Removal and identification of a subconjunctival parasite by light and scanning electron microscopy

Background: Ophthalmic dirofilariasis is an uncommon zoonotic parasitic infection caused by species of Dirofilaria, a dog tapeworm that is transmitted to human by mosquitoes. Man is a dead?end host for the parasite. Ophthalmic involvement is rare and includes periorbital, subconjunctival, subtenon, and intra?ocular involvement. We report the removal of a subconjunctival worm and identification by light microscopy (LM) and scanning electron microscopy (SEM). Purpose: A 62?year?old female presented with complaints of redness, discharge, and foreign body sensation with difficulty in opening eyes in the left eye for the last 3 days. The patient is a non?vegetarian. On examination, her best corrected visual acuity in both eyes was 20/20. On slit lamp examination, there was a long, thin, round, coiled white subconjunctival live worm in the left eye superiorly. The rest of anterior segment evaluation, intra?ocular pressure, and fundus was normal in both eyes. The parasite was removed under local anesthesia from subconjunctival space [Video]. External surface morphology under LM revealed fine transverse cuticular striations with tapered cephalic and caudal ends. Uterus was long and coiled with indistinguishable masses inside. The finding was also confirmed by SEM. Synopsis: A subconjuctival parasite was removed and identified as Dirofilaria repens by characteristic LM and SEM findings. Highlight: Dirofilaria species may lodge in many tissues of human bodies including eye and adnexa. Dirofilaria is a natural parasite of carnivorous animals, mostly dogs, cats, and foxes.[1] The most common mode of transmission to human is usually by bite of mosquitoes like Culex and Aedes, which are considered as vectors, and it is often thought that parasitemia is because of accidental conduction.[1] Simple surgical removal of the worm is curative. After removal, the worm should be visualized directly under LM. All the internal structures of the transparent worm could be seen and compared with those under SEM.

Serological survey of canine vector-borne diseases in two animal shelters in central Peninsular Malaysia

@#Canine vector-borne diseases (CVBDs) are increasingly becoming a cause for global concern because of their high morbidity and mortality rates in dogs. However, information on their occurrence in Malaysia is still scanty. In this study, a total of 103 dog blood samples were collected from two animal shelters in central Peninsular Malaysia and tested for the antibodies against Ehrlichia spp., Anaplasma spp., Borrelia burgdorferi, and the antigen of Dirofilaria immitis. Of the 103 tested dogs, 44.7% (46) were found to be seropositive for Ehrlichia spp., 30.1% (31) for Anaplasma spp. and 13.6% (14) for D. immitis. Co-infections of Anaplasma spp. + Ehrlichia spp. (18.5%, 19) were most prevalent, followed by Anaplasma spp. + D. immitis (1.9%; two) and D. immitis + Ehrlichia spp. (1.0%; one). Furthermore, three dogs (2.9%) were also found to have triple infection, testing seropositive for Ehrlichia spp., Anaplasma spp. and D. immitis. The dogs which were found to be seropositive with at least one pathogen were 66.7% (32/51) at shelter A, and 55.8% (29/52) at shelter B. Serological evidence showed that the exposure of major vector-borne diseases in dogs in shelters was relatively high in the surveyed areas. Routine detection and control of vector-borne diseases are of paramount importance for reducing the risk of CVBDs transmission in dogs and humans.

Report of Dirofilaria immitis infection with acute cardiopulmonary complications in a cat from Northeastern Brazil / Relato de infecção por Dirofilaria immitis com complicações cardiopulmonares agudas em um gato no Nordeste do Brasil

Dirofilariasis is a zoonotic disease caused by Dirofilaria immitis, a nematode found mainly in the pulmonary artery and right chambers of the heart, lungs, and large vessels of dogs. This parasitism also occasionally occurs in cats, causing an amicrofilaremic and asymptomatic infection, resulting in severe illness and rapid death. In this case report, it was described acute clinical signs and histopathological alterations in a domestic cat with heartworm disease from the city of Mossoró, the Rio Grande do Norte, Brazil. The nematode species, D. immitis, was confirmed by morphological and molecular analyses. This is the first documented and full report of feline heartworm disease in northeastern Brazil.(AU)

