Viral Infections Flashcards

1
Q

Herpesviruses

A

Herpesviruses 1&2

Varicella Zoster Virus (herp 3)

Epstein-Barr virus infections (herp 4)

Cytomegalovirus

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2
Q

Random good ex. of test Q: If a pregnant woman has a + TB test

A

Treat right away or wait until the baby comes out to treat?
Treat as soon as detected!! no harmful effects found on fetus

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3
Q

Herpesviruses 1&2

A

1: Primarily oral herpes
2: Primarily genital herpes

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4
Q

Risk factors for HSV transmission include:

A

black race,
female gender,
a history of sexually transmitted infections,
increased number of partners,
contact with commercial sex workers,
lower socioeconomic status,
young age at onset of sexual activity
total duration of sexual activity

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5
Q

In US in adult pop:

A

50-85% are seropositive for HSV-1

10-25% are seropositive for HSV-2

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6
Q

Herpesviruses 1&2: types

A

Mucocutaneous (HSV-1):

Herpes labialis: painful vesicles on and around lips

Herpetic whitlow: herpes lesion on finger

Herpes gladiatorum: commonly spread in contact sports such as wrestling

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7
Q

Mucocutaneous HSV-2

A

Involves the genital area
The virus lays latent in the presacral ganglia

Other symptoms:
Women: dysuria, cervicitis, urinary retention
Men: urethritis, dysuria

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8
Q

Mucocutaneous Diagnosis (1&2):

A

Usually made clinically

Viral cultures of vesicular fluid (vesicle: clear, fluid-filled blister)

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9
Q

Herpes 1&2: Meds

A

Oral antivirals (-ovir):
Acyclovir(!!)
Valacyclovir
Famciclovir

Can also be given prophylactically for those who get frequent recurrent infections

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10
Q

Herpes 1&2: Ocular

A

Ocular disease:
-Can lead to scarring and blindness
-Blepharitis (affects eyelids)

Ocular disease diagnosis: Fluorescein staining shows dendric (branching) ulcers

Ocular herpes treatment:
-Keratitis: oral antivirals or topical antivirals (ophthalmic trifluridine, vidarabine,acyclovir and ganciclovir)
-Uveitis: oral antivirals

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11
Q

Herpes 1&2: Congenital

A

Treatment:
Acyclovir
C-section

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12
Q

Herpesvirus 3: Varicella

A

Varicella Zoster Virus (VZV)
-Varicella: Chicken Pox
-Herpes Zoster: Shingles

(shingles is the same virus, just chicken pox returning in adulthood)

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13
Q

VZV: Chicken Pox

A

Usually occurs at childhood

Incubation period 10-20 days

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14
Q

Varicella signs/symptoms:

A

Fever and malaise
Rash: 3 stages

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15
Q

VZV Virus remains dormant in:

A

cranial nerve sensory ganglia

spinal dorsal root ganglia

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16
Q

Varicella: Diagnosis

A

Usually made clinically

Confirmation by direct immunofluorescent antibody staining or PCR of scrapings from lesions

Multi-nucleated giant cells usually apparent on a Tzanck smear

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17
Q

Varicella Complications

A

Infection (bacteria enters popped blisters)
Interstitial VZV pneumonia
Encephalitis (brain tissue inflamm)
Reyes syndrome
Congenital malformations

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18
Q

Varicella Treatment

A

Isolation
Acetaminophen (pain killer)
Pruritis

for itching we can do steroids

Who needs to be treated with antivirals? when it progresses to like pneumonia or another complication

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19
Q

Herpes Zoster: Shingles

A

Reactivation of varicella

Rate increases with age due to lessened immunity from VZV

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20
Q

Herpes Zoster: Shingles S&S

A

Similar lesions to varicella

Pain usually precedes the rash

Lesions follow dermatomal distribution (only shingles)

(dermatome: area of skin innervated by single spinal nerves)

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21
Q

Other Herpes zoster complications

A

ophthalmicus

Ramsay Hunt syndrome (infection of facial nerves, knocks out functioning)

Post-herpetic neuralgia (herpes pain forever)

Ocular

Neurological

Bacterial

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22
Q

Herpes Zoster: Shingles Treatment

A

Valacylovir (preferred) or Famciclovir

Acyclovir (when?)

(-ovir)!!

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23
Q

Treatment of post-herpetic neuralgia (ongoing pain)

A

Difficult to treat and less than half achieve pain control

Gabapentin

Lidocaine patches!!

