Rare. Hepatitis A became a rare infection in the US especially among children since the institution of universal vaccination against it.
Hard to be certain. There are about 25, 000 new cases of hep. A reported each year. However the number is thought to be much higher because many cases are asymptomatic or mild and are never reported. The number of cases has dropped significantly because of the effectiveness of Hep. A vaccine.
Hep C prevalence. Epidemiologic data (nhanes iii study) suggests about 3%. But there are flaws with the methodology and the acutal % may be higher. Currently the CDC are contemplating changing screening recommendations to all people born between 1946 and 1964, possilby to 1970. http://www. Hhs. Gov/ash/initiatives/hepatitis/actionplan_viralhepatitis2011.pdf.
Varies. Estimates are from 2.7 to 4.5 millions, but most patients are in the baby group born between 1946 and 1964. If you are in that group or older, you should get tested.