Adam Lima - Academia.edu (original) (raw)
Papers by Adam Lima
Figure S1. US hunting dog longitudinal study timeline. Dogs were sampled three times designated b... more Figure S1. US hunting dog longitudinal study timeline. Dogs were sampled three times designated by up and down arrows, over a tick season. Peak tick season for all kennel locations is designated by black. The bridge to tick season, dependent on seasonal variation and geographic location, shown in grey. Figure S2. Age and sex distribution of dogs based on tick-borne disease exposure at enrollment. Tick exposure based on SNAPŽ 4DxŽ Plus Test. a Age distribution. b Sex distribution. Abbreviations: CanL: canine leishmaniosis; qPCR: quantitative polymerase chain reaction; RR: risk ratio; ARR: adjusted risk ratio; OR: odds ratio; CI: confidence interval. (ZIP 212 kb)
Revista Brasileira de Ciência Veterinária, 2016
O presente estudo avaliou o estresse oxidativo e a adesão de leucócitos (AL) em cães naturalmente... more O presente estudo avaliou o estresse oxidativo e a adesão de leucócitos (AL) em cães naturalmente infectados por Leishmania infantum. Foram utilizados cães saudáveis (CN = 10) e cães acometidos por leishmaniose visceral na forma sintomática (CS = 10), submetidos previamente a exames de imunofluorescência indireta (IFI), ensaio imunoenzimático (ELISA) e pesquisa do parasito em aspirados de medula óssea. Soro foi utilizado para avaliação de malondialdeído (MDA) no ensaio para espécies reativas ao ácido tiobarbitúrico (TBARS) e AL foi determinada pelo método da coluna de náilon em sangue em EDTA, heparina e citrato. Os dados de AL foram expressos em porcentagem e MDA em média ± desvio padrão, submetidos ao teste T de student não pareado (p < 0,05). Amostras em heparina apresentaram níveis mais elevados de AL no grupo CS (55,62%, p < 0,05) quando comparadas com EDTA e citrato (10,46% e 5,28%). Citrato e EDTA inibiram AL em cães doentes e saudáveis, enquanto a heparina preservou a AL. A proporção neutrofílica se apresentou reduzida nas amostras em heparina (85% para 67%, p <0,05) quando comparadas com citrato e EDTA, que por sua vez mantiveram-se estáveis (83% para 80%). Os níveis de MDA apresentaram-se mais elevados em CS (0,0117µM ± 0,002) quando comparado com CN (0,0057µM ± 0,001) (p <0,05). Estes dados dão suporte à conclusão de que na LVC ocorre elevação do estresse oxidativo e aumento da expressão das moléculas de adesão nos leucócitos, evidenciando resposta inflamatória sistêmica. A escolha do anticoagulante é importante para a implementação do ensaio de AL.
Revista Brasileira de Higiene e Sanidade Animal, 2015
Avaliação da resposta inflamatória em cães naturalmente infectados por Leishmania infantum Inflam... more Avaliação da resposta inflamatória em cães naturalmente infectados por Leishmania infantum Inflammatory response evaluation in naturally infected dogs by Leishmania infantum
Cómo citar el artículo Número completo Más información del artículo Página de la revista en redal... more Cómo citar el artículo Número completo Más información del artículo Página de la revista en redalyc.org
Acta Scientiae Veterinariae
Background: Canine vector borne diseases (CVBD) are common in tropical countries where the clima... more Background: Canine vector borne diseases (CVBD) are common in tropical countries where the climate favors arthropods abundance. Comorbidity with one or more CVBD are reported as clinical complication and worsen prognostic. Canine visceral leishmaniosis (CanL) is an endemic zoonotic disease in Brazil caused by Leishmania infantum, with several restrictions to canine treatment and suggestion of reservoirs euthanasia for disease control. Heart worm (HW) is a helminthic disease caused by Dirofilaria immitis infection in dogs. It is a chronic heart disease, which can lead to death by congestive heart failure. Canine ehrlichiosis (CE) is caused by Ehrlichia canis bacterial infection with a zoonotic potential and fatal to dogs in acute and chronic presentations. Exposed the above, this study aims to describe a successful treatment and management of a dog with CanL, CE, and HW comorbidity. Case: A 3-year-old male uncastrated black Labrador dog, weighing 35 kg, was admitted to the veterinar...
