Herpes And Pox Viruses

Question 1

Give a brief description of the herpesviridae family

Answer 1

Enveloped dsDNA viruses

MW: 80-150,000kD

Latent infection after initial entry

Reactivation to produce recurrent infections

Some are associated with cancer
Eg EBV with nasopharyngeal carcinoma and Burkitt’s lymphoma

Human Herpes virus 8 with Kaposi sarcoma

Question 2

Classify herpes viruses

Answer 2

HHV1- Herpes Simplex virus type 1

HHV2- Herpes Simplex virus type 2

HHV3- Varicella Zoster virus

HHV4- Epstein-Barr virus

HHV5- Human cytomegalovirus

HHV6- Human Herpes virus 6

HHV7- Human Herpes virus 7

HHV8- Kaposi sarcoma associated herpes virus

Question 3

HHV1, 2, 3 (VSV) have their site of latency in the sensory nerve ganglia

True or false

Answer 3

True

HSV1- Trigeminal ganglion
HSV2- Sacral ganglion

Question 4

HHV4 (EBV) has its site of latency where❓

Answer 4

B-lymphocytes

Question 5

HHV5 (CMV) has its site of latency where❓

Answer 5

Epithelial cells

Leukocytes

Question 6

Which HHVs have their site of latency in T lymphocytes❓

Answer 6

HHV6

HHV7

Question 7

HHV8 (KSHV) has its site of latency in❓

Answer 7

B lymphocytes

Epithelial cells

Question 8

In most developing countries, 90% of population have HSV1 antibody by the age of 30

Answer 8

True

Question 9

The detection of HSV-2 antibody before puberty is a usual occurrence

True or false

Answer 9

False, it’s unusual

Question 10

What is the prevalence of HSV-2 antibody in Africa❓

Answer 10

51-68%

More common in women

Question 11

How is HSV-1 transmitted❓

How is HSV-2 transmitted❓

Answer 11

1.
Kissing
Direct contact with infected saliva
Respiratory droplets

2. Sexual transmission

Question 12

Is the primary infection of HHV is usually asymptomatic or symptomatic❓

Is the reactivation of HHV symptomatic or asymptomatic❓

Answer 12

Asymptotic or mild; painful blistering rash 1-3days post exposure

Asymptomatic; symptoms are less severe

Question 13

Is viraemia more common in HSV-2 or HSV-1

Answer 13

HSV-2, usually occurs in immunocompromised patients

Question 14

What are the stimuli for the reactivation of HHV❓

Answer 14

Fever

Stress

Sunlight

Immunosuppression

Question 15

Oropharyngeal Herpes is characterized by❓

It is usually seen in what age group❓

How long does it last❓

It is usually seen in what category of HHV❓

Answer 15

1.
Fever blisters/Cold sores

Gingivostomatitis: ulcerative lesions involving the buccal mucosa, tongue, gums, pharynx

2. Children <5 years
3. Lasts 5-12 days

4.
HSV-1

Question 16

Genital herpes, a very common sexually transmitted infection, is caused by❓

The efficiency of sexual transmission is greater from which sex❓

Answer 16

1.
HSV-1
HSV-2

2.
Men➡️Women

Question 17

1. In the primary infection of HSV-1 and HSV-2, what’s the incubation period of the virus❓
2. How long does the primary infection last❓
3. How would you identify it❓
4. What course does it follow❓
5. Is the primary infection more severe than the recurrent or vise versa❓
6. Is a symptomatic viral shedding greater in HSV1/HSV2 ❓

Answer 17

5days

11-12days

• Multiple painful vesicopustular lesions, bilateral and extensive
• Bilateral enlarged tender inguinal lymph nodes

4. 
Papules
  ⬇️
 Vesicles 
  ⬇️
 Pustules 
  ⬇️
 Ulcers 
  ⬇️
 Crusts 
  ⬇️
 Healed 

5. The primary infection is more severe; recurrent is mild and of short duration
6. HSV2

Question 18

A recurrent symptomatic infection with genital herpes is usually mild and short in duration

