Question 1

Which assay is the current recommended method of detection in most laboratories for influenza A and B viruses?
A)Conventional cell culture
B)Enzyme immunoassays
C)Reverse transcriptase polymerase chain reaction (RT-PCR)
D)Shell vial culture

Accepted Answer

Influenza A and B viruses can be detected by using conventional cell culture,shell vial culture,membrane enzyme immunoassay (EIA),direct staining of respiratory tract secretions using fluorescent-antibody (FA)methods ,and RT-PCR.RT-PCR is the current recommended method of detection in most laboratories.

Question 2

A 2-year-old girl is suspected of having a rotavirus infection.The specimen of choice to collect to identify the agent is:
A)stool.
B)blood.
C)urine.
D)throat.

Accepted Answer

Stool and rectal swabs of fecal specimens are used to detect rotavirus,enteric adenoviruses (serotypes 40 and 41),and enteroviruses.

Question 3

The most used EIA for antigen detection that uses a solid phase and membrane is used for detecting which virus?
A)Influenza
B)Adenovirus
C)HSV
D)Respiratory syncytial virus (RSV)

Accepted Answer

The most used EIA for antigen detection are those for RSV (solid phase and membrane),rotavirus (solid phase and membrane),and influenza viruses (membrane).

Question 4

To detect immunoglobulin M (IgM)antibodies in an acute phase,blood should be collected in _____ days after the onset of infection.
A)2 to 5
B)5 to 7
C)7 to 14
D)longer than 21

Accepted Answer

To help diagnose active disease,two approaches are helpful.The detection of virus-specific IgM in an acute-phase specimen collected at least 7 to 14 days after the onset of infection indicates current or very recent disease.The detection of a fourfold (or equivalent increase if twofold dilutions are not tested)antibody titer rise between acute and convalescent sera also indicates current or recent disease.

Question 5

If a virus is referred to as naked,it means it lacks which structure?
A)Protein coat
B)Capsid
C)Envelope
D)Nucleocapsid

Accepted Answer

Viruses that do not have an envelope are often referred to as naked.Naked viruses are resistant to environmental factors.As a result of their stability,they are typically transmitted via the fecal-oral route.

Question 6

Match the virus with the specimen in which it is most commonly isolated.
-Nasopharyngeal
A)Varicella-zoster virus
B)Enterovirus
C)Human papillomavirus (HPV)
D)Parainfluenza virus
E)CMV

Accepted Answer

Parainfluenza virus is most commonly isolated from nasopharyngeal specimens, as it primarily causes respiratory infections.

Question 7

Match the virus with the specimen in which it is most commonly isolated.
-Stool
A)Varicella-zoster virus
B)Enterovirus
C)Human papillomavirus (HPV)
D)Parainfluenza virus
E)CMV

Accepted Answer

Enterovirus is most commonly isolated from stool specimens.

Answer: A
 Varicella-zoster virus is not typically isolated from stool specimens. It is most commonly isolated from respiratory secretions or skin lesions.

Answer: C
 Human papillomavirus (HPV) is not typically isolated from stool specimens. It is most commonly detected through vaginal or cervical swabs.

Answer: D
 Parainfluenza virus is not typically isolated from stool specimens. It is most commonly isolated from respiratory secretions.

Answer: E
 CMV (Cytomegalovirus) is not typically isolated from stool specimens. It is most commonly isolated from urine or blood specimens.

Question 8

Match the virus with the specimen in which it is most commonly isolated.
-Genital
A)Varicella-zoster virus
B)Enterovirus
C)Human papillomavirus (HPV)
D)Parainfluenza virus
E)CMV

Accepted Answer

Human papillomavirus (HPV) is most commonly isolated in genital specimens.

Other options:
A) Varicella-zoster virus is commonly isolated in skin lesions or respiratory secretions for diagnosis of chickenpox or shingles.
B) Enterovirus is commonly isolated in respiratory secretions, CSF or stool for diagnosis of enterovirus infections.
D) Parainfluenza virus is commonly isolated in respiratory secretions for diagnosis of upper respiratory infections.
E) CMV is commonly isolated in blood, urine or other body fluids for diagnosis of CMV infections.

Question 9

If Negri bodies are identified in brain tissue through cytologic means,then the virus is identified as a(n):
A)adenovirus.
B)parvovirus.
C)rabies virus.
D)varicella virus.

