaniasis than qPCR. Moreover, circulating Leishmania DNA can be found even in healthy dogs. This finding is important in clinical practice because in endemic areas it suggests a transfusion risk and a possible transmission to the vector.


Assuntos
Doenças do Cão/parasitologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/veterinária , Parasitemia/veterinária , Animais , DNA de Protozoário/sangue , DNA de Protozoário/genética , Doenças do Cão/epidemiologia , Cães , Leishmania infantum/genética , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Carga Parasitária/veterinária , Parasitemia/epidemiologia , Parasitemia/parasitologia , Prevalência , Reação em Cadeia da Polimerase em Tempo Real/veterinária
4.
Acta Vet Scand ; 62(1): 42, 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32746875

RESUMO

Canine vector-borne diseases are caused by pathogens transmitted by arthropods including ticks, mosquitoes and sand flies. Many canine vector-borne diseases are of zoonotic importance. This study aimed to assess the prevalence of vector-borne infections caused by Dirofilaria immitis, Ehrlichia canis, Borrelia burgdorferi sensu lato, Anaplasma spp. and Leishmania infantum in a dog kennel in Argeș County, Romania. Dog kennels are shelters for stray dogs with no officially registered owners that are gathered to be neutered and/or boarded for national/international adoptions by various public or private organizations. The international dog adoptions might represent a risk in the transmission of pathogens into new regions. In this context, a total number of 149 blood samples and 149 conjunctival swabs from asymptomatic kennel dogs were assessed using serology and quantitative real-time polymerase chain reaction. Antibodies against B. burgdorferi s.l. were detected in one dog (0.6%), anti-Anaplasma antibodies were found in five dogs (3.3%), while ten dogs (6.7%) tested positive for D. immitis antigen. Overall, 20.1% (30/149) of dogs were positive for L. infantum DNA. All samples were seronegative for anti-Leishmania antibodies. When adopting dogs from this region of Romania, owners should be aware of possible infection with especially L. infantum. The travel of infected dogs may introduce the infection to areas where leishmaniasis is not present.


Assuntos
Anaplasmose/epidemiologia , Doenças do Cão/epidemiologia , Ehrlichiose/veterinária , Leishmaniose Visceral/veterinária , Doença de Lyme/veterinária , Anaplasma/isolamento & purificação , Anaplasmose/microbiologia , Animais , Anticorpos Antibacterianos/análise , Borrelia burgdorferi/isolamento & purificação , DNA de Protozoário/análise , Vetores de Doenças , Doenças do Cão/microbiologia , Doenças do Cão/parasitologia , Cães , Ehrlichia canis/isolamento & purificação , Ehrlichiose/epidemiologia , Ehrlichiose/microbiologia , Feminino , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Doença de Lyme/epidemiologia , Doença de Lyme/microbiologia , Masculino , Prevalência , Romênia/epidemiologia
5.
PLoS Negl Trop Dis ; 14(7): e0007986, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32716941

RESUMO

Genetic polymorphisms in natural Leishmania populations have been reported in endemic areas. Microsatellite typing is a useful tool to elucidate the genetic variability of parasite strains, due to its capability for high-resolution mapping of genomic targets. The present study employed multilocus microsatellite typing (MLMT) to explore the genotypic composition of Leishmania infantum in naturally infected dogs by genotyping parasites infecting different tissues with or without in vitro expansion. Eighty-six samples were collected from 46 animals in an endemic region of visceral leishmaniasis (VL). MLMT was performed for 38 spleen samples and 48 L. infantum cultures isolated from different tissues. Of the 86 samples, 23 were effectively genotyped by MLMT, identifying nine multilocus genotypes (MLG; referred to as MLG A-I). MLGs A, B and C were detected in more than one type of tissue and in more than one sample. Conversely, MLG D-I were uniquely detected in one sample each. The results showed that multiple genotype infections occur within a single host and tissue. Paired sample analysis revealed the presence of different MLMT alleles in 14 dogs, while the same MLG allele was present in 15 animals. STRUCTURE analysis demonstrated the presence of two populations; 13 samples displayed a similar admixture of both ancestral populations, and these were not assigned to any population. Only samples for which Q ≥ 0.70 after CLUMPP alignment were considered to be part of Population 1 (POP1) or Population 2 (POP2). POP2 comprised the majority of samples (n = 54) compared to POP1 (n = 19). This study presents evidence of multiple genotype infections (caused by L. infantum) in dogs in an area with high VL transmission. Further investigations must be undertaken to determine the effects of multiple infection on the host immune response and disease dynamics and treatment.


