Additional file 3: Figure S3. of Dengue virus infection-enhancement activity in neutralizing antibodies of healthy adults before dengue season as determined by using FcγR-expressing cells

Fold-enhancement activity in serum samples obtained from 18 individuals who were DENV IgG negative pre-dengue season but seropositive post-dengue season (Non patient group) versus patient group. Fold- enhancement value was determined by the ratio of (mean plaque count at 1:20 serum dilution)/(mean plaque count in the absence of human serum samples) by using FcγR expressing BHK cells. Positive infection-enhancing activity was defined as fold-enhancement value greater than cut-off value plus 2 times SD (above dash line). P-value was determined by Mann -Whitney test. P value £0.05 = significant. Non patient = Non patient group; Patient = Patient group. NA(-): Neutralizing antibody titer <10; NA(+): Neutralizing antibody titer ≥ 10. The results were represented as Median ±IQR. (DOCX 21 kb)