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We report two cases of disseminated hyperinfection by filariae in free‐living primates Saimiri sciureus and Saguinus niger from eastern Amazon. Histopathological examination showed the presence of Dipetalonema gracile microfilariae in blood, liver, lungs, spleen, small intestine, kidney, brain, liver, and adults in peritoneal thoracic cavity. [ABSTRACT FROM AUTHOR]

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Zoonotic disease risk is greatly influenced by cultural practices and belief systems. Yet, few studies have investigated how different ways of knowing are commensurate with one another in the context of zoonotic disease. By stressing methodological pluralism and explicitly challenging the nature-culture dichotomy, an ethnoprimatological approach is particularly well suited to bridging different ontologies for understanding zoonotic transmission. We seek to integrate molecular phylogenetics, histopathology, and ethnography to characterize a filarial nematode found within the abdominal cavity of spider monkeys (Ateles paniscus). The filarid is recognized as "spider monkey cotton" by Indigenous Waiwai in the Konashen Community Owned Conservation Area, Guyana. Ethnographic data revealed that the Waiwai perceive of "spider monkey cotton" as a normal characteristic within the "spider monkey person." Furthermore, the Waiwai indicated that "cotton" was ubiquitous with spider monkeys and is not understood to be infectious nor zoonotic. This distinction is in contrast to other internal parasites found within spider monkeys that the Waiwai believe cause disease in both monkeys and humans. Our morphological and molecular characterization support the classification of the filarid as Dipetalonema caudispina, a minimally studied, nonzoonotic parasite. While this identification contrasts with Waiwai understanding of the filarid as a component of the spider monkey itself, the ubiquity of the filarid in spider monkeys in the region and its nonzoonotic nature suggest scientific knowledge and Waiwai ontology are commensurate. More broadly, this work highlights the importance of integrating multiple knowledge systems and leveraging advanced genomics to better understand and prevent emerging zoonotic diseases. [ABSTRACT FROM AUTHOR]

Background: Dirofilaria immitis is responsible for heartworm disease in dogs in endemic areas worldwide. Screening for this infection is done by blood tests. Antigen testing is the most sensitive method to detect an infection with adult (female) worms. Microscopic examination of a blood smear or Knott's test can be used to detect circulating microfilariae, the infective larvae. To increase the sensitivity of the antigen test by decreasing the false negative test results, heating of the blood sample has been recommended in recent guidelines. Heating is believed to remove blocking immune-complexes. Circulating microfilariae are not specific findings for heartworm infection, as other nematodes (among others, Acanthocheilonema dracunculoides) can also result in microfilaremia. Although the type of microfilariae cannot be determined by microscopy alone, real-time PCR can reliably identify the infecting nematode species. Correct identification of the parasite is of major importance, as an infection with D. immitis requires antiparasitic therapy, whereas A. dracunculoides is thought to be a clinically irrelevant coincidental finding. The present case report describes a microfilaremic dog where the initial antigen test for D. immitis turned positive after heat treatment, whereas real-time PCR revealed that the microfilariae were A. dracunculoides (syn. Dipetalonema dracunculoides). Results: A circa 5-year old, asymptomatic Spanish mastiff dog was referred for heartworm therapy because microfilariae were found via a screening blood test. The dog was recently imported to the Netherlands from Spain, where it had been a stray dog. Antigen tests on a plasma sample for D. immitis were performed with three different test kits, which all turned out to be negative. However, heat treatment of two of these samples were carried out and both of them led to a positive antigen test result. Real-time PCR showed that the circulating microfilariae belonged to A. dracunculoides species. Three administrations of moxidectin spot-on at monthly intervals resulted in a negative antigen and a negative Knott's tests one month after the last treatment. Conclusions: We conclude that heat treatment of initially negative blood samples for D. immitis could lead to false positive antigen test results if the dog is infected with A. dracunculoides. [ABSTRACT FROM AUTHOR]

Despite the economic importance of camels, the parasites that affect them have not received adequate attention so far and molecular studies are scarce compared to other livestock. In this study, we characterized peripheral blood microfilariae in 200 healthy one-humped camels ( Camelus dromedarius) from south-east Iran by microscopy and molecular tools to receive a more detailed insight into prevalence and species that affect them. Moreover, adult specimens of the filarial nematode Dipetalonema evansi were collected from the carcass of an infected animal. Microscopic examination was performed on Giemsa-stained blood smears, and blood was also spotted on Whatman FTA cards for DNA analysis. Genomic DNA was extracted, and PCR was carried out for the detection of filaroid helminths, followed by sequence analysis of positive samples. Four samples were positive for microfilariae by microscopy, while 16 animals (8 %) were positive by PCR. Sequence analysis revealed D. evansi in all cases. Phylogenetic analysis of a cytochrome C oxidase subunit I (COI) sequence of filaroid nematodes showed that most species in a single genus cluster in the same clade; however, D. evansi and D. gracile are not monophyletic and branch rather at the base of the tree. Further studies on the life cycle of D. evansi, specifically the identification of intermediate host(s), have become feasible with the provision of the first specific COI sequences in this study. [ABSTRACT FROM AUTHOR]

Serum IgE levels were measured by radioimmunoassay in rats infected with various doses of L3 infective stage larvae of Dipetalonema viteae. A high stimulation in total scrum IgE levels was found with minute doses as well as with large doses of parasite, and IgE levels remained elevated for several months. No further increase in IgE levels was induced by a secondary infection. [ABSTRACT FROM AUTHOR]