A dirofilariose é uma doença zoonótica causada por Dirofilaria immitis, um nematódeo que parasita cães, principalmente a artéria pulmonar e as câmaras direitas do coração, pulmões e grandes vasos. Este parasita também ocorre ocasionalmente em gatos, geralmente causando uma infecção amicrofilarêmica e assintomática, que pode resultar em doença grave e morte rápida. Neste relato de caso, são apresentados os sinais clínicos agudos e alterações histopatológicas em um gato doméstico do município de Mossoró, Rio Grande do Norte, Brasil, com dirofilariose. A espécie de nematóide, D. immitis, foi confirmada por análises morfológicas e moleculares. Este é o primeiro relato documentado e completo de dirofilariose felina no Nordeste do Brasil.(AU)

Rare cause of floaters: A motile live worm in vitreous cavity

Ocular filariasis commonly presents as subconjunctival or eyelid nodules. We report a rare case of a live, motile worm causing floaters. The worm was isolated from the vitreous cavity and revealed to be Dirofilaria repens. Correct recognition of the worm is necessary as human dirofilariasis does not present as microfilaremia and does not require systemic therapy; in contrast to other causes of ocular filariasis, which require systemic therapy. As ophthalmologist may be the first physician to encounter such patients, a high index of suspicion is required for timely and adequate management.

Human pulmonary dirofilariasis with secondary myocarditis

Abstract Dirofilariasis is a little-known zoonosis, with dogs and cats as definitive hosts. It is caused by nematodes and transmitted by mosquito bites. We report the case of a 67-year-old man with a consumptive syndrome with two subpleural pulmonary opacities. A transthoracic lung biopsy revealed a Dirofilaria worm. Myocardial nuclear magnetic resonance (NMR) demonstrated dilated cardiomyopathy after myocarditis related to dirofilariasis. Human infection is rare and occurs accidentally. The most common radiological alteration is a mainly subpleural coin lesion. Dirofilariasis is a neglected emergent disease and knowledge about it is important for differential diagnoses from neoplastic pulmonary nodules.

Subcutaneous human Dirofilariasis in Vidarbha.

Zoonotic filariasis due to Dirofilaria repens is prevalent in several regions of the world. Human dirofilariasis due to D. repens has not been widely recognized in India, but few cases reported from some parts of India. Dirofilaria species are commonly encountered in the subcutaneous tissue of dogs, foxes, and cats and it can accidentally infect humans. Here, we report a case of subcutaneous dirofilariasis, presenting as a subcutaneous nodule on the right leg of a 25-year old female from Vidarbha region.

Subconjunctival dirofilariasis caused by Dirofilaria repens: A case report with short review.

Human dirofi lariasis is a rare infection caused by fi larial worms of genus Dirofi laria. Subconjunctival dirofi lariasis has been reported from Asia, Europe, Italy and Africa. In India majority cases are from Kerala, Karnataka and very few from Maharashtra. We report the rare case of subconjunctival dirofi lariasis caused by Dirofi laria repens from Maharashtra, western India.

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.

Human ocular dirofilariasis due to Dirofilaria repens in Sri Lanka

Objective: To identify worms obtained from patients with eye lesions and to describe the demographic factors of patients with ocular dirofilariasis. Methods: A retrospective descriptive study was conducted in 31 worm samples from 30 patients referred by consultant ophthalmologists between 2006 and February 2014. Data on age, sex and site of the lesion were ascertained from the details given in the referral letters. Morphological identification of the worm was based on the maximum width, length and appearance of the cuticle. The sex of the worm was determined by the width, length and presence or absence of vulva opening. PCR was performed using Dirofilaria repens specific primers to confirm the species of worms which couldnot be identified morphologically. Results: Most of the patients belonged to the age group of 40-49 years (mean age = 42 years). Majority of them were females (70%). Subconjunctival lesions were the most frequent presentation, while the rest (n = 4) were found on eyelids. Female worms were extracted from 18 cases, and 11 had male worms. One individual had both male and female worms in a single nodule. Adults were the most commonly affected. This pattern was different from the previous studies in Sri Lanka where the most common age group affected was younger than 9 years old. Conclusions: The present study showed a considerably high incidence of ocular dirofilariasis, stressing the importance of implementing preventive measures to reduce the transmission of this zoonotic filarial disease.

