SM SM Virology & Molecular Diagnostics 2

Question 1

Which molecular method is used to detect and quantify HIV viral load in clinical practice?

Accepted Answer

Real-time quantitative RT-PCR (qRT-PCR)

Answer

Real-time qRT-PCR quantifies HIV RNA copies/mL in plasma, guiding treatment decisions and monitoring antiretroviral therapy effectiveness.

Question 2

Herpes simplex virus (HSV) DNA PCR of cerebrospinal fluid is considered the gold standard for diagnosing:

Accepted Answer

HSV encephalitis

Answer

CSF HSV PCR has >95% sensitivity and specificity for HSV encephalitis, replacing brain biopsy as the standard diagnostic approach.

Question 3

Which enzyme is the target of nucleoside reverse transcriptase inhibitors (NRTIs) used in HIV therapy?

Accepted Answer

Reverse transcriptase

Answer

NRTIs are nucleoside analogs that competitively inhibit HIV reverse transcriptase, terminating DNA chain elongation during reverse transcription of viral RNA.

Question 4

Cytomegalovirus (CMV) disease in immunocompromised transplant patients is monitored using which laboratory approach?

Accepted Answer

CMV pp65 antigenemia or quantitative PCR from blood

Answer

CMV pp65 antigenemia assay and quantitative PCR are the standard methods for monitoring CMV viremia in transplant patients to guide preemptive antiviral therapy.

Question 5

Which feature distinguishes a virus's tropism for specific cell types?

Accepted Answer

Interaction between viral surface proteins and specific host cell receptors

Answer

Viral tropism is determined by the compatibility between viral attachment proteins (e.g., glycoproteins, spikes) and specific host cell surface receptors required for entry.

(SM) Specialist in Microbiology Practice Test

(SM) Specialist in Microbiology Practice Test

SM SM Virology & Molecular Diagnostics 2