A leishmaniose visceral canina (LVC) e manifestada por danos ao organismo dos animais infectados ... more A leishmaniose visceral canina (LVC) e manifestada por danos ao organismo dos animais infectados com Leishmania infantum e apresenta-se como doenca assintomatica ou sintomatica. Os diferentes quadros clinicos estao associados a resposta do hospedeiro atraves da resposta inflamatoria e da resposta imunologica especifica. Objetivou-se avaliar a resposta inflamatoria de caes naturalmente infectados por L. infantum . Caes (n = 12), ambos os sexos, foram divididos em dois grupos: soropositivos (n = 6) e soronegativos (n = 6). Amostras de sangue foram coletadas dos animais para a determinacao das contagens de Leucocitos Totais e Neutrofilos e os niveis sericos de proteina C reativa (PCR), fibrinogenio (FIB) e especies reativas ao acido tiobarbiturico (TBARS). Os dados foram expressos em media e desvio padrao e para comparacao dos grupos foi utilizado o teste t Student (p < 0,05). Os animais soropositivos apresentaram neutrofilia (p < 0,05), PCR acima dos valores de referencia para a...
Acta Scientiae Veterinariae, 2014
Background: Canine visceral leishmaniasis (CVL) is a multisystem inflammatory disease caused by t... more Background: Canine visceral leishmaniasis (CVL) is a multisystem inflammatory disease caused by the Leishmania genus protozoa, characterized by increased production of pro-inflammatory mediators. The parasite presence has been reported in various organs and tissues, such as bone marrow, lymph nodes, spleen, liver and skin, in addition the cardiac muscle. Cardiac muscle lesions provide the substances release, among which we can mention the creatine kinase (CK), its MB subunit (CK-MB) and troponin. The changes that cause these injuries depend not only of the parasite presence, but also the increased concentrations of proinflammatory cytokines. Although most studies focus on the proinflammatory cytokines action, regulatory cytokines of the inflammatory process has gained evidence in the immune response to the Leishmania infantum and can be directly associated with the cardiac damage pathogenesis. Therefore, this study aimed to evaluate the TNF-α and IL-10 serum levels in naturally infe...
Background : Canine ehrlichiosis (CE) is a disease caused by Ehrlichia canis , transmitted by Rhi... more Background : Canine ehrlichiosis (CE) is a disease caused by Ehrlichia canis , transmitted by Rhipicephalus sanguineus and dogs can present variable clinical manifestations, ranging from subclinical, acute to chronic illness. This pathogen preferentially infects leukocytes. In Brazil illness is described nationwide with the seropositivity varying from 4.8% to over 50%. The control of Ehrlichia spp. infection was related to cellular immune response mediated by Th1 while the CE acute phase is related to humoral immune response mediated by Th2, with high production of antibodies. Th1 and Th2 balance can be measured by cytokine profile. TNF-α is associated with inflammatory responses while IL-10 inhibits mechanisms which prevent tissue damage caused by the intense inflammatory response. The aim of this study was to evaluate the TNF-α and IL-10 serum levels in naturally infected dogs by Ehrlichia spp. Material, Methods & Results : Twenty five dogs, both sexes, one to eight years ...
Background: Leishmaniosis are a chronic disease complex, which may vary from simple cutaneous les... more Background: Leishmaniosis are a chronic disease complex, which may vary from simple cutaneous lesions to a fatal visceral form, with elevated expansion within the urban centers. Fortaleza is an endemic area for VL and it has been presenting registers of human death in the past decade. The HVL seasonality, the HVL and CVL tendencies have been evaluated, along with the correlation and infl uence of the seroreactive dogs, of the euthanized dogs, of the abiotic environmental factors and the human and canine population over the coeffi cient of the HVL incidence, in the Fortaleza town between 2006 and 2012. Materials, Methods & Results: The experimental protocol was approved by the Ethics Committee for the State University of Ceara Animal Use (CEUA/UECE), protocol no 08622833-1. As a data source for the analysis of HVL and CVL, the monthly quantitative of notifi ed and registered cases in the State of Ceara Health Secretariat (SESA) and in the Fortaleza Zoonosis Control Center (CCZ) was u...
