Canine heartworm and heat treatment: An evaluation using a well based enzyme-linked immunosorbent assay (ELISA) and canine sera with confirmed heartworm infection status.

Heat treatment of serum has demonstrated improved detection of Dirofilaria immitis antigen in sera of sheltered dogs without knowing the true infection status of the animals and in dogs confirmed experimentally to be infected with heartworm. Utilizing archived sera with necropsy confirmed heartworm infection status (n = 665) and a micro-titer well based ELISA antigen assay, this study evaluated how the composition of heartworm infections affects antigen test results pre- and post-heat treatment, determined subsequent changes to the antigen test sensitivity and specificity, and application of optical density values. The composition of heartworm infections present in dogs with sera initially testing antigen negative consisted of infections by dead 1/34 (2.9 %), immature 10/34 (29.4 %), male only 7/34 (20.6 %), female only 5/34 (14.7 %), and mixed sex infections 11/34 (32.4 %) with 2-62 heartworms of which 6 were microfilaremic. The composition of heartworm infections remaining antigen negative post-heat treatment consisted of infections by dead 1/14 (7.1 %), immature 9/14 (64.3 %), male only 2/14 (14.3 %), and mixed sex infections 2/14 (14.3 %) with 6 and 62 heartworms of which 1 was microfilaremic. The overall sensitivity for all infections, mature heartworms, and mature females before heat treatment were 86.9 %, 90.7 %, and 93.3 % and after heat treatment sensitivity increased to 94.6 %, 98.4 %, and 99.2 % respectively. A decrease in specificity from 97.8%-96.1% was observed following heat treatment of heartworm negative sera. Optical density values for the varying infection intensities present in this study clearly indicate that result intensity is not reflective of the number of heartworms present. This study provides additional context for interpreting post-heat antigen results for dogs originating from animal shelters, demonstrates diagnostic utility of optical density, and highlights the need for improved heartworm diagnostics.

Dirofilarioses in cats: European guidelines from the ABCD on prevention and management.

OVERVIEW: Dirofilaria immitis and Dirofilaria repens are the most important filarial worms, causing heartworm disease and subcutaneous dirofilariosis, respectively. D repens is currently considered an emerging zoonotic agent in Europe. LIFE CYCLE AND INFECTION: Filarial worms infect mainly dogs, but also cats, ferrets, wild carnivores and humans. The life cycle involves an intermediate mosquito host. Compared with dogs, cats are imperfect hosts for dirofilarial worms. After inoculation, only a low number of L3 larvae develop to the adult stage in a small percentage of cats. Heartworm disease in cats may be associated with severe pulmonary thromboembolism and an eosinophilic inflammatory response in the lungs, potentially leading to sudden death. Otherwise self-cure occurs in most cases after 18-48 months. Subcutaneous dirofilariosis may present as subcutaneous nodules or dermatitis. DIAGNOSIS AND TREATMENT: Diagnosis in cats is more difficult compared with dogs and needs a multistep approach (antigen and antibody tests, as well as diagnostic imaging). Cats with acute heartworm disease require stabilisation within an intensive care unit. Cats with respiratory signs or suggestive radiographic changes should receive prednisolone and follow-up with a similar multistep approach. Adulticidal therapy is not safe in cats. PREVENTION: In endemic areas cats should receive year-round chemoprophylaxis from 2 months of age.

Case Report: Successful Treatment of a Patient with Microfilaremic Dirofilariasis Using Doxycycline.

We report the case of a 56-year-old woman with microfilaremic dirofilariasis due to Dirofilaria repens, which is a very rare condition in humans. Of note, just one of six large-volume blood samples of this patient was positive for microfilariae. Polymerase chain reaction (PCR) and sequencing of the parasite gene determined the geographic origin of the causative helminth. The patient was treated successfully with doxycycline. This drug was chosen because of the patient's reluctance to the use of ivermectin and to provide an anthelmintic effect by targeting the bacterial endosymbiont Wolbachia present in most filarial species.

Feline asthma and heartworm disease: Clinical features, diagnostics and therapeutics.

