A simpler diagnostic method using blood collection on filter paper to determine anti-natural octyl disaccharide-leprosy infectious disease research institute diagnostic in household contacts of leprosy patients

The high prevalence among children shows continued transmission from adult and lack of disease control by the health system. Detection of anti-NDO-LID-1 has been known to be more effective to predict the development of leprosy in household contacts than just detecting PGL-1 or LID-1 alone. However, serodiagnosis is not available in poorer-settings area and the procedure (venepuncture) is still inconvenient to some people. These problems can be solved by using finger-prick blood sample on filter paper. This study aims to prove the effectiveness of using capillary blood samples on filter paper to detect the positivity of Ig G antibody against NDO-LID-1 antigen in asymptomatic household contacts. Seventeen samples of capillary blood on filter paper and sera were tested for IgG anti-NDO-LID-1 using ELISA. There was no significant difference between IgG level from filter paper and serum (p=0.754) and there was also a strong positive correlation (R=0.906) between the two procedures. These findings show that the use of filter paper and NDO-LID-1 is worthy of further investigations, especially for those with lower bacillary load or contacts of leprosy patients.