Dirofilariasis involving the oral cavity: report of the first case from South America.

Oral dirofilariasis is very rare with non-specific clinical manifestations. Here, we report the case of a 65-year-old South American woman with a submucosal nodule on her right buccal mucosa. The nodule was slightly tender and painful. Differential diagnoses included mesenchymal (lipoma or fibrolipoma, solitary fibrous tumor, and neurofibroma) or glandular benign tumors (pleomorphic adenoma) with secondary infections. We performed excisional biopsy. A histopathological examination revealed a dense fibrous capsule and a single female filarial worm showing double uterus appearance, neural plaque, well-developed musculature and intestinal apparatus. Dirofilariasis was diagnosed, and the patient was followed-up for 12 months without recurrence.

Dirofilariasis involving the oral cavity: report of the first case from South America

Oral dirofilariasis is very rare with non-specific clinical manifestations. Here, we report the case of a 65-year-old South American woman with a submucosal nodule on her right buccal mucosa. The nodule was slightly tender and painful. Differential diagnoses included mesenchymal (lipoma or fibrolipoma, solitary fibrous tumor, and neurofibroma) or glandular benign tumors (pleomorphic adenoma) with secondary infections. We performed excisional biopsy. A histopathological examination revealed a dense fibrous capsule and a single female filarial worm showing double uterus appearance, neural plaque, well-developed musculature and intestinal apparatus. Dirofilariasis was diagnosed, and the patient was followed-up for 12 months without recurrence.

Dirofilariose humana em Joinville-SC: avaliação clinicopatológica dos primeiros casos relatados na região Sul / Human dirofilariasis in Joinville-SC: clinical-pathological assessment of the first cases reported in the Southern region

INTRODUÇÃO: Dirofilariose é uma zoonose rara causada pelo gênero Dirofilaria e acomete principalmente os pulmões, sendo capaz de simular neoplasia pulmonar. Pouca informação está disponível na literatura sobre a ocorrência e a distribuição de dirofilariose humana na América do Sul. Até 2004, haviam sido descritos apenas 50 casos de dirofilariose humana pulmonar no Brasil, sendo 37 apenas em São Paulo. OBJETIVO: Comprovar a existência de dirofilariose na região de Joinville-SC. MATERIAIS E MÉTODOS: Revisão de arquivos de laboratórios de anatomia patológica da cidade à procura de casos com os termos granuloma parasitário, helminto, helmintíase, verme, Dirofilaria e dirofilariose. Foram incluídos na pesquisa casos que satisfizeram os critérios para dirofilariose, segundo literatura específica. Os prontuários foram revisados e as amostras reprocessadas e analisadas histologicamente por seis colorações diferentes. RESULTADOS: Encontrou-se um caso em globo ocular e sete casos pulmonares, sendo o lobo inferior a localização preferencial (cinco casos). A análise microscópica revelou, nos casos pulmonares, nódulo bem delimitado, frequentemente centrado em uma artéria, com reação granulomatosa e necrose associada à fibrose e infiltrado inflamatório mono e polimorfonuclear, sendo possível identificar segmentos do parasita degenerado, compatível com Dirofilaria immitis. DISCUSSÃO: Todos os parasitas encontrados apresentam características morfológicas idênticas às relatadas na literatura para Dirofilaria immitis. A presença de D. immitis no globo ocular, como observada em um dos pacientes na presente revisão, é rara. CONCLUSÃO: A ocorrência de dirofilariose humana foi confirmada em Joinville e região, sendo causada pela Dirofilaria immitis.

