Lecture 7: Viral Diseases Part 1 Flashcards
What are the 3 types of viruses?
DNA virus
Single stranded RNA virus
Retrovirus
What is unique about a retrovirus?
Their RNA becomes directly integrated with the host’s RNA.
What is the difference in replication of a DNA virus vs a RNA virus?
DNA viruses replicate in the NUCLEUS.
RNA viruses replicate in the CYTOPLASM.
Where do we interrupt the viral replication process?
Whenever it requires an enzyme to go to the next step.
How many types of herpes viruses are there?
8
What is unique about the herpes virus in terms of infection?
After you get infected once, it remains latent and can re-activate at a later time.
It can turn normal cells into malignant cells.
What are the 8 herpes viruses?
HSV1
HSV2
VZV
EBV
CMV
HHV6 & 7
HHV8
What does HSV1 generally affect? HSV2?
HSV1 = oral
HSV2 = genital
1 mouth 2 balls
What is a sex-related risk factor for contracting HSV?
WSW
What other way can you contract HSV besides through sexual contact?
Fluid from lesions.
What can trigger outbreaks of HSV lesions?
Hormonal changes
Immunocompromised state.
What are some signs of HSV1?
Mucocutaneous lesions.
Often described as vesicles in the upper lips, nares, and mouth.
Herpetic whitlow (digital vesicular lesions)
What are some signs of HSV2?
Multiple vesicles forming crusts and ulcers.
Commonly appear on external genitalia, vaginal canal, and perianal.
May have pain or itching prior.
How does HSV as an oral infection typically present?
Pain, burning, tingling of skin
Pain with eating (if inside mouth)
Swollen lymph nodes
Low grade fever
How does HSV severity change with subsequent outbreaks?
The initial outbreak is generally the worst, with longer and worse symptoms.
After you get exposed and it flares up again, the symptoms are generally more milder.
How does HSV as a genital infection present?
Pain, burning, tingling of skin
Dysuria
Cervicitis
Urinary retention
Swollen lymph nodes
Fever, body aches
What generally causes an IP admission because of HSV?
Urinary retention.
How does HSV stay in the body?
Remains dormant in NERVE GANGLIA.
What are general triggers for HSV flares?
Febrile illness
Hormonal changes (Pregnancy, menstruation)
Physical or emotional stress
Overexposure to sunlight
If a person has HSV lesions near their eye, what am I worried about?
HSV Keratoconjuctivitis.
What is HSV keratoconjuctivitis?
A dangerous complication of HSV infections that affect the eye.
How does HSV keratoconjuctivitis present?
Typically:
unilateral blepharitis with associated impaired visual acuity, eye pain, photophobia, and a sensation that there is something in the eye.
What is the danger of having HSV keratoconjuctivitis?
Trigeminal nerve spread. Opthalmology consult is indicated ASAP if suspicious.
Blindness and permanent visual changes.
What are some uncommon presentations of an HSV infection seen usually only in immunocompromised pts?
HSV encephalitis
Disseminated (Pneumonia)
Esophagitis
Proctitis
What are some of the diagnostic tests to confirm an HSV infection?
Cultures
PCR (CSF for HSV encephalitis)
Tzanck smear (multinucleated giant cells = positive for HSV or VZV in general)
What are the pitfalls of the tzanck smear?
Can be positive from varicella. Non-specific between HSV1 and 2.
How is HSV keratoconjuctivitis diagnosed?
Dendritic lesions when examined with a slit-lamp and stained with fluorescein.
Why is HSV not screened for?
Practically everyone has it.
It is self-limiting in most cases.
No cure.
Why are antivirals used for HSV?
Shorten duration
Lessen severity
Prophylaxis for people with recurrent flares.
For HSV in the mouth, what are some things we can recommend to patients?
Topical anesthetics:
Dyclonine (sucrets)
Benzocaine (Anbesol, cannot use on babies)
Magic mouthwash
What is the magic mouthwash formula?
1/3 lidocaine/xylocaine
1/3 maalox/mylanta
1/3 benadryl
3oz, 2 refills, take TID or QID.
What should I counsel patients on regarding using the magic mouthwash?
If you swallow it by accident, you may feel drowsy dt the benadryl.