Assuntos
Doenças do Cão/parasitologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/veterinária , Animais , Cães , Feminino , Variação Genética , Genótipo , Leishmania infantum/classificação , Leishmania infantum/genética , Leishmaniose Visceral/parasitologia , Masculino , Repetições de Microssatélites , Filogenia
6.
Am J Trop Med Hyg ; 103(4): 1490-1492, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32720633

RESUMO

Human visceral leishmaniasis (HVL) is a parasitic disease infecting children in the Mediterranean region. Here, we portray a case of a 2-year-old child with an epidemiological description of the situation surrounding the case. The patient was suffering from recurrent fever, weakness, and abdominal discomfort associated with loss of appetite. Routine blood investigations showed pancytopenia, whereas examination revealed hepatomegaly. A diagnosis of HVL was made by demonstrating amastigotes in a Giemsa-stained smear from a bone marrow aspirate followed by genotyping by PCR and sequencing. In conclusion, early detection of VL infection followed by appropriate treatment protocols is essential to saving the patient.


Assuntos
Medula Óssea/parasitologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral , Animais , Gluconato de Antimônio e Sódio/uso terapêutico , Antiprotozoários/uso terapêutico , Pré-Escolar , Reservatórios de Doenças , Cães/parasitologia , Diagnóstico Precoce , Feminino , Humanos , Insetos Vetores , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/patologia , Oriente Médio/epidemiologia , Phlebotomus/parasitologia
7.
Rev Bras Parasitol Vet ; 29(2): e003520, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32520088

RESUMO

Blood samples and swabs from ocular conjunctiva and mouth were obtained from 64 cats. Of 64 serum samples, 19 were positive for Leishmania antibodies by ELISA (29.80%). Eight cats were positive by PCR (12.5%) in swab samples from mouth and/or ocular mucosa. Poor kappa agreement between serological and molecular results (k = 0.16) was obtained. From five positive PCR samples one was L. braziliensis and four were L. infantum. Phylogenetic analysis performed with the five isolates of Leishmania, showed that samples of L. infantum isolated from the cats were phylogenetically close to those isolated from domestic dogs in Brazil, while the L. braziliensis is very similar to the one described in humans in Venezuela. The study demonstrated that, despite high seropositivity for Leishmania in cats living in the study region, poor agreement between serological and molecular results indicate that positive serology is not indicative of Leishmania infection in cats. Parasite DNA can be detected in ocular conjunctiva and oral swabs from cats, indicating that such samples could be used for diagnosis. Results of phylogenetic analyzes show that L. infantum circulating in Brazil is capable of infecting different hosts, demonstrating the parasite's ability to overcome the interspecies barrier.


Assuntos
Doenças do Gato/parasitologia , Leishmania braziliensis/isolamento & purificação , Leishmania infantum/isolamento & purificação , Leishmaniose/parasitologia , Animais , Anticorpos Antiprotozoários/sangue , Doenças do Gato/diagnóstico , Gatos , DNA de Protozoário/análise , Ensaio de Imunoadsorção Enzimática/veterinária , Leishmania braziliensis/genética , Leishmania braziliensis/imunologia , Leishmania infantum/genética , Leishmania infantum/imunologia , Leishmaniose/diagnóstico , Filogenia , Reação em Cadeia da Polimerase/veterinária
8.
BMC Infect Dis ; 20(1): 401, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32503461

RESUMO

BACKGROUND: Visceral leishmaniasis is an important but neglected disease that is spreading and is highly lethal when left untreated. This study sought to measure the Leishmania infantum seroprevalence in dogs, the coverage of its control activities (identification of the canine reservoir by serological survey, dog culling and insecticide spraying) and to evaluate its relationship with the occurrence of the disease in humans in the municipalities of Araçatuba and Birigui, state of São Paulo, Brazil. METHODS: Information from 2006 to 2015 was georeferenced for each municipality and modeling was performed for the two municipalities together. To do this, latent Gaussian Bayesian models with the incorporation of a spatio-temporal structure and Poisson distribution were used. The Besag-York-Mollie models were applied for random spatial effects, as also were autoregressive models of order 1 for random temporal effects. The modeling was performed using the INLA (Integrated Nested Laplace Approximations) deterministic approach, considering both the numbers of cases as well as the coverage paired year by year and lagged at one and two years. RESULTS: Control activity coverage was observed to be generally low. The behavior of the temporal tendency in the human disease presented distinct patterns in the two municipalities, however, in both the tendency was to decline. The canine serological survey presented as a protective factor only in the two-year lag model. CONCLUSIONS: The canine serological coverage, even at low intensity, carried out jointly with the culling of the positive dogs, suggested a decreasing effect on the occurrence of the disease in humans, whose effects would be seen two years after it was carried out.