INTRODUCTION: Dirofilariasis is a rare zoonosis caused by Dirofilaria genus, which affects mainly the lungs and may be misdiagnosed as lung cancer. Little information is available regarding the occurrence and distribution of human dirofilariasis in South America. Only 50 cases of human pulmonary dirofilariasis were described in Brazil until 2004, of which 37 were located in São Paulo. OBJECTIVE: To prove the existence of dirofilariasis in Joinville, SC. MATERIAL AND METHODS: The records of anatomic pathology laboratories of the city were reviewed in search for cases with the terms parasitic granuloma, helminth, helminthiasis, worm, Dirofilaria and dirofilariasis. According to specific literature, the cases that met the criteria for dirofilariasis were included in the study. The medical records were reviewed and the samples reprocessed and histologically analyzed by six different stains. RESULTS: We found one ocular case and seven pulmonary cases. The lower lobe was the main location (five cases). In all pulmonary cases, microscopic analysis revealed well defined nodules, frequently centered in a pulmonary artery, with granulomatous reaction and necrosis associated with fibrosis and mono and polymorphonuclear inflammatory infiltrate. It was also possible to identify segments of the deteriorated worm consistent with Dirofilaria immitis. DISCUSSION: All parasites found in this study show morphological characteristics similar to those reported in the literature on Dirofilaria immitis. The presence of D. immitis in the eye, as reported in one of the patients from this review, is rare. CONCLUSION: The occurrence of human dirofilariasis was confirmed in Joinville and region and it was caused by Dirofilaria immitis.

Structural and ultrastructural changes in the lungs of cats Felis catus (Linnaeus, 1758) experimentally infected with D. immitis (Leidy, 1856).

Clinical signs are seldom observed in feline heartworm disease, and the pathophysiological changes in the lungs of infected animals remain undefined. The goal of this study was to evaluate the structural and ultrastructural changes in the lungs of cats experimentally infected with Dirofilaria immitis. Six healthy cats were each infected with two adult heartworms by intravenous transplantation (Receptor Group, RG). The control group consisted of two uninfected animals kept under the same conditions as the RG. At 42 days after transplantation, all cats were euthanized and necropsied for worm recovery and collection of lung samples for examination by light microscopy (LM) and transmission electron microscopy. By LM, lung sections from the six infected cats exhibited bronchial and bronchiolar lesions. Alterations in all tissues of the pulmonary arteries were observed in the infected animals. In conclusion, cats infected experimentally with D. immitis developed lesions in their lungs as a consequence of arterial disease and intense interstitial pneumonia.

Dirofilaria immitis and Trypanosoma cruzi natural co-infection in dogs.

Dirofilariasis (Dirofilaria immitis) and American trypanosomiasis (Trypanosoma cruzi) are zoonotic parasitic diseases affecting the hearts of a variety of mammalian host species, including dogs. In this study, some of the immunopathological characteristics of natural co-infection by these two parasites were compared with T. cruzi infection in dogs from Mexico. Antibody analysis in serum indicated significantly lower anti-T. cruzi IgG levels in co-infected dogs (n = 4) compared to those with T. cruzi infection alone (n = 9), together with a somewhat lower IgG2/IgG1 ratio. Cardiac tissue inflammation was limited and focal in co-infected animals whereas T. cruzi infected dogs had extensive and diffuse tissue inflammation. Three out of nine T. cruzi infected dogs and 1/4 of T. cruzi and D. immitis co-infected dogs showed cardiac alterations. The results showed that co-infections may interfere with host responses, and their significant prevalence (4/13 T. cruzi infected dogs) suggests that they should be taken into account by researchers and clinicians.

Dirofilariosis en caninos: estudio anatomopatológico de 15 casos / Canine dirofilariosis: a pathologic anatomy study of 15 cases

El objetivo del presente estudio es reportar los cambios anatomopatológicos que ocurren en la dirofilariosis canina en su forma cardiopulmonar así como los daños relevantes que se producen en órganos vitales en la forma sistémica en caninos. La dirofilariosis canina también llamada enfermedad del gusano del corazón, es una enfermedad parasitaria producida por el nemátodo Dirofilaria inmitis que ocurre con una alta prevalencia a nivel mundial y constituye uno de los problemas patológicos más relevantes en el ámbito de la cría de caninos. La patogénesis de la enfermedad es bien conocida y sus cambios anatomopatológicos han sido bien documentados en otros países. En Venezuela se ha reportado la enfermedad con sus aspectos clínicos pero los cambios relevantes, tanto macroscópicos como la histopatología, no han recibido la atención que merecen. Quince caninos, 8 machos y 7 hembras de diferentes razas y entre 5 y 14 años de edad fueron necropsiados. Los cambios macro y microscópicos en órganos y tejidos de corazón, pulmón, bazo, hígado y riñon más relevantes son reportados. Se realizaron frotis sanguíneos detectándose la presencia de microfilarias con sus características típicas y se realizó la evaluación morfológica de parásitos adultos.

