Hepatitis B Virus And Blood Transfusion Safety In Sub-Saharan Africa

[Guest guest]

FULL TEXT:

http://www.ispub.com/journal/the_internet_journal_of_infectious_diseases/volume_\

7_number_2a/article/hepatitis-b-virus-and-blood-transfusion-safety-in-sub-sahara\

n-africa.html

The Internet Journal of Infectious Diseases™ ISSN: 1528-8366

2009 Volume 7 Number 2

--------------------------------------------------------------------------------

Hepatitis B Virus And Blood Transfusion Safety In Sub-Saharan Africa

Ogbonnaya Ogbu

Department of Applied Microbiology

Faculty of Applied and Natural Sciences

Ebonyi State University

Address:

Abakaliki

Nigeria

Chigozie Uneke

Department of Medical Microbiology

Faculty of Clinical Medicine

Ebonyi State University

Abstract

Hepatitis B virus (HBV) is the most common cause of serious liver infection in

the world. It is estimated that worldwide more than two billion people have been

infected by HBV and 350 million people have chronic infection. The HBV is highly

contagious and transmission of HBV occurs via percutaneous or permucosal routes,

and infective blood or body fluids can be introduced at birth, through sexual

contact or by contaminated needles. Transfusion-transmitted HBV infection is

increasingly becoming a major mode of transmission of HBV in the high-prevalence

areas in sub-Saharan Africa. There is a high level of occurrence of blood

demanding health conditions in many parts of sub-Saharan Africa. Due to

endemicity of infections causing anemia, malnutrition, and surgical and

obstetrical emergencies associated with blood loss in the sub-Saharan Africa,

the demand for blood transfusion services is high and increase the possibility

of the transmission of HBV (and other blood-borne pathogens) through

contaminated blood. Blood safety remains an issue of major concern in

transfusion medicine in this part of the globe because national blood

transfusion services and policies, appropriate infrastructure, trained personnel

and financial resources are inadequate. As part of public health interventional

measures, the transmission of HBV can be minimized by the screening of donors

prior to donation, exclusion of high-risk donors, followed by the in-vitro

screening of donations for HBsAg prior to transfusion. Accurate assessment of

transfusion-transmitted HBV infection which necessitates knowledge about

donation histories and person-years at risk is very essential in order to

establish comprehensive frameworks for monitoring blood donations and infectious

disease markers which remains a key to monitoring blood safety.

--------------------------------------------------------------------------------

Introduction

Hepatitis B virus (HBV) is the most common cause of serious liver infection in

the world. It is estimated that worldwide more than two billion people have been

infected by HBV and 350 million people have chronic infection 1. The virus

causes transient and chronic infections of the liver. Transient infections may

produce serious illness, and approximately 0.5% terminates with fatal, fulminant

hepatitis while chronic infections may also have serious consequences: nearly

25% terminate in untreatable liver cancer 2. Worldwide deaths from liver cancer

caused by HBV infection probably exceed one million per year 3,4. The clinical

presentation Hepatitis B ranges from subclinical hepatitis to symptomatic

hepatitis and, in rare instances, fulminant hepatitis 5. Long-term complications

of hepatitis B include cirrhosis and hepatocellular carcinoma 6. Hepatitis B

infection has thus assumed an important public health problem due to its chronic

serious sequelae. It has been estimated that at the most, 33% of the infected

subjects have evidence of clinical hepatitis 7, and depending on the age of

infection, up to one third of infected patients become chronic carriers of

hepatitis B surface antigen (HBs Ag) 7. Chronic carriers have a higher incidence

of and mortality due to hepatocellular carcinoma and cirrhosis 8. Perinatal or

childhood infection is associated with few or no symptoms, but it has a high

risk of becoming chronic 5.

Persons with chronic HBV infection are predisposed to chronic liver disease and

have a greater than 200-fold increased risk of hepatocellular carcinoma 9.

Fulminant hepatic failure occurs in approximately 0.1-0.5% of patients and is

believed to be caused by massive immune-mediated lysis of infected hepatocytes.

Various extrahepatic manifestations, including urticarial rashes, arthralgia,

and arthritis, are associated with acute clinical and subclinical HBV infection,

as well as multiple immune-complex disorders such as Gianotti-Crosti syndrome

(papular acrodermatitis), necrotizing vasculitis, and hypocomplementemic

glomerulonephritis 9,10. HBV is associated with 20% of the cases of membranous

nephropathy in children. Essential mixed cryoglobulinemia, pulmonary hemorrhage

related to vasculitis, acute pericarditis, polyserositis, and Henoch-Schönlein

purpura have been reported in association with HBV infection 9. The pathogenesis

and clinical manifestations are due to the interaction of the virus and the host

immune system. The latter attacks the HBV and causes liver injury. Activated

CD4+ and CD8+ lymphocytes recognize various HBV-derived peptides located on the

surface of the hepatocytes, and an immunologic reaction occurs. Impaired immune

reactions (eg, cytokine release, antibody production) or relatively tolerant

immune status results in chronic hepatitis 10. In particular, a restricted T

cell–mediated lymphocytic response occurs against the HBV-infected hepatocytes.

The final state of the disease is cirrhosis. Patients with cirrhosis and HBV

infection are likely to develop hepatocellular carcinoma 6,10.