PRACTICAL RELEVANCE: For feline practitioners, the cat with a cough or respiratory distress and thoracic radiographs with a bronchial or bronchointerstitial pattern suggests lower airway disease. Two important differentials, allergic asthma and heartworm disease (HWD), have many overlapping clinicopathologic features, but also clear and important differences in terms of cause and disease progression, treatment and prognosis. Notably, asthma is readily treatable and HWD is preventable. CLINICAL SIGNIFICANCE: Feline HWD comprises two clinical syndromes: the comparatively recently described heartworm-associated respiratory disease (HARD) and adult HWD. The former is much more common; very few cats with HARD develop adult HWD. In HARD, following death of immature worms, pulmonary lesions may improve over time ('self-cure'). Lesions of adult HWD also improve over time as long as reinfection does not occur; however, with death of adult heartworms, mortality is high, and the prognosis is guarded. In asthma, morbidity is relatively high, but mortality is low, with an overall good to excellent prognosis. DISEASE RECOGNITION: Feline asthma is encountered worldwide. In the authors' impression, feline HWD is often under-recognized. AIMS: The aim of this review is to assist clinicians in differentiating feline asthma from feline HWD; as such, the emphasis is on distinguishing clinical features, as well as on diagnostics, therapy and prognosis. In differentiating these conditions, clinicians can attempt the goal of properly managing these diseases and can best educate owners on prognosis. EVIDENCE BASE: For both feline asthma and feline HWD, the authors have drawn on the available peer-reviewed literature studies involving experimental models as well as spontaneous disease.

Approaches to Canine Heartworm Disease Treatment Among Alumni of a Single College of Veterinary Medicine.

This descriptive study was designed to ascertain the current heartworm treatment strategies employed by veterinary graduates of a single college of veterinary medicine, to assess the frequency with which each of these treatment strategies is prescribed, and to report the motivation behind the use of these treatment strategies. A survey containing a combination of multiple-choice and open-ended questions was distributed via e-mail with an online link during 2013 to graduates of the University of Georgia College of Veterinary Medicine. Demographic data and opinions regarding treatment for cases of canine heartworm disease (HWD) were obtained, and motivation for recommending different treatment strategies was assessed. Nearly all 170 respondents (99%) indicated that they recommend melarsomine dihydrochloride for first-line treatment of canine HWD. Exercise restriction (80%) and monthly heartworm preventive (75%) were components of the treatment approach to HWD with no clinical signs. The majority of respondents (74%) indicated that when first-line treatment recommendations were declined, they endorsed long-term administration of ivermectin (i.e., "slow-kill" method) despite current American Heartworm Society guidelines that recommend against the use of long-term macrocyclic lactone administration for the monotherapy treatment of canine HWD. Respondents also indicated that owners' financial concerns frequently result in modification of HWD treatment. Routine inclusion of exercise restriction is commonly, but not universally, utilized and may represent an opportunity for improvement in the management of this disease. In addition, when first-line recommendations for heartworm disease treatment are declined, a two-dose melarsomine protocol instead of the slow-kill method should be considered.

[Update on cutaneous dirofilariasis]. / La dirofilariose cutanée.

Dirofilariasis is a worldwide zoonotic infection that rarely affects humans and is caused by filarial nematodes of the genus Diroflaria transmitted by mosquitoes. Cutaneous dirofilariasis, due to D. repens, presents as inflammatory lesions that develop into subcutaneous nodules. These clinical symptoms may be consistent with Wells' cellulitis. Diagnosis of dirofilariasis involves demonstration of the presence of the nematode during skin biopsy and identification of the worm through macroscopic, histological and PCR analysis. Surgical resection of the nodule remains the gold standard treatment. The number of cases of human cutaneous dirofilariasis has increased in the recent years and the disease must not be misdiagnosed.

Dirofilariasis pulmonar: un reto diagnóstico en la práctica clínica / Pulmonary dirofilariasis: A diagnostic pitfall in clinical practice

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Periocular dirofilariasis: A case series.