Assuntos
Formigas/parasitologia , Doenças do Cão/diagnóstico , Doenças do Cão/patologia , Leishmaniose Visceral/patologia , Animais , Teorema de Bayes , Brasil/epidemiologia , Doenças do Cão/epidemiologia , Cães , Humanos , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/epidemiologia , Distribuição de Poisson , Fatores de Risco , Estudos Soroepidemiológicos
9.
Hautarzt ; 71(6): 437-442, 2020 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-32394080

RESUMO

Here we describe two complicated cases of complex Old World cutaneous Leishmaniasis due to L. infantum and L. aethiopica. Both of our patients infected with the Leishmania parasite presented with a completely different clinical picture, course of disease, and treatment response. Clinical healing was achieved after multiple courses of treatment with a variety of different antileishmanial drugs. Nephrotoxity was a limiting side effect.


Assuntos
Leishmania infantum/isolamento & purificação , Leishmania/isolamento & purificação , Leishmaniose Cutânea/diagnóstico , Anti-Infecciosos/efeitos adversos , Anti-Infecciosos/uso terapêutico , Antiprotozoários/efeitos adversos , Antiprotozoários/uso terapêutico , Progressão da Doença , Humanos , Leishmania/classificação
10.
Vet Ital ; 56(1)2020 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-32343094

RESUMO

Canine Leishmaniasis caused by Leishmania infantum is endemic in Mediterranean countries. The disease represents an important public health issue in Kosovo in which the autochthonous cases by humans were reported in the last years. The objective of this study was to survey the serological and clinical data of Canine Leishmaniasis in dogs in southwestern region of Kosovo. The blood samples were collected from stray dogs in four municipalities, respectively Prizren, Gjakova, Rahovec and Deçan. The total 125 samples were collected between April/September 2016. Antibodies of Leishmania infantum were detected by competitive enzyme-linked immunosorbent assay (ELISA IgG). Out of total 125 serum samples, 23 dogs (18.4%) were positive for Leishmania infantum. In three of 23 infected dogs (13%) were shown the clinical signs of Canine Leishmaniasis as skin and ocular lesions, decreased appetite, lameness, diarrhea, lethargy and progressive weight loss. The highest infection rate was detected in Prizren municipality (21.6%), followed by Gjakova (17.6%), Rahovec (17.1%) and Deçan (7.8%). The present study confirmed that the Leishmaniasis is endemic in southwestern part of Kosovo and emphasized the need to establish the surveillance and control of this disease.


Assuntos
Doenças do Cão/epidemiologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/veterinária , Animais , Doenças do Cão/sangue , Cães , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Kosovo/epidemiologia , Leishmaniose Visceral/epidemiologia , Masculino , Prevalência
11.
PLoS Negl Trop Dis ; 14(4): e0008253, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32324738

