Question 1

What is the significance of a positive RPR test for syphilis?

Accepted Answer

A positive serological test for syphilis is often a false-positive result in volunteer donors because it is not specific for the presence of an infection with Treponema pallidum.

Question 2

Which of the following patients should not receive cytomegalovirus (CMV)-positive blood?

Accepted Answer

Cytomegalovirus is an opportunistic virus,affecting people with a lower-level immune response.

Question 3

Some donor centers have implemented the practice of diverting the first few milliliters of blood collected into a pouch attached to the collection bag.What is the purpose of this procedure?

Accepted Answer

Bacterial contamination of blood units from the phlebotomy procedure can be avoided by diverting the first couple of milliliters of blood collected into a pouch.

Question 4

What is the organism that causes Chagas disease?

Accepted Answer

Chagas disease is caused by infection with the protozoal parasite Trypanosoma cruzi,which can be transmitted by blood transfusion.

Question 5

If a donor is positive for hepatitis C virus by nucleic acid testing,why is the process of "look-back" initiated?

Accepted Answer

The purpose of look-back is to locate and quarantine current and previously donated units from a donor who tests positive for either hepatitis,HIV,West Nile virus,or Chagas disease.It also notifies the recipients of units that were transfused.Because test methods have become more sensitive,viral contaminants in prior donations may not have been detected.The process of look-back avoids additional cases of viral transmission.

Question 6

What is the advantage of testing donors' blood using nucleic acid test methods?

Accepted Answer

The advantage of nucleic acid testing is to be able to amplify small amounts of the virus and detect viruses before the antibody levels are measurable.

Question 7

What is the most common mode of transmission for hepatitis C virus?

Accepted Answer

Hepatitis C is most commonly transmitted by intravenous drug use.

Question 8

Why is Hepatitis A virus transmission in blood unusual?

Accepted Answer

Hepatitis A is not a blood-borne virus and is not chronic; therefore,it is not transmitted by transfusion.

Question 9

How is the sensitivity of a viral marker assay described?

Accepted Answer

Sensitivity is the ability of an assay to identify samples from infected individuals as positive.

Question 10

What of the following measures is taken to prevent cytomegalovirus infection from blood units?

Accepted Answer

Because cytomegalovirus resides in white cells,leukoreduction has been documented to reduce the transmission of this virus through blood.

Question 11

Define a hepatitis B virus carrier.

Accepted Answer

A carrier can transmit the virus but often does not show symptoms; the carrier remains positive for the antigen marker.

Question 12

Transfusion-associated hepatitis can be caused by hepatitis __________ virus.

Accepted Answer

Hepatitis B,C,and D can be transmitted by blood transfusion.Because the hepatitis D virus requires co-infection with hepatitis B,hepatitis D is not tested for directly in donor testing.

Question 13

What is the true statement regarding West Nile virus testing?

Accepted Answer

West Nile virus testing is performed by nucleic acid testing on all donors since 2003.

Question 14

Which of the following diseases relies on obtaining a thorough donor history to reduce potential transmission in blood donors?

Accepted Answer

Because there is no screening test for malaria,the only way to prevent its transmission is through questions about donor history regarding potential exposure.

Question 15

Which of the following characteristics is associated with human T-cell lymphotropic virus-I?

Accepted Answer

Human T-cell lymphotropic virus-I is associated with tropical spastic paraparesis and adult T-cell leukemia,and because it can be transmitted through blood transfusion,testing is required.

Question 16

Which of the following is the most common transfusion-transmitted infection?

Accepted Answer

Hepatitis viruses are the most common cause of transfusion-transmitted infection.

Question 17

Persons who have had injections of human growth hormone are indefinitely deferred as blood donors.What disease is associated with the injections?

Accepted Answer

Human growth hormone has been associated with transmission of Creutzfeldt-Jakob disease.

Question 18

Which of the following blood products is tested for bacterial contamination following storage?

Accepted Answer

Bacterial contamination of stored platelets is monitored by culture techniques as well as pH.

Question 19

What diseases are currently screened using nucleic acid tests?

Accepted Answer

Nucleic acid tests detect hepatitis B and C viruses,HIV-1,and West Nile virus.

Question 20

Which hepatitis virus is transmitted similar to hepatitis A?

Accepted Answer

Both hepatitis A and hepatitis E are transmitted by the oral-fecal route.

Quiz 14: Testing of Donor Blood