Tricyclic antidepressants

Opioids

Capsaicin cream

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24
Q

Prevention of spread

A

Varicella Vaccination
-over 98% effective after 13 months of age (given again 5 years later)

Shingrix: new one for 50 years or older, 97%

Even people with a prior history of herpes zoster should be vaccinated

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25
Q

Herpesvirus 4: Epstein-barr virus (aka Mono!!)

A

Infects >95% of the population and persists for a lifetime

Infectious Mononucleosis is a common manifestation of EBV
“The Kissing Disease”

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26
Q

Symptoms

A

maculopapular or occasionally petechial rash in under 15%

lymph nodes swelling in posterior cervical chain!!

(buzz word: posterior cervical lymphatinopathy)!!

systemic: high fever, chills, aches

tonsils, spleen, stomach

slide 34

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27
Q

Mono/Epstein-Barr: Diagnosis

A

Heterophile antibody test (Monospot) (hetero kissing)

During acute illness:
-rise and fall in immunoglobulin M (IgM) antibody to EB virus capsid antigen (VCA)
-rise in immunoglobulin G (IgG) antibody to VCA, which persists for life

Antibodies (IgG) to EBV nuclear antigen (EBNA) appear after 4 weeks of onset and also persist

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28
Q

Epstein-barr virus: complications

A

(watch video slide 36)

Secondary bacterial pharyngitis

Splenomegaly –> splenic rupture (can bleed out very quick)

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29
Q

Mono treatment:

A

supportive, reduce symptoms (virus will stick around regardless)

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30
Q

Mono prognosis:

A

Fever and lymphadenopathy usually resolve within 10 days

Splenomegaly usually lasts 4 weeks and contact sports should be avoided until then

Fatigue can last several months

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31
Q

Herpesvirus type 5: Cytomegalovirus

A

Most are asymptomatic (in healthy people)

Seroprevalence in developed countries is 60-80% and higher in developing countries

Transmission occurs through:
sexual contact,
breastfeeding,
blood products,
Transplantation
person-to-person (eg, day care centers)
congenital

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32
Q

Cytomegalovirus

A

Virus remains latent after primary infection and can reoccur from time to time

Half of people by age 40 have been infected with the virus

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33
Q

Cytomegalovirus: 3 clinical syndromes

A

(1) Perinatal disease andCMVinclusion disease
(2) Diseases in immunocompetent persons
(3) Diseases in immunocompromised persons

34
Q

1: perinatal (before/after birth)

A

Perinatal disease and CMV inclusion disease:

About 10% of infected newborns will be symptomatic and have the following:

Hepatitis,
Thrombocytopenia,
Microcephaly,
Periventricular CNS calcifications,
Mental retardation,
Motor disability.
HEARING LOSS develops in more than 50% of infants who are SYMPTOMATIC AT BIRTH!!

Asymptomatic newborns:

Neurologic deficits may ensue later in life, including hearing loss in 15% and mental retardation in 10–20%

35
Q

Cytomegalovirus: diagnosis for type I

A

Newborn screening of congenital CMV has been government mandated for babies that fail their initial hearing test in some states

If they test positive, early intervention with antivirals can help prevent late onset complications

36
Q

2: immunocompetent

A

AcuteCMVinfection is the most common cause of the mononucleosis-like syndrome (but negative for heterophile antibodies)

37
Q

TEST Q:

A

Mono with negative mono test?

38
Q

Cytomegalovirus complications

A

Complications include
mucosal gastrointestinal damage,
encephalitis,
severe hepatitis,
thrombocytopenia
Guillain-Barré syndrome,
pericarditis,
myocarditis

CMVappears to be involved in the malignant manifestations of glioblastoma multiforme

CMVhas been associated with inflammatory bowel disease, atherosclerosis, cognitive decline, and breast cancer; its role in pathogenesis remains to be further elucidated

39
Q

3: immunocompromised

A

Solid organ and Bone Marrow transplant

HIV positive patient
-CD4 Count less than 50cells/mcL

-CMV Retinitis
-Gastrointestinal and -Hepatobiliary CMV
-Respiratory CMV
-Neurologic CMV

40
Q

Cytomegalovirus: lab testing

A

Mothers and newborns
Mothers with infection in 1st trimester should be tested every 3 months to check for CMV viremia

Congenital CMV:
-In newborns in the first 3 weeks of life:
-Polymerase chain reaction (PCR) on saliva, with urine usually collected and tested for confirmation

Immunocompetent & Immunocompromised patients:
-ELISA Serologic tests that detect CMV antibodies (IgM and IgG)

41
Q

Cytomegalovirus: Treatment

A

Immunocompetent patients: supportive, self-limiting

Immunocompromised patients: antivirals

Congenital CMV: antivirals

(know overall what drug endings represent antivirals, etc.)

