What Is Hepatitis B,History,Symptoms,Treatment

What Is Hepatitis B?  
Hepatitis B is an acute systematic infection caused by hepatitis B virus which is characterized by long incubation period  and symptoms similar to that of hepatitis A but tend to be more severe and life threatening.


Epidemiology:

A.Occurrence
Hepatitis B is endemic world wide with the highest rates found in developing countries.
B.Ecological triad
1.Agent:Hepatitis B virus
HBV(which is severe)is the only heptane virus causing infection in humans.
It comprises a capsule and a core for containing DNA in polymerase enzyme. 

2.Host:
a)Age- In highly endemic areas ,much infection occurs perinatally or during childhood.
b)Humoral and cellular responses-The appearance of surface antibody signals recovery of HBV infection and the development of immunity
3.Environment:Hepatitis B may occur around the year and it has no seasonal pattern.

History:

1.Reservoir:Patients and carriers(defined as the presence of HBs Ag for more than six months)

2.Source of infection: Several months (occasionally years in chronic carriers )or until disappearence of HBsAg and appearance of surface antibody.

Preventive And Control Measures: 

Diagnosis

1.Clinical diagnosis 

2.Laboratory diagnosis:The most important test for the detection of HBV infection is the immunoassy for HBsAg.

B.Isolation:
The patient should be isolated from it and put on rest.
C.Treatment
No specific treatment for acute or chronic HBV infection exists although and interferon holds some promise.
D.Prevention
Immunization:Active immunization-By hepatitis B vaccines