Immunodiagnostic studies on Onchocerca volvulus and Mansonella perstans infections using a recombinant 33 kDa O. volvulus protein (Ov33)

Tawill, S.A.; Kipp, Walter; Lucius, Richard; Gallin, Michaela Y.; Erttmann, Klaus D.; Büttner, Dietrich W.

doi:10.1016/0035-9203(95)90656-8

Cited by 18 publications

(8 citation statements)

References 11 publications

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“…The 100% sensitivity of our test recorded in four of the five geographic regions tested is an improvement of previous results, 9,[11][12][13]19,26,27 and shows that the combination of both immunodiagnostic antigens into one hybrid protein had a cumulative effect. Currently, we do not have an explanation for the lack of seroreactivity of two Ecuadorian onchocerciasis sera with OvH2 or OvH3.…”

Section: Discussionsupporting

confidence: 63%

“…This is supported by previous data that demonstrated that Ov33 is recognized by sera from patients with onchocerciasis before the onset of patency. 26 Early seroconversion is conceivable, since both Ov20 and Ov33 are expressed by infective larvae of O. volvulus, 8,14 which makes the hybrid protein a sensitive tool to monitor exposure to O. volvulus. The potential of OvH2 for diagnosing exposure to O. volvulus transmission as well as early and light infections, might be particularly valuable, i.e., in situations where it is difficult to diagnose onchocerciasis by detection of microfilariae or microfilarial DNA, e.g., in situations after interruption of transmission and/or following prolonged treatment with ivermectin.…”

Section: Discussionmentioning

confidence: 99%

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Sensitive and specific serodiagnosis of onchocerciasis with recombinant hybrid proteins.

Nde¹,

Pogonka²,

Bradley³

et al. 2002

The American Journal of Tropical Medicine and Hygiene

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Abstract. Onchocerciasis remains a major health hazard in many tropical countries. However, the existing tools for diagnosis of the disease have limitations, particularly regarding the detection of low level or early infections. To design an optimized reagent, we exploited the high antibody reactivity of patient sera against the Onchocerca volvulus proteins Ov20 and Ov33, which have been described as highly sensitive and specific immunodiagnostic reagents for producing hybrid proteins. The construct OvH2 was composed of Ov20 fused to Ov33, while OvH3 consisted of the C-terminus of Ov20 linked to Ov33. When these constructs were tested with sera from patients with onchocerciasis and control sera, OvH2 showed a sensitivity of 98.5% and a specificity of 97.7% and OvH3 showed a sensitivity of 98.5% and a specificity of 95.35%. All non-responders were from Ecuador. These results surpass those of existing single recombinant antigens, suggesting that our hybrid proteins combined the sensitivity of the two parent proteins. Tests based on OvH2 should prove suitable for monitoring onchocerciasis control programs and individual diagnosis.

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Section: Discussionsupporting

confidence: 63%

Section: Discussionmentioning

confidence: 99%

Sensitive and specific serodiagnosis of onchocerciasis with recombinant hybrid proteins.

Nde¹,

Pogonka²,

Bradley³

et al. 2002

The American Journal of Tropical Medicine and Hygiene

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“…Brown et al (1970) observed M. perstans mff during health surveys in primary schools in Uganda, and a review by Hawking (1977) stated that 40%-50% of inpatients at the main referral hospital in Kampala had M. perstans mff in their blood. More recently, attention has been drawn to this infection in Uganda as the result of the activities of the national onchocerciasiscontrol programme (Tawill et al, 1995;Fischer et al, 1996).…”

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confidence: 99%

Rapid assessment of the geographical distribution ofMansonella perstansinfections in Uganda, by screening schoolchildren for microfilariae

Onapa

Simonsen²,

Baehr³

et al. 2005

Annals of Tropical Medicine & Parasitology

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The geographical distribution of Mansonella perstans infections in Uganda was assessed by day-time examination of school-aged children for microfilariae. Overall, 12,207 children from 76 sites representing the various topographical and ecological zones in the country were examined. Children with M. perstans microfilaraemia were detected at 47 (61.8%) of the study sites, with prevalences ranging from 0.4% to 72.8%. A broad, east-west-oriented belt of high endemicity was identified, stretching across the central part of the country from the southern end of Lake Albert to the north-western shores of Lake Victoria. To the north and south of this belt prevalences generally decreased, although high-prevalence foci were also identified in the far north-western and south-eastern corners of the country. Geostatistical interpolation was used to create a map showing the geographical distribution of M. perstans prevalences in Uganda (by ordinary kriging), and to assess the population exposed to M. perstans transmission. Estimates based on population data from 2002 indicated that 20.4 million people (82.6% of the national population) and 6.8 million people (27.5% of the national population) lived in areas where, respectively, >1% and >10% of the school-aged children had M. perstans microfilaraemias. Since the prevalence of M. perstans microfilaraemia is known to increase with age, the overall population prevalences are likely to be even higher than the prevalences observed in the school-aged children. More attention needs to be paid to the public-health implications of this wide-spread but neglected infection.