42
Q

Cytomegalovirus: Prevention

A

No vaccine available yet but it is currently under trial

Pregnant women should decrease the risk of contracting the virus

43
Q

Influenza

A

Seasonal Influenza: Orthomyxovirus (only one)

Types A, B, and C:
-Type A can affect other mammals
-Influenza B & C are exclusive to humans
-Influenza A is further divided into subtypes based on the hemagglutinin (H) and the neuraminidase (N) expressed on their surface
-There are 18 subtypes of hemagglutinin and 11 subtypes of neuraminidase (things stuck to influenza that can make it different/change)

44
Q

Influenza: annually

A

Annual epidemics occur in the fall and winter with sporadic cases occurring throughout the year

Up to 5 million cases of severe influenza occur annually, with up to 0.5 million annual deaths

45
Q

Influenza: Signs/Symptoms

A

Type A & B produce clinically indistinguishable symptoms

Type C is more mild(!!)

incubation: 1-4 days

46
Q

Symptoms cont.

A

Begin abruptly

Systemic: fever, chills
Respiratory: cough
GI: upset stomach, not hungry, rarely vomit/diarrhea

47
Q

Physical Exam findings:

A

PE findings: clear snot, nothing infected, sickness

48
Q

Diagnostic testing for the flu:

A

Rapid flu tests are widely available

Results within 15 minutes

High false-negative

49
Q

Influenza: high risk patients

A

Asthmatics
Residents of nursing homes and long-term care facilities,
Adults aged 65 years or older,
Persons who are morbidly obese,
Persons with underlying medical conditions
Pregnant women

50
Q

Influenza complications:

A

Secondary bacterial infection

Diffuse viral pneumonitis

Cardiovascular disease

Neurologic complications

Reye syndrome

51
Q

Flu treatment

A

Supportive

antiviral therapy (oral oseltamivir aka tamiflu preferred)

if fever reoccurs or persists over 4 days, secondary bacterial infection should be considered

52
Q

Flu prognosis:

A

uncomplicated illness is 1–7 days

Mortality among adults hospitalized with influenza ranges from 4-8%

53
Q

Flu prevention:

A

vaccine

chemoprophylaxis

Oseltamivir (tamiflu)

54
Q

contraindications to vaccination:

A

History of severe allergic reaction to influenza

history of Guillain-Barré syndrome 6 weeks following an influenza vaccine

If patients have a moderate to severe acute illness

Persons with a history of egg allergy need close monitoring (egg whites are used as replicating medium when making vaccine)

55
Q

Flu: patient education

A

PPE

contagious 1 day prior to onset of symptoms, and 1 week after

56
Q

flu: when to admit

A

Limited availability of supporting services

Pneumonia or decreasedoxygensaturation

Changes in mental status

Consider with pregnancy

57
Q

Rabies

A

Viral Encephalitis caused by rhabdovirus

Transmitted by saliva and enters the body through an open wound (i.e bite wound)

17 million animal bites yearly

60,000 deaths annually due to rabies (worldwide)

1-3 reported cases of rabies in the US annually

(TEST: bit by rabid dog)

58
Q

rabies vectors

A

Vectors for Rabies in US:
Skunk
Fox
Raccoon
Mongoose
Bats
Cattle
Dog
Cats

Vaccination of domestic animals is key in controlling rabies

59
Q

Rabies prognosis

A

incubation period can be 10 days to many years!! (but usually 3-7 weeks)

could feel find for 7 years then get killed, very poor prognosis

PEARL!!

