Hepatitis C is a chronic liver infection that can be eithersilent (with no noticeable symptoms) or debilitating. Either way,80% of infected persons experience continuing liver destruction.Chronic hepatitis C infection is the leading cause of livertransplants in the United States. The virus that causes it is bloodborne, and therefore patients who undergo frequent proceduresinvolving transfer of blood are particularly susceptible toinfection. Kidney dialysis patients belong to this group. In 2008,a for-profit hemodialysis facility in New York was shut down afternine of its patients were confirmed as having become infected withhepatitis C while undergoing hemodialysis treatments there between2001 and 2008.

When the investigation was conducted in 2008, investigatorsfound that 20 of the facility’s 162 patients had been documentedwith hepatitis C infection at the time they began their associationwith the clinic. All the current patients were then offeredhepatitis C testing, to determine how many had acquired hepatitis Cduring the time they were receiving treatment at the clinic. Theywere considered positive if enzyme-linked immunosorbent assay(ELISA) tests showed the presence of antibodies to the hepatitis Cvirus.

Health officials did not test the workers at the hemodialysisfacility for hepatitis C because they did not view them as likelysources of the nine new infections. Why not?

Why do you think patients were tested for antibody to the virusinstead of for the presence of the virus itself