The dengue virus belongs to the genus Flavivirus of the family Flaviviridae. There are four
dengue virus serotypes: DEN-1, DEN-2, DEN-3 and DEN-4.
Immunity against a given serotype is definitive with a neutralizing antibody response.
Infection with a serotype only provides transient immune protection against
Viral isolation by cell culture is made from sera obtained between the 1st and the 5th day
of the disease, detection of the virus can be carried out by isolation from continuous lines of
The tests used for the detection of NS1 antigen, fast and achievable in most
laboratories, allow the detection of NS1 antigen in the serum of patients of the 1st
at the 5th day after the appearance of the clinical signs.
The detection of the genome of the virus is done by conventional RT-PCR (Reverse Transcriptase – Polymerase Chain Reaction) and RT-PCR in real time.
The serological diagnosis of dengue is based on the detection of IgM and IgG according to their
kinetics of appearance over time.
Given its performance below the RT-PCR test, the NS1 test should not be
used only in case of epidemic context and if the RT-PCR test can not be performed. In these
If RT-PCR is not available, NS1 antigen detection tests can then be performed.
useful for routine diagnosis at the point of care (given their positive predictive value
high). On the other hand,NS1 ELISA tests, and a fortiori NS1 ICT tests, have a predictive value
Suspicion of dengue usually occurs in two clinical situations:
• suggestive symptomatology in a patient returning from an area affected by dengue fever;
• suggestive symptomatology in a patient in one of the zones of activity of the vector during the period of activity of the vector as defined each year in the national anti-dissemination plan.