RESUMO

BACKGROUND: In the Mediterranean basin, Leishmania infantum is the causative agent of visceral leishmaniasis (VL), a zoonosis in which the dog is the primary domestic reservoir, although wildlife may have a leading role in the sylvatic cycle of the disease in some areas. Infections without disease are very frequent. There is limited information regarding the role that VL patients and asymptomatic infected individuals could be playing in the transmission of L. infantum. Xenodiagnosis of leishmaniasis has been used in this descriptive study to explore the role of symptomatic and asymptomatic infected individuals as reservoirs in a recent focus of leishmaniasis in southwestern Madrid, Spain. METHODOLOGY AND MAIN FINDINGS: Asymptomatic blood donors (n = 24), immunocompetent patients who were untreated (n = 12) or treated (n = 11) for visceral leishmaniasis (VL), and immunocompromised patients with VL (n = 3) were enrolled in the study. Their infectivity to Phlebotomus perniciosus was studied by indirect xenodiagnosis on peripheral blood samples. Quantitative polymerase chain reaction of blood samples from immunocompetent patients untreated for VL and immunocompromised untreated, treated and under secondary prophylaxis for VL was performed. Antibodies against Leishmania were studied by indirect fluorescent antibody and rK39-immunochromatographic tests. A lymphoproliferative assay with a soluble Leishmania antigen was used to screen for leishmaniasis infection in the healthy population. Sixty-two xenodiagnostic tests were carried out and 5,080 sand flies were dissected. Positive xenodiagnosis was recorded in four patients, with different sand fly infection rates: 1 immunosuppressed HIV / L. infantum coinfected asymptomatic patient, 1 immunosuppressed patient with multiple myeloma and symptomatic active VL, and 2 immunocompetent patients with untreated active VL. All blood donors were negative for both xenodiagnosis and conventional PCR. CONCLUSIONS / SIGNIFICANCE: There is no consensus amongst authors on the definition of an 'asymptomatic case' nor on the tools for screening; we, therefore, have adopted one for the sake of clarity. Immunocompetent subjects, both infected asymptomatics and those treated for VL, are limited in number and appear to have no epidemiological relevance. The impact is limited for immunocompetent patients with untreated active VL, whilst immunosuppressed individuals undergoing immunosuppressive therapy and immunosuppressed individuals HIV / L. infantum coinfected were the most infectious towards sand flies. It is noteworthy that the HIV / L. infantum coinfected patient with asymptomatic leishmaniasis was easily infectious to sand flies for a long time, despite being under continuous prophylaxis for leishmaniasis. Accordingly, screening for latent Leishmania infection in HIV-infected patients is recommended in scenarios where transmission occurs. In addition, screening for VL in HIV-infected patients who have spent time in VL-endemic areas should also be implemented in non-endemic areas. More research is needed to better understand if some asymptomatic coinfected individuals contribute to transmission as 'super-spreaders'.


Assuntos
Reservatórios de Doenças , Transmissão de Doença Infecciosa , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/transmissão , Adulto , Animais , Anticorpos Antiprotozoários/sangue , Doenças Assintomáticas/epidemiologia , DNA de Protozoário/sangue , Feminino , Humanos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Psychodidae/parasitologia , Espanha/epidemiologia
12.
Acta Trop ; 207: 105495, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32305295

RESUMO

The applicability of molecular biology/PCR for canine visceral leishmaniasis diagnosis presents challenges, mainly due to the diversity of targets described. The objectives of this study were to compare the sensitivities and reliability of five targets (kDNA/120, kDNA/145, ITS1, hsp70/234 and hsp70/1300) in four different tissue samples (bone marrow, popliteal lymph node, skin and conjunctival swab). Sixty-five dogs (32 males and 33 females) naturally infected with Leishmania infantum and ten dogs without infection were examined. Dogs were characterized by serological and parasitological methods. The parasitological test was considered the gold standard for analysis. All tests presented high specificity 100% (95% CI 0.72-1), and variable sensitivity. The targets kDNA/145, ITS1, kDNA/120, hsp70/234 and hsp70/1300 detected 100% (65/65), 93.4% (61/65), 92.3% (60/65), 84.61% (55/65) and 72.3% (77/65) of positive animals respectively. The performance of PCR methods was analyzed in two different scenarios. The highest sensitivity value identified in all scenarios studied was kDNA/145. Our results suggest that popliteal lymph node and conjunctival swab samples, besides being less invasive collections, represent a good substratum for PCR-based diagnosis, and the target kDNA/145 is the best choice for detecting L. infantum DNA in naturally infected dogs.


Assuntos
Doenças do Cão/diagnóstico , Cães/parasitologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/veterinária , Reação em Cadeia da Polimerase/métodos , Animais , DNA de Cinetoplasto/genética , Feminino , Leishmania infantum/genética , Masculino
13.
Rev Soc Bras Med Trop ; 53: e20190446, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32130324

RESUMO

INTRODUCTION: Visceral leishmaniasis (VL) represents a public health concern in several areas of the world. In the American continent, VL transmission is typically zoonotic, but humans with active VL caused by Leishmania infantum are able to infect sandflies. Thus, individuals with cutaneous parasitic infections may act as reservoirs and allow interhuman transmission. Additionally, the skin may be responsible for reactivation of the disease after therapy. This study's objective was to evaluate cutaneous parasitism in humans with VL in an American endemic area. METHODS: A cross-sectional hospital-based study was conducted in northeast Brazil from October 2016 to April 2017. Biopsies of healthy skin for histopathology and immunohistochemistry were performed prior to treatment in all study patients. RESULTS: Twenty-two patients between the ages of five months to 78 years were included in the study. Seven patients (31.8%) tested positive for HIV. Only one patient had cutaneous parasitism, as confirmed by immunohistochemistry prior to treatment. Parasitism was not detected after treatment. CONCLUSIONS: Cutaneous parasitism in the healthy skin of humans with visceral leishmaniasis, although unusual, may be a source of infection for phlebotomine sandflies.