60
Q

Rabies: S&S

A

Prodromal:
-Pain at the site of the bite in association with fever, malaise, headache, nausea, and vomiting

Aerophobia: skin is sensitive to change in air temperatures

Percussion Myoedema persists throughout the disease (tap and a lump pops out at you)

61
Q

Rabies:CNS stage

A

begins about 10 days after prodrome:

Encephalitic form (80%):

Paralytic form:

Both forms progress relentlessly to coma, autonomic nervous system dysfunction, and death

62
Q

Rabies: animals

A

Domestic biting animals should be observed or quarantined for 10 days

Biting wild animal should be caught and sacrificed and the brain should be tested for evidence of rabies virus

When the animal cannot be examined, raccoons, skunks, bats, and foxes should be presumed to be rabid

63
Q

Rabies: testing in humans

A

Direct fluorescent antibody testing of skin biopsy material from the posterior neck (where hair follicles are highly innervated) has a sensitivity of 60–80%

Quantitative RT-PCR, nucleic acid sequence-based amplification, direct rapid immunohistochemical test, and viral isolation from the CSF or saliva are advocated as definitive diagnostic assays

Rabies virus forms cytoplasmic inclusion bodies, Negri bodies.
Negri bodies are 100% diagnostic but only found in 20% of cases

64
Q

Rabies: Treatment

A

Survival is rare

Management requires intensive care

Postexposure Prophylaxis(expensive!):
-Any contact or suspect contact with a bat, skunk, or raccoon is usually deemed a sufficient indication to warrant prophylaxis
1. Humanrabies immune globulinadministered once
2. Vaccines:
-A human diploid cell vaccine (HDCV, Immovax) OR
-A purified chick embryo cell vaccine (PCEC, RabAvert)

Rabies vaccines and HRIG should never be given in the same syringe or at the same site

65
Q

Rabies: preexposure prophylaxis indications:

A

High risk for exposure:

-veterinarians
-animal handlers
-lab workers
-peace corps workers and travelers

66
Q

Measles (Rubeola)

A

Endemic throughout the world but low incidence in US due to vaccine

Transmission: person-to-person via large respiratory droplets

67
Q

Measles: observations

A

Incubation period: 10-12 days to onset of fever and 14 days to onset of rash

Contagious for 4 days prior to and 4 days after the onset of the rash

68
Q

Measles: Clinical findings

A

Prodrome: Fever (103-105 degrees), cough, coryza, conjunctivitis!! lasting 2-4 days

Koplik spots (small bluish-white lesions on the buccal mucosa) are pathognomonic

(Maybe PEARL?)

69
Q

Measles: clinical features cont.

A

2-4 days after fever onset:
Red, maculopapular rash that begins on the face and head and spreads downward!!!!

70
Q

Measles: rare presentations

A

Rare but severe presentations:
Encephalitis and pneumonia
Most often in children <5 and adults >20 years

71
Q

Measles: Diagnosis & Management

A

Diagnosis:
-Usually made clinically
-Report to local or state health depts
-Confirmatory testing (antibody or RT-PCR) is typically performed by the CDC

Management:
-Supportive care
-Vitamin A has been shown to decrease morbidity and mortality

72
Q

Mumps

A

mild vaccine-preventable viral illness

endemic throughout the world

transmission: Direct contact with saliva

“mumps give you bumps”

73
Q

Mumps: incubation

A

16-18 days

Contagious for several days before to several days after the illness onset

74
Q

Mumps: Clinical features

A

1/3 are asymptomatic
In symptomatic patients, about 70% develop parotitis (unilateral or bilateral)aka balloon cheeks!!!

75
Q

Clinical features cont.

A

Respiratory symptoms, low-grade fever, malaise, headache

Symptoms resolve in 7-10 days

76
Q

Mumps: Complications

A

Orchitis in postpubertal males (sterility is rare)

Aseptic meningitis, encephalitis, pancreatitis (all very rare)

Mumps is one of the most common causes of unilateral acquired sensorineural deafness (cuz carotid gland is right there)(PEARL!!)

77
Q

Mumps: Diagnosis and Treatment

A

Can usually be made clinically but testing is needed for confirmation
Antibody testing
Viral isolation (buccal and oral swab)
RT-PCR

Treatment: supportive care

78
Q

Rubella

A

AKA German measles

mild, vaccine-preventable viral illness causing fever and rash

Endemic throughout the world but incidence is low in US

79
Q

Rubella Transmission

A

Droplets

Incubation period: 14-17 days

Infectious period: 7 days before to 5-7 days after onset of rash

80
Q

Rubella: Clinical features

A

Asymptomatic in about 50% of patients

Signs and symptoms:

General:

Rash:

Other: conjunctivitis, Forchheimer spots (petechiae) on soft palate (grainy dots on roof of mouth), orchitis (testicle)

Arthralgia and arthritis are common and more frequently occur in adult females

81
Q

Rubella in pregnancy

A

the fetus and neonate are at risk for multiple short- and long-term adverse outcomes:

82
Q

Confirmatory test and management:

A

Confirmatory tests:
Antibody testing
RT-PCR

Management:
Supportive care