Pubvet
O objetivo desta revisão é esclarecer o triplo papel, reservatório-vítima-sentinela, que o cão ex... more O objetivo desta revisão é esclarecer o triplo papel, reservatório-vítima-sentinela, que o cão exerce na leishmaniose visceral e discutir o foco na eliminação do “melhor amigo do homem” para proteção do ecossistema, levando-se em conta os três pilares epidemiológicos, parasito-vetor-hospedeiro, e os aspectos éticos. Logo, inicialmente serão abordados aspectos epidemiológicos relacionados a Leishmaniose Visceral (LV) e a Leishmania Visceral Canina (LVC). Posteriormente, uma reflexão sobre o papel do cão neste contexto, tido como principal reservatório da Leishmania infantum no ambiente urbano, será realizada visando a compreensão de medidas como a eutanásia, de animais positivos; a manutenção do cão parasitado na família (vítima) e o uso destes animais como sentinelas para a detecção da LV e LVC. Finalmente, conclui-se que a LVC é um problema que aflige a família multiespécie brasileira, afetando seres humanos e cães. Os métodos de controle e vigilância paras a LV implementadas no Br...
PLOS Neglected Tropical Diseases
Background Dogs are the primary reservoir for human visceral leishmaniasis due to Leishmania infa... more Background Dogs are the primary reservoir for human visceral leishmaniasis due to Leishmania infantum. Phlebotomine sand flies maintain zoonotic transmission of parasites between dogs and humans. A subset of dogs is infected transplacentally during gestation, but at what stage of the clinical spectrum vertically infected dogs contribute to the infected sand fly pool is unknown. Methodology/Principal findings We examined infectiousness of dogs vertically infected with L. infantum from multiple clinical states to the vector Lutzomyia longipalpis using xenodiagnosis and found that vertically infected dogs were infectious to sand flies at differing rates. Dogs with mild to moderate disease showed significantly higher transmission to the vector than dogs with subclinical or severe disease. We documented a substantial parasite burden in the skin of vertically infected dogs by RT-qPCR, despite these dogs not having received intradermal parasites via sand flies. There was a highly significa...
Parasites & Vectors
Background Both incidence and geographical range of tick-borne disease has increased across the U... more Background Both incidence and geographical range of tick-borne disease has increased across the USA. Similar to people, dogs are hosts for Anaplasma spp., Babesia spp., Ehrlichia spp. and Borrelia burgdorferi. Dogs also share our homes and beds, making them both a sentinel for the ticks in our backyards but also increasing our exposure to ticks. Measures to better track, prevent, and/or treat tick-borne diseases in companion animals can lead to better control and prevention of human tick-borne disease. This study identifies demographic and co-infection risk factors for canine seropositivity to tick-borne infections in a cohort of hunting dogs across the USA. Results Human patterns of tick-borne disease co-infection in the USA have been predominantly driven by the geographical distribution of the tick vector. Dogs who tested seropositive for Anaplasma spp. were 1.40 times more likely (P = 0.0242) to also test seropositive for Babesia spp. and vice versa (1.60 times more likely, P = 0...
Acta Scientiae Veterinariae
Background: Canine leishmaniasis (CanL) is caused by an obligatory intracellular parasite of Leis... more Background: Canine leishmaniasis (CanL) is caused by an obligatory intracellular parasite of Leishmania genus that affects organs and tissues. Several studies evaluate the role of reactive oxygen species (ROS) in the pathogenesis of many diseases. The overproduction of ROS on infectious diseases can induce an imbalance between oxidants and antioxidants at cellular or systemic level. Thus, the aim of this study was to evaluate the activity of antioxidant enzymes in CanL.Materials, Methods & Results: Females (n = 17) and males (n = 10), at different ages and with different weight, were selected for this study. Dogs were divided into two groups according classical clinical signs and sorological test to CanL. Animals were considered infected based on indirect immunofluorescent assay and ELISA titration ≥ 1:40. Group B (n = 15) composed by positive dogs to CanL from Zoonosis Control Center of Fortaleza (Ceará, Brazil) and group A (n = 12) was composed by dogs from private kennel that w...
