CD40LG and scrub typhus: In the case of the NMRC in-house ELISA studies, the majority of studies (80.0%, 4/5) (Table 3), instead of calculating a single cut-off, patients were diagnosed with scrub typhus if they passed two criteria: 1) IgM OD ≥0.5 at a 1:100 dilution, and 2) a summed total OD of ≥1.0 of 4 sequential 4-fold dilutions.