RESUMO
Dogs are a reservoir for Chagas disease, caused by Trypanosoma cruzi (T. cruzi), and other companion vector-borne diseases, including ehrlichiosis (Ehrlichia canis and Ehrlichia ewingii), anaplasmosis (Anaplasma phagocytophilum and Anaplasma platys), dirofilariasis (Dirofilaria immitis) and Lyme disease (Borrelia burgdorferi). This study has two key objectives: 1) to determine seroreactivity against T. cruzi in dogs from the town of Colón, in Portoviejo city, in the central coast of Ecuador; and 2) to establish the coinfection frequency of other companion vector-borne diseases in dogs positive for T. cruzi. Antibodies against T. cruzi were detected using two enzyme-linked immunosorbent assays. Diagnostic consensus between ELISA tests was established using the Cohen's Kappa coefficient. Other haemoparasitic diseases were detected using the IDEXX SNAP® 4Dx® kit in dogs previously diagnosed as T. cruzi-seropositive. From 84 dogs sampled, 57.14% (48/84) tested positive for T. cruzi. Co-infection analysis of 25 dogs positive for T. cruzi revealed antibodies also against Ehrlichia spp. (48%), Anaplasma spp. (28%), and Dirofilaria immitis (12%). These results provide a novel perspective regarding the status of these pathogens which co-infect dogs in Colón. Since all these pathogens are zoonotic, our findings should warn regional health authorities to implement sanitary programs, to better prevent and control vectors associated to these pathogens. On the other hand, human and veterinarian doctors, should consider that patients with a cardiac infection condition could be suffering co-infections with two or more vector transmitted pathogens.
Assuntos
Anaplasmose , Borrelia burgdorferi , Doença de Chagas , Coinfecção , Doenças do Cão , Ehrlichiose , Doença de Lyme , Trypanosoma cruzi , Doenças Transmitidas por Vetores , Anaplasma , Anaplasmose/epidemiologia , Animais , Anticorpos Antibacterianos , Doença de Chagas/epidemiologia , Doença de Chagas/veterinária , Coinfecção/epidemiologia , Coinfecção/veterinária , Doenças do Cão/epidemiologia , Cães , Equador/epidemiologia , Ehrlichiose/epidemiologia , Ehrlichiose/veterinária , Humanos , Estudos SoroepidemiológicosRESUMO
The efforts for the development and testing of vaccines against Trypanosoma cruzi infection have increased during the past years. We have designed a TcVac series of vaccines composed of T. cruzi derived, GPI-anchored membrane antigens. The TcVac vaccines have been shown to elicit humoral and cellular mediated immune responses and provide significant (but not complete) control of experimental infection in mice and dogs. Herein, we aimed to test two immunization protocols for the delivery of DNA-prime/DNA-boost vaccine (TcVac1) composed of TcG2 and TcG4 antigens in a BALB/c mouse model. Mice were immunized with TcVac1 through intradermal/electroporation (IDE) or intramuscular (IM) routes, challenged with T. cruzi, and evaluated during acute phase of infection. The humoral immune response was evaluated through the assessment of anti-TcG2 and anti-TcG4 IgG subtypes by using an ELISA. Cellular immune response was assessed through a lymphocyte proliferation assay. Finally, clinical and morphopathological aspects were evaluated for all experimental animals. Our results demonstrated that when comparing TcVac1 IDE delivery vs IM delivery, the former induced significantly higher level of antigen-specific antibody response (IgG2aâ¯+â¯IgG2bâ¯>â¯IgG1) and lymphocyte proliferation, which expanded in response to challenge infection. Histological evaluation after challenge infection showed infiltration of inflammatory cells (macrophages and lymphocytes) in the heart and skeletal tissue of all infected mice. However, the largest increase in inflammatory infiltrate was observed in TcVac1_IDE/Tc mice when compared with TcVac1_IM/Tc or non-vaccinated/infected mice. The extent of tissue inflammatory infiltrate was directly associated with the control of tissue amastigote nests in vaccinated/infected (vs. non-vaccinated/infected) mice. Our results suggest that IDE delivery improves the protective efficacy of TcVac1 vaccine against T. cruzi infection in mice when compared with IM delivery of the vaccine.
Assuntos
Doença de Chagas/prevenção & controle , Eletroporação/métodos , Vacinas Protozoárias/administração & dosagem , Vacinação/métodos , Animais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Linfócitos T CD8-Positivos/imunologia , Doença de Chagas/imunologia , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Feminino , Imunidade Celular , Imunização Secundária , Imunoglobulina G/sangue , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Vacinas Protozoárias/imunologia , Absorção Cutânea , Trypanosoma cruzi/imunologia , Vacinas de DNA/administração & dosagem , Vacinas de DNA/imunologiaRESUMO
American trypanosomiasis is a growing health issue in the Americas. México is an endemic country, where some locations such as in the State of México are considered highly prevalent. In the valley of Toluca city, the capital of the State of Mexico, there exists an apparent high prevalence in dogs. The absence of triatomine vectors suggests that dogs may not be infected. Therefore, we conducted a directed survey to domiciliated and nondomiciliated dogs to reassess dogs' T. cruzi seroprevalence status. HAI and ELISA serologic tests were applied to 124 and 167 serums of domiciliated and nondomiciliated dogs in the target city. Risk factors were estimated, but the results did not show any evidence to assess them. No domiciliated dogs tested positive to both tests, whereas only one non-domiciliated dog resulted positive. This animal may have acquired the infection in an endemic area and then migrated to Toluca. Research results indicate that T. cruzi infection is not actively transmitted among dogs, and it is pointed out that dogs are the main sentinel animal population to evaluate a possible expansion of the territory affected by Chagas' disease.
