HBV treatment indications and options US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for HBV treatment indications and options. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
HBV treatment indications and options US Medical PG Question 1: A 29-year-old man comes to the physician for a routine health maintenance examination. He feels well. He works as a nurse at a local hospital in the city. Three days ago, he had a needlestick injury from a patient whose serology is positive for hepatitis B. He completed the 3-dose regimen of the hepatitis B vaccine 2 years ago. His other immunizations are up-to-date. He appears healthy. Physical examination shows no abnormalities. He is concerned about his risk of being infected with hepatitis B following his needlestick injury. Serum studies show negative results for hepatitis B surface antigen, hepatitis B surface antibody, and hepatitis C antibody. Which of the following is the most appropriate next step in management?
- A. Revaccinate with 3-dose regimen of hepatitis B vaccine
- B. Revaccinate with two doses of hepatitis B vaccine
- C. Administer hepatitis B immunoglobulin
- D. Administer hepatitis B immunoglobulin and 3-dose regimen of hepatitis B vaccine (Correct Answer)
- E. Administer hepatitis B immunoglobulin and single dose hepatitis B vaccine
HBV treatment indications and options Explanation: ***Administer hepatitis B immunoglobulin and 3-dose regimen of hepatitis B vaccine***
- This patient had prior vaccination but current serology shows **negative HBsAb**, indicating **non-response** to the vaccine (failure to develop protective antibodies).
- Given exposure to a hepatitis B positive patient, immediate post-exposure prophylaxis with **HBIG** is crucial for passive immunity and immediate protection.
- A **complete 3-dose revaccination series** should be initiated simultaneously, as per **CDC/ACIP guidelines** for vaccine non-responders with occupational exposure [1].
- This provides both immediate passive protection (HBIG) and attempts to establish active immunity through revaccination [1].
*Revaccinate with 3-dose regimen of hepatitis B vaccine*
- While revaccination is necessary due to the non-response, starting a 3-dose regimen alone without **HBIG** would leave the patient vulnerable during the initial period before vaccine response develops.
- After high-risk exposure in a non-responder, both passive (HBIG) and active (vaccine) immunity are required.
*Revaccinate with two doses of hepatitis B vaccine*
- A 2-dose regimen is insufficient; the standard revaccination schedule for non-responders is **3 doses** at 0, 1, and 6 months [1].
- Additionally, this option lacks **HBIG** for immediate protection after the high-risk exposure.
*Administer hepatitis B immunoglobulin*
- **HBIG** alone provides immediate passive immunity, which is crucial given the recent exposure and the patient's non-immune status.
- However, offering only HBIG without initiating active immunization (vaccine series) would leave the patient unprotected once the passive immunity wanes (approximately 3-6 months).
- This approach fails to address the need for long-term protection through revaccination.
*Administer hepatitis B immunoglobulin and single dose hepatitis B vaccine*
- While HBIG is appropriate for immediate protection, giving only a **single dose** of vaccine is inadequate.
- Standard post-exposure management for vaccine non-responders requires initiating a **complete 3-dose revaccination series**, not just one dose [1].
- A single dose would not provide adequate long-term protection for this non-responder.
HBV treatment indications and options US Medical PG Question 2: A 30-year-old man presents to clinic. He was born in southeast Asia and immigrated to the US three years ago. He has a history of chronic hepatitis C which he contracted from intravenous drug use. He reports that he has been receiving treatment for his hepatitis C, but unfortunately has started using heroin again. The patient was seen in the clinic last week and had blood work done. His results are as follows:
HBsAg - negative;
HBsAb - negative;
HBcAb - negative.
In addition to encouraging the patient to seek treatment for his heroin addiction, what else should be done at this health visit for general health maintenance?
- A. Vaccinate the patient for Hepatitis B (Correct Answer)
- B. Write a prescription for a colonoscopy
- C. Obtain a PSA
- D. Draw blood for an HIV western blot
- E. Write a prescription for a fecal occult blood test
HBV treatment indications and options Explanation: ***Vaccinate the patient for Hepatitis B***
- The patient's serology (HBsAg negative, HBsAb negative, HBcAb negative) indicates he is **not immune to Hepatitis B virus** and is susceptible to infection.