Accepted Answer

Less commonly,inclusions characteristic of measles and rabies viruses are detected by examining stained tissues .Rabies virus inclusions in brain tissue are called Negri bodies.Cytologic and histologic identification and analysis are less sensitive than culture but are especially helpful for those viruses that are difficult or dangerous to isolate in the laboratory,such as the parvovirus and rabies virus,respectively.

Question 10

Some viruses have the ability to stimulate uncontrolled growth of the host cells,resulting in cancer.Which virus has oncogenic properties?
A)Measles
B)Papilloma
C)Retroviruses
D)Influenza

Accepted Answer

Viruses with the ability to stimulate uncontrolled growth of host cells are referred to as oncogenic viruses.Some papillomaviruses (e.g. ,wart viruses)are oncogenic,giving rise to human cervical cancer.

Question 11

The function of the glycoprotein spike on some viruses is to:
A)allow viral entry into the host cell.
B)protect the nucleic acid.
C)prevent drying out and the destruction of the virus.
D)stabilize attachment for the lipid envelope.

Accepted Answer

The glycoprotein spikes assist in the stabilization of attachment for the lipid envelope,as well as attachment to the host cell to facilitate viral entry.

Question 12

Match the virus with the specimen in which it is most commonly isolated.
-Skin and mucous membranes
A)Varicella-zoster virus
B)Enterovirus
C)Human papillomavirus (HPV)
D)Parainfluenza virus
E)CMV

Accepted Answer

Varicella-zoster virus is most commonly isolated from skin and mucous membranes, causing chickenpox and shingles.

Answer: B
 Enteroviruses, such as coxsackievirus and echovirus, can be isolated from skin and mucous membranes, as well as feces and respiratory secretions.

Answer: C
 Human papillomavirus (HPV) is typically isolated from genital specimens, such as cervical swabs, due to its association with cervical cancer and genital warts.

Answer: D
 Parainfluenza virus is primarily isolated from respiratory specimens, such as nasopharyngeal swabs and tracheal aspirates.

Answer: E
 CMV (Cytomegalovirus) can be isolated from a variety of specimens, including urine, blood, and respiratory secretions, but is most commonly associated with congenital infections and immunocompromised individuals.

Question 13

Which type of swab is not suitable for the collection of a viral specimen as a result of its ability to interfere with certain tests?
A)Dacron
B)Calcium alginate
C)Cotton
D)Rayon

Accepted Answer

Swab specimens should not contain chemicals or other compounds that may be toxic to cultured cells and are therefore unsuitable for viral specimen collection.Calcium-alginate swabs interfere with polymerase chain reaction (PCR),the recovery of some enveloped viruses,and fluorescent-antibody tests;therefore they should not be used.

Question 14

The enzyme-linked virus-inducible system (ELVIS)uses a cloned β-galactosidase gene that is expressed only when cells are infected with what virus?
A)RSV
B)Human immunodeficiency virus (HIV)
C)HSV
D)Cytomegalovirus (CMA)

Accepted Answer

The ELVIS uses a baby hamster kidney (BHK)cell culture system with a cloned (added) β-galactosidase gene that is expressed only when cells are infected with an HSV.

Question 15

Amie's,Leibovitz-Emory,and Stuart's are all types of:
A)cell lines.
B)cell culture media.
C)automated systems.
D)transport media.

Accepted Answer

Examples of successful transport media include Stuart's medium,Amie's medium,Leibovitz-Emory medium,Hanks' balanced salt solution (HBSS),Eagle's tissue culture medium,and the commercially available M4 transport media.Respiratory and stool specimens can be maintained in modified Stuart's,modified HBSS,or Leibovitz-Emory medium containing antimicrobials.

Question 16

Match the virus with the specimen in which it is most commonly isolated.
-Urine
A)Varicella-zoster virus
B)Enterovirus
C)Human papillomavirus (HPV)
D)Parainfluenza virus
E)CMV

Accepted Answer

CMV (Cytomegalovirus) is most commonly isolated from urine, especially in congenital infections and in immunocompromised patients.