[Human pulmonary dirofilariasis at Rio de Janeiro, Brazil: a case report]. / Dirofilaríase pulmonar humana no Estado do Rio de Janeiro, Brasil: relato de um caso.

We report a case of human pulmonary dirofilariasis in a female patient 45-years-old, derived from Rio de Janeiro, Brazil. The chest radiologic finding consisted of single pulmonary nodule located on the left lower lobe that simulated lung tumor. Human pulmonary dirofilariasis might be investigated in nodules that are not malignants and require conclusive diagnosis.

Kidney ultrastructural lesions in dogs experimentally infected with Dirofilaria immitis (Leidy, 1856).

Kidneys of 16 beagles with experimentally induced heartworm (Dirofilaria immitis) infections and 4 heartworm-nai;ve dogs were studied by light and electron microscopy. The infections were induced either by subcutaneous injection of infective larvae or by the transplantation of adult parasites, and infection periods varied from 111 to 818 days and 365 to 923 days, respectively. One control group of heartworm-naïve dogs and four groups of heartworm-infected dogs, which were divided according to the type and the length of infection, were used. In the infected dogs, thickening of the glomerular basement membrane (GBM), the presence of dense deposits in the GBM, and foot process effacement were the most frequent lesions observed. In some dogs, electron dense deposits were seen in the GBM and the mesangium and/or enlargement of the mesangial matrix could be characterized. The longer the infection period, the thicker the GBM and the more common the occurrence of foot process effacement. In general, these alterations were more evident in animals that had been infected for more than 1 year, had high microfilaremia, and had 14 or more parasites in the main pulmonary artery and its branches. The presence of dense deposits suggests that the pathogenesis of kidney disease in dirofilariasis is associated with deposits of immune complexes in the membrane. The finding of ultrastructural changes in dogs with early prepatent infections suggests that immature heartworms, as well as microfilariae and possibly adult worms, contribute to the glomerulonephropathy.

Dirofilariose pulmonar humana: relato de sete casos / Human pulmonary dirofilariasis: a report of seven cases

Dirofilariose pulmonar humana é uma doença rara causada pelo parasita Dirofilaria immitis. Apresenta-se usualmente como um nódulo pulmonar solitário que mimetiza câncer de pulmão. Embora considerada uma doença clinicamente benigna, uma biópsia pulmonar excisional é quase sempre necessária para o diagnóstico. Relatam-se as características epidemiológicas, clínicas e radiológicas de sete casos de dirofilariose pulmonar humana em Florianópolis. De sete pacientes relatados, seis tiveram como achado radiológico um nódulo pulmonar e foram submetidos à biópsia pulmonar excisional para o diagnóstico. Em um paciente, a imagem radiológica não estava disponível para revisão e, portanto, não foi descrita no trabalho; o diagnóstico foi estabelecido pela biópsia transbrônquica

Human pulmonary dirofilariasis: analysis of 24 cases from São Paulo, Brazil.