- Given his history of **intravenous drug use**, he is at high risk for acquiring Hepatitis B, making vaccination a crucial preventive measure.
*Write a prescription for a colonoscopy*
- **Screening colonoscopies** are generally recommended starting at age 45 for individuals at average risk, or earlier if there's a family history or specific symptoms.
- This patient is only 30 years old and has no mentioned risk factors or symptoms that would warrant an immediate colonoscopy.
*Obtain a PSA*
- **Prostate-specific antigen (PSA) screening** for prostate cancer is typically recommended for men starting at age 50-55, depending on individual risk factors and shared decision-making.
- A 30-year-old man is **far too young** for routine PSA screening.
*Draw blood for an HIV western blot*
- While the patient's history of **intravenous drug use** puts him at high risk for HIV and screening is appropriate, the **Western blot** is a confirmatory test, not a primary screening test.
- Initial and routine HIV screening should be performed with a **fourth-generation HIV-1/2 antigen/antibody immunoassay**, followed by confirmatory tests if positive.
*Write a prescription for a fecal occult blood test*
- **Fecal occult blood tests (FOBT)** are a screening method for colorectal cancer, usually recommended for individuals starting at age 45 or 50.
- This 30-year-old patient is not in the appropriate age range for routine colorectal cancer screening using FOBT.
HBV treatment indications and options US Medical PG Question 3: A 59-year-old woman comes to the physician for a routine health maintenance examination. She feels well. She has systemic lupus erythematosus and hypertension. She does not drink alcohol. Her current medications include lisinopril and hydroxychloroquine. She appears malnourished. Her vital signs are within normal limits. Examination shows a soft, nontender abdomen. There is no ascites or hepatosplenomegaly. Serum studies show:
Total bilirubin 1.2 mg/dL
Alkaline phosphatase 60 U/L
Alanine aminotransferase 456 U/L
Aspartate aminotransferase 145 U/L
Hepatitis A IgM antibody negative
Hepatitis A IgG antibody positive
Hepatitis B surface antigen positive
Hepatitis B surface antibody negative
Hepatitis B envelope antigen positive
Hepatitis B envelope antibody negative
Hepatitis B core antigen IgM antibody negative
Hepatitis B core antigen IgG antibody positive
Hepatitis C antibody negative
Which of the following is the most appropriate treatment for this patient?
- A. Pegylated interferon alpha therapy
- B. Tenofovir therapy (Correct Answer)
- C. Referral to a liver transplantation center
- D. Reassurance and follow-up
- E. Lamivudine therapy
HBV treatment indications and options Explanation: ***Tenofovir therapy***
- This patient has **chronic hepatitis B** with evidence of **active viral replication** (positive HBsAg, HBeAg, and elevated liver enzymes), indicating a need for antiviral treatment.
- **Tenofovir** is a highly effective and well-tolerated oral antiviral agent for chronic hepatitis B, suitable for initial therapy.
*Pegylated interferon alpha therapy*
- While an option for chronic hepatitis B, **pegylated interferon alpha** has more significant side effects and is generally avoided in patients with **systemic lupus erythematosus (SLE)** due to the risk of exacerbating the autoimmune condition.
- It also requires subcutaneous injections and has a lower rate of HBeAg seroconversion compared to nucleos(t)ide analogs in many patient populations.
*Referral to a liver transplantation center*
- This patient currently shows **elevated liver enzymes** but no immediate signs of **decompensated liver disease** (e.g., ascites, encephalopathy, variceal bleeding) or severe liver failure that would warrant urgent transplantation.
- Treatment with antiviral medication is the first step to prevent progression to end-stage liver disease.
*Reassurance and follow-up*
- The patient has **elevated transaminases** and markers of **active viral replication** (positive HBeAg), indicating ongoing liver injury and potential progression to cirrhosis.
- Simply observing the patient without treatment would be inappropriate and could lead to irreversible liver damage.
