Hepatitis B/C

Hepatitis B/C 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

Hepatitis B/C 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.

Hepatitis B/C US Medical PG Question 2: 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

Hepatitis B/C 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.

Hepatitis B/C US Medical PG Question 3: 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

Hepatitis B/C 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

Hepatitis B/C US Medical PG Question 4: A 26-year-old woman who is a medical student is undergoing evaluation after sticking herself with a needle while drawing blood from a patient. The patient’s medical history is unknown. A blood sample from the medical student is drawn and processed, and the results are presented below: Anti-HAV IgM negative Anti-HAV IgG positive HBsAg negative HBeAg negative Anti-HBs negative Anti-HBc IgG negative Anti-HBc IgM negative Anti-HBe negative Anti-HCV negative What is true about the student’s laboratory findings?

• A. She has not been vaccinated against the hepatitis B virus. (Correct Answer)
• B. She recovered from a hepatitis B virus infection.
• C. She is infected with the hepatitis D virus.
• D. She can transmit the hepatitis A virus.
• E. She is an asymptomatic carrier of the hepatitis B virus.

Hepatitis B/C Explanation: ***She has not been vaccinated against the hepatitis B virus.*** - A **negative Anti-HBs** indicates a lack of protective antibodies developed either through vaccination or past infection. - A **negative Anti-HBc IgG** and **IgM** further confirms no prior exposure to the hepatitis B core antigen, which would be present with natural infection. *She recovered from a hepatitis B virus infection.* - Recovery from HBV infection would typically show **positive Anti-HBs** and **positive Anti-HBc IgG**, neither of which are present here. - The absence of **Anti-HBc antibodies** rules out past natural infection, whether resolved or chronic. *She is infected with the hepatitis D virus.* - Hepatitis D virus (HDV) infection only occurs in the presence of an active **Hepatitis B virus (HBV) infection**. - The student's **HBsAg negative** status indicates no active HBV infection, thereby ruling out HDV. *She can transmit the hepatitis A virus.* - **Anti-HAV IgG positive** indicates prior exposure to HAV or vaccination, leading to immunity. - **Anti-HAV IgM negative** suggests no acute HAV infection, meaning she is not currently infectious. *She is an asymptomatic carrier of the hepatitis B virus.* - An asymptomatic carrier of HBV would have **positive HBsAg** and likely **positive Anti-HBc IgG**, but both are negative in this case. - The absence of **HBsAg** definitively rules out an active carrier state.

Hepatitis B/C US Medical PG Question 5: An investigator is studying the rate of multiplication of hepatitis C virus in hepatocytes. The viral genomic material is isolated, enzymatically cleaved into smaller fragments and then separated on a formaldehyde agarose gel membrane. Targeted probes are then applied to the gel and visualized under x-ray. Which of the following is the most likely structure being identified by this test?

• A. Lipid-linked oligosaccharides
• B. Transcription factors
• C. Polypeptides
• D. Ribonucleic acids (Correct Answer)
• E. Deoxyribonucleic acids

Hepatitis B/C Explanation: ***Ribonucleic acids*** - The description of isolating "viral genomic material," which is then "enzymatically cleaved" and run on a "formaldehyde agarose gel," followed by the application of "targeted probes" and X-ray visualization, perfectly matches the technique of **Northern blotting**. - Northern blotting is used to detect and quantify specific **RNA sequences**, which is consistent with the hepatitis C virus being an RNA virus. *Lipid-linked oligosaccharides* - These molecules are involved in protein glycosylation and are typically analyzed using techniques like **mass spectrometry** or **chromatography**, not Northern blotting. - They are not nucleic acid material, which is implied by "viral genomic material" and enzymatic cleavage steps. *Transcription factors* - **Transcription factors** are proteins that regulate gene expression and would typically be identified using techniques like **Western blotting** (for protein detection) or Electrophoretic Mobility Shift Assay (EMSA) for DNA binding. - They are not directly "genomic material" that would be cleaved and run on an agarose gel in this manner. *Polypeptides* - **Polypeptides** are chains of amino acids, i.e., proteins, which are normally detected using **Western blotting** after separation on an SDS-PAGE gel. - The use of "formaldehyde agarose gel" and "enzymatic cleavage" points specifically to nucleic acid analysis, not protein analysis. *Deoxyribonucleic acids* - While DNA is genomic material and is often analyzed similarly, the use of a **formaldehyde agarose gel** is characteristic of RNA electrophoresis because formaldehyde prevents RNA from forming secondary structures. - Furthermore, hepatitis C is a **single-stranded RNA virus**, meaning its genome is RNA, not DNA.