Why would I recommend topical ABX to a patient with herpetic lesions?
Picking of the lesions can lead to a secondary staph/strep SSTI.
What are the 3 main antivirals for HSV? What is the primary one?
Acyclovir (Zovirax) - PRIMARY, since cheap and comes in like every formulation.
Famciclovir (Famvir)
Valacylovir (Valtrex)
FAV antivirals
What is the antiviral for an HSV infection in the eye?
Trifluridine (Viroptic)
What is an OTC antiviral we can recommend to patients for HSV?
Docosanol/abreva
What common antivirals are renally excreted? Liver metabolized?
Valtrex and Famvir are RENALLY EXCRETED.
Acyclovir is liver metabolism.
Which common antiviral is not a prodrug?
Acyclovir
What should I monitor for a patient on an antiviral?
BUN/Cr.
Valcyclovir and famciclovir are dangerous in renal failure.
Are antivirals ok in pregnancy?
Generally considered safe, cat B.
When is foscavir indicated for HSV?
Resistance to acyclovir, but mainly used in CMV infections for AIDS patients.
What is the only indication for ganciclovir and valganciclovir?
CMV infections in AIDS.
What are the BBW of ganciclovir and valganciclovir?
Seizures
Renal impairment
Hematologic abnormalities
Possible carcinogen
How long do you treat a patient with an initial outbreak of genital HSV?
7-10 days on any of the 3 common antivirals.
When should treatment begin for an genital HSV infection?
Within 48 hrs of onset and before 72 hours have passed.
Recurrences should be within 24 hrs.
What are the tx options for Oral HSV?
Oral antivirals
Zovirax ointment (hydrocortisone 1% + acyclovir 5%)
Penciclovir (Denavir)
OTC Docosanol (Abreva)
How do I treat HSV prophylactically for recurrent patients?
Same 3 antivirals. Dosing is 1 less per day than if you actually had the infection active.
What is the treatment for HSV Keratitis?
Trifluridine drops + Oral acyclovir
What is the treatment for Disseminated/neonatal HSV?
IV Acyclovir.
What are some prevention methods for HSV?
Barrier methods during sex
C-section for women with genital lesions
Sunscreen
What is the etiology of Shingles/Herpes Zoster?
Previous infection with VZV (Varicella zoster virus)
What kind of vaccine is the shingles vaccine?
Inactivated recombinant vaccine.
Shingrix/RZV
What are the main risk factors for shingles?
Age > 60
Immunocompromised
What is the common description of a skin lesion in chickenpox or shingles?
Dew drop on a rose petal.
What is a common symptom prior to the rash in shingles?
PAIN
How does shingles typically present?
Unilateral, dermatomal lesions.
MC in thorax and lumbar.
What is the concern with shingles on the face?
Trigeminal nerve involvement
Blindness
Herpes Zoster opthalmicus
What is Hutchinson’s sign?
Lesions in the corner of the eye and side of the nose.
What is the main complication of Shingles?
Post-herpetic neuralgia, which occurs in 30-40% of patients > 60y.
Causes prolonged, DEBILITATING pain.
What are some other complications of shingles?
Bacterial secondary skin infections
Vision loss (Herpes zoster opthalmicus)
Bell’s palsy
How do we treat shingles?
Generally, it is self-limiting.
Our treatment goals are mainly to reduce duration, lessen severity, and reduce the risk of post-herpetic neuralgia.
Antivirals: Zovirax, Famvir, Valtrex within 72 hours of onset.
How do we treat herpes zoster opthalmicus?
ER admission with IV acyclovir and topical steroids.
How do we manage post-herpetic neuralgia?
Opioids
TCAs
Gabapentin/Neurontin
What is the current Herpes zoster vaccine?
RZV or Shingrix.
Previous is Zostavax.
Who gets RZV/Shingrix?
People => 50y
2 vaccines 2-6 months apart, even if you got zostavax already.
How efficacious is RZV/Shingrix?
90% reduction in shingles and PHN incidence.
What is the primary reason we vaccinate for shingles?
To reduce the risk of PHN.
What causes Mono?
EBV, aka HHV4
What are the common symptoms of infectious mononucleosis?