*Lamivudine therapy*
- **Lamivudine** is an older nucleos(t)ide analog for hepatitis B that has a significantly **higher rate of drug resistance** compared to newer agents like tenofovir.
- It is generally not recommended as a first-line treatment due to its resistance profile.
HBV treatment indications and options US Medical PG Question 4: A 32-year-old woman comes to the physician because of a 3-month history of fatigue and myalgia. Over the past month, she has had intermittent episodes of nausea. She has a history of intravenous drug use, but she has not used illicit drugs for the past five years. She has smoked one pack of cigarettes daily for 14 years and drinks one alcoholic beverage daily. She takes no medications. Her last visit to a physician was 4 years ago. Her temperature is 37°C (98.6°F), pulse is 90/min, respirations are 20/min, and blood pressure is 110/70 mm Hg. Physical examination shows jaundice and hepatosplenomegaly. There are also blisters and erosions on the dorsum of both hands. The remainder of the examination shows no abnormalities. Laboratory studies show:
Hemoglobin 12 g/dL
Leukocyte count 8,300/mm3
Platelet count 250,000/mm3
Serum
Glucose 170 mg/dL
Albumin 3.0 g/dL
Total bilirubin 2.2 mg/dL
Alkaline phosphatase 80 U/L
AST 92 U/L
ALT 76 U/L
Hepatitis B surface antigen negative
Hepatitis B surface antibody positive
Hepatitis B core antibody positive
Hepatitis C antibody positive
Which of the following is the most appropriate next step in diagnosis?
- A. PCR for viral DNA
- B. Western blot for HIV
- C. Serology for anti-HAV IgM
- D. PCR for viral RNA (Correct Answer)
- E. Liver biopsy
HBV treatment indications and options Explanation: ***Correct: PCR for viral RNA***
- The patient has high suspicion for **chronic hepatitis C infection** due to a history of intravenous drug use, the presence of **fatigue**, **myalgia**, **jaundice**, hepatosplenomegaly, and **elevated liver enzymes (AST and ALT)**
- The **blisters and erosions on the dorsum of both hands** are highly suggestive of **porphyria cutanea tarda (PCT)**, a well-established complication of chronic hepatitis C caused by hepatic uroporphyrinogen decarboxylase deficiency
- The positive **Hepatitis C antibody** indicates exposure to HCV, but does not distinguish between acute, chronic, or resolved infection
- **PCR for viral RNA (HCV RNA)** is required to confirm **active viral replication** and diagnose current hepatitis C infection, which is crucial for treatment decisions
- The elevated glucose (170 mg/dL) may also represent hepatogenous diabetes related to chronic liver disease
*Incorrect: PCR for viral DNA*
- This test is primarily used for diagnosing active infections caused by **DNA viruses**, such as **hepatitis B** (HBV DNA) or cytomegalovirus
- The patient's hepatitis B serology indicates **past infection with immunity** (HBsAg negative, HBsAb positive, HBcAb positive), so HBV DNA testing is not indicated
- The clinical picture points toward HCV (an RNA virus), not a DNA virus
*Incorrect: Western blot for HIV*
- While the patient has a history of intravenous drug use (a risk factor for HIV), initial HIV screening is done with a **fourth-generation antigen/antibody combination assay**, not Western blot
- **Western blot** is a confirmatory test used only when initial HIV screening tests are reactive
- HIV testing may be appropriate given her risk factors, but it does not address the most pressing concern of active hepatitis C infection with complications (PCT)
*Incorrect: Serology for anti-HAV IgM*
- **Anti-HAV IgM** indicates **acute hepatitis A infection**, typically transmitted via the fecal-oral route
- The patient's symptoms, risk factors (IV drug use), positive HCV antibody, and characteristic skin findings (PCT) are not consistent with hepatitis A as the primary diagnosis
- Hepatitis A would not explain the chronic nature of symptoms or the skin manifestations
*Incorrect: Liver biopsy*
- **Liver biopsy** is an invasive procedure used to assess the **extent of liver damage**, inflammation, and fibrosis/cirrhosis after diagnosis of liver disease has been established
- It is not the most appropriate initial step to confirm **active viral replication**; PCR for HCV RNA should be performed first to establish that there is ongoing infection
- Once active HCV is confirmed, non-invasive methods (e.g., FibroScan, serum markers) are often preferred over biopsy for staging liver fibrosis
HBV treatment indications and options US Medical PG Question 5: A 35-year-old man with no known past medical history presents to his physician because he is applying for a job as a healthcare worker, which requires screening for the hepatitis B virus (HBV). The patient states that he is in good health and denies any symptoms. His vital signs and physical exam are unremarkable. Labs are drawn, and the patient's HBV serology shows the following:
HBsAg: positive
anti-HBsAg antibody: negative
anti-HBcAg IgM: negative
anti-HBcAg IgG: positive
HBeAg: negative
anti-HBeAg antibody: positive
Which of the following best describes this patient's results?
