Infectious Disease (Block 6): Herpes Viruses

Front 1

general structure of herpes viruses

Back 1

enveloped
dsDNA

Front 2

in terms of glycoproteins, g__ is the most important "neutralizing epitope," whereas g__ and g__ are required for infectivity of the viruses (bc it allows them to bind to tissues)

Back 2

gB

gB and gD

Front 3

how are herpes simplex viruses (HSV) 1 and 2 classified?

Back 3

based on antibodies to gG

Front 4

HSV1 occurs _______ (and it's VERY common), whereas HSV2 doesn't appear until ____ (much less common).

Back 4

early in life; puberty

Front 5

how is HSV transmitted? tell me about how it's reactivated...

Back 5

through break in skin (intimate contact/perinatal) --> virus moves up the nerves to sensory ganglia and reside there --> latency period

viruses rest there until reactivation occurs through some stress (menstraution, fever, stres) ==> most reactivation in healthy persons brief and asymptomatic

Front 6

although >90% of primary infections of herpes are asymptomatic, what are the clinical manifestations of HSV1 in the case of primary infection(4)? reactivation?

Back 6

TEND TO BE ABOVE BELT
Primary:
- gingivostomatitis (gum/tongue inflammation)
- keratoconjunctivitis
- herpetic whitlow (HSV infection of finger)
- encephalitis

Reactivation: herpes labialis (cold sore)

Front 7

although >90% of primary infections of herpes are asymptomatic, what are the clinical manifestations of HSV2 in the case of primary infection? reactivation?

Back 7

TEND TO BE BELOW BELT
Primary:
- genital/neonatal herpes

Reactivation: genital herpes (reactivation cases are often milder)

Front 8

Most common cause of corneal blindness in the US

Back 8

HSV keratitis

Front 9

what are the organisms that can cross the blood-placenta barrier?

Back 9

TORCHES

TO: TOxoplasmosis
R: Rubella
C: cytomegalovirus
HE: HErpes, HIV
S: syphilis

Front 10

What is most common cause of viral encephalitis in the US?

Back 10

HSV-1

Front 11

painful grouped vesicles on an erythematous base is typical finding of what virus?

Back 11

HSV 1/2

Front 12

Dx and prevention of herpes simplex virus

Back 12

Dx:
- Tzanck smear for MULTINUCLEATED GIANT CELLS (TSANCK HEAVENS I DO NOT HAVE HERPES!!)
- culture
-serology

Prevention: NO VACCINE AVAILABLE!!

- c section for infected mother

Front 13

why do patients get hallucinations with herpes simplex virus?

Back 13

virus targets temporal lobe -- but don't worry, it's TREATABLE!!

Front 14

VZV stands for _________.

Back 14

Varicella (chickenpox) zoster (shingles) virus. Most kids get varicella, but afterwards, the virus remains latent until later in late adulthood, can reactivate as zoster (usually with stressors or immunocompromised situations)

Front 15

how is VZV transmitted? how long is the incubation period

Back 15

respiratory transmission and incubates for 2 weeks, infects T cells and then followed by viremia (hematogenous spread to skin and sensory ganglia (site of lantency))

Front 16

For VZV, what are the clinical presentations for primary (varicella) vs. recurrent infections (zoster)?

Back 16

primary:
- fever, malaise/headache, characteristic rash that starts on face/trunk and goes all over body (chicken pox)
- severity inc with age (immunocompromed can develop pneumonia, encephalitis, hepatiis, nephritis as complication)

Recurrent infection:
- zoster (shingles) reactivate and follow distinct dermatomal distribution
- trigeminal reactivation may cause blindness

Front 17

can you get perinatal infection of VZV?

Back 17

yes, if mom gets sick right before pregnancy -- these perinatal infections may lead to congential abnormalities

Front 18

Dx of VZV
Prevention of VZV
Tx of VZV

Back 18

Dx: same as HSV, remember??

prevention: live attenuated vaccine for children/adults wiht no history of chickenpox
- high dose zoster vaccine for elderly

Tx: acyclovir, famciclovir, valacyclovir

Front 19

the highest infection rate of cytomegalovirus (CMV) is in CHILDHOOD/ADULTHOOD

Back 19

childhood (risk factors include day care attendance, homosexuality in men, mexicans/blacks, transplant/transfusion recipients)

Front 20

how can you get CMV (3 ways)?

