PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

Heartworm disease is a zoonosis caused by Dirofilaria immitis, a nematode parasite of worldwide distribution and considered one of the most virulent of dogs, which are definitive and infected hosts during the blood meal of vector mosquitoes (Aedes sp., Anopheles sp. and Culex sp.). The disease has a worldwide prevalence, with a higher incidence in tropical and subtropical climate areas, and affects animals of any breed, sex, and age group. Most animals are asymptomatic, but the disease can cause various cardiovascular and respiratory symptoms. The pathophysiology is related to vessel obstruction and an intense inflammatory reaction in the lung parenchyma, with cardiovascular and respiratory symptoms leading to signs that can be severe and lead to the death of the host. It can be diagnosed through blood tests, and chest X-rays are used to assess the severity of clinical signs and help establish a prognosis. Cardiovascular alterations appear as an increase in vascular caliber, an increase in the right heart silhouette, and pulmonary patterns compatible with infection. This study aimed to describe the conditional radiographic changes caused by the parasite in the lungs, intrathoracic vessels and heart in 30 dogs, independent of breed and sex, with an average age of 9.9 years and an average weight of 10.25kg, originating from routine care at a veterinary hospital in the city of Rio de Janeiro, from January 2022 to December 2022. All animals were diagnosed with a positive heartworm infection and cardiorespiratory symptoms as essential conditions for participation in the study. The animals were x-rayed and had their lung patterns evaluated, in addition to measuring their vascular caliber and cardiac indices using vertebral-heart size (VHS), manubrium-heart size (MHS) and sphericity index (CSI). Most animals presented pulmonary patterns such as bronchoalveolar and bronchial and increased VHS and MHS indices. Increased and borderline values of CSI measurements were found in half of the patients, demonstrating that the parasite can trigger significant radiographic changes or present potential further worsening.

• Dirofilaria immitis diagnostic imaging radiographic changes

Abstract in Portuguese:

A dirofilariose é uma zoonose causada pela Dirofilaria immitis, parasita nematoide de distribuição mundial e considerado um dos mais patogênicos de cães, que são hospedeiros definitivos e infectados durante o repasto sanguíneo de mosquitos vetores (Aedes sp., Anopheles sp. e Culex sp.). A doença apresenta prevalência mundial, com maior incidência em áreas de clima tropical e subtropical, acometendo animais de qualquer raça, sexo e faixa etária. A maioria dos animais é assintomática, entretanto, a doença pode causar diversos sintomas cardiovasculares e respiratórios. A fisiopatologia se relaciona com a obstrução de vasos e com intensa reação inflamatória no tecido pulmonar, com sintomatologia cardiovascular e respiratória, levando a sinais que podem ser graves e levar ao óbito do hospedeiro. Pode ser diagnosticada através de exames de sangue e as radiografias de tórax são utilizadas para avaliar a gravidade dos sinais clínicos e auxiliar no estabelecimento do prognóstico. Alterações cardiovasculares surgem como aumento de calibre vascular, aumento de silhueta cardíaca direita e padrões pulmonares compatíveis com infecção. No presente artigo objetivou-se descrever as alterações radiográficas estabelecidas pelo parasita nos pulmões, nos vasos intratorácicos e no coração em 30 cães, independente de raça e sexo, com média de idade 9,9 anos e média de peso 10,25kg, oriundos da rotina de atendimento de um hospital veterinário na cidade do Rio de Janeiro, entre Janeiro de 2022 e Dezembro de 2022. Todos os animais possuem diagnóstico positivo para infecção por dirofilariose e sintomatologia cardiorrespiratória como condição indispensável para pertencerem ao estudo. Os animais foram radiografados e tiveram os padrões pulmonares avaliados, além da medição do calibre vascular e dos índices cardíacos através do VHS (índice cardio-vertebral), MHS (ou índice manúbrio-esternal) e CSI (índice de esfericidade). A maioria dos animais apresentou padrão pulmonar como broncoalveolar e bronquial e índices de VHS e MHS aumentados. Aumento e valores limítrofes das medidas de CSI foram encontrados em metade dos pacientes, demonstrando que o parasita pode desencadear alterações radiográficas significativas ou apresentar potencial agravamento posterior.

