A hepatitis C avidity test for determining recent and past infections in both plasma and dried blood spots.
J Clin Virol
; 57(1): 29-35, 2013 May.
Article
en En
| MEDLINE
| ID: mdl-23369886
ABSTRACT
BACKGROUND:
DBS testing has been used successfully to detect HCV antibody positive individuals. Determining how long someone has been infected is important for surveillance initiatives. Antibody avidity is a method that can be used to calculate recency of infection.OBJECTIVES:
A HCV avidity assay was evaluated for both plasma and DBS. STUDYDESIGN:
To measure antibody avidity a commercial HCV ELISA was modified using 7 M urea. The plasma samples were split into group 1 (recently infected N = 19), group 2 (chronic carrier N = 300) and group 3 (resolved infection N = 82). Mock DBS made from group 1 (N = 12), group 2 (N = 50), group 3 (N = 25) and two seroconverter panels were evaluated. 133 DBS taken from patients known to have a resolved infection or be a chronic carrier were also tested.RESULTS:
The avidity assay cut-off was set at AI≤30 for a recent infection. Using sequential samples the assay could detect a recent infection in the first 4-5 months from the point of infection. Most of the false positive results (AI < 30 among cases known not to have had recent infection) were detected among known resolved infections, in both the plasma and DBS; as a result, a testing algorithm has been designed incorporating both PCR and two dilution factors. The sensitivity and specificity of the assay on plasma was 100% and 99.3%, respectively, while DBS had 100% sensitivity and 98.3% specificity.CONCLUSION:
The HCV avidity assay can be used to distinguish between chronic and recent infection using either plasma or DBS as the sample type.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ensayo de Inmunoadsorción Enzimática
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Hepatitis C
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Anticuerpos contra la Hepatitis C
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Pruebas con Sangre Seca
Tipo de estudio:
Diagnostic_studies
Límite:
Adolescent
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Adult
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Aged
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Child
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Child, preschool
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Humans
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Middle aged
Idioma:
En
Revista:
J Clin Virol
Asunto de la revista:
VIROLOGIA
Año:
2013
Tipo del documento:
Article
País de afiliación:
Reino Unido