SM Virology & Molecular Diagnostics Flashcards

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

Answer: Analytical sensitivity expressed as limit of detection (LoD)

The limit of detection (LoD) determines the lowest pathogen concentration the assay can reliably detect, directly impacting clinical sensitivity and diagnostic accuracy.

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

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

SARS-CoV-2 is a positive-sense single-stranded RNA virus; reverse transcriptase converts genomic RNA into complementary DNA (cDNA) for subsequent PCR amplification.

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

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

HIV reverse transcriptase converts the RNA genome to double-stranded DNA, which integrase then incorporates into host chromosomal DNA, establishing a provirus.

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

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

Multiplex PCR can detect simultaneous co-infections; reporting both results is appropriate as co-infections occur and affect clinical management decisions.

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

Answer: Hepatitis A virus (HAV)

HAV is a non-enveloped positive-sense RNA virus transmitted fecal-orally that causes self-limiting acute hepatitis without progression to chronic disease.

The Baltimore classification system groups viruses primarily based on:

Answer: Genome type and strategy for mRNA production

The Baltimore classification groups viruses into 7 classes based on their genome nucleic acid type and the pathway used to produce mRNA for protein synthesis.