OBJECTIVE: To cite a series of patients presenting with complaints of a lid swelling associated with preseptal cellulitis. METHODS: Three patients on three different occasions came with complaints of a unilateral lid swelling associated with preseptal cellulitis. Examination showed palpable mass in the upper eyelid localized, firm in consistency and was freely mobile and occasionally disappeared during palpation. CT scan showed nonspecific preseptal inflammation. A trial of antibiotics was given in each of the cases with temporary reduction in the swelling but a consecutive flare up following which patient was subjected to excision biopsy. Each of the biopsies was subjected to histopathological and microbiological examination. RESULTS: On excision biopsy in all the three cases it was reported to be a parasitic infestation belonging to the genus Dirofilaria. CONCLUSIONS: Dirofilariaiasis is a common zoonotic infection among wild animals but rarely infects human beings with ocular involvement. Hence dirofilariasis should be considered as a differential diagnosis for migratory subcutaneous swellings and conjunctival nodules in the southern belt of India.

DIROFILARIASIS: CURRENT ASPECTS OF STUDIES.

The review touches upon the main directions and some of the most important results of an investigation of dirofilariasis the species of the genus Dirofilaria, their spread, and hosts. It describes cases of human infection with Candidatus Dirofilaria hongkongensis, a study of the prevalence of filariasis using a geographic information system, data on the contamination of Dirofilaria in Europe, and current views on the endosymbiotic relations of Dirofilaria with the Wolbachia bacterium.

HUMAN SUBCUTANEOUS DIROFILARIASIS - CASE REPORT.

INTRODUCTION: Human dirofilariasis is a zoonotic disease caused by Dirofilaria repens and Dirofilaria immitis. It usually presents as a nodular lesion in the lung, subcutaneous tissues or eyes. In animals, dirofilariasis is a very common disease with serious cardiovascular and respiratory manifestations. If adequate therapy is not given at the beginning ofthe disease, dirofilariasis can lead to animal death. On the contrary, human dirofilariasis is frequently mild, sporadic and asymptomatic disease. Complications in humans are very rare. In Europe, human dirofilariasis is a very rare zoonotic disease even in endemic areas such as Italy, Spain and the Mediterranean. CASE REPORT: The authors reported the case of a 43-year-old male with a subcutaneous nodule caused by Dirofilaria repens. The patient who lives in Budva, Montenegro, had a nodule in the right-hand side of the anterior abdominal walljust below the sternum with maximum diameter of 3 cm. His health condition was good and all laboratory analyses were normal. The lesion was surgically removed and the histopathological examination confirmed the parasitic infection by Dirofilaria repens. After surgical excision, the patient was treated with dual antimicrobial therapy (100 mg doxycycline per os twice a day for 28 days and 200 mg albendazole per os twice a day for 10 days). CONCLUSION: It is very difficult to make the diagnosis of a subcutaneous nodule. The difficulties arise in the differential diagnosis because subcutaneous nodules are suspected to be malignant neoplasm or other pathologies such as tuberculosis, fungal infections, sebaceous cysts, hamartomas, abscesses, and so on. Although human dirofilariasis is a rare disease, the number of reported cases has recently been increasing worldwide.

Description of five dirofilariasis cases in South Hungary and review epidemiology of this disease for the country.

BACKGROUND: Dirofilariasis is an emerging zoonosis (supported by climate change) in Central Europe. Human infections are usually caused by Dirofilaria repens and Dirofilaria immitis with mediation of mosquito vectors. Aims of this publication were to report our dirofilariasis cases, and to summarize Hungarian epidemiological data by reviewing literature. METHODS AND RESULTS: We present five (four ophthalomological, one subcutaneous) cases observed within a 2-year period in Southern Hungary. Ages of infected patients were between 31 and 74 years. First case during pregnancy is also reported. There was no travel history in the anamnesis of patients which could explain acquisition of the infection. Moving, intact worms eliminated by surgical interventions were identified on the basis of morphological features as D. repens. Since the first report of human case, 115 further episodes (in addition to ours) were diagnosed in Hungary. Mean age of the patients was 47 years. Reviewing national reports, the ratio of subcutaneous infections was higher than that of the ocular ones (66 and 45, respectively). Evaluation of the territorial distribution of human episodes revealed that most infections occurred in patients living in the Danube-Tisza interfluvial region and eastern part of the country. However, sporadic cases were also found in western counties during 2014. CONCLUSION: Most of the Hungarian dirofilariasis cases were autochthonous infections. Occurrence in the western counties may suggest the spreading of this emerging zoonosis to these areas. Comprehensive monitoring and data analysis are desirable, therefore reporting the epidemiologic data in the case of human infections should be made mandatory.