Vaccine, Oct 15, 2018
Better tools are necessary to eliminate visceral leishmaniasis (VL). Modeling studies for regiona... more Better tools are necessary to eliminate visceral leishmaniasis (VL). Modeling studies for regional Leishmania elimination indicate that an effective vaccine is a critical tool. Dogs are the reservoir host of L. infantum in Brazil and the Mediterranean basin, and therefore are an important target for public health interventions as well as a relevant disease model for human VL. No vaccine has been efficacious as an immunotherapy to prevent progression of already diagnostically positive individuals to symptomatic leishmaniasis. We performed a double-blinded, block-randomized, placebo-controlled, vaccine immunotherapy trial testing the efficacy of a recombinant Leishmania A2 protein, saponin-adjuvanted, vaccine, LeishTec®, in owned hunting dogs infected with L. infantum. The primary outcome was reduction of clinical progression, with reduction of mortality as a secondary outcome. Vaccination as an immunotherapy reduced the risk of progression to clinically overt leishmaniasis by 25% in ...
Revista da Sociedade Brasileira de Medicina Tropical
FIGURE 1-Splenomegaly and several nodular formations in naturally infected dog by Leishmania infa... more FIGURE 1-Splenomegaly and several nodular formations in naturally infected dog by Leishmania infantum. FIGURE 2-Spleen amyloidosis (Congo red and polarized light microscopy) in naturally infected dog by Leishmania infantum (400x).
Parasites & Vectors
Background: Visceral leishmaniasis (VL) is a vector borne zoonotic disease endemic in humans and ... more Background: Visceral leishmaniasis (VL) is a vector borne zoonotic disease endemic in humans and dogs in Brazil. Due to the increased risk of human infection secondary to the presence of infected dogs, public health measures in Brazil mandate testing and culling of infected dogs. Despite this important relationship between human and canine infection, little is known about what makes the dog reservoir progress to clinical illness, significantly tied to infectiousness to sand flies. Dogs in endemic areas of Brazil are exposed to many tick-borne pathogens, which are likely to alter the immune environment and thus control of L. infantum. Results: A cross-sectional study of 223 dogs from an area of Natal, in the Rio Grande do Norte, Brazil, were studied to determine the association between comorbid tick-borne disease and Leishmania infection in this endemic area. The risk of Leishmania seropositivity was 1.68× greater in dogs with tick-borne disease seropositivity compared to those without (Adjusted RR: 1.68, 95% CI: 1.09-2.61, P = 0.019). A longitudinal study of 214 hunting dogs in the USA was conducted to determine the causal relationship between infection with tick-borne diseases and progression of VL. Hunting dogs were evaluated three times across a full tick season to detect incident infection with tick-borne diseases. A logistic regression model with generalized estimating equations to estimate the parameters was used to determine how exposure to tick-borne disease altered VL progression over these three time points when controlling for other variables. Dogs infected with three or more tick-borne diseases were 11× more likely to be associated with progression to clinical VL than dogs with no tick-borne disease (Adjusted RR: 11.64, 95% CI: 1.22-110.99, P = 0.03). Dogs with exposure to both Leishmania spp. and tick-borne diseases were five times more likely to die during the study period (RR: 4.85, 95% CI: 1.65-14.24, P = 0.0051). Conclusions: Comorbid tick-borne diseases dramatically increased the likelihood that a dog had clinical L. infantum infection, making them more likely to transmit infection to sand flies and people. As an important consequence, reduction of tick-borne disease exposure through topical or oral insecticides may be an important way to reduce progression and transmissibility of Leishmania infection from the canine reservoir to people.
