ID: viruses Flashcards
How many types of herpes viruses can affect humans
-the group is called?
8
known as Herpes Human Viruses HHV
how many types of herpes simplex viruses are there
two HSV-1 (above the waist) and HSV-2 (genital lesions)
when is HSV most contagious
-when else can it spread
when virus-filled lesions are present
can also spread during asympto shedding in saliva and genital secretions
herpes labialis
- also called
- which virus
HSV-1
cold sore
genital herpes
HSV-2
HHV-3 also called
varicella zoster virus
Varicella zoster virus also called
HHV-3
HHV-4
Epstein-barr virus
Epstein barr virus also called
HHV-4
HHV-5
Cytomegalovirus
Cytomegalovirus also called
HHV-5
Kaposi-sarcoma associated herpesvirus also called?
HHV-8
HHV-8
Kaposi-sarcoma associated herpesvirus
roseola infantum
HHV-6
Cytomegalovirus Mononucleosis
CMV or HHV-5
infectious mononucleosis
EBV or HHV-4
chicken pox
varicella zoster virus ir HHV-3
where does the herpes virus reside in for life?
sensory neurons—trigeminal and sacral ganglia
what general s/s occur before a HSV lesion develops
burning and stinging
herpetic whitlow
HSV infection of finger
Herpes gladiatorum
-common among?
HSV infection of trunnk and extremities (Common among wrestlers)
Keratoconjunctivitis
HSV infection of the eye
HSV in CNS causes?
meningitis or encephalitis
which strains of HHV can cause certain kinds of CA
HHV-8 or Kaposi sarcoma associated herpesvirus
and
EBV or HHV-4
Varicella Zoster (HHV-3):
- what dz does it cause
- transmission–how long is someone contagious–start to end
- prodrome?
- classic evolution of the rash?
- PE… hallmark?
- diagnosis— best one?
- tx: immunocompetent vs immunocomp
- prevention
Primary: varicella —>chicken pox
Reactivation: herpes zoster–>shingles
CHICKEN POX:
- transmission=aerosol droplets or direct contact
- contagious 48 hours prior to the onset of the rash up until ALL the lesions have crusted over**
Prodrome:
- fever
- malaise
- anorexia and/or pharyngitis followed by——>generalized vesicular rash usually w/in 24 hours
RASH: evolution
- *start as erythematous macules–>papules–>vesicular (crops)–>crust over
- *starts on face–>trunk–>spreads to extremities
- ***pruritic ** DEW DROPS ON A ROSE PETAL
PE:
**HALLMARK= maculopapules, vesicles, and scabs in various stages of evolution
Diagnosis:
- ***clinical
- *but can do a
1. Tznack smear= take scraping from the vesicle and will see MULTI NUCLEATED GIANT CELLS
2. VZV DNA via PCR
3. Immunofluorescent detection of viral antigen in lesions or culture
4. serologic tests - **BEST TEST IS PCR ***
TX:
1. health children <12 YO= supportive and sympto tx–tylenol and calamine lotion–NO NO NO NSAIDS it can cause superinfection
- Adults/adolescents >12, and immunocomp: Acylovir to help prevent complications— win 72 hrs of onset
* avoid contact with pregnant women
PREVENTION:
- Varicella (VAR) vaccine: live attenuated
* 1st dose=12-15MO
* 2nd dose=4-6 YO
what do we not want to give kids as anti-pyretic tx?
ASA because it can lead to Reye Syndrome
what do we not want to give as anti-pyretic for chicken pox
NSAIDS— can risk superinfection
complications from chicken pox
- MC comp in kids?
- MC in adults?