- A. Immune due to previous infection
- B. Chronically infected, low infectivity (Correct Answer)
- C. Immune due to previous vaccination
- D. Acutely infected
- E. Chronically infected, high infectivity
HBV treatment indications and options Explanation: ***Chronically infected, low infectivity***
- The presence of **HBsAg positive** for more than 6 months indicates **chronic HBV infection**. The presence of **anti-HBeAg antibody** and **negative HBeAg** suggests **low viral replication activity** and thus low infectivity.
- **HBeAg negativity** along with positivity for **HBV DNA** (if tested, though not provided here) would further differentiate this state as **"HBeAg-negative chronic hepatitis B,"** which typically implies lower, but still present, infectivity compared to HBeAg-positive chronic infection.
*Immune due to previous infection*
- Immunity due to previous infection is characterized by **negative HBsAg** and **positive anti-HBsAg antibody**, along with **positive anti-HBcAg IgG**.
- This patient, however, is **HBsAg positive** and **anti-HBsAg antibody negative**, ruling out resolved infection.
*Immune due to previous vaccination*
- Immunity due to vaccination is characterized by **negative HBsAg**, **positive anti-HBsAg antibody**, and **negative anti-HBcAg antibody** (both IgM and IgG).
- This patient has **positive HBsAg** and **positive anti-HBcAg IgG**, indicating either current or past infection, not vaccination-induced immunity.
*Acutely infected*
- **Acute infection** is characterized by **positive HBsAg**, **negative anti-HBsAg antibody**, and typically **positive anti-HBcAg IgM**.
- This patient has **negative anti-HBcAg IgM**, which makes acute infection unlikely, as IgM antibodies are present early in acute infection.
*Chronically infected, high infectivity*
- **High infectivity** in chronic HBV infection is typically indicated by **positive HBsAg** and **positive HBeAg**, often with high levels of HBV DNA.
- This patient is **HBeAg negative** and **anti-HBeAg antibody positive**, indicating a lower level of viral replication and thus lower infectivity.
HBV treatment indications and options US Medical PG Question 6: A 52-year-old woman comes to the physician because of abdominal discomfort, anorexia, and mild fatigue. She has systemic lupus erythematosus and takes hydroxychloroquine. She does not drink alcohol or use illicit drugs. Physical examination shows no abnormalities. Laboratory studies show:
Alanine aminotransferase 455 U/L
Aspartate aminotransferase 205 U/L
Hepatitis B surface antigen positive
Hepatitis B surface antibody negative
Hepatitis B envelope antigen positive
Hepatitis B core antigen IgG antibody positive
Which of the following is the most appropriate pharmacotherapy for this patient?
- A. Acyclovir
- B. Tenofovir (Correct Answer)
- C. Pegylated interferon-alpha
- D. Dolutegravir
- E. Sofosbuvir
HBV treatment indications and options Explanation: ***Tenofovir***
- This patient has **chronic active hepatitis B infection**, as indicated by **positive HBsAg**, **HBeAg**, and elevated liver enzymes. Antiviral therapy with **tenofovir** is highly effective and appropriate to suppress viral replication.