Back 20

sexual transmission
transfusions
perinatal (major cause of congenital abnormality) -- CMV most common viral cause of mental retardation

Front 21

what's the important thing about reactivation of CMV?

Back 21

there's NO REACTIVATION of CMV in immunoCOMPETENT hosts

Front 22

incubation period of CMV

Back 22

1-2 months

Front 23

although most infections of CMV are asymptomatic (80%), what are the perinatal clinical manifestations? what about in older children/adults?
what about in immunocompromised pts?

Back 23

perinatal:
- Mental retardation
- Microcephaly (small head)
- DIsseminated dz
- Vision/hearing loss
"Mr. M. Div."

older children/adults:
- mononucleosis (similar to EBV) ==> fever, mild hepatitis, lymphocytosis

immunocompromised: hepatitis, retinitis, colitis, encephaliits, pneumonia

Front 24

Dx and prevention of CMV

Back 24

Dx:
- in blood and urine: antigen detection, viral DNA detection
- serology: presence of IgM antibodies
- histopathology: cytomegalic cells with nuclear and cytoplasmci inclusions ("owls' eyes)

prevention: screening prior to transfusion or organ transplantation
- there are antivirals for high risk population(ganciclovir/foscamet)??

Front 25

most childhood infections of EBV are _______, whereas in young adults they are ________.

Back 25

asymptomatic; symptomatic

Front 26

how is EBV transmitted?

Back 26

via oropharynx (direct contact w/ secretions "the kissing dz")
- also in genital secretions

EBV then infects the B cells!!

Front 27

what are the symptoms of EBV mononucleosis due to?

Back 27

the CD8 response against proliferating B cells infected with EBV (they become atypical lymphocytes! )

Front 28

do normal hosts get reactivation of EBV?

Back 28

no, they don't.

Front 29

what are the clinical manifestations of EBV?

Back 29

- infectious mononucleosis + fever (sore throat, lymphadenopathy, splenomegaly)
- oral hairy leukoplakia: occurs in HIV pts

Front 30

name the associated tumors of EBV

Back 30

nasopharyngeal carcinoma
Burkitt's lymphoma
non-Hodgkin's lymphoma
Hodgkin's dz

Front 31

in terms of Dx for EBV, what does CBC show up as?
2 other ways to Dx (which one is definitive)?

Back 31

lymphocytosis with atypical lymphocytes

heterophile antibodies (Monospot test)- non-specific

IgM to VCA (viral capsid antigen) -- DEFINITIVE!!

Front 32

What does IgG-VCA show?

Back 32

marker of infection at previous time

Front 33

prevention and Tx for EBV?

Back 33

prevention: avoid contact sports (prevent splenic rupture)
- steroids (to prevent complications)

Tx: NO ANTIVIRALS -- bc syptoms are due to immune response!! KNOW IT!

Front 34

Most infection of HHV 6 occurs during early childhood (6 monts -2 years). what's the clinical manifestation for children vs. adults vs. immunocompromised pts?

Back 34

children: roseola "sixth dz" (parvovirus causes "fifth dz")
- febrile illness for 3-5 days followed by diffuse rash as fever abates

adults: resembles infectious mono

immunocompromised pts: severe fever+rash

Front 35

HHV 8 is transmitted how? what does it infect?

Back 35

sexual contact
oral (saliva)
perinatal

infects endothelial cells

Front 36

what tumors is HHV8 associated wiht?

Back 36

Karposi's sarcoma (involves lower extremity)

primary effusion and body cavity lymphoma

multicentric castlemans' dz

Front 37

Tx of HHV8

Back 37

chemo, radiation, antiviral

Front 38

What is a common lethal complication with Herpes B (Herpes Simiae)?

Back 38

CNS involvment (in untreated pts) -- effective antiviral therapy is availbae and must be given early during course of illness