Microbio Week 11 - Herpesviruses and VZV (Exam 3) Flashcards
Describe herpesviruses
dsDNA
Linear
Icosahedral
Enveloped
T/F: Herpesviruses are inactivated by detergents, acid, and drying
True, they are enveloped
What are the 2 types of infections involved with herpesviruses?
Lytic
Latent
Are all herpesviruses localized or systemic/generalized?
Systemic/generalized
Name the antivirals for herpesviruses
Acyclovir
Valacyclovir
Famciclovir
Gangciclovir
What does the acyclovir class of antivirals stop?
Viral DNA replication
What is acyclovir activated by?
Viral thymidine kinase
Once acyclovir is activated by a viral
thymidine kinase, it is used by the viral DNA polymerase and causes what?
Viral DNA chain termination
T/F: The acyclovir antivirals must be activated by a protein found in an infected cell, a viral thymidine kinase
True
Acyclovir can only act on which type of cells?
Cells infected by the herpesvirus
Which antiviral is just a prodrug of acyclovir?
Valacyclovir
What is valacyclovir metabolized in the body to?
Acyclovir
Why is valacyclovir useful?
Has a longer 1/2 life (can take fewer pills/day)
Which antiviral is the oral prodrug of the topical ointment penciclovir?
Famciclovir
Which drug is often used interchangeably with acyclovir and valacyclovir?
Famciclovir
Which antiviral is used for CMV infections?
Ganciclovir
Which antiviral has a prodrug called valganciclovir that has a longer half life in the body?
Ganciclovir
Resistance to the acyclovir class of drugs usually occurs where?
In the viral thymidine kinase
What drugs can be used if resistance to acyclovir develops?
Drugs NOT phosphorylated by the viral thymidine kinase
Which forms of herpesvirus can infect mucosal epithelial cells, cause lesions, and become latent in nerve ganglia?
HSV 1 and 2
Which nerve ganglia do oral HSV 1 and 2 become latent?
Trigeminal ganglia
Which nerve ganglia do genital HSV 1 and 2 become latent?
Sacral ganglia
T/F: HSV 1 and HSV 2 are identical viruses
FALSE, they are similar but NOT identical
Can a person be infected with both HSV 1 and HSV 2?
Yes
What occurs during latency in HSV 1 and 2 infections that allows the infected cells to be hidden from the immune system?
Virus doesn’t express proteins
How do HSV and VZV go up the nerve?
Retrograde axial transport
T/F: HSV and VZV will go up the nerve via retrograde axial transport and lay dormant, latent
True
Is any virus produced in latency?
No
Can a latent virus be reactivated in order to produce the virus again?
Yes
T/F: HSV-1 causes oral herpes and HSV-2 causes genital herpes
FALSE, either virus can cause oral or genital herpes!
What is the vast majority of oral herpes caused by?
HSV 1
What is the majority of genital herpes caused by?
HSV 1 or HSV 2 (both!)
What does oral HSV 1 protect against?
Protects against acquiring genital HSV 1
(since you already have the ABs from the oral infection)
What is the name for the first infection with oral HSV?
Gingivostomatitis
What is the primary causative agent in gingivostomatitis?
HSV 1
What are the symptoms of gingivostomatitis?
Gingivitis
Vesicles on buccal mucosa, tongue, hard palate, gingiva, lips, face
Vesicles from gingivostomatitis break down into ________ and then crust over on the lips and face but usually don’t _________
ulcers; scar
How long do symptoms from gingivostomatitis last?
1-2 weeks
(can be painful, children can become dehydrated)
There is often _________ and enlarged ___________ in gingivostomatitis
fever; lymph nodes
What is the name for any reactivation/recurrent oral herpes after the primary infection?
Herpes labialis
T/F: Herpes labialis (recurrent oral herpes) is usually more severe with more lesions and appears in a different place as primary lesions
FALSE, it is LESS severe with LESS lesions and appears in the SAME place as primary lesions
Name 4 things that can trigger a recurrence (herpes labialis)
Stress
UV light
Menstruation
Dental procedures
T/F: Herpes labialis is less severe, with no fever or lymph node swelling
True
What is common in people who have been infected with HSV-1?
Oral asymptomatic shedding of HSV-1
A large proportion of the US are seropositive for ________, almost all from genital infection. The vast majority of them do not know they are positive.
HSV-2
T/F: There is an increasing amount of people infected genitally with HSV-1
True
Is it common to get HSV from an asymptomatic shedding partner (meaning the person infected with HSV has no visible sores)?
Yes
Are asymptomatic infections common?
Yes
Where are genital herpes lesions present?
Genital epithelium
Upper thighs
Anal area
T/F: As in primary oral infections, the
primary genital infection is the worst and can result in lymph node swelling, fever, and more sores than will be present in reactivation events
True
HSV-2 tends to cause (more/less) recurrences and asymptomatic shedding than genital HSV-1
More
For oral and genital recurrent herpes sores, which 3 drugs can be taken prophylactically or at the first signs of an outbreak?