A Rare Human Case of Dirofilaria repens Infection in the Subcutaneous Posterior Thorax with Molecular Identification

The emergence of Dirofilarial infections in Asia including Vietnam is a clinically significant threat to the community. We here report a rare case of subcutaneous Dirofilaria repens infection on the posterior thoracic wall in a young woman presenting a painful, itchy, and palpable nodule. The adult worm was identified by mitochondrial cox1 and nuclear ITS-2 sequence determination. The diagnosis was additionally confirmed by 16S rRNA sequencing of the endosymbiont Wolbachia pipientis commonly co-existing with D. repens. This is a rare case of subcutaneous human infection on the posterior thoracic region caused by D. repens.

Human ocular dirofilariasis due to Dirofilaria repens in Sri Lanka

OBJECTIVE@#To identify worms obtained from patients with eye lesions and to describe the demographic factors of patients with ocular dirofilariasis.@*METHODS@#A retrospective descriptive study was conducted in 31 worm samples from 30 patients referred by consultant ophthalmologists between 2006 and February 2014. Data on age, sex and site of the lesion were ascertained from the details given in the referral letters. Morphological identification of the worm was based on the maximum width, length and appearance of the cuticle. The sex of the worm was determined by the width, length and presence or absence of vulva opening. PCR was performed using Dirofilaria repens specific primers to confirm the species of worms which couldnot be identified morphologically.@*RESULTS@#Most of the patients belonged to the age group of 40-49 years (mean age = 42 years). Majority of them were females (70%). Subconjunctival lesions were the most frequent presentation, while the rest (n = 4) were found on eyelids. Female worms were extracted from 18 cases, and 11 had male worms. One individual had both male and female worms in a single nodule. Adults were the most commonly affected. This pattern was different from the previous studies in Sri Lanka where the most common age group affected was younger than 9 years old.@*CONCLUSIONS@#The present study showed a considerably high incidence of ocular dirofilariasis, stressing the importance of implementing preventive measures to reduce the transmission of this zoonotic filarial disease.

A rare case of subconjunctival dirofilariasis by Dirofilaria repens in rural Gujarat.

Dirofi lariasis is a worldwide zoonotic fi lariasis with over 782 cases reported so far from diff erent parts of the world. Human dirofi lariasis, caused by Dirofi laria repens, have been reported to occur widely throughout Asia, Europe, and Africa. It has not been widely recognized in India, however; several cases have been reported in last few years. There is probably a focus of human infection with D. repens in Kerala. Herein, we present a review of human infections by D. repens, along with a case report of subconjunctival dirofi lariasis from rural part of Gujarat.

Oral dirofilariasis.

Filariasis affecting animals can rarely cause infections in human beings through the accidental bite of potential vectors. The resulting infection in man, known as zoonotic filariasis occur worldwide. Human dirofilariasis, the most common zoonotic filariasis, is caused by the filarial worm belonging to the genus Dirofilaria. Dirofilarial worms, which are recognized as pathogenic in man can cause nodular lesions in the lung, subcutaneous tissue, peritoneal cavity or eyes. Oral dirofilariasis is extremely rare and only a few cases have been documented. We report an interesting case of dirofilariasis due to Dirofilaria repens involving buccal mucosa in a patient who presented with a facial swelling. The clinical features, diagnostic issues and treatment aspects are discussed. This paper stresses the importance of considering dirofilariasis as differential diagnosis for subcutaneous swelling of the face, especially in areas where it is endemic.