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“…1,3 Cross-reactions between O. volvulus and Mansonella species impede the differentiation of these parasites by serologic diagnosis using worm extracts. 4 Although isolated microfilariae (mf) of both species can be differentiated morphologically, species differentiation in histologic sections is difficult. Since the mf densities of M. streptocerca are often relatively low, methods other than the standard skin snip technique are required for accurate detection of this species.…”

mentioning

confidence: 99%

Detection of the filarial parasite Mansonella streptocerca in skin biopsies by a nested polymerase chain reaction-based assay.

Fischer

Büttner²,

Bamuhiiga³

et al. 1998

Am J Trop Med Hyg

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Abstract. To differentiate the skin-dwelling filariae Mansonella streptocerca and Onchocerca volvulus, a nested polymerase chain reaction (PCR) assay was developed from small amounts of parasite material present in skin biopsies. One nonspecific and one specific pair of primers were used to amplify the 5S rDNA spacer region of M. streptocerca. Biopsies with different microfilaria densities obtained from 104 Ugandans living in an area endemic for M. streptocerca were tested using both the nested PCR assay and standard parasitologic assessment of microfilariae. All 82 samples from microfilaria carriers were positive when tested using the nested PCR assay. In addition, M. streptocerca DNA could be detected in 16 samples thought to be microfilaria negative. Furthermore, six days following ivermectin treatment, M. streptocerca DNA was found in 12 of 14 microfilaria-negative biopsies. Control skin samples from patients infected with O. volvulus were all negative in the nested PCR assay. This assay improves the diagnosis of M. streptocerca and will facilitate further epidemiologic studies.When evaluating skin disease cases in large regions of Africa, the two skin-dwelling filarial species, Mansonella streptocerca and Onchocerca volvulus, must be considered as possible causative agents. Mansonella streptocerca infection is characterized by acute and more often chronic papular dermatitis mainly on the upper part of the body, which make it difficult to differentiate streptocerciasis and onchocerciasis clinically. 1, 2 In addition, after treatment with diethylcabarmazine or ivermectin, persons infected with M. streptocerca also show a typical Mazzotti reaction. 1, 3 Cross-reactions between O. volvulus and Mansonella species impede the differentiation of these parasites by serologic diagnosis using worm extracts. 4 Although isolated microfilariae (mf) of both species can be differentiated morphologically, species differentiation in histologic sections is difficult. Since the mf densities of M. streptocerca are often relatively low, methods other than the standard skin snip technique are required for accurate detection of this species. Collagenase digestion of the skin snips is an appropriate procedure, 2 but if a patient is also heavily infected with O. volvulus it may be difficult to detect one M. streptocerca mf among hundreds of O. volvulus mf. In these cases, a specific but more sensitive assay to detect M. streptocerca is clearly required.The polymerase chain reaction (PCR) is a sensitive technique to detect parasite DNA. Sensitive and specific PCR assays have been developed for the diagnosis of the human filarial parasites Wuchereria bancrofti, Brugia malayi, Loa loa, and O. volvulus. 5-10 All of these assays are based on different repetitive target sequences found only within a distinct filarial genus. In the present study, we have developed a PCR assay based on a target sequence present in all filarial and all other nematode species. 11 The 5S rDNA spacer region was amplified from DNA prepared from human skin biopsi...

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Immunodiagnostic studies on Onchocerca volvulus and Mansonella perstans infections using a recombinant 33 kDa O. volvulus protein (Ov33)

Cited by 18 publications

References 11 publications

Sensitive and specific serodiagnosis of onchocerciasis with recombinant hybrid proteins.

Sensitive and specific serodiagnosis of onchocerciasis with recombinant hybrid proteins.

Rapid assessment of the geographical distribution ofMansonella perstansinfections in Uganda, by screening schoolchildren for microfilariae

Detection of the filarial parasite Mansonella streptocerca in skin biopsies by a nested polymerase chain reaction-based assay.

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