DNA Viruses: Herpesviruses — MCQs
What does a Tzanck smear in varicella-zoster virus infection typically show?
A child presents with a fever and a rash. Urine examination showed cells with owl's eye appearance. What is the most likely diagnosis?
Multinucleated giant cell on Tzanck smear is not seen in?
A 30 month old deaf boy whose development is slower than normal is being followed for congenital cytomegalovirus (CMV) infection in your clinic.The child's mother is pregnant again and is worried about her new baby. Which of the following is true?
A 24-year-old woman presents with painful genital ulcers and lymphadenopathy. Tzanck smear shows multinucleated giant cells. What is the most appropriate initial treatment?
Dangerous type of Herpes virus -
EBV is most strongly associated with which of the following?
Topical antiviral drugs are not indicated in:
In lymphoid tissue biopsy from a patient with suspected measles, multinucleated giant cells with 'clockwise' nuclear arrangement are observed. What are these cells called?
Which of the following statements about paramyxoviruses is false?
DNA Viruses: Herpesviruses Indian Medical PG Practice Questions and MCQs
Question 1: What does a Tzanck smear in varicella-zoster virus infection typically show?
- A. Acantholytic cells
- B. Epidermal spongiosis
- C. Multinucleated giant cells (Correct Answer)
- D. Necrotic cells
Explanation: ***Multinucleated giant cells*** - A Tzanck smear identifies **multinucleated giant cells** with intranuclear inclusions, which are characteristic **cytopathic effects** of herpesviruses like VZV [1]. - These cells result from the fusion of infected keratinocytes, a hallmark finding in **herpes simplex** and **varicella-zoster infections** [1]. *Acantholytic cells* - Acantholytic cells are seen in conditions like **pemphigus vulgaris**, where there is loss of cell-to-cell adhesion between keratinocytes, leading to intraepidermal blistering. - While VZV can cause blistering, the primary cytological finding on Tzanck smear is not acantholysis but rather the presence of multinucleated cells. *Epidermal spongiosis* - Spongiosis refers to **intercellular edema** of epidermal cells, leading to widening of the intercellular spaces, typically seen in **eczematous dermatoses** [1]. - This finding is not specific to viral infections and does not represent the characteristic cytopathic effect of VZV on a Tzanck smear. *Necrotic cells* - Necrotic cells, or dead cells, are a general finding in many inflammatory and infectious processes where tissue damage occurs. - While VZV infection can lead to cell necrosis, the presence of isolated necrotic cells is not the specific, diagnostic feature for VZV on a Tzanck smear. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 366-367.
Question 2: A child presents with a fever and a rash. Urine examination showed cells with owl's eye appearance. What is the most likely diagnosis?
- A. Herpes simplex virus infection
- B. Toxoplasmosis caused by Toxoplasma gondii
- C. Cytomegalovirus (CMV) infection (Correct Answer)
- D. Infectious mononucleosis caused by Epstein-Barr virus
Explanation: ***Cytomegalovirus (CMV) infection*** - The presence of cells with an **owl's eye appearance** in urine sediment is a classic histological hallmark of **CMV infection**. - CMV can cause a variety of symptoms in children, including **fever and rash**, making this the most likely diagnosis. *Herpes simplex virus infection* - HSV causes characteristic **vesicular lesions** on mucocutaneous surfaces, often associated with fever. - While HSV can cause systemic illness, it does not typically present with **owl's eye inclusions** in urine cells. *Toxoplasmosis caused by Toxoplasma gondii* - **Toxoplasmosis** can cause fever and rash, especially in congenital infections or immunocompromised individuals. - However, it does not lead to **owl's eye inclusions** in urinary cells, which are pathognomonic for CMV. *Infectious mononucleosis caused by Epstein-Barr virus* - **Infectious mononucleosis** commonly presents with fever, fatigue, and lymphadenopathy, sometimes with a rash. - **Epstein-Barr virus (EBV)** infection does not produce cells with an **owl's eye appearance** in the urine; that is specific to CMV.
