INTRODUCTION TO DENGUE FEVER

One strain can affect only once

As soon as the body detects antigen it releases Antibodies against it,which neutralises the virus and stays in the body throughout life,thus preventing future attack from that strain.

 

 

it is because of ENHANCING ANTIBODIES ,along with the antibodies  for present attack the antibodies present in the body of previous attack  is also released.In this condition the previous antibodies cannot neutralise the antigen and they react with body tissue due to molecular mimicry.

In molecular mimicry ,Antibodies attack similar protein as of Antigen 

 

If Antibodies attack platelet it leads to thrombocytopenia, increased chance of bleeding which leads to Dengue hemorragic fever

If Antibodies attack endothelium cells of capillaries,there will be fluid leak from blood vessel causing decreased blood volume leading to Dengue shock syndrome