True or false

Answer 18

True

Question 19

Is asymptomatic viral shedding greater in HSV-1/HSV-2❓

Answer 19

HSV-2

Question 20

What is the mortality of Neonatal Herpes❓

What is usually the sequelae in those who survive❓

Answer 20

60%

Neurologic

Question 21

Is viral encephalitis usually seen in HSV1/HSV2❓

Is meningitis usually seen in HSV1/HSV2❓

Answer 21

HSV-1, may also present with ocular infections (keratoconjunctivitis)

Meningitis is usually seen in HSV-2

Question 22

1. a. In using Tzanck test to diagnose HSV, what would you watch out for❓
   b. Is this test sensitive and specific❓

2.
a. If the type specific serological test is positive for HSV2, what would that denote❓

b. Does the type specific serological test positive for HSV1 distinguish between an anogenital and orolabial infection❓

Answer 22

1.
a. Intranuclear inclusions/multinucleated giant cells

b. This test is insensitive and nonspecific for HSV

2.
a. An anogenital infection

b. A +ve HSV1 can’t distinguish btwn an anogenital and orolabial infection

Question 23

How would you diagnose a case of HSV-1 / HSV-2❓

Answer 23

Viral culture

PCR

Antigen detection

Type specific serological test

Tzanck

Question 24

How would you treat a case of HSV-1 / HSV-2❓

Would it eradicate the latent virus❓

Answer 24

1. Acyclovir 400mg orally 7-10days

Valacyclovir 1g orally 7-10days

Famciclovir

Episodic and suppressive treatments ⬇️fq of recurrence by 70-80% in px w recurrence >6 per year

2. No, it wouldn’t eradicate the latent virus

Question 25

Varicella zoster virus VZV... 1. Is transmitted by❓ 2. Is a highly contagious childhood disease, T/F❓ 3. Has an incubation period of❓ 4. Is presented clinically as❓ 5. Describe the disease progression

Answer 25

1. Respiratory droplets 2. T, it’s a highly contagious childhood dx 3. Incubation period: 11-21 days 4. Generalized vesiculopapular rashes ``` 5. Macules ⬇️ Papules ⬇️ Vesicles ⬇️ Pustules ⬇️ Crust ```

Question 25

Herpes zoster (Shingles)... 1. Occurs by reactivation of❓ 2. Is most common in the elderly, T/F❓ 3. Is presented clinically as❓ 4. What is it’s complication❓

Answer 25

``` 1. Reactivation of latent VZV ⬇️ multiplication with a sensory ganglion ⬇️ Travels down the sensory nerve to the skin ``` 2. T, most common in the elderly 3. Vesicular lesions on the skin 4. Post herpetic neuralgia

Question 25

1. What methods can be used to prevent and control VZV❓ 2. How would you diagnose a case of VZV❓ 3. What treatment will you give❓

Answer 25

1. Use of Varicella Immune Globulin Use of attenuated varicella/shingle vaccine Isolation 2. Viral culture Antigen detection (immunoflourescence antibody staining) PCR 3. Acyclovir for >18yrs children w severe dx

Question 25

CMV... 1. Is transmitted via what routes❓ 2. Causes which infections❓

Answer 25

``` 1. Intra-uterine Perinatal Blood transfusion Organ transplantation ``` 2. Pneumonia Ocular infections

Question 25

What do you know about CMV❓

Answer 25

* Most individuals are infected with in the first few years of life * Rarely causes disease in healthy pple * It is an infectious mononucleosis-like syndrome, with subclinical infections * Establishes lifelong latent infections * Viral shedding through pharynx and urine, months to years after primary infection

Question 26

What diseases can occur in a CMV infected immunocompromised pt❓

Answer 26

Intestinal pneumonia (most common) Retinitis Enteritis Disseminated infection

Question 27

How would you diagnose a case of CMV❓ What treatment will you give❓ How can you control it❓

Answer 27

1. PCR Isolation of virus (human fibroblasts) Antigen detection; pp65 assay (immunoflourescence) Antibody detection (IgG past infection, IgM new infection) 2. Ganciclovir 3. Isolation of newborn Screening of transplant donors and recipients for CMV antibody

Question 28

What do you know about EBV❓

Answer 28

Most pple are infected by adulthood Causes immortalization of infected cell lines Viral shedding occurs through saliva