Question 17

The cytomegalovirus (CMV)produces cytopathic effects (CPE)in diploid fibroblast cells in an average of 7 days.The results are available within 16 hours using which type of assay?
A)Conventional cell culture
B)Shell vial
C)Paired sera
D)Western blot

Accepted Answer

CMV can be detected in clinical specimens using conventional cell culture,shell vial assay,antigenemia immunoassay,or molecular methods.CMV produces CPE in diploid fibroblast cells in 3 to 28 days,averaging 7 days.CMV shell vial assay sensitivity is equivalent to conventional cell culture,and the results are available within 16 hours.

Question 18

Match the virus with its corresponding property.
-pp65 protein
A)RSV
B)HIV
C)CMV
D)Adenovirus
E)HSV
F)Pediatric respiratory virus
G)Hepatitis B virus (HBV)
H)Influenzas A and B

Accepted Answer

The pp65 protein is a major viral protein of CMV and is often used as a diagnostic marker for CMV infection.

Answer: A
 RSV does not have a specific property associated with the pp65 protein.

Answer: B
 HIV does not have a specific property associated with the pp65 protein.

Answer: D
 Adenovirus does not have a specific property associated with the pp65 protein.

Answer: E
 HSV does not have a specific property associated with the pp65 protein.

Answer: F
 Pediatric respiratory viruses do not have a specific property associated with the pp65 protein.

Answer: G
 Hepatitis B virus (HBV) does not have a specific property associated with the pp65 protein.

Answer: H
 Influenzas A and B do not have a specific property associated with the pp65 protein.

Question 19

The specimen of choice to collect in suspected cases of respiratory syncytial virus (RSV)is:
A)buccal mucosa.
B)sputum.
C)throat.
D)nasopharyngeal.

Accepted Answer

Nasopharyngeal aspirates are superior,in general,to throat or nasopharyngeal swabs for recovering viruses;however,swabs are considerably more convenient.Throat swabs are acceptable for the recovery of enteroviruses,adenoviruses,and human simplex virus (HSV),whereas nasopharyngeal swab or aspirate specimens are preferred for the detection of RSV,influenza,and parainfluenza viruses.

Question 20

The appropriate temperature in which to store specimens for viral isolation is ____°C.
A)4
B)25
C)30
D)37

Accepted Answer

Specimens for viral isolation should not be allowed to sit at room or higher temperature.Specimens should be kept cool (4°C)and immediately transported to the laboratory.If a delay in transport is unavoidable,the specimen should be refrigerated,not frozen,until processing occurs.Every attempt should be made to process the specimen within 12 to 24 hours of collection.Under unusual circumstances,specimens may need to be held for several days before processing.For storage up to 5 days,hold the specimen at 4°C.Storage for 6 or more days should be at -20°C or preferably at -70°C.

Quiz 63: Overview of the Methods and Strategies in Virology

Which assay is the current recommended method of detection in most laboratories for influenza A and B viruses?

A 2-year-old girl is suspected of having a rotavirus infection.The specimen of choice to collect to identify the agent is:

The most used EIA for antigen detection that uses a solid phase and membrane is used for detecting which virus?

To detect immunoglobulin M (IgM) antibodies in an acute phase,blood should be collected in _____ days after the onset of infection.

If a virus is referred to as naked,it means it lacks which structure?

Match the virus with the specimen in which it is most commonly isolated. -Nasopharyngeal

Match the virus with the specimen in which it is most commonly isolated. -Stool

Match the virus with the specimen in which it is most commonly isolated. -Genital

If Negri bodies are identified in brain tissue through cytologic means,then the virus is identified as a(n) :

Some viruses have the ability to stimulate uncontrolled growth of the host cells,resulting in cancer.Which virus has oncogenic properties?

The function of the glycoprotein spike on some viruses is to:

Match the virus with the specimen in which it is most commonly isolated. -Skin and mucous membranes

Which type of swab is not suitable for the collection of a viral specimen as a result of its ability to interfere with certain tests?

The enzyme-linked virus-inducible system (ELVIS) uses a cloned β-galactosidase gene that is expressed only when cells are infected with what virus?

Amie's,Leibovitz-Emory,and Stuart's are all types of:

Match the virus with the specimen in which it is most commonly isolated. -Urine

The cytomegalovirus (CMV) produces cytopathic effects (CPE) in diploid fibroblast cells in an average of 7 days.The results are available within 16 hours using which type of assay?

Match the virus with its corresponding property. -pp65 protein

The specimen of choice to collect in suspected cases of respiratory syncytial virus (RSV) is:

The appropriate temperature in which to store specimens for viral isolation is ____°C.