Virology Practice Questions

Q: Which of the following viruses is from the Herpes virus family?

EBV. ***EBV*** - **Epstein-Barr Virus (EBV)** is a member of the **Herpesviridae** family, specifically **Human Herpesvirus 4 (HHV-4)**. - It is a **DNA virus** (double-stranded DNA), which is characteristic of all herpesviruses. - It is known to cause **infectious mononucleosis** and is associated with various malignancies. *Rubella* - **Rubella virus** belongs to the family **Togaviridae** and is the causative agent of **German measles**. - It is an **RNA virus** and is not classified within the Herpesviridae family. *Rabies* - **Rabies virus** is a member of the **Rhabdoviridae** family, specifically the genus **Lyssavirus**. - It is a neurotropic **RNA virus** causing a rapidly progressive, fatal encephalitis. *Measles* - **Measles virus**, also known as **Rubeola**, belongs to the family **Paramyxoviridae**. - It is an **RNA virus** responsible for a highly contagious airborne disease.

Q: Infantile myocarditis and pericarditis is due to

Coxsackie B. **Coxsackie B** - **Coxsackie B virus** is a well-established cause of **viral myocarditis and pericarditis**, particularly in infants and young children. - The virus can directly infect myocardial cells, leading to inflammation and damage. - Coxsackie B is the **most common viral cause** of infantile myocarditis. *Pox virus* - **Poxviruses** primarily cause **skin lesions** (e.g., smallpox, molluscum contagiosum) and are not a common cause of myocarditis or pericarditis. - While systemic infections can occur, cardiac involvement is **rare and not a typical presentation**. *Mumps* - **Mumps virus** is known for causing **parotitis** (inflammation of the salivary glands), and can also cause complications such as orchitis, meningitis, and pancreatitis. - While **mumps myocarditis** can occur, it is a **less common** presentation compared to Coxsackie B virus. *Coxsackie A* - **Coxsackie A viruses** are more commonly associated with conditions like **herpangina** (oral lesions) and **hand-foot-and-mouth disease**. - While they can occasionally cause myocarditis, **Coxsackie B viruses** are far more frequently implicated in cases of viral myocarditis and pericarditis.

Q: Roseola infantum is caused by ______

HHV 6. ***HHV 6*** - **Roseola infantum**, also known as **exanthem subitum**, is characteristically caused by **Human Herpesvirus 6 (HHV 6)**. - This virus typically causes an illness in infants and young children featuring a **high fever for several days** followed by a **maculopapular rash** after the fever subsides. *Rubeola* - **Rubeola** is the virus responsible for **measles**, a disease distinctly different from roseola with prominent symptoms like **Koplik spots** and a rash that appears during the fever. - Measles rash typically starts on the face and spreads downwards, while roseola rash appears after the fever breaks. *Rubella* - **Rubella** causes **German measles**, characterized by a **milder rash** and relatively few systemic symptoms compared to measles. - Unlike roseola, rubella's rash often appears coincident with or shortly after the fever, and the fever is generally not as high. *HHV 5* - **HHV 5** refers to **Cytomegalovirus (CMV)**, which is associated with a wide range of clinical manifestations, including congenital infections, mononucleosis-like syndrome, and opportunistic infections in immunocompromised individuals. - CMV typically does not cause the classic fever-then-rash presentation seen in roseola infantum.

Q: In HIV patients, Kaposi's sarcoma is most likely caused by which of the following?

Virus. ***Virus*** - The image likely depicts **Kaposi's sarcoma**, a common lesion in HIV patients, which is caused by **Human Herpesvirus 8 (HHV-8)**. - Other viral infections like **Herpes Simplex Virus (HSV)** can also cause mucocutaneous lesions in immunocompromised individuals. *Bacteria* - While HIV patients are susceptible to bacterial infections (e.g., **Staphylococcus aureus** causing skin abscesses), the described lesion type is not characteristic of common bacterial skin infections. - Bacterial lesions often present as pustules, cellulitis, or ulcers with purulent discharge, which differ from typical Kaposi's sarcoma. *Parasite* - Parasitic infections can occur in HIV patients (e.g., **scabies** or **leishmaniasis**), but these typically present with different dermatological features like intensely itchy papules or nodular ulcerative lesions. - Lesions caused by parasites do not usually manifest as the violaceous, nodular, or plaque-like appearances seen in Kaposi's sarcoma. *Fungus* - Fungal infections in HIV patients can cause skin lesions (e.g., **candidiasis** with oral thrush or esophagitis, or **cryptococcosis** with molluscum-like lesions). - However, the morphology of these fungal lesions generally differs from the classic appearance of Kaposi's sarcoma or other common viral lesions in HIV.