• Dirofilaria immitis diagnóstico por imagem alterações radiográficas

Abstract in English:

Dirofilaria immitis is a heart and large vessel parasite that mainly affects domestic dogs and has shown a re-emerging zoonosis in recent years. The objective of this study was to determine the prevalence, associated factors, and geographic areas of D. immitis in dogs in the city of Sousa, Paraíba, Northeast Brazil. A total of 320 dogs were selected and evaluated, 160 domiciled and 160 wandering, from the 32 districts of the city. Clinical examination, blood collection, and epidemiological data retrieval were performed for each animal. The sanitation conditions of the environment were visually observed at the time of evaluation. Three methods were used to investigate the morphometric diagnosis of microfilariae: capillary blood smear (ESC), peripheral blood smear (ESP), and modified Knott test. The data were subjected to univariate and multivariate statistics for the observation of risk factors and qualitative assessment of the examinations. Of the 17.5% (56/320) of animals testing positive for D. immitis, 25% (40/160) were wandering and 10% (16/160) were domiciled dogs. Positive dogs were found in 24 of the 32 neighborhoods evaluated, with Angelim and Doutor Zezé having the highest percentages of 1.56% (5/320) each. Only the categories of cardiac alterations (OR 6.231 [1,539-25,236]) and stray dogs (OR 2.463 [1,281-4,735]) demonstrated potential risk factors for infection. Of the 56 positive animals, 28 were positive in the three tests, and another 28 showed variance between methods and/or between prepared slides. No other filaridae were observed. The city of Sousa is considered to have a significant prevalence of infection by D. immitis, and forms of control and prophylaxis are required to reduce the risks of transmission to animals, as well as to humans.

• Dirofilaria immitis infection dogs Brazil arrhythmia parasite wandering zoonosis

Abstract in Portuguese:

Dirofilaria immitis é um parasito de coração e de grandes vasos que acomete principalmente cães domésticos, também causador de uma zoonose reemergente nos últimos anos. O objetivo deste trabalho foi determinar a prevalência, fatores associados e áreas geográficas de D. immitis em cães na cidade de Sousa, Paraíba, Nordeste do Brasil. Para isso, foram selecionados e avaliados 320 cães, sendo 160 domiciliados e 160 errantes, provenientes dos 32 bairros da cidade. Foi realizado o exame clínico, coleta de sangue e dados epidemiológicos de cada animal. O ambiente foi observado visualmente quanto as condições de saneamento no momento de avaliação. Para pesquisa de microfilárias, foram realizados três métodos: esfregaço sanguíneo capilar (ESC), periférico (ESP) e teste de Knott-modificado, associado ao diagnóstico morfométrico das microfilárias. Os dados foram submetidos a estatísticas uni e multivariadas para observação de fatores de risco e avaliação qualitativa dos exames. Obteve-se prevalência de 17,5% (56/320) de animais positivos para D. immitis, sendo 25% (40/160) errantes e 10% (16/160) domiciliados. Dos 32 bairros avaliados, em 24 foram encontrados cães positivos, sendo Angelim e Doutor Zezé, os bairros com maior percentual 1,56% (5/320) cada. Somente as categorias de alterações cardíacas (OR 6,231 [1.539-25.236]) e cães errantes (OR 2,463 [1.281-4.735]) demonstraram potencial fator de risco para infecção. Dos 56 animais positivos, 28 apresentaram positividade nos três testes, e outros 28 demonstraram variância entre métodos e/ou entre lâminas confeccionadas. Não foram observados outros filarídeos. Considerou-se que a cidade de Sousa apresenta prevalência significativa de infecção por D. immitis, sendo necessário estabelecer formas de controle e profilaxia, para reduzir os riscos da transmissão para animais, como também para humanos.

• Infecção Dirofilaria immitis cães caninos arritmia errante parasito zoonose

Abstract in English:

Dirofilaria immitis, a parasite that mainly infects domestic or wild canids, but can infect felines or humans as well, is frequent in many Brazilian areas. The main objective of this research was to determine the prevalence of natural canine infection at the Algodoal‑Maiandeua Island complex, in the coastal region of the state of Pará, Brazil. A total of 67 dogs were sampled for blood microfilariae detection and for D. immitis DNA detection. Microfilaria and D. immitis DNA could be detected in 35.8% (24/67) of the animals. In one dog’s sample no microfilariae were detected, but the PCR was positive, suggesting that either larvae recently were eliminated or adults died shortly before sample collecting. Therefore, it can be concluded that the occurrence of D. immitis is a health threat for domestic and wild canids at the Island of Algodoal, as well as for feline or human health.

