Deck 23: Serology and Molecular Detection of Viral Infections

Question 1

A patient has the following hepatitis profile: anti-HAV IgM = not detected; HBsAg = detected; anti-HBc IgM = detected; anti-HBc total = detected; anti-HBs = not detected; anti-HCV = not detected.What is his diagnosis?

A) Acute hepatitis A
B) Acute hepatitis B
C) Chronic hepatitis B
D) Immune to hepatitis B

Answer 1

Acute hepatitis B

Question 2

A patient has an antibody profile for Epstein-Barr virus (EBV)performed,with the following results: EB-VCA IgM = pos; EB-VCA IgG = pos; EBV-EBNA = neg; EBV-EA-D = neg.This patient has which of the following?

A) Acute EBV infection
B) Convalescent EBV
C) Past exposure to EBV
D) Lack of EBV infection

Answer 2

Acute EBV infection

Question 3

A patient has the following serologic profile: HBsAg = negative; HBeAg = negative; anti-HBc IgM = negative; anti-HBc IgG = positive; anti-HBs = positive; anti-HBe = positive.These results indicate:

A) early acute hepatitis B infection.
B) chronic infection with hepatitis B
C) a patient vaccinated against hepatitis B.
D) past infection with hepatitis B.

Answer 3

past infection with hepatitis B.

Question 4

Serology is performed on a patient with a rash and fever.Results are: rubella IgM = positive; rubella IgG = positive; measles IgM = negative; measles IgG = positive; varicella-zoster IgM = negative; varicella-zoster IgG = negative.What is the interpretation of these results?

A) Acute infection with rubella virus
B) Acute infection with measles virus
C) Not immune to measles or rubella viruses
D) Immune to varicella-zoster virus only

Question 5

A physician wants to know if his patient,who currently has a rash and fever,has an active rubeola virus infection.IgG against rubeola virus is detected.IgM against rubeola virus is not detected.What do these results mean?

A) The patient has a current measles infection.
B) The patient has a current chickenpox infection.
C) The patient has never had either measles or chickenpox.
D) The patient has had a previous exposure to measles, either through natural infection or vaccination.

Question 6

In infectious mononucleosis,which of the following would be detectable earliest in the infection,thereby indicating a current infection?

A) Anti-EA-IgG
B) Anti-EBNA
C) Anti-VCA-IgM
D) Anti-VCA-IgG

Question 7

Which of the following positive antibody tests may be an indication of recent rubella vaccination or early primary rubella infection in a patient with no clinical symptoms?

A) Only IgG positive
B) Only IgM positive
C) Both IgG and IgA antibodies positive
D) Fourfold rise in titer for IgG

Question 8

A 14-year-old boy presents to the physician complaining of sore throat,fatigue,and fever for the past week.A monotest is performed and is reported as positive.It is likely that this boy has:

A) infectious mononucleosis.
B) streptococcal pharyngitis.
C) acute glomerulonephritis.
D) a common cold.

Question 9

The causative agent of infectious mononucleosis is:

A) Streptococcus pyogenes.
B) Staphylococcus aureus.
C) Epstein-Barr virus.
D) HIV.

Question 10

A 36-year-old male presents to a free clinic with symptoms of anorexia,malaise,vomiting,abdominal pain,and mild jaundice.The patient is a known IV drug abuser.The physician orders liver function tests and an acute hepatitis serum panel.The laboratory reports the following results: anti-HAV IgM = not detected; HBsAg = not detected; anti-HBc IgM = not detected; anti-HBc total = detected; anti-HBs = detected; anti-HCV = detected.These findings are consistent with:

A) acute hepatitis B
B) chronic hepatitis B
C) acute hepatitis A.
D) acute hepatitis C.

Question 11

A patient has detectable levels of IgG and IgM against the viral capsid antigens of Epstein-Barr virus (EBV).This patient has:

A) been infected with EBV in the past.
B) an infection with HIV, too.
C) a current infection with EBV.
D) never had EBV.

