Hepatitis transfusion-transmitted

It has been postulated that transfusion-transmitted virus (TT virus) can be transmitted through heat-treated blood products (16). Transfusion-transmitted virus is a common DNA virus in healthy Japanese, and it lacks a lipid envelope, similar to parvovirus B19 (16,17). Transmission of transfusion-transmitted virus often occurs with blood transfusion and it can cause post-transfusion hepatitis with high postoperative peak alanine transaminase activity (17). No patients with hepatitis due to transfusion-transmitted virus have clinically apparent hepatitis (17). The incidence of transfusion-transmitted virus viremia in patients with hemophiha... 

Several other viruses have been proposed as causes of liver injury these include hepatitis G yirus (discussed below), transfusion-transmitted virus (TTV), and the closely related SEN-V virus. Although all three are blood borne chronic viral infections and, in the case of TTV and SEN-V, have been known to replicate in the liver, none of these viruses appear to cause acute or chronic liver injuryd " The various hepatitis viruses are outlined in Table 47-2. 

In 1983 the move to develop red cell substitutes intensified when it was recognized that the acquired immune deficiency syndrome (AIDS) could be transmitted by the blood-bome human immunodeficiency vims (HIV). Concern for the nation s blood supply followed. Since that time other retrovimses have been identified, efforts to screen blood not only for these agents but also for vimses that cause hepatitis have intensified, the indications for transfusion have been reevaluated, and the use of blood products has become much more efficient. More carehil screening of donors, testing of all donated units, and a general awareness in the donor population have all contributed to a decreased risk from transfusion-contracted AIDS. 

The hepatitis C virus was defined in 1989. Prior to this, hepatitis following blood transfusion that was not caused by hepatitis A or B was referred to as non-A, non-B hepatitis. HCV is a positive, single-stranded RNA virus of the Flaviviridae family. HCV can be subdivided into groups depending upon the genotype of the virus, which may be important in determining the severity of the disease and the response to treatment. It has been estimated that around 170 million people worldwide are infected with hepatitis C [15]. HCV is primarily transmitted... 

Transmission of viral hepatitis continues to be a serious problem related to the transfusion of whole blood, cellular blood components, and to a lesser degree plasma-derived prodncts (8,155). It is difficult and probably impossible to obtain complete data on the true incidence of hepatitis transmitted by blood or blood products the incubation time is long, mild anicteric cases are not recognized, and systematic follow-up studies of transfused patients are difficnlt and expensive (156). In addition, the epidemiology of viral hepatitis is different in different regions. 

Hepatitis B transmission can only be prevented by a thorough understanding of the routes of transmission. The virus is transmitted by contact with blood or body fluids of an infected person in the same way as human immunodeficiency virus (HIV). However, HBV is 50-100 times more infectious than HIV. In brief, the main ways of getting infected with HBV are perinatal (from mother to baby at the birth), child-to-child transmission, unsafe injections (Hutin et al. 1999), transfusions and sexual contact. The virus is not spread by contaminated food or water, and cannot be spread casually in the workplace. 

Hepatitis C is usually transmitted by unsafe sex practices, contaminated needles, or unscreened blood transfusions. 

An additional problem with transfusions of donated blood is the potential risk of transmitting bacterial or viral diseases, such as hepatitis or the human immunodeficiency (HIV) virus. Blood donors have to be carefully screened for their past and present diseases to reduce the risk of disease transmittal. 

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