Viral Infections

Question 1

Clinical features of measles

Answer 1

Fever + 3Cs: Cough, Coryza, Conjunctivitis

Maculopapular rash (cephalocaudal spread)

Koplik spots

Question 2

Ulcerated mucosal lesions near Stensen duct

Answer 2

Koplik spots

Question 3

Multinucleated giant cells with eosinophilic nuclear/cytoplasmic inclusions of measles

Answer 3

Warthin-Finkeldey cells

Question 4

Complications of measles

Answer 4

Pneumonia, Encephalitis

Pregnancy Risks: Fetal death

Late Pregnancy: Subacute Sclerosing Panencephalitis

Question 5

Clinical features of Mumps

Answer 5

Parotitis (bilateral in 70% of cases)

Orchitis (testicular inflammation)

Pancreatitis

Encephalitis

Question 6

Morphology of the mumps

Answer 6

Mononuclear cell infiltration

Edema

Question 7

Most common extrasalivary gland complication: Aseptic meningitis

Sterility (in cases of severe testicular damage)

Answer 7

Mumps (Paramyxoviridae)

Question 8

Orofacial infections:

Cold sores

Gingivostomatitis

Herpetic whitlow (fingers, palms)

Answer 8

HSV-1 (α-herpesvirus)

Question 9

Genital herpes

Answer 9

HSV-2 (α-herpesvirus)

Question 10

Keratitis (eye infection)

Encephalitis (brain infection)

Esophagitis

Pneumonia

Hepatitis

Answer 10

HSV 1 and 2

Question 11

Characteristic CPE (Cytopathic Effect) of HSV

Answer 11

Round cells

Clumping

Syncytial giant cells

Question 12

Gross pathology of HSV

Answer 12

Painful vesicles → rupture → crusting/ulceration

Lesions not following dermatomal distribution

Question 13

Micro pathology of HSV

Answer 13

Cowdry Type A inclusion bodies:
Large
Pink/purple
Intranuclear

Multinucleated syncytia

Question 14

Incubation: 14–21 days

Prodrome → Pruritic rash

Centrifugal spread: Torso → Extremities

Macule → Vesicle (“Dewdrop on a rose petal”) → Rupture → Crusting

Answer 14

Varicella-Zoster Virus (VZV) (α-herpesvirus)

Question 15

Reactivation (common in immunocompromised)

Painful vesicular rash in dermatomal distribution

Answer 15

Herpes Zoster (Shingles)

Question 16

Vesicular centripetal rash

Answer 16

chickenpox

Question 17

This is the appearance (clear vesicles on red base) of varicella zoster

Answer 17

Dewdrop on a rose petal

Question 18

Caused by geniculate ganglion involvement

Leads to facial nerve paralysis

Answer 18

Ramsay Hunt Syndrome

Question 19

Remains latent in:

Dorsal root ganglia

Peripheral cranial nerves

Answer 19

Varicella Zoster

Question 20

Reactivation of VZV

Painful vesicular rash in dermatomal distribution

Answer 20

Shingles

Question 21

Complications of VZV

Answer 21

Postherpetic neuralgia

Ophthalmic involvement: Keratitis, Ophthalmia

Neurological: Hearing loss, Facial paralysis, Aseptic meningitis

Question 22

Characteristics of CMV

Answer 22

Enveloped virus with icosahedral nucleocapsid

Contains linear dsDNA

Cultured in shell vial tubes

Negative heterophil test (distinguishes from EBV)

Question 23

CMV transmission routes

Answer 23

Body fluids (saliva, urine, semen, vaginal secretions)

Transplacental (congenital CMV)

Organ transplantation

Blood transfusion

Question 24

Clinical forms of CMV

Answer 24

Congenital
Perinatal
Mononucleosis
Immunocompromised

Question 25

Enlarged cells with basophilic intranuclear inclusions surrounded by clear halo Small basophilic intracytoplasmic inclusions

Answer 25

Owl's eye from CMV

Question 26

Clinical forms of EBV

Answer 26

Infectious Mononucleosis

Question 27

EBV associated features

Answer 27

Burkitt lymphoma Nasopharyngeal carcinoma Hodgkin lymphoma (in immunocompromised)

Question 28

What are the key histopathologic findings in EBV infection?

Answer 28

Lymph node: Paracortical hyperplasia (T-cell zone expansion) Blood smear: Atypical lymphocytes + smudge cells

Question 29

What are the 3 major EBV-associated malignancies?

Answer 29

Burkitt lymphoma Nasopharyngeal carcinoma Hodgkin lymphoma

Question 30

What molecular event drives Burkitt lymphoma development?

Answer 30

t(8;14) translocation → MYC overexpression (EBV first causes polyclonal B-cell expansion)

Question 31

How does LMP-1 promote oncogenesis? (3 mechanisms)

Answer 31

Mimics CD40 → activates NF-κB/JAK-STAT Upregulates BCL2 (anti-apoptotic) Promotes B-cell survival/proliferation

Question 32

What is EBNA2's oncogenic mechanism?

Answer 32

Mimics Notch → activates: Cyclin D SRC proto-oncogenes

Question 33

How does EBV evade immunity?

Answer 33

vIL-10 suppresses T-cell activation

Question 34

What are 2 life-threatening complications of mono?

Answer 34

Splenic rupture (avoid contact sports) Liver dysfunction

Question 35

How are herpesviruses classified by subfamily?

Answer 35

α: HSV-1/2, VZV (sensory ganglia latency) β: CMV, HHV-6/7 (lymphocyte/salivary gland latency) γ: EBV, KSHV (B-cell latency, oncogenic)

Question 36

What are key features of poliovirus?

Answer 36

Picornaviridae RNA virus, 3 serotypes Pre-vaccine: Teens (industrialized) vs infants (developing) Complications: Paralysis (<1%), post-polio syndrome (decades later)

Question 37

What are the γ-herpesviruses and their cancer associations?

Answer 37

EBV (HHV-4): Burkitt lymphoma, nasopharyngeal CA KSHV (HHV-8): Kaposi sarcoma

Question 38

What's the #1 complication of polio infection?

Answer 38

Paralysis (asymmetric, lower limbs) Post-polio syndrome occurs 30-40 yrs later