Question 12

Which of the following statements is true of infection with hepatitis B?

A) Anti-HBs is the first detectable antibody in serum.
B) Anti-HBe is the first detectable antibody in serum.
C) Anti-HBc is the first detectable antibody in serum.
D) Anti-HBs, anti-HBe, and anti-HBc are detectable at the same time.

Question 13

A patient was diagnosed with acute hepatitis B infection 9 months ago.Follow-up testing performed today obtains these results: anti-HAV IgM = not detected; HBsAg = not detected; anti-HBc IgM = not detected; anti-HBc total = detected; anti-HBs = detected; anti-HCV = not detected.What is the diagnosis now?

A) Acute hepatitis B
B) Chronic hepatitis B
C) Chronic hepatitis C
D) Convalescent hepatitis B

Question 14

Which of the following serologic test results indicate that a patient is a chronic carrier of hepatitis B?

A) HBsAb positive; HBsAg negative
B) HBcAb and HBsAb positive
C) HBsAb negative; HBsAg positive for 12 months
D) HBeAb and HBeAg negative

Question 15

A patient presents to the physician complaining of a 4-week history of fever,malaise,and irritability.The patient admits to feeling better compared with how he felt even a week ago.The physician thinks that the patient might have had cytomegalovirus (CMV).Which of the following sets of serologic results would you see in this patient if he is recovering from CMV?

A) CMV IgM pos; CMV IgG neg
B) CMV IgM neg; CMV IgG pos
C) CMV IgM neg; CMV IgG neg
D) CMV IgM neg; CMV IgA pos

Question 16

A patient has a hepatitis B profile performed and is positive for hepatitis B surface antibody only.This patient:

A) was vaccinated against hepatitis B
B) had a previous hepatitis B infection.
C) is a chronic carrier of hepatitis B.
D) has acute hepatitis B.

Question 17

A patient has the following hepatitis profile after presenting with jaundice,nausea,and vomiting: anti-HAV IgM = detected; HBsAg = not detected; anti-HBc IgM = not detected; anti-HBc total = detected; anti-HBs = not detected; anti-HCV = not detected.What is his diagnosis?

A) Acute hepatitis A
B) Acute hepatitis B
C) Acute hepatitis C
D) Chronic hepatitis B

Question 18

A patient has the following hepatitis profile: anti-HAV IgM = not detected; HBsAg = not detected; anti-HBc IgM = not detected; anti-HBc total = not detected; anti-HBs = detected; anti-HCV = not detected.What is his diagnosis?

A) Acute hepatitis A
B) Acute hepatitis B
C) Chronic hepatitis B
D) Immune to hepatitis B

Question 19

In the routine diagnosis of hepatitis C virus,which type of laboratory test should be ordered first?

A) Antigen detection in liver biopsy
B) Antibody detection in blood
C) Viral culture of stool
D) Viral culture of biliary drainage

Question 20

What is the most common routine diagnostic test for rubella virus infection in a young adult?

A) Antigen detection
B) Antibody detection
C) Viral culture
D) Polymerase chain reaction

Question 21

Human T-cell lymphotropic virus type I preferentially infects:

A) B lymphocytes.
B) CD4 T lymphocytes.
C) CD8 T lymphocytes.
D) macrophages.

Question 22

A physician suspects that his patient has infectious mononucleosis.Heterophile antibody tests are negative.Serological testing for Epstein-Barr virus (EBV)was performed,with the following results obtained: EBV VCA IgM = neg; EBV VCA IgG = neg; EBV-EA = neg; EBV-NA = neg.What is this person's status with regard to EBV?

A) Acute EBV
B) Convalescent EBV
C) Never infected with EBV
D) Past exposure to EBV

Question 23

Interferons alpha and beta help the host in defense against viral infections by:

A) enhancing antibody production.
B) stimulating cytotoxic T cells.
C) activating Toll-like receptors.
D) inhibiting viral replication.