Question 3: Multinucleated giant cell on Tzanck smear is not seen in?
- A. Herpes simplex
- B. Molluscum contagiosum (Correct Answer)
- C. Varicella
- D. Herpes zoster
Explanation: **Molluscum contagiosum** - Tzanck smear typically reveals **Henderson-Paterson bodies**, which are large eosinophilic intracytoplasmic inclusions within epithelial cells. - **Multinucleated giant cells** are not characteristic findings in lesions caused by the molluscum contagiosum virus (a poxvirus). *Herpes simplex* - Tzanck smear often shows **multinucleated giant cells** and **acantholytic cells**, which are specific cytopathic effects of HSV. - The presence of these cells helps in the rapid diagnosis of **herpes simplex viral infections**. *Varicella* - Similar to herpes simplex, **varicella-zoster virus (VZV)** infection also produces **multinucleated giant cells** on Tzanck smear. - These cells are a hallmark of **herpesvirus infections**, indicating viral cytopathic effects in epithelial cells. *Herpes zoster* - Herpes zoster, caused by the **reactivation of VZV**, also presents with **multinucleated giant cells** on Tzanck smear. - This finding aids in confirming the diagnosis of **shingles**, distinguishing it from other vesicular rashes.
Question 4: A 30 month old deaf boy whose development is slower than normal is being followed for congenital cytomegalovirus (CMV) infection in your clinic.The child's mother is pregnant again and is worried about her new baby. Which of the following is true?
- A. The new infant should be isolated from the older child
- B. The mother has antibodies to CMV that are passed to the fetus (Correct Answer)
- C. Termination of pregnancy is advised
- D. The mother's infection cannot become reactivated
Explanation: ***The mother has antibodies to CMV that are passed to the fetus*** - The mother has a history of CMV infection, meaning she has developed **antibodies** against the virus. These maternal **IgG antibodies** can cross the placenta and provide passive immunity to the fetus. - This passive immunity helps protect the unborn baby from initial infection or reduce the severity of disease if exposure occurs, although it doesn't guarantee complete protection. *The new infant should be isolated from the older child* - Isolation is generally not necessary in this scenario because CMV is widespread and transmission through casual contact is common; strict isolation would be impractical and not significantly reduce risk. - While CMV can be shed in urine and saliva, the risk of symptomatic infection in the new infant from an older sibling with congenital CMV, especially if the mother is seropositive, is relatively low. *Termination of pregnancy is advised* - Termination of pregnancy is a major medical decision and is not advised solely based on a previous CMV infection in an older child. - The risk of severe congenital CMV in a subsequent pregnancy when the mother is already seropositive is significantly lower compared to a primary maternal infection during pregnancy. *The mother's infection cannot become reactivated* - CMV is a **herpesvirus** that establishes **latency** after primary infection, meaning it can reactivate later in life. - While reactivation can occur, particularly in immunocompromised individuals, it typically poses a much lower risk to a developing fetus compared to a primary infection during pregnancy, especially if the mother has pre-existing antibodies.
Question 5: A 24-year-old woman presents with painful genital ulcers and lymphadenopathy. Tzanck smear shows multinucleated giant cells. What is the most appropriate initial treatment?