Malaise/fatigue, fever, sore throat, tonsillar enlargement, myalgia
Classic triad: sore throat, posterior cervical LAN, fever
Often presents as very exhausted.
What are the common signs of infectious mononucleosis?
POSTERIOR CERVICAL LAN
Pharyngeal irritation
Splenomegaly (50% of pts)
Palatal petechiae
Maculopapular rash in 20% of pts.
Bonus: What increases the rash percentage to 90% in infectious mononucleosis?
Erroneous administration of ampicillin when misdiagnosed with strep!
Bonus: What throat complaint common presents with ANTERIOR cervical LAN?
Strep throat
How do we diagnose EBV/Mononucleosis?
Monospot: heterophile agglutination test
Blood smear: Atypical large lymphocytes
CBC: leukopenia and lymphocytosis
EBV Antibodies: IgM or IgG
Who is a monospot not recommended in?
Children < 5
What are some complications of EBV?
Splenomegaly/splenic rupture.
Hepatitis
CNS involvement
What labs should we monitor in mono pts?
LFTs and CBCs
How do we treat EBV?
Fluids and antipyretics
NO antivirals, NO abx
How long does it take Mono to resolve typically?
10 days for the fever and sore throat.
4 weeks for the LAN and splenomegaly
Fatigue can last for months.
What are the associated disorders with EBV?
Burkitt lymphoma
B-cell malignancies in immuncomped pts
Nasopharyngeal carcinomas.
How prevalent is CMV?
60-90% of the population has it asymptomatically.
What is unique about CMV transmission?
Transplacental is possible!
What are the 3 clinical syndromes from CMV?
CMV inclusion disease in newborns
Acute viral syndrome in regular people
CMV disease in immunocomped people
How does CMV inclusion disease present?
Hepatitis, mental retardation, hearing loss
Stillbirth
How does acute viral syndrome due to CMV present?
Fever, malaise, arthralgia (Like mono without the pharyngitis)
How does CMV disease in immunocompromised pts present?
CMV retinitis + GI irritation + pneumitis + Encephalitis
How is CMV diagnosed?
Serologic testing
When is CMV treated and how?
Only for severe presentiations such as CMV retinitis, encephalitis, or CMV inclusion disease
Ganciclovir (newborns use this one specifically) or valganciclovir
Foscarnet (Foscavir)
How is HPV transmitted?
Sexual contact only.
How many strains of HPV exist?
100+, but we most only care about 4! :)
What are the important strains of HPV and what do they cause?
HPV 6 & 11 do genital warts (condyloma acuminatum)
HPV 16 & 18 do 70% of cervical cancers and are the #1 cause of cervical cancer.
16 is the primary cause.
What does HPV infect?
Epithelial tissue
What is a unique way HPV can be transmitted?
Birth canal, so newborns can get it.
What gender commonly gets condyloma acuminata more?
Women
What is the main concern of condyloma acuminata?
Increased risk of malignancy.
How does condyloma acuminata present?
Scaly, raised, skin colored to pearly lesions
Often occur in clusters and may be pedunculated.
Occurs anywhere in genital, perineal, or anal region.
Associated pruritis, burning, bleeding, or pain
How do we diagnose condyloma acuminata?
Clinical diagnosis
Anoscopy, speculum exam, Colposcopy to assess extent of involvement to guide treatment
How do we treat condyloma acuminata?
Chemical Destruction: Podophyllin/podofilox
Cryotherapy in the office
Systemic treatment (interferon)
Laser surgery/Surgical excision
Aldara cream/topical
How is podophyllin/podofilox used?
Spread it around the base of lesion
What should we counsel pts on regarding HPV and cervical cancer?
Potential of malignancy
Cervical, oropharyngeal, vulvar, and penile cancer
How is HPV typically found?
Pap smear and routine screenings
How do we treat cervical cancer?
Laser ablation
Cone biopsy/LEEP
Surgery
How is HPV prevented?
HPV Vaccine Gardasil!!!
Cover strains: 6,11,16,18 (primary 4), and 31,33,45,52,58
AKA Gardasil 9
Who can get Gardasil? When should you get it?
As young as 9
Best to be given prior before becoming sexually active
What are the two primary causes of seasonal influenza?
Influenza A or B
How do influenza viruses mutate?