Risk factors for human heartworm infections (dirofilariasis) in the South.

Human pulmonary dirofilariasis (HPD) is caused by the transmission of infective third stage larvae of the canine heartworm, Dirofilaria immitis, during blood-feeding by several species of infected mosquitoes. Since humans are incidental hosts and cannot support the parasite's life cycle, infective larvae die after migrating to the pulmonary vascular bed, where an initial subclinical inflammatory reaction is typically followed by a single pulmonary granuloma. The resulting nodular granuloma is described radiographically as a "coin lesion" that resembles a neoplastic lesion, which must be ruled out by invasive lung biopsy. Since HPD cases have been reported mainly from regions with high canine heartworm prevalence, such as the southern United States (US), the objectives of this review were (1) to describe the microbiology of the parasite; (2) to resolve any misconceptions regarding the pathophysiology and outcomes of canine versus human heartworm infections; (3) to describe the prevalence and parasite burden of canine dirofilariasis in the South compared to other areas; (4) to describe the prevalence of HPD in the South; (5) to identify the most important species of mosquito vectors of dirofilariasis based on seroprevalence rates of infection and transmission efficiency; (6) to identify the key risk factors for HPD in the South; and (7) to recommend new strategies for the diagnosis, management, control, and prevention of HPD. Future investigations should focus on targeting specific mosquito species for improved vector control of D. immitis transmission and on developing new immunologic and molecular methods for diagnosing HPD and eliminating the need for invasive diagnostics for differential diagnosis of innocuous, parasitic "coin lesions".

Dirofilaria presenting as orbital mass.

Dirofilaria is a common roundworm infection of dogs, cats, raccoons, and other animals that is commonly referred to as "heartworm." The genus Dirofilaria includes D. immitis, which is a common cause of animal disease in the western hemisphere and primarily manifests as pulmonary lesions in humans, and D. repens, which is the more common causative agent of animal disease in Eurasia and primarily results in subcutaneous and ocular lesions in humans. Humans are accidental end hosts, with infection resulting from bites by mosquitoes of the Culicidae family in which ingested microfilaria have matured to infectious larvae.

Interventional cardiology for the criticalist.

OBJECTIVE: To review indications, procedures, and prognosis for common cardiovascular emergencies requiring intervention in small animals. ETIOLOGY: Pericardial effusion, symptomatic bradycardia, and heartworm-induced caval syndrome are examples of clinical scenarios commonly requiring intervention. Pericardial effusion in small animals occurs most frequently from cardiac neoplasia, idiopathic pericarditis, or congestive heart failure. Indications for temporary pacing include transient bradyarrhythmias, ingestions resulting in chronotropic incompetence, and emergency stabilization of critical bradyarrhythmias. Caval syndrome results from a large dirofilarial worm burden, pulmonary hypertension, and mechanical obstruction of right-sided cardiac output with resultant hemolysis and organ dysfunction. DIAGNOSIS: The diagnosis of pericardial effusion is suspected from signalment and physical findings and confirmed with cardiac ultrasound. Symptomatic bradycardias often present for syncope and definitive diagnosis derives from an ECG. Caval syndrome is diagnosed upon clinical, hematologic, and ultrasonographic evidence of severe heartworm infestation, cardiovascular compromise, and/or mechanical hemolysis. THERAPY: Pericardial effusion is alleviated by pericardiocentesis in the emergency setting, though may require further intervention for long-term palliation. Temporary transvenous pacing can be performed emergently to stabilize the symptomatic patient with a bradyarrhythmia. Dirofilariasis leading to caval syndrome requires urgent heartworm extraction. PROGNOSIS: The prognosis for pericardial effusion is dependent upon the underlying etiology; the prognosis for cardiac pacing is favorable, and the prognosis for caval syndrome is grave if untreated and guarded to fair if heartworm extraction is performed.

