Non HIV viruses Flashcards
Varicella zoster virus (vzv)
- Alpha herpesvirus
- DNA is singular, linear, double stranded molecule
Chicken pox
Shingles
Chicken pox (vzv)
Primary infection in child hood
Typically benign - maculopapular, vesicular, and pappular rash
Late winter to early spring
Shingles
- Latent virus mainly in the elderly (sensory ganglia)
- associated with significant pain - unilateral vascular rash
- No seasonal predilection
Mild to moderate chicken pox treatment
No treatment
Moderate to severe chicken pox treatment
2-12 years old
Valacyclover 20 mg 1 kg po 3x daily
Acyclovir 20 mg kg po 4x daily (start within 24 hours of rash)
Moderate-severe Chickenpox
adolescent, young adults
-acyclovir 800 PO 5x daily ( start within 24 hours of rash)
-valacyclovir 1000mg PO 4x daily
-Famciclovire 500 PO 3x daily (effective data lacking)
risk factors for chickenpox
chronic cutaneous or pulmonary diseases
chronic salicylate treatment
( increased risk of reyes syndrome )
what is not clear for the treatment of shingles
benefits of antiviral therapy >72 hours of symptoms
treatment of Shingles for mild to moderate
-Valacyclovir
-Famciclovir
duration 7 days
treatment of shingles for severe (ocular or neurologic or disseminated disease)
Acyclovir IV* 7 - 10 day
Treatment for Post-herpetic neuralgia (PHN)
-observed frequently following herpers zoster ophthalmic and upper body involvement
-gabapentin
-lidocaine patch 5%
-opiod alagesic
-nortriptyline or amitriptyline
prednisone-added to acyclovir does nit reduce incidence or duration of PHN
-
Prevention Pre-exposure: Chickenpox
Varicella vaccine
-live attenuated virus
-two dose series first administration at 12 - 15 months and then 4-6 years
Prevention Pre-exposure: shingles
-Zostavax: live attenuated single shot
-Shingrix: for 50 years and older (new and preferred)
–non live subunit two shot given 2-6 months apart
Prevention Post exposure of shingles
high-titer varcrella-zoster immune globulin 125 units/ 10 IM for high risk patients to prevent infection
–ASAP <96 hours after exposure
if rash develops initiate with acyclovir within 24 hrs
Human a- herpesvirus (HSV)
-two types: HSV-1 & HSV-2
-large, double stranded, linear DNA genome
HSV-1: acquired more commonly and earlier than HSV-2
HSV-2 seroprevalence incidence is estimates at 23 million cases per year
HSV Manifestation
-healthy children and adults
- initial episode more severe than recurrent
-presentation varies by site, age, and immune status of host and HSV type
What is the most common and initial clinical manifestation of HSV-1?
orofacial infection (gingivostomatitis and pharyngitis)
latent infection–> recurrent lesions on the vermillion border of the lips (herpes labials)
what are clinially similar between HSV 1 and HSV 2
genital infections
reoccurrences are common with HSV 2
HSV: Treatment of Oral Lesions
Valacyclovir 2 gm x 1 day **
Famciclovir ( approved for HIV only)
Acyclovir x 5 days ( Not FDA approved)
Topical regimens (less preferred)
-Penciclovir cream
- Acyclovir cream
HSV: treatment of genital lesions
primary (initial episode)
acyclovir, valacyclovir, famciclovir
PO
7-10 days
HSV: treatment of genital lesions
subsequent recurrent episodes
immunocompetent
-acyclovir, valacyclovir, famciclovir
- PO x 5 days
immunocompromised, HIV
-acyclovir, valacyclovir, famciclovir
-PO x 5-10 days
HSV: treatment of genital lesions
severe
Acyclovir IV 5-7 days
HSV: treatment of genital lesions
acyclovir resistant HSV
Forcarnet IV x 7days
HSV: treatment of genital lesions
chronic suppression (daily)
immunocompetent
-acyclovir PO BID
-Famciclovir PO BID
-valacyclovir PO daily
—pts with <9 recurrences per year should use 500mg PO then 1000mg PO if breakthrough
immunocompromised
-acyclovir PO BID
-Famciclovir PO BID
-valacyclovir PO daily
what does suppression therapy do for genital herpes reccurance
reduce the frequency by 70-80% among pts that have frequent recurrences (>6/year)
influenza Virus