Antigenic drift (slow changes, like they’re drifting in the wind)
Antigen shift (Sudden change, sudden shift)
What kind of mutation can we predict in influenza virus? Why is it significant?
Antigenic drift.
We cannot predict antigenic shift, which is when pandemics occur.
What are some pandemic-level influenza strains in the past?
H1N1 2009 (swine)
H3N2v 2012 (swine)
H5N1 (bird flu, highly pathogenic), began in 2003
H7N9 (china only)
How does influenza typically present?
Sudden onset of fever, chills, HA, myalgia, and prostration/malaise.
Non-productive cough, sore throat, nasal discharge
PE is typically unremarkable
What kind of CXR would I see on influenza?
Clear. Similar to atypical pneumonia.
What are the complications of influenza?
Secondary bacterial infections like pneumonia or sinusitis.
Rhabdomyolysis, myositis
Encephalitis, aseptic meningitis
Cardiac complications
How do we diagnose influenza?
RIDT (rapid influenza diagnostic test)
NP swabs, nasal aspirate
HIGH FALSE NEGATIVE RATE
Viral cultures
When do we order viral cultures for influenza suspicion?
All hospitalized patients or a different strain of influenza is suspected.
Takes much longer.
What are the general treatment options for influenza?
Antipyretics
Fluids
Analgesics
Antivirals
What two drug classes are indicated for Influenza?
Neuraminidase inhibitors (A and B)
NMDA Receptor Antagonists (A only)
What are the neuraminidase inhibitors?
Oseltamivir (Tamiflu) Oral
Zanamivir (Relenza) Inhalation
Peramivir (Rapivab) IV
What are the NMDA receptor antagonists?
Amantadine (mainly for parkinson’s)
Rimantadine
What is the concern with NMDA receptor antagonists?
Growing resistance in strain A.
Which antivirals can be used prophylactically for influenza also?
Tamiflu and Zanamivir (Relenza)
What is the dosing for tamiflu?
75mg PO BID x 5 days
When are neuraminidase inhibitors supposed to be started?
Within 48 hours of onset.
What is Relenza CId in?
People with lung disorders
What should we counsel patients in regards to neuraminidase inhibitors?
GI SE (sometimes very strong and people prefer the flu over treating it)
Bronchospasms with Relenza
Rare Behavioral disturbances
How is tamiflu excreted?
Renally. Must adjust for renal failure.
When can you start getting the flu vaccine?
October generally.
Starting at 6mo and older.
What are the two types of common flu vaccines?
Inactivated influenza vaccine (flu shot)
Live attenuated influenza vaccine (IN administration)
Flumist (CId in lung disorders)
What are the primary causes of viral pneumonia in adults?
Influenza virus
RSV (Also causes pneumonia and bronchiolitis in children)
Parainfluenza (Also causes croup in kids)
Adenovirus (also the common cold)
Coronaviruses
How does viral pneumonia often present?
Fever, chills, myalgia
NON-PRODUCTIVE cough
Possible bilateral rhonchi
Non-diagnostic CXR
What is the treatment for viral pneumonia?
Antipyretics and fluids.
What does adenovirus do in general?
Affects every mucuous membrane in the body.
What can adenovirus do to urine?
Sterile pyuria
What are two other viruses that cause minor respiratory diseases?
Rhinovirus (common cold)
Adenovirus
What animals are reservoirs of Rabies?
Bats
Raccoons
Skunks
Foxes
Woodchucks
Coyotes
How is rabies almost always transmitted?
BITE of an infected animal.
What does rabies eventually cause?
Encephalitis.
Why is rabies so dangerous?
Irreversible binding, so it must be treated ASAP.
What is the survival rate of someone who is exhibiting neurological symptoms from rabies?
Extremely rare.
10 cases have survived per the CDC.
What are some neurologic symptoms from rabies?
Initially: Anxiety, confusion, agitation
Progresses: Delirium, abnormal behavior, hallucinations, insomnia.
Seizures + hydrophobia
How do we treat Rabies?
Immediately wash the wound and go to the ER!!
Requires 1 dose of immune globulin and 4 doses of a rabies vaccine over a 2 week period. 1,3,7,14 (aka the day doubles + 1 pretty much)
