Figure 3.

Summary receiver operating characteristic curves of different positive results for antibodies. (A) IgM⁺IgG⁻. (B) IgG⁺IgM⁻. (C) IgM⁺IgG⁺. (D) IgM⁺ or IgG⁺. A₁–D₁, antibodies were detected without stratification of detection time. A₂–D₂, antibodies were detected 0–7 days after symptom onset. A₃–D₃, antibodies were detected 8–14 days after symptom onset. A₄–D₄, antibodies were detected >14 days after symptom onset.