1.] Also called “delta agent” and “hepatitis delta virus”.
2.] Hepatitis – D virus [HDV] is an unique RNA virus that is replication defective, causing infection only when it is encapsulated by HBsAg.
3.] Thus, taxonomically distinct from HBV, HDV is absolutely dependent on the genetic information provided by HBV for multiplication and causes hepatitis only in the presence of HBV.
4.] Delta hepatitis thus arises in two settings :-
- Acute coinfection occurs following exposure to serum containing both the HDV and HBV.
- Superinfection of a chronic carrier of HBV with a new inoculum of HDV results in disease about 30 – 50 days later. The carrier may have been previously “healthy” or may have had underlying chronic hepatitis.
5.] Endemic region for HDV are Southern Europe, Middle – East, South India and parts of Africa.
6.] The high risk individuals of HDV infection are the same as for HBV infection i.e. intravenous drug abusers, homosexuals, transfusion recipient and health care workers.
HEPATITIS DELTA VIRUS [HDV] :-
1.] It is small single stranded RNA particle with a diameter of 36nm.
2.] It is double – shelled – the outer shell consist of HBsAg and the inner shell consist of delta antigen provided by a circular RNA strand.
3.] It is highly infectious and can induce hepatitis in any HBsAg – positive host.
4.] HDV replication and proliferation takes place within the nuclei of the liver cell.
5.] Markers of HDV infection include the following :-
- HDV identification in the blood and in the liver cell nuclei.
- HDAg detectable in the blood and on the fixed liver tissue specimens.
- Anti – HD antibody in acute hepatitis which is initially IgM type and is later replaced by IgG type anti – HD antibody which persist for life to confer immunity against reinfection.
1.] HDV, unlike HBV, is thought to cause direct cytopathic effect on hepatocytes.
2.] There are some example of transmission of HDV infection from individuals who themselves have not suffered from any attack of hepatitis, suggesting that it may not be always cytopathic.
There are no known treatments for acute or chronic hepatitis D. Unlike other forms of hepatitis, antiviral medications don’t seem to be very effective in treating HDV.
You may be given large doses of a medication called interferon for up to 12 months. Interferon is a type of protein that may stop the virus from spreading and lead to remission from the disease. However, even after treatment, people with hepatitis D can still test positive for the virus. This means that it’s still important to use precautionary measures to prevent transmission. You should also remain proactive by watching for recurring symptoms.
If you have cirrhosis or another type of liver damage, you may need a liver transplant. A liver transplant is a major surgical operation that involves removing the damaged liver and replacing it with a healthy liver from a donor. In cases where a liver transplant is needed.
MULTIPLE CHOICE QUESTIONS [MCQs] :-
1.] Hepatitis – D virus is also called ?
a. Delta virus
b. Hepatitis delta virus
c. Both (a) and (b)
d. None of the above
2.] The most serious infection is ?
a. Superinfection of and HBsAg carrier by HDV
b. Infection with HBV alone
c. Coinfection of HBV and HDV
d. None of the above
3.] The defective satellite virus is ?
a. Hepatitis – B
b. Hepatitis – C
c. Hepatitis – D
d. Hepatitis – E
4.] What is the diameter of HDV ?
a. 36 µm
b. 40 nm
c. 36 nm
d. 35 µm
5.] Which of the following viruses can be transmitted by the parental route ?
d. All of the above
6.] HDV virus is an ?
a. Single stranded DNA particle
b. Double stranded RNA particle
c. Single stranded RNA particle
d. Double stranded DNA particle
7.] Hepatitis – D is which type of virus ?
a. Small, single stranded RNA with diameter of 36 nm
b. Large, single stranded DNA with diameter of 36 nm
c. Small,double stranded RNA with diameter of 36 µm
d. Large, double stranded DNA with diameter of 36 µm
8.] HDV has how many layers ?
a. Double layered
b. Single layered
c. Their is no layer
d. May be double layered or single
9.] Incubation period for hepatitis – D is ?
a. 1 week
b. 10 – 15 days
c. Approx. 35 days
d. 2 – 3 days
10.] The outer shell of HDV virus consist of ?
2.] (a) superinfection of an HBsAg carrier by HDV
3.] (c) hepatitis – D
4.] (c) 36 nm
6.] (c) single stranded RNA particle
7.] (a) small, single stranded RNA with diameter of 36 nm
8.] (a) double layered
9.] (c) approx. 35 days
10.] (d) HBsAg
1.] Textbook Of Pathology By Harsh Mohan; 7th edition; Page no. 592 – 593.
2.] Robbin’s Basic Pathology; 5th edition; Page no. 848.