Question 24

A patient has the following Epstein-Barr virus (EBV)antibody profile: EB-VCA IgM = neg; EB-VCA IgG = pos; EBV-EA-R IgG = pos; EBV-EBNA IgG = pos.Which of the following is the correct interpretation of these data?

A) Never infected with EBV
B) Acute infection with EBV
C) Recent convalescence from EBV
D) Reactivation of past infection with EBV

Question 25

The most common cause of congenital infections is:

A) cytomegalovirus.
B)rubella.
C) varicella-zoster virus.
D) human T-cell lymphotropic virus type I

Question 26

Which virus is transmitted primarily by aerosolized respiratory droplets?

A) Epstein-Barr virus
B) Hepatitis E
C) Human T-cell lymphotropic virus type I
D) Varicella-zoster virus

Question 27

Viruses can evade host defenses by:

A) maintaining a stable genetic identity.
B) inducing increased expression of MHC class I.
C) inducing increased expression of MHC class II.
D) hiding from the immune system in a latent state.

Question 28

Swollen parotid glands are key diagnostic indicators of:

A) measles.
B) mumps.
C) varicella.
D) rubella.

Question 29

The primary clinical manifestation of a human T-cell lymphotrophic virus (HTLV)-I infection is:

A) increased susceptibility to gram-negative bacterial infections.
B) gastrointestinal inflammation.
C) leukemia or lymphoma.
D) immunosuppression.

Question 30

A positive rubella titer in a healthy,nonpregnant 22-year-old female most likely indicates which of the following?

A) Immunity after administration of the vaccine
B) Current presence of the disease
C) No immunity
D) Possibility of congenital rubella

Question 31

Which test is most specific for infectious mononucleosis?

A) Monospot
B) CBC with differential
C) Anti-EBV titers
D) Paul-Bunnell test

Question 32

A 12-year-old girl presented to her physician with a sore throat,lymphadenopathy,and fatigue.Her laboratory results were 5,000 lymphocytes/microliter with 10% atypical lymphocytes,cytomegalovirus antibody negative,and heterophile antibody screen negative.These laboratory results:

A) confirm a diagnosis of infectious mononucleosis.
B) indicate that the diagnosis is not infectious mononucleosis because the heterophile antibody screen is negative.
C) suggest a diagnosis of infectious mononucleosis but should be followed by a heterophile antibody titer to strengthen the diagnosis.
D) suggest a diagnosis of infectious mononucleosis but should be followed by a test for IgM anti-VCA to strengthen the diagnosis.

Question 33

Infection by which of the following viruses is not preventable by routine immunization?

A) Cytomegalovirus
B) Rubella virus
C) Rubeola virus
D) Varicella-zoster virus

Question 34

A 17-year-old female with suspected mononucleosis tested negative for heterophile antibody using the slide agglutination monotest.Her serum was sent to a reference laboratory,and the following results were obtained: negative for IgM anti-VCA,positive for antibody to EA-D.What do these results suggest?

A) She does not have mononucleosis.
B) She is a healthy carrier of the virus.
C) Mononucleosis has been reactivated.
D) She is in the early stages of the disease.

Question 35

Which types of hepatitis are transmitted primarily through contact with blood or other body fluids?

A) Hepatitis B, C, and D
B) Hepatitis A, B, and C
C) Hepatitis A, C, and E
D) Hepatitis C, D, and E

Question 36

Rubeola virus causes:

A) mumps.
B) shingles.
C) measles.
D) chickenpox.

Question 37

A patient with infectious mononucleosis would have what outstanding feature in the hematology evaluation?

A) Decreased total white blood cells
B) Presence of atypical lymphocytes
C) Increased percentage of eosinophils
D) Absence of neutrophils

Question 38

A newborn infant tests positive for anti-HBc IgG.This result is evidence that:

A) the infant is infected with hepatitis B
B) the mother was infected with hepatitis B.
C) both mother and infant are infected with hepatitis B.
D) Both mother and infant are immune to hepatitis B.