Assuntos
Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/parasitologia , Pele/parasitologia , Adolescente , Adulto , Idoso , Biópsia , Criança , Pré-Escolar , Estudos Transversais , Escolaridade , Doenças Endêmicas , Feminino , Humanos , Imuno-Histoquímica , Lactente , Leishmaniose Visceral/patologia , Masculino , Pessoa de Meia-Idade , Pele/patologia , Adulto Jovem
14.
PLoS Negl Trop Dis ; 14(3): e0008077, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32214313

RESUMO

BACKGROUND: Phlebotomus (Larroussius) perniciosus and Canis familiaris are respectively the only confirmed vector and reservoir for the transmission of Leishmania (L.) infantum MON-1 in Tunisia. However, the vector and reservoir hosts of the two other zymodemes, MON-24 and MON-80, are still unknown. The aim of this study was to analyze the L. infantum life cycle in a Tunisian leishmaniasis focus. For this purpose, we have focused on: i) the detection, quantification and identification of Leishmania among this sand fly population, and ii) the analysis of the blood meal preferences of Larroussius (Lar.) subgenus sand flies to identify the potential reservoirs. METHODOLOGY AND FINDINGS: A total of 3,831 sand flies were collected in seven locations from the center of Tunisia affected by human visceral leishmaniasis. The collected sand flies belonged to two genus Phlebotomus (Ph.) (five species) and Sergentomyia (four species). From the collected 1,029 Lar. subgenus female sand flies, 8.26% was positive to Leishmania by ITS1 nested PCR. Three Leishmania spp. were identified: L. infantum 28% (24/85), L. killicki 13% (11/85), and L. major 22% (19/85). To identify the blood meal sources in Ph. Lar. subgenus sand flies, engorged females were analyzed by PCR-sequencing targeting the vertebrate cytochrome b gene. Among the 177 analyzed blood-fed females, 169 samples were positive. Sequencing results showed seven blood sources: cattle, human, sheep, chicken, goat, donkey, and turkey. In addition, mixed blood meals were detected in twelve cases. Leishmania DNA was found in 21 engorged females, with a wide range of blood meal sources: cattle, chicken, goat, chicken/cattle, chicken/sheep, chicken/turkey and human/cattle. The parasite load was quantified in fed and unfed infected sand flies using a real time PCR targeting kinetoplast DNA. The average parasite load was 1,174 parasites/reaction and 90 parasites/reaction in unfed and fed flies, respectively. CONCLUSION: Our results support the role of Ph. longicuspis, Ph. perfiliewi, and Ph. perniciosus in L. infantum transmission. Furthermore, these species could be involved in L. major and L. killicki life cycles. The combination of the parasite detection and the blood meal analysis in this study highlights the incrimination of the identified vertebrate in Leishmania transmission. In addition, we quantify for the first time the parasite load in naturally infected sand flies caught in Tunisia. These findings are relevant for a better understanding of L. infantum transmission cycle in the country. Further investigations and control measures are needed to manage L. infantum transmission and its spreading.


Assuntos
DNA/análise , Comportamento Alimentar , Conteúdo Gastrointestinal/química , Conteúdo Gastrointestinal/parasitologia , Especificidade de Hospedeiro , Leishmania infantum/isolamento & purificação , Phlebotomus/fisiologia , Animais , DNA/genética , Impressões Digitais de DNA , DNA Espaçador Ribossômico/genética , Transmissão de Doença Infecciosa , Feminino , Humanos , Leishmania infantum/genética , Masculino , Phlebotomus/parasitologia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Tunísia
15.
Parasitol Res ; 119(4): 1381-1386, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32107620