Expression of Translationally Controlled Tumor Protein (TCTP) Gene of Dirofilaria immitis Guided by Transcriptomic Screening

Dirofilaria immitis (heartworm) infections affect domestic dogs, cats, and various wild mammals with increasing incidence in temperate and tropical areas. More sensitive antibody detection methodologies are required to diagnose asymptomatic dirofilariasis with low worm burdens. Applying current transcriptomic technologies would be useful to discover potential diagnostic markers for D. immitis infection. A filarial homologue of the mammalian translationally controlled tumor protein (TCTP) was initially identified by screening the assembled transcriptome of D. immitis (DiTCTP). A BLAST analysis suggested that the DiTCTP gene shared the highest similarity with TCTP from Loa loa at protein level (97%). A histidine-tagged recombinant DiTCTP protein (rDiTCTP) of 40 kDa expressed in Escherichia coli BL21 (DE3) showed immunoreactivity with serum from a dog experimentally infected with heartworms. Localization studies illustrated the ubiquitous presence of rDiTCTP protein in the lateral hypodermal chords, dorsal hypodermal chord, muscle, intestine, and uterus in female adult worms. Further studies on D. immitis-derived TCTP are warranted to assess whether this filarial protein could be used for a diagnostic purpose.

Periorbital dirofilariasis—Clinical and imaging findings: Live worm on ultrasound.

Ocular dirofilariasis is a zoonotic filariasis caused by nematode worm,Dirofilaria. We present a case of dirofilariasis affecting the upper eyelid in a 2-year-old child presenting as an acutely inflammed cyst, from southern Indian state of Kerala. Live adult worm was surgically removed and confirmed to be Dirofilaria repens. Live worm showing continuous movement was seen on the pre-operative high-resolution ultrasound. Ultrasound can be helpful in pre-operative identification of live worm. Imaging findings reported in literature are very few. We describe the clinical, ultrasound, and magnetic resonance imaging (MRI) findings.

A Case of Human Pulmonary Dirofilariasis in a 48-Year-Old Korean Man

Dirofilariasis is a rare disease in humans. We report here a case of a 48-year-old male who was diagnosed with pulmonary dirofilariasis in Korea. On chest radiographs, a coin lesion of 1 cm in diameter was shown. Although it looked like a benign inflammatory nodule, malignancy could not be excluded. So, the nodule was resected by video-assisted thoracic surgery. Pathologically, chronic granulomatous inflammation composed of coagulation necrosis with rim of fibrous tissues and granulations was seen. In the center of the necrotic nodules, a degenerating parasitic organism was found. The parasite had prominent internal cuticular ridges and thick cuticle, a well-developed muscle layer, an intestinal tube, and uterine tubules. The parasite was diagnosed as an immature female worm of Dirofilaria immitis. This is the second reported case of human pulmonary dirofilariasis in Korea.

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.

Identificación morfológica y molecular de filarías caninas en una comuna semi-rural de la Región Metropolitana, Chile / Morphological and molecular identification of canine filariae in a semi-rural district of the Metropolitan Region in Chile

Introduction: To date, there has been no definitive confirmation of the presence of zoonotic dirofilariasis in dogs in Chile. Objectives: To study the presence of dirofilarias in blood samples from dogs collected in a semi-rural district near Santiago and to compare their frequency in dogs with and without dermatological manifestations. Methods: We examined 100 blood samples for dog filariae infections using microscopic methods (modified Knott technique). 50 dogs presented dermatological symptoms or signs compatible with filarial infections and 50 were asymptomatic. ITS-2 and 12s rDNA gene amplification by PCR and sequencing were performed in samples microscopically positive for microfilariae. Results. We observed microfilariae in 22 dogs (22%). Of these, 16/50 (32%) were symptomatic and 6/50 (12%) were asymptomatic (p = 0.02). Morphologically, the majority of micro-filariae were similar to Dirofilaria repens, although many had a bigger size than previously described. Nucleotide sequencing of the amplified genes showed no more than 95% homology with the D. repens sequences available for comparison. D. reconditum and D. dracunculoides infections were also identified. Conclusions: These features might indicate the presence of new species of Dirofilaria or a D. repens close related variant in Chile.

