Detection of antibodies against hepatitis A virus in eluates of blood spotted on filter-paper: a pilot study in Rio de Janeiro, Brazil

• Published in: Transactions of the Royal Society of Tropical Medicine and Hygiene 1999-07, Vol.93 (4), p.401-404
• Main Authors: de Almeida, Liz Maria, Azevedo, Raymundo Soares, Marandino Guimarães, Angélica Arpon, da Silva Freire Coutinho, Evandro, Struchiner, Claudio José, Massad, Eduardo
• Format: Article
• Language: English
• Subjects: Adolescent; Age Distribution; Biological and medical sciences; Biomarkers - blood; Brazil; Brazil - epidemiology; Child; Child, Preschool; Cross-Sectional Studies; Enzyme-Linked Immunosorbent Assay; epidemiological survey; filter paper blood collection; hepatitis A; Hepatitis A - diagnosis; Hepatitis A - epidemiology; Hepatitis A - immunology; Hepatitis A Antibodies; Hepatitis Antibodies - blood; Human viral diseases; Humans; Infant; Infectious diseases; Medical sciences; Pilot Projects; Predictive Value of Tests; Prevalence; Sensitivity and Specificity; Tropical medicine; validation; Viral diseases; Viral hepatitis
• ISSN: 0035-9203; 1878-3503
• DOI: 10.1016/S0035-9203(99)90133-5

The validity of blood spotted on to filter-paper (BSOFP) eluates for the detection of antibodies against hepatitis A virus (HAV) was investigated in 718 individuals (children and adults) during a field study in a small area in Rio de Janeiro State, Brazil. Serum samples were considered the ‘gold standard’. BSOFP eluates were analysed by 2 different techniques: microplate competitive enzyme-linked immunosorbent assay (ELISA) of the whole study group and microparticle enzyme immune assay (MEIA) of a subsample of 59 individuals. For BSOFP eluates by ELISA, sensitivity and specificity were 89·6% (95% CI: 84·7–93·1) and 97·5% (95% CI: 95·6–98·7), respectively. For a seroprevalence of anti-HAV antibodies of 32%, the positive predictive value was 94·5% (95% CI: 90·3–97·0) and the negative predictive value was 95·2% (95% CI: 92·8–96·8). The test efficiency was 95·0% (95% CI: 93·1–96·4). Similar results were found for BSOFP eluates by MEIA. Agreement between the 2 techniques used for BSOFP (ELISA and MEIA) was also high (κ = 0·93). These results encourage the more widespread application of BSOFP as a means of surveillance for large-scale epidemiological studies for hepatitis A.