HCV (Hepatitis C Virus) Exam Study Guide 2025/2026
Disclaimer: This guide is for educational purposes and reflects current standards of
care. Always follow the latest clinical guidelines and consult with a supervising physician
for patient-specific decisions.
Section 1: Virology and Pathogenesis
1. What is the genetic makeup of the Hepatitis C virus?
ANSWER ✓ The Hepatitis C virus is a single-stranded, positive-sense RNA virus.
2. Which family of viruses does HCV belong to?
ANSWER ✓ HCV belongs to the Flaviviridae family.
3. What is the primary reason HCV infection often becomes chronic?
ANSWER ✓ The high genetic variability of the HCV genome, particularly in the E1 and
E2 envelope regions, allows it to rapidly mutate and evade the host's adaptive immune
response.
4. What are the major genotypes of HCV, and which is most common in the United
States?
ANSWER ✓ The major genotypes are 1 through 6. Genotype 1 is the most common in
the United States.
5. Why is genotyping crucial in the management of HCV?
ANSWER ✓ While less critical with modern pangenotypic regimens, genotyping was
historically essential for selecting the correct antiviral therapy and determining
treatment duration.
6. What is the primary cell type that HCV infects in the liver?
ANSWER ✓ HCV primarily infects hepatocytes, the main parenchymal cells of the liver.
, 7. How is HCV primarily transmitted?
ANSWER ✓ HCV is primarily transmitted through percutaneous exposure to infected
blood.
8. What are the six major genotypes of HCV, and what is their global distribution
significance?
ANSWER ✓ Genotypes 1-6 have distinct geographical distributions, which can influence
the choice of pangenotypic therapy and help in understanding epidemiological patterns.
9. Define the "quasispecies" nature of HCV and its clinical implication.
ANSWER ✓ Within a single infected individual, HCV exists as a mixture of closely related
but genetically distinct variants known as quasispecies. This diversity is a major
mechanism for escaping host immune control and can lead to treatment failure with
older, less robust regimens.
10. What viral proteins are the primary targets for Direct-Acting Antivirals (DAAs)?
ANSWER ✓ The key non-structural (NS) proteins targeted by DAAs are NS3/4A
protease, NS5A, and NS5B polymerase.
Section 2: Epidemiology and Transmission
11. What is the most common risk factor for HCV acquisition historically?
ANSWER ✓ Injection drug use, specifically the sharing of needles and other drug
paraphernalia, is the most common risk factor.
12. Can HCV be transmitted sexually?
ANSWER ✓ Yes, but the risk is considered low, especially in heterosexual couples. The
risk is higher among men who have sex with men (MSM), particularly those with HIV co-
infection or who engage in traumatic sexual practices.
13. What is the risk of HCV transmission from a needlestick injury?
ANSWER ✓ The average risk is approximately 0.1% to 0.3% per needlestick injury from
an HCV-positive source.
14. Is mother-to-child (vertical) transmission of HCV common?
Disclaimer: This guide is for educational purposes and reflects current standards of
care. Always follow the latest clinical guidelines and consult with a supervising physician
for patient-specific decisions.
Section 1: Virology and Pathogenesis
1. What is the genetic makeup of the Hepatitis C virus?
ANSWER ✓ The Hepatitis C virus is a single-stranded, positive-sense RNA virus.
2. Which family of viruses does HCV belong to?
ANSWER ✓ HCV belongs to the Flaviviridae family.
3. What is the primary reason HCV infection often becomes chronic?
ANSWER ✓ The high genetic variability of the HCV genome, particularly in the E1 and
E2 envelope regions, allows it to rapidly mutate and evade the host's adaptive immune
response.
4. What are the major genotypes of HCV, and which is most common in the United
States?
ANSWER ✓ The major genotypes are 1 through 6. Genotype 1 is the most common in
the United States.
5. Why is genotyping crucial in the management of HCV?
ANSWER ✓ While less critical with modern pangenotypic regimens, genotyping was
historically essential for selecting the correct antiviral therapy and determining
treatment duration.
6. What is the primary cell type that HCV infects in the liver?
ANSWER ✓ HCV primarily infects hepatocytes, the main parenchymal cells of the liver.
, 7. How is HCV primarily transmitted?
ANSWER ✓ HCV is primarily transmitted through percutaneous exposure to infected
blood.
8. What are the six major genotypes of HCV, and what is their global distribution
significance?
ANSWER ✓ Genotypes 1-6 have distinct geographical distributions, which can influence
the choice of pangenotypic therapy and help in understanding epidemiological patterns.
9. Define the "quasispecies" nature of HCV and its clinical implication.
ANSWER ✓ Within a single infected individual, HCV exists as a mixture of closely related
but genetically distinct variants known as quasispecies. This diversity is a major
mechanism for escaping host immune control and can lead to treatment failure with
older, less robust regimens.
10. What viral proteins are the primary targets for Direct-Acting Antivirals (DAAs)?
ANSWER ✓ The key non-structural (NS) proteins targeted by DAAs are NS3/4A
protease, NS5A, and NS5B polymerase.
Section 2: Epidemiology and Transmission
11. What is the most common risk factor for HCV acquisition historically?
ANSWER ✓ Injection drug use, specifically the sharing of needles and other drug
paraphernalia, is the most common risk factor.
12. Can HCV be transmitted sexually?
ANSWER ✓ Yes, but the risk is considered low, especially in heterosexual couples. The
risk is higher among men who have sex with men (MSM), particularly those with HIV co-
infection or who engage in traumatic sexual practices.
13. What is the risk of HCV transmission from a needlestick injury?
ANSWER ✓ The average risk is approximately 0.1% to 0.3% per needlestick injury from
an HCV-positive source.
14. Is mother-to-child (vertical) transmission of HCV common?
