Viral Infections Flashcards

Question

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

Answer 1

Infects >95% of the population and persists for a lifetime Infectious Mononucleosis is a common manifestation of EBV “The Kissing Disease”

Answer 2

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

Answer 3

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

Answer 4

(watch video slide 36) Secondary bacterial pharyngitis Splenomegaly --> splenic rupture (can bleed out very quick)

Answer 5

supportive, reduce symptoms (virus will stick around regardless)

Answer 6

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

Answer 7

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

Answer 8

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

Answer 9

(1) Perinatal disease and CMV inclusion disease (2) Diseases in immunocompetent persons (3) Diseases in immunocompromised persons

Answer 10

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%

Answer 11

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

Answer 12

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

Answer 13

Mono with negative mono test?

Answer 14

Complications include mucosal gastrointestinal damage, encephalitis, severe hepatitis, thrombocytopenia Guillain-Barré syndrome, pericarditis, myocarditis CMV appears to be involved in the malignant manifestations of glioblastoma multiforme CMV has been associated with inflammatory bowel disease, atherosclerosis, cognitive decline, and breast cancer; its role in pathogenesis remains to be further elucidated

Answer 15

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

Answer 16

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)

Answer 17

Immunocompetent patients: supportive, self-limiting Immunocompromised patients: antivirals Congenital CMV: antivirals (know overall what drug endings represent antivirals, etc.)

Answer 18

No vaccine available yet but it is currently under trial Pregnant women should decrease the risk of contracting the virus

Answer 19

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)

Answer 20

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

Answer 21

Type A & B produce clinically indistinguishable symptoms Type C is more mild(!!) incubation: 1-4 days

Answer 22

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

Answer 23

PE findings: clear snot, nothing infected, sickness

Answer 24

Rapid flu tests are widely available Results within 15 minutes High false-negative

Answer 25

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

Answer 26

Secondary bacterial infection Diffuse viral pneumonitis Cardiovascular disease Neurologic complications Reye syndrome

Answer 27

Supportive antiviral therapy (oral oseltamivir aka tamiflu preferred) if fever reoccurs or persists over 4 days, secondary bacterial infection should be considered

Answer 28

uncomplicated illness is 1–7 days Mortality among adults hospitalized with influenza ranges from 4-8%

Answer 29

vaccine chemoprophylaxis Oseltamivir (tamiflu)

Answer 30

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)

Answer 31

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

Answer 32

Limited availability of supporting services Pneumonia or decreased oxygen saturation Changes in mental status Consider with pregnancy

Answer 33

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)

Answer 34

Vectors for Rabies in US: Skunk Fox Raccoon Mongoose Bats Cattle Dog Cats Vaccination of domestic animals is key in controlling rabies

Answer 35

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!!

Answer 36

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)

Answer 37

begins about 10 days after prodrome: Encephalitic form (80%): Paralytic form: Both forms progress relentlessly to coma, autonomic nervous system dysfunction, and death

Answer 38

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

Answer 39

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

Answer 40

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. Human rabies immune globulin administered 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

Answer 41

High risk for exposure: -veterinarians -animal handlers -lab workers -peace corps workers and travelers

Answer 42

Endemic throughout the world but low incidence in US due to vaccine Transmission: person-to-person via large respiratory droplets

Answer 43

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

Answer 44

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?)

Answer 45

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

Answer 46

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

Answer 47

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

Answer 48

mild vaccine-preventable viral illness endemic throughout the world transmission: Direct contact with saliva "mumps give you bumps"

Answer 49

16-18 days Contagious for several days before to several days after the illness onset

Answer 50

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

Answer 51

Respiratory symptoms, low-grade fever, malaise, headache Symptoms resolve in 7-10 days

Answer 52

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!!)

Answer 53

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

Answer 54

AKA German measles mild, vaccine-preventable viral illness causing fever and rash Endemic throughout the world but incidence is low in US

Answer 55

Droplets Incubation period: 14-17 days Infectious period: 7 days before to 5-7 days after onset of rash

Answer 56

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

Answer 57

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

Answer 58

Confirmatory tests: Antibody testing RT-PCR Management: Supportive care