• Occurrence canids Dirofilaria immitis infection dogs Algodoal Island Brazilian Amazon heartworm PCR

Abstract in Portuguese:

Dirofilaria immitis, um parasito que infecta principalmente canídeos domésticos ou selvagens, embora também possa infectar felinos e humanos, é frequente em muitas áreas do Brasil. O objetivo deste estudo foi determinar a ocorrência da infecção natural em cães provenientes do complexo da Ilha de Algodoal-Maiandeua, região litorânea do estado do Pará, Brasil. Um total de 67 cães tiveram o sangue coletado para detecção de microfilárias de D. immitis e seu DNA. Microfilárias e o DNA de D. immitis foram detectados em 35,8% (24/67) dos animais. Na amostra de um animal, não foram observadas microfilárias, mas o seu DNA foi detectado, sugerindo que as larvas tenham sido recentemente eliminadas ou os adultos tenham morrido antes da coleta da amostra. Portanto, pode-se concluir que a ocorrência de D. immitis é uma ameaça à saúde de canídeos domésticos no complexo da Ilha de Algodoal-Maiandeua, bem como para felinos e seres humanos.

• Ocorrência cães infecção Dirofilaria immitis verme do coração PCR Ilha de Algodoal Amazônia brasileira

Abstract in English:

ABSTRACT.- Filoni C., Pena H.F.J., Gennari S.M., Cristo D.S., Torres L.N. & Catão-Dias J.L. 2009. Heartworm (Dirofilaria immitis) disease in a Brazilian oncilla (Leopardus tigrinus). Pesquisa Veterinária Brasileira 29(6):373-478. Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo, SP 05508-270, Brazil. E-mail: claudiafiloni@triade.org.br Heartworm disease is caused by the intravascular nematode Dirofilaria immitis, a pathogen of public health importance usually associated to domestic dogs and cats, and to a lesser extend to other mammal species. The oncilla (Leopardus tigrinus) is a threatened neotropic felid species that naturally occurs in Brazil. Here, we report the encounter of adult and larval stages of heartworms in a female specimen of L. tigrinus, probable of free-ranging origin, from Ubatuba, São Paulo, Brazil, which died showing clinical signals compatible with heartworm disease. This was the first reported case of D. immitis infection and associated disease in L. tigrinus, also suggesting that the oncilla acted as a definitive host for this parasite. The present findings confirmed D. immitis as a pathogenic agent for this felid species, thus supporting the recommendation for the inclusion of diagnostic testing for this pathogen in routine health screening procedures for captive and free-ranging oncillas in Brazil, especially in those localities where climate conditions support the occurrence of the parasite. Potential reservoirs as oncillas are established beyond the reach of veterinary care, thus representing a continuing risk for domestic animals and humans acquiring heartworm infection. We encourage further serologic and molecular studies aiming to establish D. immitis prevalences in L. tigrinus and other wild carnivores in the region of Ubatuba, as well as ecological and veterinary studies to access the role of this pathogen for the survival of this threatened felid species.

• Dirofilaria immitis heartworm disease Leopardus tigrinus neotropic felid Brazil

Abstract in Portuguese:

ABSTRACT.- Filoni C., Pena H.F.J., Gennari S.M., Cristo D.S., Torres L.N. & Catão-Dias J.L. 2009. Heartworm (Dirofilaria immitis) disease in a Brazilian oncilla (Leopardus tigrinus). Pesquisa Veterinária Brasileira 29(6):373-478. Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, Cidade Universitária, São Paulo, SP 05508-270, Brazil. E-mail: claudiafiloni@triade.org.br Heartworm disease is caused by the intravascular nematode Dirofilaria immitis, a pathogen of public health importance usually associated to domestic dogs and cats, and to a lesser extend to other mammal species. The oncilla (Leopardus tigrinus) is a threatened neotropic felid species that naturally occurs in Brazil. Here, we report the encounter of adult and larval stages of heartworms in a female specimen of L. tigrinus, probable of free-ranging origin, from Ubatuba, São Paulo, Brazil, which died showing clinical signals compatible with heartworm disease. This was the first reported case of D. immitis infection and associated disease in L. tigrinus, also suggesting that the oncilla acted as a definitive host for this parasite. The present findings confirmed D. immitis as a pathogenic agent for this felid species, thus supporting the recommendation for the inclusion of diagnostic testing for this pathogen in routine health screening procedures for captive and free-ranging oncillas in Brazil, especially in those localities where climate conditions support the occurrence of the parasite. Potential reservoirs as oncillas are established beyond the reach of veterinary care, thus representing a continuing risk for domestic animals and humans acquiring heartworm infection. We encourage further serologic and molecular studies aiming to establish D. immitis prevalences in L. tigrinus and other wild carnivores in the region of Ubatuba, as well as ecological and veterinary studies to access the role of this pathogen for the survival of this threatened felid species.