Transfusion Related Hepatitis C, D, and E

• Hepatitis C was formerly known as non-A-non-B hepatitis (NANB)
• Hepatitis C is recognized as a primary transfusion-transmitted form of viral hepatitis
• HCV is 30-60 nm and is most likely a flavivirus (family of arbovirus)
• HCV is a ssRNA enveloped virus
• The HCV envelope mutates rapidly, changes envelope proteins
• The number of cases of HCV are falling, from 230k cases per year in 1980 to 19k cases per year in 2006
• HCV is spread through blood and body fluids
• HCV spreads through blood in body fluid
• HCV is spread primarly through parenteral (not alimentary) exposure and sexual contact (less likely)
• HCV is usually through blood exposure and 55% of infections in the US are associated with injection drug use or transfusions (before screening was started in 1992).
• the risk for infection of HCV is now 1 in 1.1 million
• For healthcare workers, needlesticks can be a route of infection:

  •Per OSHA: you are 20-40x more likely to get HCV than HIV through a needlestick

  •Per the CDC: the risk is 6x greater than HIV
• the incubation phase of HCV is 5-12 weeks
• in the acute phase of HCV, the symptoms are mild
• Most HCV infections are asymptomatic
• about 75% of HCV cases result in jaundice
• ALT levels are not extremely elevated in HCV
• a characteristic of HCV is fluctuation in ALT levels
• 80% of HCV cases become chronic
• HCV can lead to cirrhosis (10% of cases) and liver cancer
• chronic HCV cases are seen in particularly in adults born from 1945-1965 (75% of chronic cases in US). The risk factors are contaminated transfusions and the use of illicit IV drugs
• •An ALT (alanine aminotransferase) test measures the amount of this enzyme in the blood.  It is found mainly in the liver, but also in smaller amounts in the kidneys, heart, muscles, and pancreas
• •ALT was formerly called SGPT (serum glutamic pyruvic transaminase)
• • Low levels are ALT are normally found in the blood
• •When the liver is damaged or diseased it releases ALT into the blood stream and levels go up
• •The ALT test is often done along with other tests that check for liver damage, including AST (alkaline phosphatase), LDH (lactate dehydrogenase), and bilirubin
• •Both ALT and AST levels are reliable tests for liver damage
• 1990 - saw the implementation of testing of donor blood for HCV
• studies indicate that the HCV core and envelope proteins, as well as other nonstructural proteins, are immunogenic
• The exact chronology of the appearance of the HCV markers are not fully developed
• the first generation of anti-HCV testing using a single protein of HCV: c100-3 antigen
• the second generation makes use of 3 antigens for HCV testing: structural - c22-3 and nonstructural - c100-3 and c33c
• the second HCV test is more sensitive and specific
• RIBA (recombinant immunoblot assay) provides more information if needed. it's like a western blot
• for HCV testing, can also use nucleic acid amplification tests (NAAT) to detect viral RNA
• prevention and treatment of HVC

  • no vaccine currently exists
• prevention of HCV - carefully screen donors and testing
• •Currently there are 2 EIAs (enzyme linked immunoassays) and 1 chemiluminescent (light is given off by a reaction and measured) assays to detect HCV
• 2 EIAs are used to screen donor blood, RIBA and NAAT are used as confirmatory tests, usually. in donor counseling and referral
• HCV infection can be treated with interferon