RESUMO

The prevalence data of Leishmania infantum infection in cats are characterized by a large variability mainly attributed to the differences in diagnostic techniques. In the absence of consensus about the method of choice for diagnosing feline leishmaniosis, the performance of a new immunofluorescence antibody test (IFAT) was herein analytically described by the comparison with IFAT commonly used for the diagnosis of canine leishmaniosis (i.e., IFAT-OIE) and a laboratory enzyme-linked immunosorbent assay (ELISA). Sera of cats living in visceral leishmaniosis-endemic (n = 105) and visceral leishmaniosis-non-endemic (n = 50) areas were tested by the above methodologies and real-time PCR (qPCR). The most frequent result was represented by triple negativity to the three tests (IFAT-OIE, ELISA, and qPCR) in 42.9% and 80% cats from endemic and non-endemic areas, respectively. Bayes latent class analysis gave an output probability of 34.1% (posterior standard deviation, psd = 5.4%) of true L. infantum cases (TCL) which represent the true estimated prevalence of infection. The sensitivity of each variable contributing to define the TCL was 24% (psd = 6.3%) for qPCR, 78.8% (psd = 8.7%) for ELISA and 91.8% (psd = 5.2%) for IFAT-OIE. The probability to be a TCL was 94.5% for the sample from an endemic area. The cross-validation of the new IFAT by a logistic model correctly identified as positive 80.7% of subjects defined as TCL and negative 89.9% as not TCL, respectively, by the Bayesian model. The study results estimate a good accuracy of the IFAT in predicting cats exposed to L. infantum. Therefore, this procedure may be beneficial for screening cat populations for a better understanding of the epidemiology of feline leishmaniosis.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças do Gato/diagnóstico , Técnica Direta de Fluorescência para Anticorpo/métodos , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/veterinária , Animais , Teorema de Bayes , Doenças do Gato/epidemiologia , Doenças do Gato/parasitologia , Gatos , Ensaio de Imunoadsorção Enzimática/veterinária , Leishmania infantum/genética , Leishmaniose Visceral/diagnóstico , Masculino , Reação em Cadeia da Polimerase em Tempo Real/veterinária
16.
Acta Trop ; 204: 105342, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31954137

RESUMO

In the Mediterranean basin, sand flies are vectors of Leishmania parasites and phleboviruses affecting humans and animals. In this study, we aimed to investigate phlebovirus and Leishmania parasites circulating in a focus of zoonotic visceral leishmaniasis (ZVL) located in a highly irrigated area within the arid Central Tunisia, known mainly to be endemic for zoonotic cutaenous leishmaniasis (ZCL) caused Leishmania major and transmitted by Phlebotomus papatasi. Sand flies were collected using CDC light traps in the village of Saddaguia, an emergent focus of ZVL located in Central Tunisia during September-October 2014, 2015, and 2016. Pools of live female sand flies were screened for phleboviruses and Leishmania by nested PCR in the polymerase gene and kinetoplast minicircle DNA, respectively. Dead sand flies were identified morphologically to species level. Sand flies of the subgenus Larroussius mainly Phlebotomus perfiliewi, Phlebotomus perniciosus, and Phlebotomus longicuspis were predominant in this ZVL focus compared to P. papatasi. A total of 1932, 1740, and 444 sand flies were tested in 2014, 2015 and 2016, respectively. Pathogen screening performed on 4116 sand flies distributed in 148 pools revealed the presence of Leishmania infantum and Toscana virus. The minimum infection rates of sand flies with TOSV in 2014, 2015, and 2016 were 0.05%, 011%, and 0.22%, respectively. The minimum infection rates of sand flies with L. infantum in 2014, 2015, and 2016 were 0.25%, 012%, and 0.79%, respectively. No L. major was detected during the 3-years investigation in this ZVL focus. Our results showed clearly the endemic co-circulation of TOSV and L. infantum in this emergent ZVL focus. However, no co-infection of TOSV and L. infantum was detected in any of the sand fly pools investigated during the three years period. TOSV was isolated from positive pools in 2015. Phylogenetic analysis showed that the Tunisian strains of TOSV belonged to the sublineage A. Based on the present findings, our results provided strong evidence that TOSV and L. infantum are transmitted by the same predominant sand fly species of the subgenus Larroussius, and subsequently, humans and dogs could be co-infected through co-infected or successive infected bites. Our results showed clearly that the development of irrigation in arid areas contributed significantly to the establishment of stable transmission cycles of L. infantum and TOSV and subsequently to the emergence of a ZVL focus within this arid bio-geographical area characterized by the presence of multiple foci of ZCL located outside the study site. Thus, more studies are needed to better understand the impact of RNA viruses shared by vectors and reservoir hosts of L. infantum on the development of zoonotic visceral leishmaniasis.


