Deck 14: Testing of Donor Blood

Question 1

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

A) Antibodies to Treponema pallidum are present
B) Past or present venereal disease infection
C) Possibility of an infection with Treponema pallidum
D) Antigens associated with venereal disease are present

Answer 1

C
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?

A) Premature infants
B) HIV-positive patients
C) Bone marrow recipients
D) Unborn infants of pregnant women who are seronegative
E) All of the above

Answer 2

E
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?

A) Reduce leukocyte contamination
B) Prepare pedipacks for neonates
C) Avoid bacterial contamination
D) Collect blood for viral testing

Answer 3

C
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?

A) Treponema pallidum
B) Trypanosoma cruzi
C) Cytomegalovirus
D) Plasmodium vivax

Question 5

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

A) To quarantine units in the blood center that may exist from prior donations from the inventory
B) To notify recipients who may have previously received blood from this donor
C) To locate and quarantine units sent to transfusion facilities from this donor in the past
D) All of the above

Question 6

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

A) Detection of small amounts of the virus
B) Reduction of costs involved in testing
C) Quicker and easier to perform than other methods
D) All of the above

Question 7

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

A) Contaminated food and water
B) Transfusion
C) Sexual transmission
D) Intravenous drug use

Question 8

Why is Hepatitis A virus transmission in blood unusual?

A) Hepatitis A virus is usually transmitted by the enteric route
B) Hepatitis A virus is usually an acute hepatitis
C) Infectivity after a hepatitis A virus infection is usually only 2 weeks
D) All of the above

Question 9

How is the sensitivity of a viral marker assay described?

A) True positives divided by difference between true positives and false negatives
B) True negatives divided by sum of true negatives and false positives
C) True positives divided by sum of true positives and false negatives
D) True negatives divided by difference between true negatives and false positives

Question 10

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

A) Leukocyte reduction
B) Washing
C) Freezing and thawing
D) Nucleic acid testing

Question 11

Define a hepatitis B virus carrier.

A) Hepatitis B surface antigen-positive person who has liver disease because of a previous hepatitis exposure
B) Person who can transmit hepatitis B virus but may not be outwardly affected by it
C) Hepatitis B surface antibody-positive person, negative for hepatitis B surface antigen
D) Hepatitis B core antibody-positive person, negative for hepatitis B surface antigen

Question 12

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

A) B
B) C
C) D
D) All of the above

Question 13

What is the true statement regarding West Nile virus testing?

A) Testing for West Nile virus is required only in New York and California.
B) Testing for West Nile virus is necessary only in the warmer months of the year.
C) West Nile virus testing is performed using nucleic acid testing on all donor units.
D) West Nile virus testing is optional.

Question 14

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

A) Syphilis
B) Human T-cell lymphotropic virus-I
C) Cytomegalovirus
D) Malaria

Question 15

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

A) It can be transmitted in blood products.
B) It is found in patients with tropical spastic paraparesis.
C) It is found in patients with adult T-cell leukemia.
D) All of the above

Question 16

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

A) AIDS
B) Syphilis
C) Cytomegalovirus
D) Hepatitis

Question 17

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

A) Trypanosomiasis cruzi
B) Babesia microti
C) Borrelia burgdorferi
D) Creutzfeldt-Jakob disease

Question 18

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

A) Cryoprecipitated AHF
B) Red blood cells, frozen
C) Platelets
D) Fresh frozen plasma

Question 19

What diseases are currently screened using nucleic acid tests?

A) Hepatitis B and C viruses, West Nile virus, and HIV-1
B) Chagas disease, malaria, and syphilis
C) Hepatitis B virus, hepatitis C virus, and HIV
D) Human T-cell lymphotropic virus-I/human T-cell lymphotropic virus-II, HIV 1/HIV-2, and hepatitis C virus

Question 20

Which hepatitis virus is transmitted similar to hepatitis A?

A) Hepatitis E virus
B) Hepatitis B virus
C) Hepatitis C virus
D) Hepatitis D virus

Question 21

What is the most sensitive test for HIV?

A) Enzyme-linked assays
B) Chemiluminescence
C) Western blot
D) Nucleic acid

Question 22

What happens if clinically significant red cell antibodies are found in donor units?

A) Platelet and fresh frozen plasma can be transfused.
B) Red blood cells can be used if the antibody interpretation is indicated on the label.
C) The red blood cells, plasma, and platelet products must be discarded.
D) Red blood cells must be washed before transfusion.

Question 23

When are surrogate marker tests useful?

A) When the required test is too expensive
B) When direct testing is not yet available
C) When the required test detects too many false-positive results
D) When the internal controls are not valid