Table 1.

Diagnostic classification of the study participants according to their DENV serological and PCR results

Group	Laboratory diagnostic criteria
Negative group	Negative by all serological and PCR tests
Viremic 1ry infection group	Positive PCR ± IgM positive antibodies
Convalescent-phase 1ry infection group	Either exclusively positive for IgM or dual positive IgM and IgG antibodies with an IgM/IgG ratio ≥ 1.2
Viremic 2ry infection group	Simultaneously positive PCR with positive IgG ± IgM antibodies
Convalescent-phase 2ry infection	Negative PCR and dual positive IgM and IgG antibodies with an IgM/IgG ratio < 1.2
Previous exposure group	Exclusively positive for IgG antibodies