- The coexistence of **Systemic Lupus Erythematosus (SLE)** and **hydroxychloroquine** use increases the importance of managing HBV, as immunosuppression can lead to viral reactivation; tenofovir effectively targets the virus without significant interactions.
*Acyclovir*
- **Acyclovir** is an antiviral medication primarily used to treat infections caused by **herpes simplex virus (HSV)** and **varicella-zoster virus (VZV)**.
- It has **no efficacy** against hepatitis B virus (HBV) and therefore would not be appropriate for this patient's condition.
*Pegylated interferon-alpha*
- **Pegylated interferon-alpha** is an immunomodulatory agent used to treat chronic hepatitis B and C; however, it has a **less favorable side effect profile** and is often reserved for patients who cannot tolerate or respond to nucleoside/nucleotide analogs.
- The patient's underlying **SLE** could be **exacerbated by interferon**, making tenofovir a safer and more appropriate first-line choice given its better tolerability and potent antiviral effect.
*Dolutegravir*
- **Dolutegravir** is an **integrase inhibitor** used in the treatment of **HIV infection**.
- It has **no antiviral activity** against the hepatitis B virus and is therefore not indicated for this patient's condition.
*Sofosbuvir*
- **Sofosbuvir** is a direct-acting antiviral agent primarily used to treat **chronic hepatitis C virus (HCV) infection**.
- It is **not effective** against hepatitis B virus (HBV) and would not be the correct treatment for this patient.
HBV treatment indications and options US Medical PG Question 7: A 52-year-old man presents to his physician after his routine screening revealed that he has elevated liver enzymes. He complains of occasional headaches during the past year, but otherwise feels well. The patient reports that he was involved in a serious car accident in the 1980s. He does not smoke or drink alcohol. He has no history of illicit intravenous drug use. He does not currently take any medications and has no known allergies. His father had a history of alcoholism and died of liver cancer. The patient appears thin. His temperature is 37.8°C (100°F), pulse is 100/min, and blood pressure is 110/70 mm Hg. The physical examination reveals no abnormalities. The laboratory test results show the following:
Complete blood count
Hemoglobin 14 g/dL
Leukocyte count 10,000/mm3
Platelet count 146,000/mm3
Comprehensive metabolic profile
Glucose 150 mg/dL
Albumin 3.2 g/dL
Total bilirubin 1.5 mg/dL
Alkaline phosphatase 75 IU/L
AST 95 IU/L
ALT 73 IU/L
Other lab tests
HIV negative
Hepatitis B surface antigen negative
Hepatitis C antibody positive
HCV RNA positive
HCV genotype 1
A liver biopsy is performed and shows mononuclear infiltrates localized to portal tracts that reveal periportal hepatocyte necrosis. Which of the following is the most appropriate next step in management?
- A. Peginterferon alpha therapy
- B. Interferon and ribavirin therapy
- C. Sofosbuvir and ledipasvir therapy (Correct Answer)
- D. Tenofovir and entecavir therapy
- E. Tenofovir and velpatasvir therapy
HBV treatment indications and options Explanation: ***Sofosbuvir and ledipasvir therapy***
- This patient has chronic **Hepatitis C (HCV) infection** (HCV antibody positive, HCV RNA positive). **Sofosbuvir/ledipasvir** is an effective **direct-acting antiviral (DAA)** regimen for **genotype 1 HCV**, which is indicated for treatment-naïve patients without cirrhosis.
- The liver biopsy findings of **mononuclear infiltrates** and **periportal necrosis** confirm active hepatitis and the need for antiviral treatment to prevent progression to cirrhosis.
*Peginterferon alpha therapy*
- **Peginterferon alpha** was historically used for HCV, but its use has largely been replaced by **DAAs** due to significant side effects and lower efficacy.
- This therapy is associated with numerous adverse effects, including **flu-like symptoms**, **depression**, and **bone marrow suppression**.
*Interferon and ribavirin therapy*
- This combination was a standard treatment for HCV before the advent of DAAs, but it is associated with a high burden of **side effects** like **hemolytic anemia** (from ribavirin) and **flu-like symptoms** (from interferon).
- Given the availability of highly effective and well-tolerated DAAs, this regimen is no longer considered first-line for chronic HCV.