Assuntos
Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/epidemiologia , Vírus da Febre do Flebótomo Napolitano/isolamento & purificação , Zoonoses/epidemiologia , Animais , Cães , Feminino , Humanos , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/virologia , Phlebotomus/parasitologia , Tunísia/epidemiologia , Zoonoses/parasitologia , Zoonoses/virologia
17.
Prev Vet Med ; 175: 104874, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31901603

RESUMO

A molecular survey of wild mammals was performed to assess their potential as reservoirs of L. infantum. A total of 156 specimens of wild mammalian fauna were obtained for analysis from areas in Catalonia with a reported incidence of canine leishmaniasis. They consisted of 124 small mammals: 35 Mus spretus (Muridae); 64 Erinaceus europaeus (Erinaceidae), 25 Sciurus vulgaris (Sciuridae) and 32 carnivores: 11 Vulpes vulpes (Canidae), 1 Felis catus (Felidae), 15 Meles meles, 4 Martes foina and 1 Mustela vison (Mustelidae). The analysis was performed on samples of liver, spleen, skin (ear) and blood extracted from the heart. Leishmania DNA was determined by a qPCR and specific anti-Leishmania antibodies were detected by an in-house (ELISA). Among the 156 specimens studied, 29.48% were positive in at least one of the samples studied and considered infected. In M. spretus, Leishmania DNA was detected in the liver, spleen or skin of 37.1% of 35 specimens, and 2 of the 13 specimens tested serologically were positive (15.38%). In E. europaeus, 34.4% of the 64 specimens were infected. Leishmania DNA was detected in 19/51 spleens and 5/50 skins; 2 of the 37 specimens analysed in both spleen and skin gave positive results in both samples. Serology was positive in 12.8% (6/47) by ELISA; 3 specimens were positive by both ELISA and qPCR. In S. vulgaris, Leishmania DNA was detected in 5 of 25 specimens (20%). Of the 32 carnivore specimens analysed, Leishmania DNA was detected in both samples studied (spleen and liver) of 4 (12.5%) (2 M. foina, 1 M. vison and 1 F. catus), which were not studied serologically. The data obtained indicate that small mammals, above all wild rodents and carnivores, could act as naturally infected hosts of L. infantum in this endemic area. Among the rodents, M. spretus stands out with the highest prevalence of infection. In E. europaeus, the presence of L. infantum DNA in spleen and skin, and antibodies in heart blood, reported here for the first time, indicates this small mammal could be a possible reservoir. Additionally, S. vulgaris, not previously studied as an L. infantum reservoir, showed non-negligible prevalence values, indicating a potential role in leishmaniasis transmission.


Assuntos
Carnívoros , Reservatórios de Doenças/veterinária , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/epidemiologia , Doenças dos Roedores/epidemiologia , Roedores , Animais , Animais Selvagens , Reservatórios de Doenças/parasitologia , Leishmaniose Visceral/parasitologia , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Doenças dos Roedores/parasitologia , Espanha/epidemiologia
18.
Transbound Emerg Dis ; 67(1): 318-327, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31512804

RESUMO

The objective of this study was to identify changes in serum proteome in dogs that may occur after an experimental infection at subclinical and clinical stages of canine leishmaniosis (CanL). For this purpose, canine pre- and post-infection with Leishmania infantum serum proteomes in the same dogs were analysed by a high-throughput label-based quantitative LC-MS/MS proteomic approach. A total of 169 proteins were identified, and 74 of them including complement C8 alpha chain, adiponectin, transferrin, sphingomyelin phosphodiesterase acid-like 3A and immunoglobulins showed different modulation between the different stages of CanL. These proteins could be considered as potential serum biomarkers of early diagnostic or disease progression in CanL. Additionally, biological pathways modulated during CanL such as blood coagulation or gonadotropin-releasing hormone receptor were revealed, which could help to understand the pathological mechanisms of the disease.


Assuntos
Biomarcadores/sangue , Doenças do Cão/sangue , Leishmania infantum/metabolismo , Leishmaniose Visceral/veterinária , Proteoma , Animais , Cromatografia Líquida/veterinária , Doenças do Cão/fisiopatologia , Doenças do Cão/virologia , Cães , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/sangue , Leishmaniose Visceral/fisiopatologia , Leishmaniose Visceral/virologia , Proteômica , Espectrometria de Massas em Tandem/veterinária
19.
Am J Trop Med Hyg ; 102(2): 289-293, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31802736