Introducción: A la fecha no hay datos concluyentes en Chile respecto a la presencia de dirofilariasis zoonótica en perros. Objetivos: Identificar la presencia de dirofilarias en sangre de perros de una comuna semi-rural cercana a Santiago y comparar su frecuencia en animales con y sin manifestaciones dermatológicas. Materialy Métodos. Se examinó un frotis sanguíneo de 100 perros en busca de microfilarias mediante observación microscópica (técnica de Knott modificada). Cincuenta perros presentaban síntomas o signos dermatológicos que se han asociado a esta parasitosis y 50 eran asintomáticos. Se amplificaron los genes ITS-2 y 12s ADNr de filarías en las muestras con microfilarias al frotis, secuenciando los fragmentos amplificados. Resultados: Se observaron microfilarias en 22 perros (22%), 16/50 (32%) sintomáticos y 6/50 (12%) asintomáticos (p = 0,02). Morfológicamente, la mayoría de las microfilarias observadas fueron similares a D. repens; sin embargo, una gran proporción mostró un tamaño mayor al descrito para esta especie. Las secuencias nucleotídicas de los genes amplificados mostraron una homología no mayor al 95% con las secuencias de D. repens disponibles para comparación. Se identificaron además dos especies poco patógenas, D. reconditum por morfología y secuenciación genética y D. dracunculoides por morfología. Conclusiones: Los resultados indican la existencia de una nueva especie de Dirofilaria cercanamente relacionada a D. repens o de una variante de esta especie.

Diagnóstico de Dirofilaria immitis en el municipio Sucre, estado Sucre, Venezuela / Diagnosis of Dirofilaria immitis in the municipality of Sucre, Sucre state, Venezuela

La dirofilariasis es una patología parasitaria, causada por los nematodos Dirofilaria immitis y D. repens, principalmente. Mientras que D. immitis presenta distribución mundial, D. repens se extiende por el viejo mundo. Ambas especies afectan a caninos y felinos domésticos y salvajes, así como a humanos, por lo que es un problema de salud pública mundial. En este estudio se determinó la prevalencia de D. immitis, en caninos del municipio Sucre, estado Sucre, Venezuela. Se tomaron muestras sanguíneas a 138 caninos domésticos, mayores de seis meses, sin distinción de raza ni sexo, previo consentimiento informado por sus propietarios. El diagnóstico parasitológico de las microfilarias circulantes se realizó por examen directo y método de concentración Knott modificado; las características morfológicas fueron observadas en extendidos teñidos con Giemsa. Se utilizó un estuche comercial, para la captura de antígenos de excreción-secreción de D. immitis. De los 138 caninos estudiados, 12 casos positivos (8,7%) fueron detectados parasitológicamente, mientras que por el estuche comercial se detectaron antígenos en 20 caninos (14,5%), lo que demuestra que existe una dirofilariasis oculta en el 5,8% de los casos evaluados. Uno de los perros microfilarémicos, no presentó antígenos circulantes. La prevalencia de dirofilariasis en el municipio Sucre, estado Sucre fue de 15,2%. Este reporte de dirofilariasis canina en el municipio Sucre, representa un importante aporte en el levantamiento epidemiológico de la enfermedad. Futuros estudios permitirán evaluar el riesgo de infección de las personas que conviven con los perros con dirofilariasis.

Heartworm is a parasitic disease, caused by nematodes Dirofilaria immitis and D. repens, mainly. While D. immitis presents worldwide distribution, D. repens extends the old world. Both species affect canines and felines domestic and wild, as well as human, so it is a global public health problem. In this study we determined the prevalence of D. immitis in dogs in the municipality of Sucre, Sucre state, Venezuela. Blood samples were taken for 138 domestic dogs, over six months, regardless of race or sex, prior informed consent by their owners. The parasitological diagnosis of circulating microfilariae was done by direct examination and concentration method modified Knott, the morphological characteristics were observed in Giemsa-stained smears. We used a commercial kit, for the capture of excretory-secretory antigens of D. immitis. Of the 138 dogs studied, 12 cases (8.7%) were detected parasitologically, whereas the commercial kit antigens were detected in 20 dogs (14.5%), demonstrating that there is an occult infections in 5.8% of the cases. One of the dogs with microfilariae in blood, did not submit antigens circulating. The prevalence of heartworm in the municipality of Sucre, Sucre state was 15.2%. This report of canine heartworm in the municipality of Sucre, represents an important contribution in an epidemiologic survey of the disease. Future studies will assess the risk of infection for people living with dogs with heartworm disease.