[Guest guest]

FULL TEXT:

http://www.ispub.com/journal/the_internet_journal_of_infectious_diseases/volume_\

7_number_2a/article/hepatitis-b-virus-and-blood-transfusion-safety-in-sub-sahara\

n-africa.html

The Internet Journal of Infectious Diseases™ ISSN: 1528-8366

2009 Volume 7 Number 2

--------------------------------------------------------------------------------

Hepatitis B Virus And Blood Transfusion Safety In Sub-Saharan Africa

Ogbonnaya Ogbu

Department of Applied Microbiology

Faculty of Applied and Natural Sciences

Ebonyi State University

Address:

Abakaliki

Nigeria

Chigozie Uneke

Department of Medical Microbiology

Faculty of Clinical Medicine

Ebonyi State University

Abstract

Hepatitis B virus (HBV) is the most common cause of serious liver infection in

the world. It is estimated that worldwide more than two billion people have been

infected by HBV and 350 million people have chronic infection. The HBV is highly

contagious and transmission of HBV occurs via percutaneous or permucosal routes,

and infective blood or body fluids can be introduced at birth, through sexual

contact or by contaminated needles. Transfusion-transmitted HBV infection is

increasingly becoming a major mode of transmission of HBV in the high-prevalence

areas in sub-Saharan Africa. There is a high level of occurrence of blood

demanding health conditions in many parts of sub-Saharan Africa. Due to

endemicity of infections causing anemia, malnutrition, and surgical and

obstetrical emergencies associated with blood loss in the sub-Saharan Africa,

the demand for blood transfusion services is high and increase the possibility

of the transmission of HBV (and other blood-borne pathogens) through

contaminated blood. Blood safety remains an issue of major concern in

transfusion medicine in this part of the globe because national blood

transfusion services and policies, appropriate infrastructure, trained personnel

and financial resources are inadequate. As part of public health interventional

measures, the transmission of HBV can be minimized by the screening of donors

prior to donation, exclusion of high-risk donors, followed by the in-vitro

screening of donations for HBsAg prior to transfusion. Accurate assessment of

transfusion-transmitted HBV infection which necessitates knowledge about

donation histories and person-years at risk is very essential in order to

establish comprehensive frameworks for monitoring blood donations and infectious

disease markers which remains a key to monitoring blood safety.

--------------------------------------------------------------------------------

Introduction

Hepatitis B virus (HBV) is the most common cause of serious liver infection in

the world. It is estimated that worldwide more than two billion people have been

infected by HBV and 350 million people have chronic infection 1. The virus

causes transient and chronic infections of the liver. Transient infections may

produce serious illness, and approximately 0.5% terminates with fatal, fulminant

hepatitis while chronic infections may also have serious consequences: nearly

25% terminate in untreatable liver cancer 2. Worldwide deaths from liver cancer

caused by HBV infection probably exceed one million per year 3,4. The clinical

presentation Hepatitis B ranges from subclinical hepatitis to symptomatic

hepatitis and, in rare instances, fulminant hepatitis 5. Long-term complications

of hepatitis B include cirrhosis and hepatocellular carcinoma 6. Hepatitis B

infection has thus assumed an important public health problem due to its chronic

serious sequelae. It has been estimated that at the most, 33% of the infected

subjects have evidence of clinical hepatitis 7, and depending on the age of

infection, up to one third of infected patients become chronic carriers of

hepatitis B surface antigen (HBs Ag) 7. Chronic carriers have a higher incidence

of and mortality due to hepatocellular carcinoma and cirrhosis 8. Perinatal or

childhood infection is associated with few or no symptoms, but it has a high

risk of becoming chronic 5.

Persons with chronic HBV infection are predisposed to chronic liver disease and

have a greater than 200-fold increased risk of hepatocellular carcinoma 9.

Fulminant hepatic failure occurs in approximately 0.1-0.5% of patients and is

believed to be caused by massive immune-mediated lysis of infected hepatocytes.

Various extrahepatic manifestations, including urticarial rashes, arthralgia,

and arthritis, are associated with acute clinical and subclinical HBV infection,

as well as multiple immune-complex disorders such as Gianotti-Crosti syndrome

(papular acrodermatitis), necrotizing vasculitis, and hypocomplementemic

glomerulonephritis 9,10. HBV is associated with 20% of the cases of membranous

nephropathy in children. Essential mixed cryoglobulinemia, pulmonary hemorrhage

related to vasculitis, acute pericarditis, polyserositis, and Henoch-Schönlein

purpura have been reported in association with HBV infection 9. The pathogenesis

and clinical manifestations are due to the interaction of the virus and the host

immune system. The latter attacks the HBV and causes liver injury. Activated

CD4+ and CD8+ lymphocytes recognize various HBV-derived peptides located on the

surface of the hepatocytes, and an immunologic reaction occurs. Impaired immune

reactions (eg, cytokine release, antibody production) or relatively tolerant

immune status results in chronic hepatitis 10. In particular, a restricted T

cell–mediated lymphocytic response occurs against the HBV-infected hepatocytes.

The final state of the disease is cirrhosis. Patients with cirrhosis and HBV

infection are likely to develop hepatocellular carcinoma 6,10.