RESUMO

American visceral leishmaniasis (VL) is a vector-borne disease caused by Leishmania infantum (syn. chagasi) and transmitted by Lutzomyia longipalpis and Lutzomyia evansi phlebotomine sand flies. Dogs not only are the main host reservoirs of the parasite but also suffer the disease; therefore, canine VL (CVL) has assumed an important role in public health. In Colombia, human and CVL are restricted to two transmission foci: one in the north region (Caribbean coast) and other in the central south region (middle Magdalena River Valley). We present a CVL case involving a 2-year-old male dog with a history of lack of appetite, general weakness, and progressive loss of weight. A diagnosis of CVL was obtained using the direct parasitological examination in spleen and bone marrow samples stained with Giemsa and RT-qPCR. The infecting Leishmania species was identified as L. infantum by PCR-restriction fragment length polymorphism amplifying the Hsp70 gene from bone marrow and spleen samples and confirming by sequencing. The patient responded favorably to treatment with intramuscular meglumine antimoniate at a dose of 100 mg/kg daily for 8 weeks and oral allopurinol at a dose of 10 mg/kg every 12 hours until new indication. This is the first report of urban CVL in the city of Cali, Colombia, highlighting the need for surveillance and control programs in the municipalities of the department of Valle del Cauca, a region where VL has not been informed before. The findings also indicate the need to reinforce the surveillance programs in other rural and urban regions of the country where favorable eco-epidemiological conditions exist.


Assuntos
Doenças do Cão/parasitologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/veterinária , Alopurinol/uso terapêutico , Animais , Antimetabólitos/uso terapêutico , Antiprotozoários/uso terapêutico , Sequência de Bases , Cidades/epidemiologia , Colômbia/epidemiologia , DNA de Protozoário/genética , DNA de Protozoário/isolamento & purificação , Doenças do Cão/epidemiologia , Cães , Leishmania infantum/genética , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/epidemiologia , Masculino , Antimoniato de Meglumina/uso terapêutico
20.
Rev. bras. parasitol. vet ; 29(1): e009819, 2020. graf
Artigo em Inglês | LILACS | ID: biblio-1058019

RESUMO

Abstract The aim of this study was to confirm the emergence of canine visceral leishmaniasis among dogs in Foz do Iguaçu. The disease was diagnosed through the isolation and molecular identification of Leishmania infantum. In the first sample collection stage (2012), three lymph node aspirates and 46 buffy coat samples were obtained mostly from the dogs that were seroreagents for leishmaniasis. In the second sample collection stage (2013), the buffy coat samples were collected from 376 dogs located close to Paraguay, Paraná river, center and peripheral parts of the city. The DNA from the six isolates, four from the first sampling stage (4/49) and two from the second sampling stage (2/376), was subjected to polymerase chain reaction using the K26F/R primers. The isolate was confirmed as L. infantum by sequencing. As none of the dogs had ever left the city, the isolates were confirmed as autochthonous. Further, the study confirmed the emergence of canine visceral leishmaniasis in Paraná through the identification of L. infantum among dogs in Foz do Iguaçu city. Hence, collaborative control measures should be designed and implemented by the public agencies and research institutions of Brazil, Argentina, and Paraguay to control the spread of visceral leishmaniasis.


Resumo O objetivo deste estudo foi confirmar a emergência da leishmaniose visceral canina em Foz do Iguaçu próximo à fronteira com a Argentina e ao Paraguai, por meio do isolamento e identificação molecular de Leishmania infantum. Em um primeiro estágio de coleta de animais (2012), três amostras de aspirados de linfonodos e 46 camadas leucocitárias foram obtidas de cães soropositivos para leishmaniose. Em um segundo estágio de coleta (2013), foram coletadas amostras de camada leucocitária de 376 cães de 20 localidades próximas à fronteira com o Paraguai, rio Paraná, centro e periferia da cidade. Seis isolados foram obtidos, quatro da primeira etapa (4/49) e dois da segunda etapa (2/376); estes isolados foram submetidos à amplificação com iniciadores K26F/R, e a análise de sua sequência confirmou a espécie como L. infantum. A autoctonia dos casos foi confirmada, pois 100% dos cães nunca haviam saído da cidade. O estudo confirma a emergência de leishmaniose visceral canina no Paraná com identificação de L. infantum em cães da cidade de Foz do Iguaçu. Assim, medidas de controle devem ser elaboradas e implementadas por órgãos públicos e instituições de pesquisa do Brasil, Argentina e Paraguai em parceria com o objetivo de controlar a disseminação de zoonoses e os casos humanos de LV.


Assuntos
Animais , Cães , DNA de Protozoário/genética , Leishmania infantum/genética , Doenças do Cão/parasitologia , Leishmaniose Visceral/veterinária , Brasil/epidemiologia , Leishmania infantum/isolamento & purificação , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...