Hepatitis B vaccine. Vaccines of formalin-treated HBsAg, either purified from blood or produced by recombinant DNA technology, are available. Recombinant vaccines are now used routinely. All dentists and dental office personnel should be vaccinated. Hepatitis C Hepatitis C is a positive single stranded RNA virus.
Chronic infection is common and can lead to cirrhosis and hepatocarcinoma.
Transmission occurs through contaminated blood products, particularly after transfusions, and by other means. HIV preferentially infects cells bearing the CD4 surface receptor which comprise mainly T-helper cells. The immune suppression increases the susceptibility to secondary infections and cancer which eventually cause death. In addition to transmission by sexual contact, HIV can be spread through contact with contaminated blood and blood products. Primary infection is usually sub-clinical and occurs in childhood.