- A. Acyclovir 400mg TID for 7-10 days
- B. Acyclovir 200mg 5 times daily for 7-10 days
- C. Famciclovir 250mg TID for 7-10 days
- D. Valacyclovir 1g BD for 7-10 days (Correct Answer)
Explanation: ***Valacyclovir 1g BD for 7-10 days*** - This is the recommended initial treatment for **genital herpes simplex virus (HSV)** infections, especially for the **first clinical episode**. [1] - Valacyclovir offers a more convenient twice-daily dosing compared to acyclovir due to its **better bioavailability**. *Acyclovir 400mg TID for 7-10 days* - This regimen is often used for **suppressive therapy** or less severe recurrent outbreaks of genital herpes, not typically for initial severe presentations. - While acyclovir is effective, higher doses or more frequent dosing are usually recommended for the initial episode's acute treatment. *Acyclovir 200mg 5 times daily for 7-10 days* - This is an appropriate initial treatment regimen for the **first clinical episode of genital herpes**. [1] - However, valacyclovir offers better patient adherence due to less frequent dosing without compromising efficacy. *Famciclovir 250mg TID for 7-10 days* - Famciclovir is an effective antiviral for genital herpes, but the recommended dose for an initial episode is typically higher (e.g., 250 mg three times a day for 7-10 days or 500 mg twice a day for 7 days). [1] - Like valacyclovir, it's a prodrug of penciclovir, but valacyclovir generally has a more preferred dosing schedule for convenience.
Question 6: Dangerous type of Herpes virus -
- A. Cytomegalovirus
- B. Epstein Barr virus
- C. Herpes simplex-2
- D. Herpes virus simiae (Correct Answer)
Explanation: ***Herpes virus simiae*** - **Herpes virus simiae**, also known as **B virus**, is extremely dangerous to humans, often leading to severe neurological disease or death if an infection occurs. - It is naturally found in **macaques** and can be transmitted to humans through bites, scratches, or exposure to infected tissues or fluids. *Cytomegalovirus* - **Cytomegalovirus (CMV)** is generally benign in healthy individuals, causing mild or asymptomatic infections. - While CMV can be severe in immunocompromised patients or neonates (leading to **congenital CMV**), it is not inherently as dangerous as Herpes virus simiae in healthy individuals. *Epstein Barr virus* - **Epstein-Barr virus (EBV)** is famous for causing **infectious mononucleosis** in humans. - Although it can be associated with certain cancers like **Burkitt lymphoma** and **nasopharyngeal carcinoma**, it is not acutely "dangerous" in the same immediate, life-threatening way as Herpes virus simiae upon initial infection in healthy hosts. *Herpes simplex-2* - **Herpes simplex virus type 2 (HSV-2)** is the primary cause of genital herpes. - While it causes recurrent, painful lesions and can lead to **neonatal herpes** (which is serious), it does not typically cause the rapid, fatal neurological disease seen with Herpes virus simiae in humans.
Question 7: EBV is most strongly associated with which of the following?
- A. Gastric cancer
- B. Esophageal cancer
- C. Nasopharyngeal carcinoma (Correct Answer)
- D. Hepatocellular carcinoma
Explanation: ***Nasopharyngeal carcinoma*** - **Epstein-Barr virus (EBV)** is strongly and consistently associated with the development of **nasopharyngeal carcinoma**, particularly the undifferentiated (endemic) type. - EBV DNA is found in virtually **100% of undifferentiated nasopharyngeal carcinomas**, highlighting its critical role in the pathogenesis of this cancer. - This represents one of the strongest virus-cancer associations in human medicine. *Gastric cancer* - While EBV is linked to a specific subtype of **EBV-associated gastric adenocarcinoma**, it accounts for only about **10% of gastric cancers**. - This makes it a less strong and less prevalent association compared to nasopharyngeal carcinoma. *Esophageal cancer* - **Esophageal cancer** (adenocarcinoma and squamous cell carcinoma) has various risk factors such as GERD, smoking, and alcohol consumption. - **EBV is not a significant etiologic factor** for esophageal cancer. - There is no strong, consistent evidence linking EBV as a primary cause of esophageal malignancy. *Hepatocellular carcinoma* - **Hepatocellular carcinoma** is primarily associated with **hepatitis B virus (HBV)** and **hepatitis C virus (HCV)**, not EBV. - Other risk factors include chronic liver disease, cirrhosis, aflatoxin exposure, and alcohol abuse. - EBV does not play a significant role in hepatocellular carcinoma pathogenesis.