orthomyxlvirdae
-single stranded
caused by epidemic acute respiratory disease characterized by fever, cough, and sytemic symptoms
- primary viral pneumonia
-secondary bacterial pneumonia
Thee types: A, B, C
how is influenza virus transmitted
respiratory route –> large epidemics during winter in temperate climates
Influenza type A
moderate to sever
all age groups
human and animals
Influenza type B
milder
children
human
Influenza type C
non-epidemic
N/A
rarely in humans
antigenic drift
antigenic variants created by point mutations on surface antigens–> small changes in hemagglutinin and/or neuraminidase
-basis for seasonal epidemics of influenza
-resaon for changes in annual influenza vaccine
-rationale for annual vaccination recommendation
antigenic shift
influenza virus acuirei a new hemagglutinin or neuraminidase via genetic reassortment
- results in emergence of novel influenza virus
-potential for pandemic
Influenza treatment
Oseltimavir (PO x 5days )
- peds= weight base dosing
Zanamir (inhalation x 5 days)
most effective when used early in illness within 48 hrs or no clinical benefit
- ideally within 12 hrs of infection
exception; critically ill or hospitalized
-starting up to 5 days after onset is associated w survival
Corticosteroids and influenza
can cause excess mortality in pts with influenza pneumonia
AVOID!
New Influenza agents
Peramivir ( Influenza A and B)
- 1 dose (FDA)
- longer in hospitalized (5 days, limited studies)
Baloxavir ( Influenza A and B)
- 12 years or older
- weight based
-1 dose
Influenza treatment in critically illed
no benefit with 150 mg 2x daily dosing –> not recommended
-influeza B in 1 study show a trend towards benefit with higher dosing
Prevention of pre exposure: influenza
influenza vaccine
hand hygiene
respiratory etiquette
contact avoidance- stay home
chemoprophylaxis
influenza at risk population
-children age <2 years
-adults > 65 years
-chronic pulmonary, cardiovascular, renal, -hepatic, hematologic, metabolic, neurologic conditions, severe developmental delay, mental retardation
-immunosuppression, transplant, HIV
-pregnant or two weeks post partum
-<18 years who receive long term aspirin
-american indians/alaskan natives
-morbid obesity bmi >40
-residence of nursing homes and other chronic learning facilities
-high risk of complications in hSCT and organ transplant patients
Influenza Prevention Pre: vaccination
Egg allergies
can receive any licensed recommended age appropriate vaccine and do not have to monitored for 30 mins after administration
severe allergies should be administered in a medical setting
flu bloc(recombinant influenza vaccine) is not produced on eggs
egg-based vaccine update
A/Victoria
cell or recombinant based vaccine update
A/wisonsin
prevention pre-exprosure: vaccination
flumist intra nasal - live attenuated
live attenuated for health individuals between 2-29 who are not pregnant
-based on flu strain that does not cause disease
- still a living virus –> may cause infection with weaken immune system or underlying medical conditions
–ppl who have taken flu antiviral frugs within a certain amount of time \
within 48hrs - oselt, zana
past 5 days- peramivir
past 17 days- baloxavir
prevention pre- exposure
chemoprophylaxis
CDC does not recommend widespread ore routine use
- only high risk pts
-control outbreaks in long term care facilities
-only when when can be used with 48 hrs of exposure
Influenza Chemoprophylaxis
oseltamivir PO x 10 days
-peds weight based
zadnamivir inhaltion x 10 days
rabies
zoonotic encephalitis caused by different species of neurotropic viruses in the rhabovidae family
- single stranded RNA enveloped virions
highly contagious through exposure to animal saliva or nervous system tissue
– bite
– scratches
– contamination of open wounds or mucous membranes
Rabies treatment
no proven antiviral therapy
clean thoroughly with soap and water
human rabies immune globulin
-20 IU/kg on day 0