Acyclovir
Valacylovir
Famciclovir
What 3 drugs can also be taken daily to help prevent outbreaks and transmission but do not entirely stop asymptomatic shedding?
Acyclovir
Valacylovir
Famciclovir
The risk of acquiring _______ is increased if genitally infected with HSV-2
HIV
What is the name for herpetic lesions on the finger and was common in dentists and other health care workers?
Herpetic Whitlow
T/F: Children and adults can secrete herpes in saliva without visible sores
True
Herpetic Whitlow can also be caused by what?
Autoinoculation
Herpetic Whitlow lesions can shed ______ and spread the virus to others
HSV
Are recurrences common in Herpetic Whitlow?
Yes
How do you prevent Herpetic Whitlow?
Gloves and handwashing
Topical acyclovir or penciclovir, oral acyclovir, valacyclovir, or famciclovir can reduce symptoms in which type of herpes infection?
Herpetic Whitlow
What is caused by reactivating oral herpes going to the eye or spread by touching the eye and contaminating it with HSV-1?
Ocular herpes
Ocular herpes can cause more severe infections that scar the ___________
cornea
Can ocular herpes reoccur?
Yes
What is there a higher chance of if ocular herpes reoccurs?
Permanent vision loss
Antiviral eye drops and/or oral acyclovir are used to treat what type of herpes infection?
Ocular herpes
Almost all herpes simplex encephalitis infections are from which form of HSV?
HSV-1
HSV travels up ___________ or __________ nerves to the temporal or frontal lobes of the brain in herpes simplex encephalitis.
This can happen during primary infection or from the virus’s reactivation.
Olfactory or trigeminal
What causes necrosis of brain tissue in herpes simplex encephalitis?
Replication of the virus
Prompt treatment is needed with herpes simplex encephalitis.
What drug is given intravenously and can drastically reduce the fatality rate?
Acyclovir
T/F: Survivors of herpes simplex encephalitis can have neurological defects
True
How does neonatal herpes spread?
Vertically (mother to baby during pregnancy)
What form of HSV are most neonatal herpes infections caused by?
HSV-2
What else can neonatal herpes be caused by?
Reactivation of existing infection close to labor
The use of which drug in an infant can drastically reduce mortality in neonatal herpes infections?
Acyclovir
What is VZV?
Varicella zoster virus/chickenpox
Is VZV contagious?
Yes, it’s very contagious!!!
How is VZV spread?
Respiratory droplets
Lesions
Where are most VZV lesions found?
Face and trunk
Varicella can be more severe in adults, pregnant people, and the immunocompromised, with the most common risk being ____________
pneumonia
What is a defining feature of chickenpox?
Vesicular rash
T/F: Lesions of VZV are present in all stages, from just erupted to crusted over
True
Where is VZV latent?
Dorsal root and cranial nerve
Trigeminal ganglia
T/F: You should give aspirin to children with chickenpox or influenza, it is safe
FALSE, you should never give aspirin to kids, it may cause Reye’s syndrome
There is a risk for pneumonia with high mortality when pregnant and infected with ______________. The mortality can be lowered with treatment
Varicella
Varicella can cause severe congenital _____________ if a pregnant woman is infected in the first trimester
disabilities
If varicella symptoms occur before delivery, before a maternal ___________ response can occur and transfer to the fetus, the baby can contract ____________. The baby can have
disseminated disease
AB; varicella
T/F: Congenital varicella and disseminated infection of newborns are very rare
True
Reactivation of varicella virus along dermatomes causes what?
Herpes Zoster/Shingles
Reactivation of varicella virus along which dermatomes causes Herpes Zoster/Shingles most commonly?
Thoracic
Ophthalmic
Cervical
What is a shingles outbreak near the eye called?
Herpes Zoster Opthamalicus
About 1/3 of people with shingles can develop which disease that causes mild to severe pain after the resolution of lesions?
Post-herpetic neuralgia (PHN)
Shingles occur primarily in people over _____ years old when the CTL response for VZV seems to be waning
50
Herpes Zoster/Shingles can be very painful; lesions can be infectious and cause the primary infection of __________
chickenpox
What type of vaccine is recommended for all children to prevent chickenpox?
Attenuated
How many shots are needed for the chickenpox vaccine?
2
Because the varicella/chickenpox vaccine is an attenuated virus, it is contraindicated in which types of patients?
Immunocompromised
Pregnant
If contraindicated for the live-attenuated vaccine, what can be given to help prevent chickenpox infection?
Varicella IgG
What vaccine is approved for shingles?
Subunit
The shingles vaccine is very efficacious in preventing what?
Shingles
Post-herpetic neuralgia
What vaccine is recommended for all people over 50 who have had chickenpox?
Shingles vaccine
In people with HIV, there can be more recurrent oral and genital outbreaks that are more severe with which viruses?
HSV 1 and 2
In people with HIV, what are they more likely to get an earlier age and do worse if they contract chickenpox?
Shingles