- bacterial superinfection MC in kids due to itching
- ->staph aureus
- ->staph pyogenes - Varicella pneumonia leading cause of mortality and morbidity in adults (3-7 days after rash)
HHV-3 Shingles
- when does it occur
- RF (3)
- CM
- diagnosis
- tx
- prevention
after primary infection with Varicella zoster– virus remains latent in the DRG or cranial nerve ganglia—- where it can reactivate
RF:
- normal aging.. >50 YO
- poor nutrition
- immunocompromised status
* **can occur in younger PT too
CM
- prodrome of fever, malaise, sensory changes (PAIN, burning, paresthesias)
- followeed by painful eruption of vesicles on erythematous base
- unilateral rash within a single dermatome—does not cross the midline–MC thorax
* Zoster ophthalmicus: opthalmic branch of trigeminal nerve (CNV) is involved—- can cause blindness in absence of tx **HUTCHINSON’s SIGN**
* *Ramsay Hunt Syndrome: facial nerve (CN-VII) pain and vesicles appear in external auditory canal–lose sense of taste in anterior two thirds of tongue + ipsilateral facial palsy
Diagnosis:
- clinical
- if need to confirm: best test is PCR
- Tzanck smear does NOT differentiate b/w chicken pox and shingles… not best choice
TX
- Acyclovir, Valacyclovir, famicilovir
* **Valacyclovir used MC bc of the dosing - Analgesics for pain–narcotics for serious cases
- can be transmited until all the lesions crust over
PRevention: the following are both good for 5 years
- recombinant vaccine (RVZ): adults >50 YO, 2 doses
* **second dose is given 2-6 MO after first - Zostavax: live attenuated vaccine–no longer in US
what CN is invovled with ramsay hunt syndrome
CN VII– facial nerve
what CN is invovled with Zoster opthalmicus
trigeminal nerve…CN V– the opthalmic branch
complications from shingles
MC?
- post-herpetic neuralgia= persistent pain/sensory symps >90 days—–MC
- cranial neuropathies/CNS involvement
Epstein-Barr Virus aka?
- MC when
- also associated with?
- infects what
- CM
- diagnosis– TOC?
- tx
Infectious Mononucleosis—HHV-4
MC early childhood—second peak late adolescence
by adulthood— more than 90% have been infected and have antibodies
also assoc with Hodginks disease, t cell lymphoma and other tumors
infects B cells–causes them to proliferate—-CA
transmission: “kissing disease”
* close contact of infected secretions–saliva
CM: 4-6 week incubation pd
1. young children may be asympto or can have mild pharyngitis +/- tonsillitis
3. adolescents: 75% present as infectious mono–TRIAD
**Lymphadenopathy–MC is posterior cervical
**Splenomegaly (wk 2-3)
**exudative pharyngitis
PRODROME before triad: extreme fatigue, fever, HA,
**if PTs get ampicillin + mono= RASH
diagnosis:
* Lab work: lymphocytosis with >10% atypical lymphocytes–Downey cells
- elevated LFTs
- elevated billi
*heterophile antibody test (monospot) –done week 3 is the TOC
TX:
- supportive measures–rest, analgesia
- increased risk of splenic rupture–>avoid contact sports***
ampicillin + Mono infection =?
rash
CMV, HHV-5
- MC?
- assoc w?
- cm– primary and reactivation
- diagnosis
- tx
- prophylaxis
MC congenital viral infection
assoc with developmental defects and hearing loss
transmission: close contact or sexual transimssion, body fluids, blood, organ transplantation, placenta, breastmilk
CM:
- primary infection: most are asympto
* if symptom: similar to EBV w/o sore throat or lymphadenopathy - reactivation: immunocompromised patients
* colitis: diarrhea, fever, abd pain, bloody stools–MC
* Retinitis: decreased vsual acuity and floaters (imp cause of blindness in AIDS)
* esophagitis: odynophagia with large superficial ulcers on upper endoscopy
diagnosis:
* atypical lymphocytosis, heterophile antibody NEGATIVE
* negative monospot test
* pathology: intracellular inclusions surrounded by a clear halo— “owl eye cells”
TX:
- primary dz for immunocompetnet= supportive
- tx for reactivation
* Ganciclovir is first line and TOC
* others: Foscarnet, Cidofovir, Valacyclovir - HIV PT w/ CD4< 50 cell/uL–>Valganciclovir is given prophylactically
HIV prophylaxis for CMV
Valganciclovir if CD4<50
Roseola Infantum
- which virus
- transmission
- MC in?
- CM
- tx
HHV-6
- common childhood disease
- trans via resp droplets
MC in 9-12MO
CM:
**HIGH fever, over 104 sometimes–lasting 3-5 days
**other than fever— child appears fine
**fever will resolve abruptly before onset of rash
RASH: rose pink, maculopapular, blanchable rash, begins on the trunk and neck–>moves to face–lasts up to 2 days
Diagnosis: clinical
TX:
- supp
- self limitng