-infiltrated in and around the wounds and rest be administered at distant site IM
- do not give in same string as the vaccine
-do not give more than 7 days after the initiation of the vaccine
Treatment: Rabies
Vaccination schedule
Immunocomptent: 4 doses toal
- 1 dose on day 0,3,7, and 14
Immunocompromised: 5 doses
-1 dose on days 0,3,7,14,28
If already been immunized for rabies
-local wound cleaning
-NO human rabies immune globulin
-vaccination on days 0 and 3
Rabies pre exposure prophylaxis
3 doses
-1 dose on day 0, 7 and 21or 28
Rabies prevention: pre-exposure
targeted high risk groups
vets
lab workers
certain travelers
Covid 19
severe acute respiratory syndromee related corona virus
zoonotic (possible bat-borne)
spread via respiratory droplets
nesters human cells through angiotensin converting enzyme 2
symptoms after 2-14 weeks of exposure
viral shedding begin 5-6 days prior symptoms
covid 19 presentation
SOB or diffuculty breathing**
cough
fever or chills
muscle or body aches
sore throat
loss of taste
diarrhea
headache new fatigue
N/V
congestion or runny nose
Authorized treatment of Covid 19
out patient
-nirmatrelvir/ritonavir (paxlovid) within 5 days of sx onset
-Remdesivir ( within 7 days sx onset)
-alternative: molnupupiravir 18 yr and older ( with 5 days of sx onset)
inpatient
-remdesivir
-tocilizumab
-dexamethasone
-baricitinib
prevention: Covid 19
vaccination
-Moderna
-pfozer
wash hand often
- avoid touching your eyes, nose, and mouth
avoid close contact with sick individuals or stay home
analogs
purine
adenosine
n-hydroxycytidine
analog: purines
acyclovir
famciclovir
valacyclovir
analog: adenosine
remdesivir
analog: n-hydroxycytidine
molnupiravir
Inhibitors
neuraminidase
endonuclease activity
protease
Inhibitors: neuraminidase
oseltamivir
zanamivir
peramivir
Inhibitors: endonuclease activity
baloxavir
Inhibitors: protease
nirmatrelvir
purine analog acyclovir
synthesize purine nucleoside analog with inhibitory action against HSV and VZV
stops replication by competitive inhibition of DNA polymerase
Acyclovir tidbits
low bioavailability
extensive renal elinination
high concentration= nephrotoxicity, due to
-rapid infusion
-dehydration
-renal insufficiency
-increase dose
SE: neurologic toxicity mechanism unknown (reversible)
Other purine analogs
valacyclovir
-ester of acyclovir
- well absorbed 3-5 x better
FAmciclovir
-metablolized to penciclovir ( active)
Adenosine analog: remdesiver
prodrug metabolized to nucleoside monophosphate intermediate
inhibitor of SAR-CoV-2 RNA polymerase
essential for vial replication
adenosine alnalog tidbits
dosing
-inpatient: IV x 5 days
-outpatient: IV x 3 days
monitor
-Liver function test ( d/c if elevate alt )
-heat rate
-infusion rate
n-hydroxcytidine analog: mulnupiravir
prodrug metabolized into n-hydroxytidine
phhosphylated to form active triphosphate
- incorporated in SARS-CoV-2 RNA
neuraminidase inhibitors
block the function of viral neuraminidase
-preventing its reproduction by budding from the host cell
influenza a and b
neuraminidase tidbits
toxic effects are minimal and difficult to distinguish from influenza
- Nausea, vomiting, diarrhea, HA
caution with potential for confusion in dosing oral suspension
endonuclease activity inhibitor: baloxavir
inhibits replication of virus by interfering with cap snatching
-hijack the host mRNA transcription process
-5’methylated caps of the cellular mRNA are cleaved by the viral endonuclease and used to prime transcription of viral mRNA by viral RNA polymerase
endonuclease activity inhibitor: baloxavir
TIDBITS
AE:
-N/D
-HA
-bronchitis
-nasopharyngitis
avoid coadministration of multivalent cation as it can interfere with absorption
protease inhibitor: nirmatrelvir
-combined with ritinavir (paxlovid)
-is a peptidomimeti inhibitor of the SAR-CoV-2 main protease
protease inhibitor: nirmatrelvir
tidbits
AE:
-diarrhea
-taste sense altered
recommended for high risk pts
-DM, BMI> 25, lung disease, immunocompromised, cancer, . 65 etc