Assuntos
Anticorpos Antiprotozoários/sangue , Doença de Chagas/veterinária , Doenças do Cão/epidemiologia , Trypanosoma cruzi/imunologia , Animais , Doença de Chagas/epidemiologia , Cães , Doenças Endêmicas/veterinária , Feminino , Humanos , Insetos Vetores , Masculino , México/epidemiologia , Estudos SoroepidemiológicosRESUMO
American trypanosomiasis is a public health problem in Latin America and southern parts of the United States. Infection in triatomines (vector) and domestic dogs (reservoir host) is a good indicator of Trypanosoma cruzi circulation and human risk of infection. The State of Mexico, Mexico, has been considered free of T. cruzi, and no detailed epidemiologic study has been conducted to assess the intricacies of the transmission cycle of the parasite in the region. Such studies would enhance our understanding of the epidemiology of T. cruzi infection in this geographic region and provide regional sanitary authorities with stronger fundamental knowledge for making decisions and allocating funds for Chagas disease control programs in the State of Mexico. The objective of this study was to determine the prevalence of T. cruzi infection in dogs (seroprevalence) and triatomines (fecal parasites) in a previously identified, discrete endemic region of parasite circulation and to widen our studies in the Tejupilco Sanitary Region located in the southern part of the State of Mexico. Dog blood samples (n=102) were analyzed for the presence of anti-T. cruzi antibodies by two assays, namely indirect hemagglutination assay and enzyme-linked immunosorbent assay. Triatomines (n=88) were collected and fecal aliquots were analyzed for the presence of parasites by light microscopy. Average seroprevalence in dogs in the Tejupilco Sanitary region was 24.5%, and the overall triatomine infection rate was 34.01%. Triatoma pallidipennis was the only triatomine species found in this region. Our data demonstrate that T. cruzi is actively circulating in the Tejupilco Sanitary Region and emphasize the requirement for epidemiologic surveillance programs throughout the putative endemic areas of the State of Mexico.
Assuntos
Doença de Chagas/veterinária , Doenças do Cão/epidemiologia , Insetos Vetores/parasitologia , Triatoma/parasitologia , Trypanosoma cruzi/fisiologia , Animais , Anticorpos Antiprotozoários/sangue , Doença de Chagas/epidemiologia , Cães , Humanos , Entrevistas como Assunto , México/epidemiologia , Prevalência , Estudos SoroepidemiológicosRESUMO
Here we describe clinical and pathologic evidence of Chagas disease caused in dogs by circulating Trypanosoma cruzi from a newly recognized endemic area in Mexico. We show that the Zumpahuacan isolate, although less virulent than the Sylvio-X10 reference strain that caused acute myocarditis and death, was pathogenic in dogs. Dogs infected with the Zumpahuacan isolate exhibited electrocardiographic alterations, left- and right-ventricle dilation, and hydropericardium. Histologically, diffused perimysial and endomysial lymphoplasmacytic cell infiltration, cardiomyocyte necrosis, and amastigote nests were noted in Zumpahuacan-infected dogs. These findings suggest that the risk of T. cruzi infection and Chagas disease is present in the State of Mexico, and further research is needed to identify the T. cruzi bio-types circulating in southern State of Mexico.
Assuntos
Doença de Chagas/veterinária , Doenças do Cão/parasitologia , Trypanosoma cruzi/patogenicidade , Animais , Cardiomiopatia Chagásica/epidemiologia , Cardiomiopatia Chagásica/parasitologia , Cardiomiopatia Chagásica/veterinária , Doença de Chagas/epidemiologia , Doença de Chagas/parasitologia , Doença de Chagas/patologia , Modelos Animais de Doenças , Reservatórios de Doenças/veterinária , Doenças do Cão/epidemiologia , Doenças do Cão/patologia , Cães , México/epidemiologia , Camundongos , Camundongos Endogâmicos BALB C , Miocárdio/patologia , VirulênciaRESUMO
We used 5 diagnostic tests in a cross-sectional investigation of the prevalence of Trypanosoma cruzi in Tejupilco municipality, State of Mexico, Mexico. Our findings showed a substantial prevalence of immunoglobulin G (IgG) and IgM antibodies to T. cruzi in human (n = 293, IgG 2.05%, IgM 5.5%, both 7.1%) and dog (n = 114, IgG 15.8%, IgM 11.4%, both 21%) populations. We also found antibodies to T. cruzi (n = 80, IgG 10%, IgM 15%, both 17.5%) in dogs from Toluca, an area previously considered free of T. cruzi. Our data demonstrate the need for active epidemiologic surveillance programs in these regions. A direct correlation (r2 = 0.955) of seropositivity between humans and dogs suggests that seroanalysis in dogs may help identify the human prevalence of T. cruzi infection in these areas.