Virology

Question 1

Classification of viruses is made by:

Answer 1

C. Nucleic acid composition

Question 2

Which virus is the most common etiological agent of viral respiratory diseases in infants and children?

Answer 2

A. Respiratory syncytial virus (RSV)

Question 3

The most common viral syndrome of pericarditis, myocarditis, and pleurodynia (pain upon breathing) is caused by:

Answer 3

D. Coxsackie B virus

Question 4

Which of the following viruses is implicated along with Epstein–Barr virus as a cause of infectious mononucleosis?

Answer 4

A. Cytomegalovirus (CMV)

Question 5

The most common causes of viral pneumonia in adults are:

Answer 5

A. Influenza and adenovirus

Question 6

Which virus belonging to the Reoviridae group causes gastroenteritis in infants and young children but an asymptomatic infection in adults?

Answer 6

B. Rotavirus

Question 7

A very small, single-stranded DNA virus that causes a febrile illness with a rash and is called the fifth childhood disease after rubeola, rubella, varicella, and roseola is:

Answer 7

D. Parvovirus B19

Question 8

Hepatitis B virus can be transmitted by:

Answer 8

D. All of these options

Question 9

Which virus has been implicated in adult gastroenteritis resulting from ingestion of contaminated food (especially shellfish) and water?

Answer 9

A. Norwalk-like viruses

Question 10

Which virus is associated with venereal and respiratory tract warts and produces lesions of skin and mucous membranes?

Answer 10

D. Papillomavirus

Question 11

A clinical test used for the detection and identification of viral infections other than culture is:

Answer 11

D. All of these options

Question 12

Which technique is used for the confirmation of infection with human immunodeficiency virus (HIV-1)?

Answer 12

A. Western blot (immunoblot) assay

Question 13

A 13-year-old boy was admitted to the hospital with a diagnosis of viral encephalitis. History revealed that the boy harbored wild raccoons from nearby woods. What is the best method to determine if the boy has contracted rabies?

Answer 13

C. Request immunofluorescent test for antigen in cutaneous nerves obtained by nuchal biopsy of the patient

Question 14

A 65-year-old woman was admitted to the hospital with acute respiratory distress, fever, myalgia, and headache. Influenza A or B was suspected after ruling out bacterial pneumonia. Which of the following methods could be used to confirm influenza infection?

Answer 14

D. All of these options

Question 15

The most rapid definitive diagnosis of a genital herpes simplex (HSV-2) infection in a 20-year-old man is made by which method?

Answer 15

A. Direct immunofluorescence test for viral antigen
in vesicle fluid

Question 16

A 20-year-old female college student complained of a sore throat and extreme fatigue. The physician noted lymphadenopathy and ordered a rapid test for infectious mononucleosis antibodies that was negative. Bacterial cultures were negative, as were serological tests for influenza A and B, HIV-1, CMV, hepatitis B, and antistreptolysin O. What would be the next line of viral testing to establish a diagnosis?

Answer 16

C. Epstein–Barr

Question 17

A 60-year-old male gardener from New York State was hospitalized with flulike symptoms and eventually diagnosed with encephalitis. While working in his garden, he noticed several dead birds around his bird feeder. The region was known to be heavily infested with mosquitoes. What is the most likely cause of his illness?

Answer 17

A. West Nile virus

Question 18

A 30-year-old male patient who was a contractor and building inspector in the southwestern United States complained of difficulty breathing and was admitted to the hospital with severe respiratory disease. The physician noted a high fever and cough. Two days before, the patient had inspected an old warehouse, abandoned and infested with rodents. The patient was given intravenous antibiotics, but 2 days into therapy the pneumonia worsened and he developed pulmonary edema. Which organism should be suspected of causing his illness?

Answer 18

A. Hantavirus

Question 19

A 3-year-old female was admitted to the hospital following a 2-day visit with relatives over the Christmas holidays. Vomiting and diarrhea left the child severely dehydrated. No other members of the family were affected. All bacterial cultures proved negative. A stool sample should be tested for which virus?

Answer 19

D. Rotavirus

Question 20

A 25-year-old male patient was diagnosed with HIV-1 by enzyme immunoassay, testing positive twice, and the diagnosis was confirmed by Western blot testing. Which laboratory test should be performed prior to initiating antiviral therapy?

Answer 20

D. All of these options

Question 21

A 6-month-old male infant was hospitalized with a respiratory infection. He was diagnosed with apnea and bronchiolitis. Further testing revealed congenital heart disease. Bacterial cultures were negative for Streptococcus pneumoniae and Haemophilus influenzae. What further testing should be done?

Answer 21

A. Respiratory syncytial virus (RSV)

Question 22

A young male hunter encountered a fox in his path during a walk in the woods. The fox was staggering but appeared nonthreatening. The man tried to avoid contact but was attacked and bitten on the leg. The bite broke the skin but was not deep. Wildlife officials were unable to locate the fox for testing. What procedure should take place next for the hunter?

Answer 22

B. Administration of hyperimmune antirabies
globulin and rabies vaccine

Question 23

A 40-year-old female experienced a respiratory infection after returning home from a visit to her homeland of China. A rapid onset of pneumonia in the lower respiratory area prompted the physician to place her in isolation. She was diagnosed presumptively with severe acute respiratory syndrome (SARS) and placed on a respirator. What type of testing should be done next to diagnose this disease?

Answer 23

A. Molecular technique and cell culture

Question 24

A pregnant 25-year-old female with genital
lesions delivered a premature newborn with complications. The baby tested negative for bacterial infection (cultures of blood and urine). Antigen testing of the baby’s urine proved negative for group B streptococci and Streptococcus pneumoniae. The mother tested negative for bacterial sexually transmitted diseases and for group B streptococci. The baby was treated with acyclovir and failed to survive. What was the most likely cause of death?

Answer 24

D. Herpes simplex virus

Question 25

A young father of two small children complained of a rash on the torso of his body. The children had been diagnosed with chickenpox and confined to their home. The father had experienced chickenpox as a child and knew he did not have the same rash as his children. What is the most likely cause of the father’s rash?

Answer 25

B. Varicella-zoster virus

Question 26

The organs of a 65-year-old male were donated soon after a fatal auto accident. Three recipients of his corneas and kidneys died within weeks after receiving his organs. Which of the following viruses most likely caused the death of these recipients?

Answer 26

B. Rabies

Question 27

While on a 7-day cruise to Vancouver and Alaska, a number of passengers reported to the ship’s medical staff complaining of vomiting and diarrhea. Which is the most likely virus to have infected these mainly adult passengers?

Answer 27

D. Norwalk or Norwalk-like viruses

Question 28

SITUATION: A patient tested positive for HIV-1 infection using a reverse transcriptase-polymerase chain reaction (RT-PCR) method. However,
1 week later a second blood sample was collected and sent to a reference lab that performed a confirmatory test by Western blot. The Western blot test was negative. What best explains these results?

Answer 28

B. RT-PCR is more sensitive for early detection

Question 29

. SITUATION: A pregnant women was seen by
her obstetrician with signs of flulike illness during her second trimester. NAT tests were ordered for Toxoplasma gondii, rubella, cytomegalovirus,
and herpes simplex 1 and 2. All test results were negative. However, after delivery, the newborn exhibited signs of an infection and failed to survive. Which virus causes a 90% transplacental infection rate when found in the mother?

Answer 29

B. Hepatitis B

Question 30

An immunocompromised patient was admitted
to the hospital with a diagnosis of hemorrhagic cystitis. Which combination of virus and specimen would be most appropriate to diagnose a viral cause of this disorder?

Answer 30

A. BK virus—urine