Serology: recent developments, strengths, limitations and prospects: a state of the art overview.

Specific antibodies can be used as a surrogate marker for bacterial load in leprosy. Tests to detect antibodies can be used for (i) the classification of patients for treatment purposes [most multibacillary (MB) patients are seropositive, most paucibacillary (PB) patients are not], (ii) the prediction of an increased risk of relapse and (iii) the identification of contacts having an increased risk of developing leprosy. With the advent of fast, robust and easy to perform serological tests such as lateral flow, agglutination and card tests, the application of serology in the field for these purposes becomes a feasible prospect. We hereby present an overview of the current knowledge and new developments in this area and discuss the strengths, limitations and possible applications of antibody detection in leprosy research and control.