*Tenofovir and entecavir therapy*
- **Tenofovir** and **entecavir** are antiviral medications primarily used for the treatment of **chronic Hepatitis B (HBV) infection**.
- This patient's **Hepatitis B surface antigen is negative**, ruling out chronic HBV infection as the primary issue requiring these specific drugs.
*Tenofovir and velpatasvir therapy*
- While **velpatasvir** is a DAA used for HCV, its combination with **tenofovir** is not a standard HCV treatment for genotype 1.
- **Tenofovir** is primarily an anti-HBV drug; for HCV, velpatasvir is typically combined with **sofosbuvir** (as in Epclusa) for pan-genotypic coverage.
HBV treatment indications and options US Medical PG Question 8: A 42-year-old male with a history significant for IV drug use comes to the emergency department complaining of persistent fatigue and malaise for the past three weeks. On physical exam, you observe a lethargic male with icteric sclera and hepatomegaly. AST and ALT are elevated at 600 and 750, respectively. HCV RNA is positive. Albumin is 3.8 g/dL and PT is 12. A liver biopsy shows significant inflammation with bridging fibrosis. What is the current first-line treatment?
- A. Sofosbuvir/Velpatasvir (Correct Answer)
- B. Glecaprevir/Pibrentasvir
- C. Sofosbuvir/Ledipasvir
- D. Ribavirin monotherapy
- E. Interferon monotherapy
HBV treatment indications and options Explanation: ***Sofosbuvir/Velpatasvir***
- This is a **pan-genotypic direct-acting antiviral (DAA)** combination that is highly effective for all HCV genotypes and is recommended as a **first-line regimen** by AASLD/IDSA guidelines.
- It is particularly appropriate for patients with **significant fibrosis or compensated cirrhosis**, as seen in this patient with bridging fibrosis on biopsy.
- The standard treatment duration is **12 weeks** for treatment-naive patients, with high sustained virologic response (SVR) rates exceeding 95%.
- It has a favorable safety profile and is effective regardless of baseline viral load or HCV genotype.
*Glecaprevir/Pibrentasvir*
- While this is also an excellent **pan-genotypic DAA** combination with high efficacy, it requires longer treatment duration (12-16 weeks) in patients with **significant fibrosis (F3)** or cirrhosis.
- It is **contraindicated in decompensated cirrhosis (Child-Pugh B/C)**, making sofosbuvir-based regimens more universally applicable for patients with advanced liver disease.
- The often-cited 8-week treatment advantage applies primarily to patients **without cirrhosis**, not to this patient with bridging fibrosis.
*Sofosbuvir/Ledipasvir*
- This combination is primarily effective for **HCV genotypes 1, 4, 5, and 6** but is not truly pan-genotypic like sofosbuvir/velpatasvir.
- It is an acceptable alternative for genotype 1 infection but has been largely superseded by newer pan-genotypic regimens that don't require genotype testing.
- Treatment duration is typically **12 weeks** for treatment-naive patients without cirrhosis.
*Ribavirin monotherapy*
- **Ribavirin** is a nucleoside analog with **minimal antiviral activity** against HCV when used as monotherapy.
- It is only used as an **adjunctive agent** in combination with DAAs in specific circumstances (e.g., treatment-experienced patients with cirrhosis).
- Major side effect is **hemolytic anemia**, requiring close monitoring.
*Interferon monotherapy*
- **Interferon-alpha** monotherapy has very **poor efficacy** for chronic HCV, with sustained virologic response (SVR) rates of only 10-20%.
- It is associated with significant side effects including flu-like symptoms, depression, and cytopenias, making it **poorly tolerated**.
- This regimen is now **obsolete** and has been replaced by highly effective and well-tolerated DAA combinations.
