The clinical course of HDV infection depends upon the type of infection:
coinfection with HBV or superinfection in a patient who is already infected with
In coinfection, there is a simultaneous acute HDV infection in conjunction with an
acute HBV infection.
A superinfection of HDV in a hepatitis B chronic carrier produces severe damage.
It may cause fulminant hepatitis. Many superinfected carriers go on to develop
chronic delta infections.
The identification and classification of the infectious agent for hepatitis NANB is
the focus of intense research.
Concerning mode of transmission, hepatitis non-A, non-B is believed to be
capable of both parenteral and enteric transmission. However, there is strong
evidence that the parenteral route is predominant since hepatitis NANB accounts
for 80-90 percent of all post-transfusion hepatitis cases in the US and is a major source
of hepatitis among dialysis patients. Proposed nomenclature for blood-borne
hepatitis NANB is hepatitis C. (HCV).
Enteric (epidemic) NANB has been responsible for several large, well-documented
waterborne outbreaks of hepatitis. Most cases have been reported in developing
countries or among travelers who have recently returned from areas in which the
disease is known to be endemic. Proposed nomenclature for enteric hepatitis
NANB is hepatitis E (HEV).
Regarding NANB immunological assays, promising research has provided for a
possible immunological assay in the near future. Presently a diagnosis of NANB is
made through clinical symptoms, patient history, elevated liver enzymes, and the
exclusion of the other types of hepatitis through immunological assays.
End of Lesson 7