Diagnosis

Specific diagnosis depends upon virus isolation or serologic diagnosis.

Laboratory diagnosis involves collection, processing, storage, shipment, isolation and serological diagnosis of specimens.

Collection of specimens:

Blood is collected in tubes or vials. Collection of specimens, 0-5 days after the onset illness (Acute phase) is called the Acute serum, S1


 

14-21 days after the onset of illness (convalescent phase) is called Convalescent serum, S2


 

Collection of specimens, 7-21 days after the acute serum was drawn is called Late Convalescent serum, S3


 

Processing of specimens:

Acute Phase blood is processed for 2-6 hours at 40o C


 

Convalescent blood for 2-24 hours at ambient temperature.


 

Storage:

Acute Phase serum i stored at -700o C


 

Convalescent phase serum is stored at -200o C


 

Isolation of Dengue Virus :

The choice of methods for isolation and identifiation of dengue virus will depend on

  • Local availability of mosquitoes

  • Cell culture

  • and Laboratory capability.

In order to identify the different dengue virus serotypes, mosquioto head squashes and slides of infected cell cultures are by serological tests

Serological Tests for the Diagnosis of DF/DHF:

  • Haemagglutination Inhibition Test

  • Complement fixation Test

  • Neutralization Test

  • IgM-capture enzyme -linked immunosorbent assay (MAC-ELISA)

  • IgG-ELISA

  • Rapid serologic test kits.
Last Updated on:06/05/2014