Question 29

EBV/Infectious mononucleosis/Glandular Fever... 1. Is transmitted via❓ 2. Initiates infection in the❓ 3. Is replicated in the❓ 4. Is reactivated by❓ 5. Has an incubation period of❓ 6. Presents clinically as❓ 7. Last for how long❓

Answer 29

1. Close contact/Kissing 2. Oropharynx 3. Epithelial cells/surface B lymphocytes of pharynx and salivary gland 4. Immunosuppression 4-7 weeks ``` 6. Fever/Malaise Lymphadenopathy Sore throat Hepatosplenomegaly ``` 2-4 weeks

Question 30

Which cancers can be caused by EBV❓

Answer 30

Nasopharyngeal ca Burkitt’s lymphoma Hodgkin’s disease Non-Hodgkin’s lymphoma Gastric ca Oral hairy leukoplakia (esp on AIDS) Lymphoproliferative disorders

Question 31

What tests will you order for if you suspect a case of EBV❓

Answer 31

PCR Isolation of virus Antibody detection (IgG/IgM/EBNA) Heterophile antibody test/monospot

Question 32

List: 1. Latent Phase antigens 2. Late phase antigens for EBV

Answer 32

1. Latent Phase: EBNA (EBV nuclear antigens) LMP (late membrane proteins) 2. Late Phase: VCA (Viral capsid antigens) Viral glycoproteins

Question 33

70-80% of pt with acute IM develop heterophil antibodies that agglutinate sheep RBCs True or false

Answer 33

True

Question 34

Roseola/exanthem subitum 1. Is caused by which HHV❓ 2. Is characterized by❓ 3. Reactivated by❓

Answer 34

1. HHV6 2. Fever (3days) Maculopapular rash from trunk➡️extremities 3. Immunosuppression

Question 35

Give a brief description of the pox viruses

Answer 35

* Large, complex structure * Brick-shaped/ovoid * dsDNA-carrying virions * 200 * 300nm * Envelope is not acquired by budding and not essential for infectivity * Replication occurs in the cytoplasm

Question 36

Small pox (orthopoxvirus).... 1. Was eradicated in❓ 2. Presents clinically as❓ 3. Is a potential bioterrorist weapon, T/F❓

Answer 36

1979 Uniform papulovesicular rash that evolves to pustules over 1-2weeks True

Question 37

Molluscum contagiosum (molluscipoxvirus)... 1. Is transmitted via❓ 2. Has an incubation period of❓ 3. An infection presents clinically as❓ 4. Can be treated by❓

Answer 37

Direct skin to skin contact 2-8 weeks 2 to 10mm, benign, painless, nodular, pale, firm lesions in the epidermis Curettage/careful removal of the central core w forceps

Question 38

Orf/Parapoxvirus of goat and sheep... 1. Is acquired by❓ 2. Has a duration of infection of❓ 3. Presents clinically as❓ 4. Can be diagnosed using❓

Answer 38

1. Close contact with infected animal Inoculation through cuts/abrasions 2. About 35 days 3. Begins as a vesicle Evolved into nodular mass Develops central necrosis ``` 4. Clinical appearance Occupational history Serology Electron microscopy ```

Question 39

1. Describe the epidemiology of monkeypox 2. It’s similar to smallpox but milder, T/F❓ 3. Is transmitted by❓ 4. Has an incubation period of❓ 5. Clinical presentation❓ 6. Prodrome lasts for how long❓ 7. How would you treat Monkeypox❓

Answer 39

1. Rare Occurs in Central and West Africa 2. True 3. Contact w cutaneous/mucosal lesions of infected animals Contact with blood/body fluids of infected humans 5-21 days ``` 5. Fever/malaise Headache Lymphadenopathy Enanthem on tongue and mouth ``` 1-5days 7. Isolation No specific treatment available Vaccine against smallpox (85% effective)

Question 40

A seeming presentation w monkeypox could also be❓

Answer 40

``` Smallpox Chickenpox Measles Bacterial skin infections Scabies Secondary syphilis Drug related allergies ```

Question 41

Would tests would you request for to diagnose monkeypox❓

Answer 41

``` Clinical presentation ELISA Antigen detection tests PCR Virus isolation ```