Figure S1. US hunting dog longitudinal study timeline. Dogs were sampled three times designated b... more Figure S1. US hunting dog longitudinal study timeline. Dogs were sampled three times designated by up and down arrows, over a tick season. Peak tick season for all kennel locations is designated by black. The bridge to tick season, dependent on seasonal variation and geographic location, shown in grey. Figure S2. Age and sex distribution of dogs based on tick-borne disease exposure at enrollment. Tick exposure based on SNAPŽ 4DxŽ Plus Test. a Age distribution. b Sex distribution. Abbreviations: CanL: canine leishmaniosis; qPCR: quantitative polymerase chain reaction; RR: risk ratio; ARR: adjusted risk ratio; OR: odds ratio; CI: confidence interval. (ZIP 212 kb)
Revista Brasileira de Ciência Veterinária, 2016
O presente estudo avaliou o estresse oxidativo e a adesão de leucócitos (AL) em cães naturalmente... more O presente estudo avaliou o estresse oxidativo e a adesão de leucócitos (AL) em cães naturalmente infectados por Leishmania infantum. Foram utilizados cães saudáveis (CN = 10) e cães acometidos por leishmaniose visceral na forma sintomática (CS = 10), submetidos previamente a exames de imunofluorescência indireta (IFI), ensaio imunoenzimático (ELISA) e pesquisa do parasito em aspirados de medula óssea. Soro foi utilizado para avaliação de malondialdeído (MDA) no ensaio para espécies reativas ao ácido tiobarbitúrico (TBARS) e AL foi determinada pelo método da coluna de náilon em sangue em EDTA, heparina e citrato. Os dados de AL foram expressos em porcentagem e MDA em média ± desvio padrão, submetidos ao teste T de student não pareado (p < 0,05). Amostras em heparina apresentaram níveis mais elevados de AL no grupo CS (55,62%, p < 0,05) quando comparadas com EDTA e citrato (10,46% e 5,28%). Citrato e EDTA inibiram AL em cães doentes e saudáveis, enquanto a heparina preservou a AL. A proporção neutrofílica se apresentou reduzida nas amostras em heparina (85% para 67%, p <0,05) quando comparadas com citrato e EDTA, que por sua vez mantiveram-se estáveis (83% para 80%). Os níveis de MDA apresentaram-se mais elevados em CS (0,0117µM ± 0,002) quando comparado com CN (0,0057µM ± 0,001) (p <0,05). Estes dados dão suporte à conclusão de que na LVC ocorre elevação do estresse oxidativo e aumento da expressão das moléculas de adesão nos leucócitos, evidenciando resposta inflamatória sistêmica. A escolha do anticoagulante é importante para a implementação do ensaio de AL.
Revista Brasileira de Higiene e Sanidade Animal, 2015
Avaliação da resposta inflamatória em cães naturalmente infectados por Leishmania infantum Inflam... more Avaliação da resposta inflamatória em cães naturalmente infectados por Leishmania infantum Inflammatory response evaluation in naturally infected dogs by Leishmania infantum
Cómo citar el artículo Número completo Más información del artículo Página de la revista en redal... more Cómo citar el artículo Número completo Más información del artículo Página de la revista en redalyc.org
Acta Scientiae Veterinariae
Background: Canine vector borne diseases (CVBD) are common in tropical countries where the clima... more Background: Canine vector borne diseases (CVBD) are common in tropical countries where the climate favors arthropods abundance. Comorbidity with one or more CVBD are reported as clinical complication and worsen prognostic. Canine visceral leishmaniosis (CanL) is an endemic zoonotic disease in Brazil caused by Leishmania infantum, with several restrictions to canine treatment and suggestion of reservoirs euthanasia for disease control. Heart worm (HW) is a helminthic disease caused by Dirofilaria immitis infection in dogs. It is a chronic heart disease, which can lead to death by congestive heart failure. Canine ehrlichiosis (CE) is caused by Ehrlichia canis bacterial infection with a zoonotic potential and fatal to dogs in acute and chronic presentations. Exposed the above, this study aims to describe a successful treatment and management of a dog with CanL, CE, and HW comorbidity. Case: A 3-year-old male uncastrated black Labrador dog, weighing 35 kg, was admitted to the veterinar...
