ROLE OF ANTIBODIES IN DIAGNOSING DENGUE FEVER:

ROLE OF ANTIBODIES IN DIAGNOSING DENGUE FEVER:
Patients can develop dengue hemorrhagic fever in primary infection and even patients getting secondary infection can have simple dengue classical fever. But the incidence of development of dengue hemorrhagic fever in patients with secondary infection is remarkably more. Lets discuss the role of different antibodies helping us to diagnose dengue fever.
IgM antibody shows current infection and is usually positive from 5^th day till 10^th day.
IgG antibody shows previous infection and is positive usually after 10^th day of infection
Viral antigen can be detected during first three days of infection as well.
So lets discuss different scenarios:
** In a patient who has got dengue first time , during first three days we will find viral antigen positive. From day 5 to day 10 IgM would be positive , while after 10 days IgG would be positive for rest of his life.
** In patient who has got dengue second time (secondary infection) during first three days viral antigen and IgG( of previous infection) would be positive. From 5^th to 10^th days IgM and IgG would both be positive. From 10^th day onwards only IgG would be positive and would remain positive throughout his life