Hepatitis B/C US Medical PG Question 6: 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

Hepatitis B/C 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.

Hepatitis B/C US Medical PG Question 7: 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

Hepatitis B/C 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.

Hepatitis B/C US Medical PG Question 8: 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

Hepatitis B/C 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.

Hepatitis B/C US Medical PG Question 9: A 3-month-old girl is brought to the emergency department because of a 2-day history of progressive difficulty breathing and a dry cough. Five weeks ago, she was diagnosed with diffuse hemangiomas involving the intrathoracic cavity and started treatment with prednisolone. She appears uncomfortable and in moderate respiratory distress. Her temperature is 38°C (100.4°F), pulse is 150/min, respirations are 50/min, and blood pressure is 88/50 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 87%. Oral examination shows a white plaque covering the tongue that bleeds when scraped. Chest examination shows subcostal and intercostal retractions. Scattered fine crackles and rhonchi are heard throughout both lung fields. Laboratory studies show a leukocyte count of 21,000/mm3 and an increased serum beta-D-glucan concentration. An x-ray of the chest shows symmetrical, diffuse interstitial infiltrates. Which of the following is most likely to confirm the diagnosis?

• A. Tuberculin skin test
• B. Urine antigen test
• C. CT scan of the chest
• D. Bronchoalveolar lavage (Correct Answer)
• E. DNA test for CFTR mutation

Hepatitis B/C Explanation: ***Bronchoalveolar lavage*** - The patient, an infant on **prednisolone** (immunosuppression) with **diffuse interstitial infiltrates**, **uncomfortable appearance**, **respiratory distress**, and **oral thrush (white plaque that bleeds when scraped)**, points to **Pneumocystis pneumonia (PCP)**. - **Bronchoalveolar lavage (BAL)** is the gold standard for diagnosing PCP by identifying **Pneumocystis jirovecii cysts** or **trophozoites** using special stains (e.g., Giemsa, methenamine silver). *Tuberculin skin test* - The **tuberculin skin test** is used to diagnose **tuberculosis**, which typically presents with **granulomas** and **cavitary lesions** on chest X-ray, not diffuse interstitial infiltrates. - While tuberculosis can cause respiratory symptoms, the presence of oral thrush and immunosuppression suggests an opportunistic fungal infection like PCP rather than TB. *Urine antigen test* - A **urine antigen test** is commonly used for diagnosing **Legionnaires' disease** or **pneumococcal pneumonia** in adults, and is not applicable for PCP. - It does not detect *Pneumocystis jirovecii*, which is the suspected pathogen in this immunosuppressed infant. *CT scan of the chest* - A **CT scan of the chest** would show **diffuse ground-glass opacities** characteristic of PCP but is a **radiological finding**, not a definitive diagnostic test for the pathogen itself. - While it can further characterize the pulmonary findings, it cannot identify the causative organism, which is crucial for targeted treatment. *DNA test for CFTR mutation* - A **DNA test for CFTR mutation** is used to diagnose **cystic fibrosis**, a genetic disorder affecting mucus production, and is not relevant in this acute presentation of respiratory distress and immunosuppression. - Cystic fibrosis typically presents with recurrent respiratory infections, pancreatic insufficiency, and failure to thrive, not primarily with opportunistic infections like PCP.

Hepatitis B/C US Medical PG Question 10: Two viruses, X and Y, infect the same cell and begin to reproduce within the cell. As a result of the co-infection, some viruses are produced where the genome of Y is surrounded by the nucleocapsid of X and vice versa with the genome of X and nucleocapsid of Y. When the virus containing genome X surrounded by the nucleocapsid of Y infects another cell, what is the most likely outcome?