A leishmaniose visceral canina (LVC) e manifestada por danos ao organismo dos animais infectados ... more A leishmaniose visceral canina (LVC) e manifestada por danos ao organismo dos animais infectados com Leishmania infantum e apresenta-se como doenca assintomatica ou sintomatica. Os diferentes quadros clinicos estao associados a resposta do hospedeiro atraves da resposta inflamatoria e da resposta imunologica especifica. Objetivou-se avaliar a resposta inflamatoria de caes naturalmente infectados por L. infantum . Caes (n = 12), ambos os sexos, foram divididos em dois grupos: soropositivos (n = 6) e soronegativos (n = 6). Amostras de sangue foram coletadas dos animais para a determinacao das contagens de Leucocitos Totais e Neutrofilos e os niveis sericos de proteina C reativa (PCR), fibrinogenio (FIB) e especies reativas ao acido tiobarbiturico (TBARS). Os dados foram expressos em media e desvio padrao e para comparacao dos grupos foi utilizado o teste t Student (p < 0,05). Os animais soropositivos apresentaram neutrofilia (p < 0,05), PCR acima dos valores de referencia para a...
Acta Scientiae Veterinariae, 2014
Background: Canine visceral leishmaniasis (CVL) is a multisystem inflammatory disease caused by t... more Background: Canine visceral leishmaniasis (CVL) is a multisystem inflammatory disease caused by the Leishmania genus protozoa, characterized by increased production of pro-inflammatory mediators. The parasite presence has been reported in various organs and tissues, such as bone marrow, lymph nodes, spleen, liver and skin, in addition the cardiac muscle. Cardiac muscle lesions provide the substances release, among which we can mention the creatine kinase (CK), its MB subunit (CK-MB) and troponin. The changes that cause these injuries depend not only of the parasite presence, but also the increased concentrations of proinflammatory cytokines. Although most studies focus on the proinflammatory cytokines action, regulatory cytokines of the inflammatory process has gained evidence in the immune response to the Leishmania infantum and can be directly associated with the cardiac damage pathogenesis. Therefore, this study aimed to evaluate the TNF-α and IL-10 serum levels in naturally infe...
Background : Canine ehrlichiosis (CE) is a disease caused by Ehrlichia canis , transmitted by Rhi... more Background : Canine ehrlichiosis (CE) is a disease caused by Ehrlichia canis , transmitted by Rhipicephalus sanguineus and dogs can present variable clinical manifestations, ranging from subclinical, acute to chronic illness. This pathogen preferentially infects leukocytes. In Brazil illness is described nationwide with the seropositivity varying from 4.8% to over 50%. The control of Ehrlichia spp. infection was related to cellular immune response mediated by Th1 while the CE acute phase is related to humoral immune response mediated by Th2, with high production of antibodies. Th1 and Th2 balance can be measured by cytokine profile. TNF-α is associated with inflammatory responses while IL-10 inhibits mechanisms which prevent tissue damage caused by the intense inflammatory response. The aim of this study was to evaluate the TNF-α and IL-10 serum levels in naturally infected dogs by Ehrlichia spp. Material, Methods & Results : Twenty five dogs, both sexes, one to eight years ...
Background: Leishmaniosis are a chronic disease complex, which may vary from simple cutaneous les... more Background: Leishmaniosis are a chronic disease complex, which may vary from simple cutaneous lesions to a fatal visceral form, with elevated expansion within the urban centers. Fortaleza is an endemic area for VL and it has been presenting registers of human death in the past decade. The HVL seasonality, the HVL and CVL tendencies have been evaluated, along with the correlation and infl uence of the seroreactive dogs, of the euthanized dogs, of the abiotic environmental factors and the human and canine population over the coeffi cient of the HVL incidence, in the Fortaleza town between 2006 and 2012. Materials, Methods & Results: The experimental protocol was approved by the Ethics Committee for the State University of Ceara Animal Use (CEUA/UECE), protocol no 08622833-1. As a data source for the analysis of HVL and CVL, the monthly quantitative of notifi ed and registered cases in the State of Ceara Health Secretariat (SESA) and in the Fortaleza Zoonosis Control Center (CCZ) was u...