HBV treatment indications and options US Medical PG Question 9: A 33-year-old female comes to her primary care physician with complaints of fatigue and nausea. She has also noticed that her skin tone is darker than it used to be. On exam, the physician notes that the woman appears to be jaundiced and obtains liver enzymes which demonstrate an elevated AST and ALT. Further testing subsequently confirms the diagnosis of hepatitis B (HBV). The woman is extremely concerned about transmitting this disease to her loved ones and ask how HBV is transmitted. By which of the following routes can HBV be spread? (I) blood, (II) sexual contact, (III) maternal-fetal, and/or (IV) breast milk?
- A. II, III
- B. I, II, III, IV
- C. I, II, III (Correct Answer)
- D. I, III, IV
- E. I only
HBV treatment indications and options Explanation: ***I, II, III***
- **Hepatitis B virus (HBV)** is primarily transmitted through contact with infected **blood** or other bloody body fluids (e.g., semen, vaginal secretions), making routes I (blood) and II (sexual contact) major modes of transmission.
- **Maternal-fetal transmission** (route III) can occur during childbirth, especially if the mother has high viral loads, although *in utero* transmission is rare.
*II, III*
- This option is incorrect because it omits **blood transmission (I)**, which is a major route for HBV spread through shared needles, transfusions, or open wounds.
- While sexual and maternal-fetal transmissions are significant, they do not account for all primary modes of spread.
*I, II, III, IV*
- This option is incorrect because while routes I, II, and III are valid, **breast milk (IV)** is generally *not* considered a significant route for HBV transmission.
- Studies have shown a very low, if any, risk of HBV transmission through breast milk, and breastfeeding is typically safe for HBV-positive mothers, especially if the infant is vaccinated.
*I, III, IV*
- This option is incorrect because it includes **breast milk (IV)**, which is not a clinically significant route of transmission, and it excludes **sexual contact (II)**, a very common mode of HBV spread.
- Many HBV infections are acquired through unprotected sexual intercourse with an infected partner.
*I only*
- This option is incorrect as it severely underrepresents the various transmission routes of HBV, omitting **sexual contact (II)** and **maternal-fetal transmission (III)**.
- While blood transmission is critical, HBV is also frequently spread through other bodily fluids and from mother to child.
HBV treatment indications and options US Medical PG Question 10: A group of researchers conducted various studies on hepatitis C incidence and prevalence. They noticed that there is a high prevalence of hepatitis C in third-world countries, where it has a significant impact on the quality of life of the infected individual. The research group made several attempts to produce a vaccine that prevents hepatitis C infection but all attempts failed. Which of the following would most likely be the reason for the failure to produce a vaccine?
- A. Non-DNA genome
- B. Tolerance
- C. Antigenic mimicry
- D. Polysaccharide envelope
- E. Antigenic variation (Correct Answer)
HBV treatment indications and options Explanation: ***Antigenic variation***
- The **hepatitis C virus (HCV)** undergoes rapid **antigenic variation**, particularly in its envelope glycoproteins, which allows it to evade the host immune system.
- This high mutation rate presents a significant challenge for vaccine development, as a vaccine designed against one viral strain may not be effective against others.
*Non-DNA genome*
- While HCV is an **RNA virus** (non-DNA genome), this characteristic alone does not inherently prevent vaccine development; many effective RNA virus vaccines exist (e.g., measles, mumps).
- The type of genome is less critical than its stability and the virus's ability to mutate rapidly.
*Tolerance*
- **Immune tolerance** occurs when the immune system fails to respond to an antigen, often due to chronic exposure. While relevant in chronic HCV infection, it's not the primary reason for vaccine failure.
- The goal of a vaccine is to induce an effective immune response before tolerance can set in.
*Antigenic mimicry*
- **Antigenic mimicry** involves a pathogen's antigens resembling host antigens, potentially leading to autoimmune responses or immune evasion.
- While it can be a factor in some chronic infections, the rapid, diverse changes in HCV's surface antigens are a more prominent obstacle to vaccine design.
*Polysaccharide envelope*
- HCV is an **enveloped virus**, but its envelope is composed of **lipoproteins** with viral glycoproteins, not a polysaccharide capsule.
- Polysaccharide capsules are a feature of some bacteria (e.g., Streptococcus pneumoniae) and fungi, and while they can pose vaccine challenges, they are not relevant to HCV.
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