• A. Virions containing genome Y and nucleocapsid Y will be produced
• B. No virions will be produced
• C. Virions containing genome X and nucleocapsid Y will be produced
• D. Virions containing genome Y and nucleocapsid X will be produced
• E. Virions containing genome X and nucleocapsid X will be produced (Correct Answer)

Hepatitis B/C Explanation: ***Virions containing genome X and nucleocapsid X will be produced*** - The virus containing **genome X** surrounded by **nucleocapsid Y** is a pseudotype. During the infection of a new cell, the **genome X** will direct the synthesis of new viral components, including **nucleocapsid X**. - Since the genetic material (genome X) dictates the production of viral proteins, the new virions will be genetically identical to virus X, thus containing its own genome and nucleocapsid. *Virions containing genome Y and nucleocapsid Y will be produced* - This is incorrect because the infecting particle carried **genome X**, not genome Y. - The genetic information encoded in the genome determines the type of progeny viruses produced. *No virions will be produced* - This is unlikely as the pseudotyped virus is capable of infection and delivery of a functional genome into the host cell. - The cell is presumed to be permissive for virus replication. *Virions containing genome X and nucleocapsid Y will be produced* - This would only happen if the **nucleocapsid Y** was somehow replicated independently of its original genome, which is not how viral replication works. - The progeny nucleocapsids are always encoded by the genome that is replicating within the cell. *Virions containing genome Y and nucleocapsid X will be produced* - This is incorrect. The infecting virus introduced **genome X** into the cell, not genome Y. - The genetic material delivered determines the type of viral particles that will be synthesized.

Hepatitis B/C Flashcard 1 of 10

Question: Developed countries purify their _____ supply, eliminating HAV infection risk (fecal-oral transmission)

Answer: water

Hepatitis B/C Flashcard 2 of 10

Question: Upon cellular entry, partially dsDNA of HBV is repaired and used for _____

Answer: transcription

Hepatitis B/C Flashcard 3 of 10

Question: What type of vaccine is used for HBV? _____

Answer: Subunit (recombinant HBsAg)

Hepatitis B/C Flashcard 4 of 10

Question: What type of vaccine is the hepatitis A vaccine? _____

Answer: Inactivated/killed

Hepatitis B/C Flashcard 5 of 10

Question: Does hepatitis B have an envelope?_____

Answer: Yes

Hepatitis B/C Flashcard 6 of 10

Question: What type of virus is HCV? (DNA, RNA (sense), etc.)_____

Answer: Positive sense RNA

Hepatitis B/C Flashcard 7 of 10

Question: What type of virus is Hepatitis B? (DNA, RNA (sense), etc)_____

Answer: Partially double-stranded DNA

Hepatitis B/C Flashcard 8 of 10

Question: Hepatitis C virus displays antigenic variability of its _____ proteins

Answer: envelope

Extra Information:   Watch associated Bootcamp video [https://app.bootcamp.com/med-school/gastroenterology/videos/hepatic-pathology?index=4] https://onlinemeded.org/spa/gastroenterology/viral-hepatitis/acquire?ref=anki 

Hepatitis B/C Flashcard 9 of 10

Question: Developed countries purify their _____ supply, eliminating HAV infection risk (fecal-oral transmission)

Answer: water

Extra Information:   Watch Hepatitis A virus (PicoRNAviridae) [https://dashboard.sketchy.com/study/medical/courses/medical-microbiology/units/medical-microbiology-viruses/videos/medical-microbiology-viruses-rna-viruses-positive-sense-hepatitis-a-virus-picornaviridae?utm_source=anki&utm_medium=partnership&utm_campaign=february_update&utm_content=medical]Watch associated Bootcamp video [https://app.bootcamp.com/med-school/gastroenterology/videos/hepatic-pathology?index=4] https://onlinemeded.org/spa/gastroenterology/viral-hepatitis/acquire?ref=anki 

Hepatitis B/C Flashcard 10 of 10

Question: Which hepatitis virus shows antigenic variability of envelope proteins? _____

Answer: HCV

Extra Information:    https://onlinemeded.org/spa/gastroenterology/viral-hepatitis/acquire?ref=anki