Pubvet
O objetivo desta revisão é esclarecer o triplo papel, reservatório-vítima-sentinela, que o cão ex... more O objetivo desta revisão é esclarecer o triplo papel, reservatório-vítima-sentinela, que o cão exerce na leishmaniose visceral e discutir o foco na eliminação do “melhor amigo do homem” para proteção do ecossistema, levando-se em conta os três pilares epidemiológicos, parasito-vetor-hospedeiro, e os aspectos éticos. Logo, inicialmente serão abordados aspectos epidemiológicos relacionados a Leishmaniose Visceral (LV) e a Leishmania Visceral Canina (LVC). Posteriormente, uma reflexão sobre o papel do cão neste contexto, tido como principal reservatório da Leishmania infantum no ambiente urbano, será realizada visando a compreensão de medidas como a eutanásia, de animais positivos; a manutenção do cão parasitado na família (vítima) e o uso destes animais como sentinelas para a detecção da LV e LVC. Finalmente, conclui-se que a LVC é um problema que aflige a família multiespécie brasileira, afetando seres humanos e cães. Os métodos de controle e vigilância paras a LV implementadas no Br...
PLOS Neglected Tropical Diseases
Background Dogs are the primary reservoir for human visceral leishmaniasis due to Leishmania infa... more Background Dogs are the primary reservoir for human visceral leishmaniasis due to Leishmania infantum. Phlebotomine sand flies maintain zoonotic transmission of parasites between dogs and humans. A subset of dogs is infected transplacentally during gestation, but at what stage of the clinical spectrum vertically infected dogs contribute to the infected sand fly pool is unknown. Methodology/Principal findings We examined infectiousness of dogs vertically infected with L. infantum from multiple clinical states to the vector Lutzomyia longipalpis using xenodiagnosis and found that vertically infected dogs were infectious to sand flies at differing rates. Dogs with mild to moderate disease showed significantly higher transmission to the vector than dogs with subclinical or severe disease. We documented a substantial parasite burden in the skin of vertically infected dogs by RT-qPCR, despite these dogs not having received intradermal parasites via sand flies. There was a highly significa...
Parasites & Vectors
Background Both incidence and geographical range of tick-borne disease has increased across the U... more Background Both incidence and geographical range of tick-borne disease has increased across the USA. Similar to people, dogs are hosts for Anaplasma spp., Babesia spp., Ehrlichia spp. and Borrelia burgdorferi. Dogs also share our homes and beds, making them both a sentinel for the ticks in our backyards but also increasing our exposure to ticks. Measures to better track, prevent, and/or treat tick-borne diseases in companion animals can lead to better control and prevention of human tick-borne disease. This study identifies demographic and co-infection risk factors for canine seropositivity to tick-borne infections in a cohort of hunting dogs across the USA. Results Human patterns of tick-borne disease co-infection in the USA have been predominantly driven by the geographical distribution of the tick vector. Dogs who tested seropositive for Anaplasma spp. were 1.40 times more likely (P = 0.0242) to also test seropositive for Babesia spp. and vice versa (1.60 times more likely, P = 0...
Acta Scientiae Veterinariae
Background: Canine leishmaniasis (CanL) is caused by an obligatory intracellular parasite of Leis... more Background: Canine leishmaniasis (CanL) is caused by an obligatory intracellular parasite of Leishmania genus that affects organs and tissues. Several studies evaluate the role of reactive oxygen species (ROS) in the pathogenesis of many diseases. The overproduction of ROS on infectious diseases can induce an imbalance between oxidants and antioxidants at cellular or systemic level. Thus, the aim of this study was to evaluate the activity of antioxidant enzymes in CanL.Materials, Methods & Results: Females (n = 17) and males (n = 10), at different ages and with different weight, were selected for this study. Dogs were divided into two groups according classical clinical signs and sorological test to CanL. Animals were considered infected based on indirect immunofluorescent assay and ELISA titration ≥ 1:40. Group B (n = 15) composed by positive dogs to CanL from Zoonosis Control Center of Fortaleza (Ceará, Brazil) and group A (n = 12) was composed by dogs from private kennel that w...