Diagnostic, treatment, and prevention protocols for canine heartworm infection in animal sheltering agencies.

The high prevalence of heartworm infection in shelter dogs creates a dilemma for shelter managers, who frequently operate with insufficient funding, staffing, and expertise to comply with heartworm guidelines developed for owned pet dogs. The purpose of this study was to survey canine heartworm management protocols used by 504 animal sheltering agencies in the endemic states of Alabama, Florida, Georgia, and Mississippi. Open-admission shelters, which tended to be larger and more likely to perform animal control functions, were less likely (41%) to test all adult dogs than were limited-admission shelters (80%), which tended to be smaller non-profit humane agencies, and foster programs (98%) based out of private residences. Open-admission shelters were more likely to euthanize infected dogs (27%) or to release them without treatment (39%), whereas limited-admission shelters and foster programs were more likely to provide adulticide therapy (82% and 89%, respectively). Of the 319 agencies that treated infections, 44% primarily used a standard two-dose melarsomine protocol, and 35% primarily used a three-dose split-treatment melarsomine protocol. Long-term low-dose ivermectin was the most common treatment used in 22% of agencies. Open-admission shelters were less likely (35%) to provide preventive medications for all dogs than were limited-admission shelters (82%) and foster programs (97%). More agencies used preventives labeled for monthly use in dogs (60%) than ivermectin products labeled for livestock (38%). The most common reason diagnostic testing and preventive medication was not provided was cost. These results indicate a lack of protocol uniformity among agencies and insufficient resources to identify, treat, and prevent infection. Sheltering agencies and companion animal health industries should develop guidelines that are feasible for use in sheltering agencies and provide improved access to preventive and treatment strategies for management of Dirofilaria immitis.

Diagnostic, treatment, and prevention protocols for feline heartworm infection in animal sheltering agencies.

Cats are at risk for heartworm infection (Dirofilaria immitis) wherever the disease is endemic in dogs. Diagnosis is more difficult in cats, and little information is available regarding effective palliative and curative treatments for infected cats. In contrast to the challenges of diagnosis and treatment, chemoprophylaxis is highly effective, and current guidelines call for preventive medications to be administered to all cats in endemic areas. The purpose of this study was to survey feline heartworm management protocols used by 400 animal shelters and foster programs in the endemic states of Alabama, Florida, Georgia, and Mississippi. Only 23% of shelters performed feline heartworm testing. The most common reasons for not testing were expense (36%), lack of treatment options for infected cats (18%), and because the agency considers heartworm infections in cats to be less important than in dogs (12%). Most agencies (69%) did not provide preventive medication to cats. Reasons included because testing was not performed (36%), expense (35%), and the perception that local heartworm risk was low (10%). When preventive was provided, feline-labeled broad-spectrum products were used more commonly (81%) than livestock products (14%). The survey also indicated that many policy decisions were based on inaccurate knowledge of feline heartworm prevalence and pathogenesis. Issues of cost, feasibility, and education prevent most Southeastern sheltering agencies from adequately protecting cats against heartworm disease. Practical guidelines tailored to the needs of these agencies should be developed. Subsidized testing and preventive products may facilitate implementation of feline heartworm management protocols in sheltering agencies.

[Observation of dirofilariosis in the practical work of the otorhinolaryngologist].

A case of dirofilariosis is reported. The disease is believed to be caused by the contact with the cat that the patient brought in from Uzbekistan. The authors emphasize the importance of analysis of the medical history of the patients presenting with the pathology being considered, their medical examination, and correct interpretation of X-ray images of the paranasal sinuses taking into account the possibility of distribution of rare helminth species beyond their usual ranges.