In Peru, an investigation of an outbreak of leptospirosis in military recruits that used a commercial ELISA IgM assay (PanBio Leptospira IgM ELISA, PanBio, Queensland, Australia) demonstrated a paired sera sensitivity and specificity of 26% and 60%, respectively, when compared to MAT [8]. The gene discussed is CD40LG; the disease is leptospirosis.