Vaccine, Oct 15, 2018
Better tools are necessary to eliminate visceral leishmaniasis (VL). Modeling studies for regiona... more Better tools are necessary to eliminate visceral leishmaniasis (VL). Modeling studies for regional Leishmania elimination indicate that an effective vaccine is a critical tool. Dogs are the reservoir host of L. infantum in Brazil and the Mediterranean basin, and therefore are an important target for public health interventions as well as a relevant disease model for human VL. No vaccine has been efficacious as an immunotherapy to prevent progression of already diagnostically positive individuals to symptomatic leishmaniasis. We performed a double-blinded, block-randomized, placebo-controlled, vaccine immunotherapy trial testing the efficacy of a recombinant Leishmania A2 protein, saponin-adjuvanted, vaccine, LeishTec®, in owned hunting dogs infected with L. infantum. The primary outcome was reduction of clinical progression, with reduction of mortality as a secondary outcome. Vaccination as an immunotherapy reduced the risk of progression to clinically overt leishmaniasis by 25% in ...
Revista da Sociedade Brasileira de Medicina Tropical
FIGURE 1-Splenomegaly and several nodular formations in naturally infected dog by Leishmania infa... more FIGURE 1-Splenomegaly and several nodular formations in naturally infected dog by Leishmania infantum. FIGURE 2-Spleen amyloidosis (Congo red and polarized light microscopy) in naturally infected dog by Leishmania infantum (400x).
Parasites & Vectors
Background: Visceral leishmaniasis (VL) is a vector borne zoonotic disease endemic in humans and ... more Background: Visceral leishmaniasis (VL) is a vector borne zoonotic disease endemic in humans and dogs in Brazil. Due to the increased risk of human infection secondary to the presence of infected dogs, public health measures in Brazil mandate testing and culling of infected dogs. Despite this important relationship between human and canine infection, little is known about what makes the dog reservoir progress to clinical illness, significantly tied to infectiousness to sand flies. Dogs in endemic areas of Brazil are exposed to many tick-borne pathogens, which are likely to alter the immune environment and thus control of L. infantum. Results: A cross-sectional study of 223 dogs from an area of Natal, in the Rio Grande do Norte, Brazil, were studied to determine the association between comorbid tick-borne disease and Leishmania infection in this endemic area. The risk of Leishmania seropositivity was 1.68× greater in dogs with tick-borne disease seropositivity compared to those without (Adjusted RR: 1.68, 95% CI: 1.09-2.61, P = 0.019). A longitudinal study of 214 hunting dogs in the USA was conducted to determine the causal relationship between infection with tick-borne diseases and progression of VL. Hunting dogs were evaluated three times across a full tick season to detect incident infection with tick-borne diseases. A logistic regression model with generalized estimating equations to estimate the parameters was used to determine how exposure to tick-borne disease altered VL progression over these three time points when controlling for other variables. Dogs infected with three or more tick-borne diseases were 11× more likely to be associated with progression to clinical VL than dogs with no tick-borne disease (Adjusted RR: 11.64, 95% CI: 1.22-110.99, P = 0.03). Dogs with exposure to both Leishmania spp. and tick-borne diseases were five times more likely to die during the study period (RR: 4.85, 95% CI: 1.65-14.24, P = 0.0051). Conclusions: Comorbid tick-borne diseases dramatically increased the likelihood that a dog had clinical L. infantum infection, making them more likely to transmit infection to sand flies and people. As an important consequence, reduction of tick-borne disease exposure through topical or oral insecticides may be an important way to reduce progression and transmissibility of Leishmania infection from the canine reservoir to people.