Q: Which of the following is NOT a characteristic of hepatitis B infection?

HBcAg in serum indicate active infection. Hepatitis B core antigen (HBcAg) is found within the infected hepatocytes and is not secreted into the bloodstream [1]. The presence of HBcAg in serum would typically indicate a ruptured hepatocyte and damaged liver, but it is not a routine marker for active infection. Alpha interferon is a common antiviral medication used in the treatment of chronic hepatitis B infection [1]. Its mechanism of action involves modulating the immune system to clear the virus and prevent liver damage. Perinatal transmission of hepatitis B is a major route, and infants infected at birth have a high risk (up to 90%) of developing chronic hepatitis B [1]. Their immature immune systems often fail to clear the virus, leading to persistent infection. Chronic hepatitis B infection is a significant risk factor for developing hepatocellular carcinoma (HCC) [1]. The persistent inflammation and liver damage associated with chronic infection promote cellular dysplasia and malignant transformation.

Q: Most sensitive test for diagnosis of infectious mononucleosis:

Paul Bunnel test. ***Paul Bunnel test*** - The **Paul-Bunnell test** detects heterophile antibodies by agglutinating sheep red blood cells, which are characteristic of infectious mononucleosis. - While largely replaced by the **Monospot test**, it is historically known for its **sensitivity** in detecting these antibodies. *Monospot test* - The **Monospot test** is a rapid, widely used test for infectious mononucleosis that detects **heterophile antibodies**, but its sensitivity is lower in the early stages of the disease. - Although convenient, it can produce **false negatives**, especially in young children or very early in the infection. *Culture of the virus* - **Culturing Epstein-Barr virus (EBV)**, the causative agent of infectious mononucleosis, is **not practical for routine diagnosis** due to its technical complexity and long turnaround time [1]. - Viral culture is typically reserved for **research purposes** rather than clinical diagnosis [1]. *Lymphocytosis in peripheral smear* - While **atypical lymphocytosis** (more than 10% atypical lymphocytes) on a peripheral smear is a **characteristic finding** in infectious mononucleosis, it is **not specific** for the condition [1]. - This finding can also be present in other viral infections and does not confirm the diagnosis on its own; it serves as a **supportive indicator** [1].

Q: Genital warts are caused by:

Human Papilloma Virus. ***Human Papilloma Virus*** - **Human Papilloma Virus (HPV)** is the primary cause of genital warts, particularly low-risk types like **HPV-6** and **HPV-11**. - HPV infection is common and is transmitted primarily through **sexual contact**. *Chlamydia trachomatis* - **Chlamydia trachomatis** is a bacterium that causes a common sexually transmitted infection (STI), leading to **urethritis**, **cervicitis**, and pelvic inflammatory disease, but not genital warts. - It can cause symptoms like **dysuria** and **vaginal discharge**, or be asymptomatic, but does not result in wart-like lesions. *Epstein Barr virus* - **Epstein-Barr virus (EBV)** is a herpesvirus primarily known for causing **infectious mononucleosis** (glandular fever). - It is associated with certain cancers like nasopharyngeal carcinoma and lymphomas but not with sexually transmitted genital warts. *HSV* - **Herpes Simplex Virus (HSV)** causes **genital herpes**, characterized by painful **blisters** and **sores** that typically recur. - While HSV is a sexually transmitted infection, the lesions it causes are vesicular and ulcerative, distinctly different from the fleshy, wart-like lesions of HPV.

Q: Which of the following is the most common clinical manifestation of human parvovirus B19?