STUDY OBJECTIVE: To present the clinical, radiologic, and pathologic aspects of 24 cases of human pulmonary dirofilariasis (HPD) from São Paulo, Brazil. DESIGN: Retrospective study of 24 patients with a confirmed diagnosis of HPD over a 14-year period (from February 1982 to June 1996). SETTING: Thoracic Surgery and Pulmonary Division, University of São Paulo and Hospital Albert Einstein, São Paulo, Brazil. RESULTS: Seventeen patients were male (70.1%) and seven were female (29.9%). Their mean age was 51.4 years. Fifty-four percent of the patients were asymptomatic and 75% had a well-circumscribed noncalcified peripheral subpleural pulmonary nodule on the chest radiograph and thoracic CT scan, located preferentially in the lower lobes. The diagnosis was made after thoracotomy and wedge resections in 16 patients, by videothoracoscopy in six, after a pleural biopsy in one, and after necropsy in one. The pathologic examination of all the nodules revealed a central zone of necrosis, surrounded by a narrow granulomatous zone and peripherally by fibrous tissue. Pulmonary vessels exhibit varying degrees of endarteritis. In all cases, a dead worm, usually necrotic and fragmented, was found. CONCLUSIONS: A subpleural, noncalcified pulmonary nodule in the appropriate clinical and epidemiologic setting should alert the clinician, radiologist, or pathologist to the possibility of Dirofilaria. HPD should be considered in the differential diagnosis of pulmonary nodules.

Survey of Dirofilaria immitis (Leidy, 1856) in random source cats in metropolitan Rio de Janeiro, Brazil, with descriptions of lesions.

To evaluate the prevalence of heartworm disease in metropolitan Rio de Janeiro, RJ, Brazil, cats submitted for euthanasia were evaluated by laboratory tests and by necropsy for signs of heartworm infection. Of the 135 cats examined, one (0.8%)--a stray male from an urbanizing district--had one male worm (14.5 cm) in the left lung and showed severe muscular hypertrophy of small pulmonary arteries and arterioles with no right ventricle enlargement or passive congestion. Microfilariae were not detected in the blood of any cats. The prevalence of canine heartworm in the area from which this cat originated is estimated to be approximately 12%. The prevalence of canine heartworm in the urban area of Rio de Janeiro has been determined to be approximately 5%. It has been shown that the prevalence of feline heartworm disease parallels that in dogs, but at a lower rate. Results of this survey strongly suggest that heartworm prevention measures should be taken under consideration, especially among cats living in a high canine heartworm prevalence area.

Human pulmonary dirofilariasis: a review

Os autores realizaram minuciosa revisao sobre a distribuicao geografica, a clinica, a patologia e o diagnostico da dirofilariase pulmonar humana. Esta zoonose, que tem como principal agente etiologico a Dirofilaria immitis, e um problema medico porque produz um quadro clinico, embora benigno, que se confunde com neoplasia e, assim interpretado, pode conduzir o paciente a cirurgia do torax. Dos 229 casos citados na literatura, apenas 17 foram descritos no Brasil, apesar da existencia de condicoes muito favoraveis a transmissao da infeccao para o homem, admitindo-se portanto, que e uma parasitose subdiagnosticada. Finalmente, a importancia do diagnostico diferencial entre dirofilariase e neoplasias pulmonares nos casos de presenca de nodulo solitario subpleural ("coin lesion") e destacada, alem do que o desenvolvimento e aprimoramento de tecnicas modernas de diagnostico imunologico sao essenciais para distinguir esta doenca benigna de outras patologias mais serias e evitar cirurgias desnecessarias. Essas tecnicas poderao fornecer a prevalencia real da parasitose em nosso meio.

Pulmonary dirofilariasis: first reported case in Puerto Rico.

The first case of human pulmonary dirofilariasis in our country is reported. The etiopathogenesis and pathological findings of the zoonosis are discussed.

Pulmonary dirofilariasis: first reported case in Puerto Rico

The first case of human pulmonary dirofilariasis in our country is reported. The etiopathogenesis and pathological findings of the zoonosis are discussed

[Human pulmonary dirofilariasis acquired in Brazil: report of a case]. / Dirofilariose pulmonar humana, adquirida no Brasil: comunicação de um caso.

We report the second published case of human dirofilariasis acquired in Brazil. The patient had two pulmonary coin lesions seen in conventional chest roentgenogram and confirmed as solid round nodules by computerized X-ray chest scan. Diagnosis was done by surgical removal of one of the lesions and anatomopathological study of tissue removed.