To compare the sensitivity and specificity of dried blood spot with conventional blood sampling for serological and molecular testing of hepatitis B and C viruses.
The case-control study was conducted at the Pakistan Health Research Council Specialised Centre for Gastroenterology and Hepatology, Karachi, from May,2015 to April,2016 and comprised patients who were hepatitis B surface antigen-positive (group 1), anti-hepatitis C virus positive (group 2), hepatitis B virus deoxyribonucleic acid-positive (group 3), and hepatitis C virus ribonucleic acid-positive (group 4). A group of controls had healthy subjects negative for both hepatitis B and C viruses. Blood samples were collected using the conventional as well as the dried blood spot method using finger prick. Relevant tests were run for each subject using both the samples at baseline and after 3 and 6 months of storage. Receiver operative characteristic curve was plotted to determine the ideal cut-off points for dried blood spot testing and corresponding sensitivity and specificity. Data was analysed using SPSS 19.
Of the 100 subjects, there were 20(20%) in each of the four patient groups and 20(20%) in the control group. Sensitivity of dried blood spot method was 95.2%, 95%, 80% and 70% for groups 2, 1, 4 and 3 respectively when tested within a week of sampling. Specificity was 100% for all the four groups. There was a significant correlation of the two methods for all the four parameters tested (p<0.01).
Dried blood spot sampling correlated well with the conventional blood sampling method for serological and molecular testing.