Erythema infectiosum. ***Erythema infectiosum*** - This is also known as **fifth disease** and is characterized by a "slapped cheek" rash on the face followed by a lacy rash on the trunk and limbs. - It is a common and usually mild illness in children, caused by **human parvovirus B19**. *Hydrops fetalis* - While parvovirus B19 can cause hydrops fetalis in pregnant women by infecting fetal red blood cell precursors, it is a severe, less common manifestation rather than a **common clinical presentation** across all infected individuals. - Hydrops fetalis is characterized by **extensive fetal edema** and effusions, leading to high mortality. *Aplastic crisis in hemolytic anemia patients* - Parvovirus B19 can cause transient aplastic crisis, especially in individuals with **pre-existing hemolytic anemias** (e.g., sickle cell disease), due to its tropism for erythroid progenitor cells. - However, this is a specific complication in a susceptible population, not the **most common clinical manifestation** in the general population. *Anemia in neonatal period* - Parvovirus B19 infection can cause severe anemia in newborns if the mother is infected during pregnancy. - However, direct infection causing anemia in the neonatal period is less common than erythema infectiosum, which is widespread in children.

Q: Most common organism causing chronic complications in allograft transplant recipients:

Virus. ***Virus*** - Viruses, particularly **cytomegalovirus (CMV)**, **Epstein-Barr virus (EBV)**, and **BK virus**, are common causes of chronic complications such as **allograft dysfunction**, **post-transplant lymphoproliferative disorder (PTLD)**, and **nephropathy** in transplant recipients [1], [2]. - The immunocompromised state of transplant patients due to immunosuppressive therapy makes them highly susceptible to reactivation of latent viral infections or new viral exposures, leading to long-term morbidities [2]. *Bacteria* - While **bacterial infections** are common in the early post-transplant period, leading to acute complications such as **pneumonia** or **surgical site infections**, they are less frequently the primary cause of chronic complications directly affecting allograft survival over the long term [1]. - Patients can still get chronic bacterial infections, but their impact on overall chronic allograft complications is not as widespread as that of viral infections. *Fungi* - **Fungal infections** can cause severe, disseminated disease in immunocompromised transplant recipients and are associated with high mortality [1]. - However, they are generally less frequent than viral infections and tend to lead to more acute, severe complications rather than chronic allograft dysfunction in the broader transplant population. *Parasite* - **Parasitic infections** are relatively uncommon in transplant recipients in developed countries, although they can cause significant morbidity and mortality, especially in endemic regions. - They are not considered the most common cause of general chronic complications affecting allograft recipients.

Question 1

Which of the following viruses is from the Herpes virus family?

Accepted Answer

EBV

Answer

Rubella

Answer

Rabies

Answer

Measles

Question 2

Infantile myocarditis and pericarditis is due to

Accepted Answer

Coxsackie B

Answer

Pox virus

Answer

Mumps

Answer

Coxsackie A

Question 3

Prophage is defined as:

Accepted Answer

Integrated temperate bacteriophage genome into bacterial chromosome

Answer

First cycle of division of bacterial nucleic acid

Answer

Last cycle of division of bacterial nucleic acid

Answer

Insertion of viral nucleic acid into bacteria by bacteriophage

Question 4

Roseola infantum is caused by ______

Accepted Answer

HHV 6

Answer

Rubeola

Answer

Rubella

Answer

HHV 5

Question 5

In HIV patients, Kaposi's sarcoma is most likely caused by which of the following?

Accepted Answer

Virus

Answer

Bacteria

Answer

Parasite

Answer

Fungus

Question 6

Which of the following is NOT a characteristic of hepatitis B infection?

Accepted Answer

HBcAg in serum indicate active infection

Answer

Alpha interferon is used for the treatment of chronic infection

Answer

Establishes chronic infections in those infected as infants

Answer

Can cause hepatocellular carcinoma

Question 7

Most sensitive test for diagnosis of infectious mononucleosis:

Accepted Answer

Paul Bunnel test

Answer

Monospot test

Answer

Culture of the virus

Answer

Lymphocytosis in peripheral smear

Question 8

Genital warts are caused by:

Accepted Answer

Human Papilloma Virus

Answer

Chlamydia trachomatis

Answer

Epstein Barr virus

Answer

HSV

Question 9

Which of the following is the most common clinical manifestation of human parvovirus B19?

Accepted Answer

Erythema infectiosum

Answer

Hydrops fetalis

Answer

Aplastic crisis in hemolytic anemia patients

Answer

Anemia in neonatal period

Question 10

Most common organism causing chronic complications in allograft transplant recipients:

Accepted Answer

Virus

Answer

Bacteria

Answer

Fungi

Answer

Parasite

Virology — MCQs

Virology — MCQs

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