Micro - Virology (Herpesviruses)

Question 1

Name 7 major Herpesviruses.

Answer 1

(1) HSV-1 (2) HSV-2 (3) VZV (4) EBV (5) CMV (6) HHV-6 (Note: HHV-7 is less common cause of same condition as HHV-6) (7) HHV-8

Question 2

What are the 2 routes of transmission for HSV-1?

Answer 2

Respiratory secretions, saliva

Question 3

What 4 diseases result from HSV-1 infection?

Answer 3

(1) Gingivostomatitis (2) Keratoconjuctivitis (3) Temporal lobe encephalitis (4) Herpes labialis

Question 4

What is the most common cause of sporadic encephalitis in the US, and what virus causes it?

Answer 4

Temporal lobe encephalitis; HSV-1

Question 5

Where are the following herpesviruses latent: (1) HSV-1 (2) HSV-2 (3) VZV (4) EBV?

Answer 5

(1) Trigeminal ganglia (2) Sacral ganglia (3) Dorsal root or trigeminal ganglia (4) B cells

Question 6

What 2 diseases result form HSV-2 infection?

Answer 6

(1) Herpes genitalis (2) Neonatal herpes

Question 7

What 3 diseases result from VZV infection?

Answer 7

(1) Varicella-zoster (chickenpox, shingles) (2) Encephalitis (3) Pneumonia

Question 8

Where is latent HSV-1 found?

Answer 8

Latent in trigeminal ganglia

Question 9

Where is latent HSV-2 found?

Answer 9

Latent in sacral ganglia

Question 10

Where is latent VZV found?

Answer 10

Latent in dorsal root or trigeminal ganglia

Question 11

What are the 2 routes of transmission for HSV-2?

Answer 11

Sexual contact, perinatal

Question 12

What is the route of transmission for VZV?

Answer 12

Respiratory secretions

Question 13

What are the 2 routes of transmission for EBV?

Answer 13

Respiratory secretions, saliva

Question 14

What infectious disease is caused by EBV? What 4 symptoms characterize it?

Answer 14

Mononucleosis. Characterized by fever, hepatosplenomegaly, pharyngitis, and lymphadenopathy (especially posterior cervical nodes).

Question 15

How is EBV transmitted? What is another name for this infection, and why?

Answer 15

Transmitted by respiratory secretions and saliva; also called “kissing disease” since commonly seen in teens, young adults.

Question 16

What 2 herpesviruses share the same 2 routes of transmission? What are those 2 routes of transmission?

Answer 16

(1) HSV-1 (2) EBV; Respiratory secretions, saliva

Question 17

What are the 6 routes of transmission for CMV?

Answer 17

(1) Congenital (2) Transfusion (3) Sexual contact (4) Saliva (5) Urine (6) Transplant

Question 18

What 4 diseases result from CMV?

Answer 18

(1) Congenital infection (2) Mononucleosis (negative Monospot) (3) Pneumonia (4) Retinitis

Question 19

What is the characteristic histologic finding associated with CMV infection?

Answer 19

Infected cells have characteristic “owl’s eye” inclusions

Question 20

Where is latent CMV found?

Answer 20

Latent in mononuclear cells

Question 21

What is characteristic of mononucleosis due to CMV infection?

Answer 21

Negative Monospot (unlike EBV, which is positive Monospot)

Question 22

What is the route of transmission for HHV-6?

Answer 22

Transmitted by saliva

Question 23

What is the route of transmission for HHV-8?

Answer 23

Sexual contact

Question 24

What disease does HHV-6 cause? How does it present?

Answer 24

Roseola: high fevers for several days that can cause seizures, followed by a diffuse macular rash

Question 25

What disease does HHV-8 cause, and in what patient population is it seen?

Answer 25

Kaposi’s sarcoma, a neoplasm of endothelial cells. Seen in HIV/AIDS and transplant patients.

Question 26

What is the test of choice for identification of HSV in the following contexts: (1) Skin/genitalia (2) Herpes encephalitis?

Answer 26

(1) Viral culture for skin/genitalia. (2) CSF PCR for herpes encephalitis.

Question 27

What sample is taken for a Tzanck test? What does it detect? What virus is it used to identify?

Answer 27

A smear of an opened skin vesicle to detect multinucleated giant cells; HSV Identification; Think: “Tzanck heavens I do not have herpes”

Question 28

Again what finding does the Tzank test detect, and in what conditions is this finding seen? What is another finding seen in these conditions but not detected by Tzanck test?

Answer 28

Tzanck test - a smear of an opened skin vesicle to detect multinucleated giant cells, HSV identification; Infected cells also have intranuclear Cowdry A inclusions

Question 29

Aside from mononucleosis, with what other diseases/conditions is EBV associated?

Answer 29

Also associated with development of Hodgkin’s and endemic Burkitt’s lymphomas as well as nasopharyngeal carcinoma

Question 30

What is the most common complication of shingles?

Answer 30

Most common complication of shingles is post-herpetic neuralgia

Question 31

What cell type does EBV infect? Along those lines, what are the cell findings of EBV infection on peripheral blood smear?

Answer 31

Infects B cells. Atypical lymphocytes seen on peripheral blood smear are not infected B cells but rather reactive cytotoxic T cells

Question 32

What kind of test is used for EBV infection? More specifically, what is detected by this test, and how?

Answer 32

Positive Monospot test; Heterophile antibodies detected by agglutination of sheep or horse RBCS.

Question 33

Besides mononucleosis, what are 3 other conditions associated with EBV infection?

Answer 33

Associated with (1) Hodgkin lymphoma, (2) Endemic Burkitt lymphoma, (3) Nasopharyngeal carcinoma.

Question 34

Again, what virus is associated with Kaposi sarcoma? Briefly describe the appearance of Kaposi sarcoma on the skin. What are 2 other areas that this may also affect?

Answer 34

HHV-8; Dark/Violaceous flat and nodular skin lesions representing endothelial growths. Can also affect GI tract and lungs.