Onchocerca armillata:prevalence and pathology in Sudanese cattle

Mannan, Abdul; Husseinf, H. S.; Sinnary, K. El; Magzoub, M.

doi:10.1080/00034983.1984.11811873

Cited by 11 publications

(6 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although not significant in this study, a similar reduction in the density of O. armillata Mf within the epidermis of older cattle has been previously observed (Atta el Mannan et al, 1984). This trend may be due to an increase in old, less fecund or dead, calcified worms in older cattle (Trees et al, 1992); and/or a degree of immunity in hyper-endemic areas may be acquired, which has been found to occur against O. ochengi Mf (Trees et al, 1992).…”

Section: Discussionsupporting

confidence: 86%

Onchocerca armillata contains the endosymbiotic bacterium Wolbachia and elicits a limited inflammatory response

Neary

Trees

Ekale

et al. 2010

Veterinary Parasitology

View full text Add to dashboard Cite

Human onchocerciasis, also known as River Blindness, is a debilitating disease caused by the filarial nematode Onchocerca volvulus. Many, but not all, filarial nematodes carry within their tissues endosymbiotic, Rickettsia-like bacteria of the genus Wolbachia. Onchocerca spp. infections in cattle offer the most relevant, analogous host–parasite model system. West African cattle are commonly co-infected with four Onchocerca spp.; two of these are Wolbachia-positive (Onchocerca gutturosa and Onchocerca ochengi), and the remainder are of unknown Wolbachia status (Onchocerca dukei and Onchocerca armillata). Previous studies have suggested that worm survival is dependent on this bacterium. O. armillata, an abundant parasite of African cattle that has received little attention, is a primitive species that may lack Wolbachia. The objectives of this study were to determine if O. armillata carries Wolbachia and to provide preliminary descriptions of the host inflammatory cell environment around the adult worms. The findings may support or refute the hypothesis that a prime contribution of Wolbachia is to permit long-term survival and reproduction of certain Onchocerca spp. (including O. volvulus in humans). O. armillata adult worms were found in the aorta of 90.7% of cattle (n = 54) slaughtered at an abattoir in Ngaoundéré, Adamawa Region, Cameroon. The presence of Wolbachia in O. armillata was confirmed by a specific anti-Wolbachia surface protein antibody detected using a peroxidase conjugate (immunohistochemistry) and PCR for detection of Wolbachia-specific sequences within DNA extracts from frozen worms. Tissue sections stained with haematoxylin and eosin showed the host cell response to be dominated by macrophages and fibroblasts. This is unusual compared with nodule-dwelling Wolbachia-positive Onchocerca spp., where the host response is typically characterised by granulocytes, and suggests that the mechanisms for worm survival employed by this species (which is probably motile) may differ.

show abstract

Section: Discussionsupporting

confidence: 86%

Onchocerca armillata contains the endosymbiotic bacterium Wolbachia and elicits a limited inflammatory response

Neary

Trees

Ekale

et al. 2010

Veterinary Parasitology

View full text Add to dashboard Cite

show abstract

“…A similar reduction in mff skin density with age has also been observed in O. armillata infections of cattle (Atta El Mannan et al 1984). Although in that case a detailed embryological examination of adult worms was not made, the reduced mff densities were supposed to be due to an increase in old, less fecund and in dead, calcified worms, and our own observations of infections with this species would support that suggestion.…”

Section: Discussionsupporting

confidence: 83%

Age-related differences in parasitosis may indicate acquired immunity against microfilariae in cattle naturally infected with Onchocerca ochengi

et al. 1992

View full text Add to dashboard Cite

Onchocerca ochengi is a common parasite of cattle in savanna areas of West Africa and its adult stages inhabit intradermal nodules. We have exploited the accessibility of the macrofilariae to examine quantitative and qualitative differences in both the macro- and microfilariae (mff) in relation to age in naturally infected cattle. Autochthonous cattle at a site on the Adamawa plateau, North Cameroon, situated near a perennial Simulium damnosum s.l. breeding site, were examined in three age groups (1.5-2.5, n = 34; 3-5, n = 39 and greater than or equal to 8 years old, n = 21). Skin mff densities were assessed from ventral skin biopsies, total body counts of nodules were done by palpation and 1-4 nodules were excised from positive animals, collagenase digested and the numbers and condition of macrofilariae determined. Embryogenesis profiles (embryograms) were done on a representative number of female worms in each age group. The overall prevalence of infection in the study population was 71% for mff and 85% for nodules. Nodule prevalence increased significantly from the 1.5-2.5 to 3-5 years old groups, but no other inter-age prevalences were significantly different. While the mean number of nodules per animal increased with age, geometric means (gm) 3.7, 15.5 and 23.1, the skin mff density maximized in the middle age group and decreased significantly in the old animals (gm 15.8, 44.7 and 11.4 mff/g, difference between latter two parameters significant, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

show abstract

“…This may be due to the small number of camels usually available for slaughter, as for most of town-dwellers, came1 meat is not the prime choice. Principally, the pathology of this disease in camels was not different from that described for aortic onchocercosis in cattle (3,4,6). Based on the limited available information, lesions in camels, however, were fewer and smaller.…”

Section: Discussionmentioning

confidence: 69%

“…Compared to the bovine aortic onchocercosis (2,3,4,6), the pathology of infection in camels has been insufficiently studied. This may be due to the small number of camels usually available for slaughter, as for most of town-dwellers, came1 meat is not the prime choice.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Note sur Onchocerca armillata chez le dromadaire du Soudan (C. dromedarius). Approche histologique et anatomo-pathologique

Osheik¹,

Tageldin²,

Zakia³

1990

Rev. Elev. Med. Vet. Pays Trop.

View full text Add to dashboard Cite

L'onchocercose aortique due à O. armillata a été diagnostiquée dans 45 cas (41 p. 100) sur 109 examens de chameaux du Soudan. Bien que l'aorte thoracique ait été régulièrement concernée, d'autres vaisseaux ne sont pas à exclure (aorte abdominale, artères brachiocéphaliques, pulmonaires et costocervicales). Un examen général des vaisseaux affectés a révélé l'existence des cheminements tunnelliformes et tortueux des parasites bien visibles à l'oeil nu sur l'intima des vaisseaux. Les lésions nodulaires étaient plus fréquentes sur l'adventice. Au microscope, les lésions ont montré une hauteur irrégulière de la surface de l'intima. La tunique moyenne sous-jacente contenait un nombre variable de fragments de parasites encapsulés et partiellement minéralisés. La réponse inflammatoire a varié en intensité et dans sa localisation, se traduisant par la présence d'éosinop hiles, de lymphocytes, de macrophages et, à l'occasion, de cellules géantes

show abstract

Onchocerca armillata:prevalence and pathology in Sudanese cattle

Cited by 11 publications

References 15 publications

Onchocerca armillata contains the endosymbiotic bacterium Wolbachia and elicits a limited inflammatory response

Onchocerca armillata contains the endosymbiotic bacterium Wolbachia and elicits a limited inflammatory response

Age-related differences in parasitosis may indicate acquired immunity against microfilariae in cattle naturally infected with Onchocerca ochengi

Note sur <em>Onchocerca armillata</em> chez le dromadaire du Soudan (<em>C. dromedarius</em>). Approche histologique et anatomo-pathologique

Contact Info

Product

Resources

About