Neutrophils from the peripheral washings of normal rats in the presence of sera obtained from rats immune to circulating microfilariae adhered to and killed the microfilariae of Dipetalonema vitae in vitro within 16-24 hr. No significant adherence or cytotoxicity was mediated by sera collected from animals with a high microfilaraemia or from normal rats. UItrastructural studies show that neutrophils, which are bigger than microfilariae, can easily internalize the small larvae resulting in the disintegration of the parasite. Immunoadsorption and inhibition experiments showed that the adherence-promoting activity resides both in IgG and IgE classes of antibody. However, the mere participation of these two antibodies is not sufficient to effect neutrophil adherence towards microfilariae, the presence of complement is also required. Samples of fresh immune rat serum (fIRS) depleted in alternative pathway components of complement by treatment with zymosan A failed to mediate cell adherence to the parasite. fIRS inactivated for the classical pathway of complement by the chelating agent EGTA partially retains its activity in mediating cytotoxicity to microfilariae. The striking antigenic specificity of D. vitae antibodies was shown by their ability to mediate cytotoxicity only to D. vitae but not towards Brugia malayi microfilariae. [ABSTRACT FROM AUTHOR]

A field survey aimed at updating knowledge of the distribution and prevalence of filarial infections in the Piedmont region was undertaken. Blood samples were collected from 2628 dogs (10-15 dogs/100 km) which had remained in the local area, were kept in the open overnight, were more than 2 years old and had not previously been treated with microfilaricidal drugs. Infection was diagnosed by a modified Knott test. Comparison of the results with those from a similar survey carried out 25 years ago showed a 3-fold increase in the size of the endemic area, with the colonization of new habitats, and a 4-fold increase in the prevalence of Dirofilaria immitis infection. [ABSTRACT FROM AUTHOR]

The present study reports the presence of Onchocerca volvulus specific IgE in the sera obtained from onchocerciasis patients. About 70% of onchocerciasis patients showed a raised level of O. volvulus specific IgE compared to patients infected either with other human filarids (Loa loa. Wuchereria bancrofti, Brugia malayi) or with other helminths (Schistosoma manson,. Ascaris lumbricoides, Fasciola hepatica). The O. volvulus specific IgE level was significantly higher in patients exhibiting 'gale filarienne' than in microfilaraemic patients or in endemic controls. The total IgE level was significantly raised in the serum samples of all groups of subjects from endemic areas compared to European controls. There was no significant increase in the level of IgE in the onchocerciasis sera when O. volvulus antigen was replaced by the antigens from various helminths in the present assay system (radioallergosorbent test). However, there was a clear evidence of the presence of cross-reacting allergens in the crude extracts from adults of O. volvulus and Dipetalonema viteae (a rodent filarial parasite) because there was a significant reduction in IgE level in onchocerciasis sera following absorption with either O. volvolus or D. viteae sorbents. Moreover, the IgE antibodies in onchocerciasis patients sera recognized the allergens which were present in the somatic extracts of O. volvulus and D. viteae as revealed by radiolabelled anti-IgE. [ABSTRACT FROM AUTHOR]

Infective larvae of Dipetalonema viteae did not reach maturity in inbred Fischer rats. However, female adults of D. viteae when transplanted surgically into Fischer rats established and the resulting microfilaraemia from the transplanted worms persisted for about 120 days after infection. Sequential dissections showed that some of the female worms transplanted remained viable in rats for about 35 days after infection. After inoculation of infective larvae into rats a varying number transformed into stage-4 larvae but they did not develop into adult worms and were killed. However, when the rats were immunodepressed non-specifically by a pre-existing Schistosoma mansoni infection or by treatment with S. mansoni-derived substance(s), a number of stage-4 larvae renewed their development and reached sexual maturity. These worms produced microfilariae which were observed in the peripheral blood for about 40 days. The effect of previous infection with S. mansoni on the survival and growth of D. viteae in Fischer rats depends greatly on the relative timing of infection because infective larvae of D. viteae reached maturity only when rats were inoculated with infective larvae after 15 days of S. mansoni infection but not after 21 or 28 days of S. mansoni infection. D. viteae will also develop to maturity in congenitally athymic rats. In congenitally athymic rats (Nu/Nu) each given 75 infective larvae, both the microfilaraemia and adult worm recovery at post-mortem were higher than those which resulted in Nu/Nu rats given an infection of 200 larvae. These experiments show that in rats innate immunity to this filarial nematode reflects a very rapidly induced acquired immunity which kills the parasite before it reaches maturity. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Veterinary Science is the property of Archives of Veterinary Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Parasitic infestations of the eye have been reported since centuries, affecting various parts of the eye. Some are subtle, coexisting with vision, while many others damage and destroy, in part or totally, the gift of sight. This report describes a patient with live subconjunctival dipetalonema infestation of the right eye, with 22 parasites removed live in one sitting from one eye. [ABSTRACT FROM AUTHOR]

Examines the prevalence of Dipetalonema dracunculoides infection in dog breeds in Murcia, Spain. Clinical signs of the disease; Disease relationship with habitat, breed and age; Risk factors; Mean life of the parasite.

Focuses on the prevalence of Dipetalonema dracunculoide infection in dogs from Murcia, Spain. Disease risk factors.