Question 8: Topical antiviral drugs are not indicated in:
- A. Metaherpetic ulcer (Correct Answer)
- B. Dendritic ulcer
- C. Stromal necrotizing keratitis
- D. All of the options
Explanation: ***Metaherpetic ulcer*** - Metaherpetic ulcers are **neurotrophic ulcers** that develop as a result of chronic epithelial damage and impaired healing after a herpes simplex virus (HSV) infection, but they are not an active viral replication process. - Topical antivirals are ineffective because there is **no replicating virus** to target; management focuses on promoting corneal healing and preventing secondary infections. *Dendritic ulcer* - A dendritic ulcer is a classic sign of **active HSV keratitis** with replicating virus in the epithelial cells. - Topical antiviral drugs (e.g., acyclovir, ganciclovir) are the **first-line treatment** to inhibit viral replication and promote epithelial healing. *Stromal necrotizing keratitis* - This condition involves **inflammation and necrosis** in the corneal stroma, often due to an immune reaction to HSV antigens rather than direct viral invasion. - While topical antivirals may be used to suppress any residual replicating virus, **topical corticosteroids are often necessary** to control the inflammation, and close monitoring is crucial due to the risk of steroid-induced complications. *All of the options* - This option is incorrect because topical antiviral drugs *are* indicated for **dendritic ulcers** and sometimes as adjunctive therapy for **stromal necrotizing keratitis** where active viral replication might be contributing.
Question 9: In lymphoid tissue biopsy from a patient with suspected measles, multinucleated giant cells with 'clockwise' nuclear arrangement are observed. What are these cells called?
- A. Cowdry type A
- B. Warthin-Finkeldey cells (Correct Answer)
- C. Negri bodies
- D. Henderson-Paterson bodies
Explanation: ***Warthin-Finkeldey cells*** - These are **multinucleated giant cells** with many nuclei arranged in a **\"clockwise\" or syncytial pattern**, a characteristic histopathological finding in **lymphoid tissues (lymph nodes, tonsils, spleen) during prodromal measles**. - They represent a key diagnostic marker for measles infection, formed by the fusion of infected lymphoid cells. - They are typically found **before the appearance of the measles rash**. *Cowdry type A* - **Cowdry type A inclusion bodies** are intranuclear inclusions characteristic of **herpes simplex virus** and **varicella-zoster virus** infections. - They are eosinophilic inclusions surrounded by a clear halo, seen in herpesvirus-infected cells, not measles. *Negri bodies* - **Negri bodies** are eosinophilic, cytoplasmic inclusion bodies found in neurons (especially hippocampal pyramidal cells), characteristic of **rabies infection**. - They are pathognomonic for rabies virus and are not observed in measles. *Henderson-Paterson bodies* - **Henderson-Paterson bodies** are large, eosinophilic intracytoplasmic inclusions (molluscum bodies) found in epidermal cells infected with **molluscum contagiosum virus**. - They are pathognomonic for molluscum contagiosum and have no association with measles.
Question 10: Which of the following statements about paramyxoviruses is false?
- A. Belong to the family Paramyxoviridae
- B. Are DNA viruses (Correct Answer)
- C. Are RNA viruses
- D. Have linear nucleic acid
Explanation: ***Are DNA viruses*** - Paramyxoviruses are characterized by their **single-stranded, negative-sense RNA genome**, not DNA. - Their replication and transcription processes occur in the cytoplasm, which is typical for RNA viruses. *Belong to the family Paramyxoviridae* - This statement is correct; paramyxoviruses are indeed classified under the **family Paramyxoviridae**. - This family includes important human pathogens like measles, mumps, and respiratory syncytial virus (RSV). *Have linear nucleic acid* - This statement is correct as paramyxoviruses possess a **linear, non-segmented RNA genome**. - The linear nature differentiates them from viruses with segmented genomes, such as influenza viruses. *Are RNA viruses* - This statement is correct; paramyxoviruses are characterized by their **RNA genome**. - Specifically, they are **negative-sense, single-stranded RNA viruses**.
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