1. What is the impact of hepatitis B in the US?
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I think there's more and more interest and
concern and emphasis on hepatitis B evolving currently. To follow up on the question of why people
have been hung up on hepatitis C one concept is that the incidence of
hepatitis C in the United States has been judged to be over four
million people and the incidence of hepatitis B has been estimated at
1.25 million. There’s been some increased interest [in C]
because the incidence is three times that of hepatitis B. Hepatitis B is a much larger worldwide
problem than hepatitis C and is an incredibly important problem
because of the high incidence of mortality from liver cancer which is
a major cause of death across the world and one of the leading lethal
cancers across the world. Hepatitis B is of increasing concern in the
United States and there’s going to be increased concentration on
it. One of the reasons is the Asian population,
which is a big reservoir of hepatitis B, has increased tremendously in
the United States. The estimate of 1.25 million people is
probably underestimated. We have some data from very preliminary
surveys that were done in Chinatown where we found as many as
twenty-five percent of the population is infected with hepatitis
B which actually interestingly enough is
higher than the estimate for the infection in China itself. So, this is an increasing public health
concern in the metropolitan areas. Its going to be the classical problem in the
United States. In the major population centers on both
coasts where the Asian population has increased significantly in the
last few years, this is turning out to be a major problem. And you know how it goes in the United
States, as the Asian population increases, obviously their importance
as voters increases and I think the interests in this world [hepatitis
B] will increase. The other point that Dr. London made is
really that hepatitis C, in terms of increased incidence, is really a
disappearing disease. Hepatitis C is basically going to run
itself out of existence in the next twenty years because the main source of it was blood
transfusions which are now tested and excluded and the number of new cases of hepatitis C
has dropped from like hundreds and hundreds of thousands a year is now
down to less than twenty thousand new cases a year year which really takes away from it as a
new public health problem as an infectious disease. Of course, the reason that hepatitis C has
garnered so much interest is that hepatitis C is a disease which
evolves over twenty-five or thirty years. So the incidence of new cases of the
disease has dropped incredibly and this will not be a public health
problem in the future. Right now were seeing all the sequela of
the people who contracted this twenty-five years ago and they are the
ones who are developing cirrhosis, liver cancer, etc. and that’s the leading cause of liver
transplant in the United States. Its sort of split between alcohol and
hepatitis C. But this will diminish, well at first it
will peak because there is still the people that contracted this
before 1992. So if you think about it, in twenty-five
years the peak of the problems from hepatitis C will peak around 2012
- 2020, but then it will be over. And then is when hepatitis B will be coming
into its own and the number of these cases will be
increasing. This disease is much more easily
transmitted sexually than hepatitis C which is essentially
non-transmissible sexually. So we haven’t eradicated the reservoir of
the people here [in US] and you'll see that in order to eradicate this
reservoir, were going to have many more extensive means.
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2. What is the difference between acute and chronic HBV infection?
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