SM SM Virology & Molecular Diagnostics

Question 1

Which nucleic acid amplification test characteristic is most important when evaluating a new molecular diagnostic assay for clinical use?

Accepted Answer

Analytical sensitivity expressed as limit of detection (LoD)

Answer

Turnaround time for results

Answer

Cost per test compared to culture methods

Answer

Instrument footprint for laboratory space planning

Question 2

SARS-CoV-2 RT-PCR testing uses reverse transcription because the viral genome is:

Accepted Answer

Single-stranded RNA that must be converted to cDNA before PCR amplification

Answer

Double-stranded DNA that requires denaturation before amplification

Answer

Segmented negative-sense RNA requiring special primers

Answer

Circular RNA requiring rolling circle amplification

Question 3

Which viral replication strategy is used by HIV to integrate into the host genome?

Accepted Answer

Reverse transcription of RNA to DNA, followed by integration via integrase

Answer

Lytic replication using host RNA polymerase directly

Answer

Rolling circle replication producing progeny genome copies

Answer

Direct genome injection without replication intermediate

Question 4

In a multiplex PCR respiratory panel, a specimen tests positive for both influenza A and rhinovirus. What is the most appropriate interpretation?

Accepted Answer

Report both pathogens — co-infection is possible and clinically significant

Answer

Repeat testing as co-infections are not clinically possible

Answer

Report only influenza A as the dominant pathogen

Answer

Request culture confirmation before reporting either result

Question 5

Which hepatitis virus is transmitted exclusively via the fecal-oral route and does NOT cause chronic infection?

Accepted Answer

Hepatitis A virus (HAV)

Answer

Hepatitis B virus (HBV)

Answer

Hepatitis C virus (HCV)

Answer

Hepatitis D virus (HDV)

Question 6

The Baltimore classification system groups viruses primarily based on:

Accepted Answer

Genome type and strategy for mRNA production

Answer

Capsid symmetry (icosahedral vs. helical)

Answer

Presence or absence of a lipid envelope

Answer

Host range (animal, plant, or bacterial viruses)