Unequivocal diagnosis of dengue infection requires
laboratory confirmation, either by isolating the virus
or detecting dengue-specific antibodies. For virus
isolation or detection of DENV RNA in serum
specimens by serotype-specific, real-time reverse
transcriptase polymerase chain reaction (RT-PCR),
an acute-phase serum specimen should be collected
within 5 days of symptom onset. If the virus
cannot be isolated or detected from this sample,
a convalescent-phase serum specimen is needed at
least 6 days after the onset of symptoms to make a
serologic diagnosis by testing for IgM antibodies to
dengue with an IgM antibody-capture enzyme-linked
immunosorbent assay (MAC-ELISA).