Lecture 9: Enterovirus & Adenovirus Flashcards
PicoRNAviridae
-genome
-envelope
-capsid
Smallest viruses
-(+) RNA
-no envelope (naked = resistant to harsh)
-icoshedral capsid
Picornaviridae types
-enterovirus
-hepatovirus
-genome
-envelope
-poliovirus (entero)
-enterovirus (entero)
-Coxsackievirus (entero)
-Echovirus (entero)
-Rhinovirus A, B, and C (entero)
-hepatitis A (hepatovirus)
entero = comes from the virus ability to infect intestinal tract and shed virus w/o GI diseases
-genome = (+) ssRNA
-envelope = naked
Picornaviridae pathogenesis (general)
-where does the virus shed?
Enterovirus replication in the OROPHARYNX
Then primary VIREMIA
TARGET TISSUE
-liver = HAV = Hepatitis
-Meninges = Echo, polio, Coxsackie = Meningitis
-brain = Polio, Coxsackie = Encephalitis or paralytic disease
-muscle = Echo, CAV & CBV = heart or thorax = myocarditis or Pleurodynia
-skin = Echo, CAV = (HFMD) = Rash
Then secondary VIREMIA
-virus shed in stool
Coxsackie A virus (CAV)
-capsid
-genome
-envelope
-occurs mostly in
Icosahedral
(+) ssRNA
Naked
-children <5 (incidence increase during school)
CAV transmission (coxsackie A)
-fecal-oral route
-aerosol droplets
-direct contact/fomites
CAV (Coxdackie A virus) can cause:
-Hand-foot-mouth disease = fever + painful blisters in palms/soles/cheeks/ hard palate/ throat/ tongue/ gums/
-Herpangina = sores appearing in the back of the mouth or throat
-Hemorrhagic Congunctivitis = pink eye
Hand-foot-mouth disease (HFMD)
-caused by?
-contagious?
-symptoms?
-caused by CAV (enterovirus)
-highly contagious
-lesions first appear in the anterior portion of mouth before appearing on the skin
fever + painful red blisters in throat, tongue, gums, hard palate, cheeks, palms, and soles
Herpangina
-caused by?
-symptoms?
-CAV (enterovirus)
-painful blisters in the back of the throat and palate (last 1 week)
-3-10 yoa
Acute Hemorrhagic Congunctivitis
-caused by?
-symptoms?
- KNOWN AS “PINK EYE”
-CAV (Enterovirus)
-lid swelling
-mucoid discharge becomes watery
-photophobia
-rapid incubation (sudden onset in ONE eye)
-results in EPIDEMICS (highly contagious)
Diagnosing of CAV!
-how would you diagnose the difference between/w Herpangina vs. HSV diagnosis
Clinically
*Herpangina = generally causes ulcers in the BACK portion of the mouth (soft palate)
*HSV = ulcers in the hard palate, gums, tongue
Treatment for CAV (coxsackie A virus)
Supportive care only
Adenovirus
-capsid
-genome
-envelope
-how do Adenoviruses differentiate between Enteroviruses?
-Icosahedral
-dsDNA
-naked
-Adenovirus = dsDNA vs. Enterovirus = (-) ssRNA
The enteroviruses are a genus of the family picornaviruses and can infect the intestinal tract and shed the virus into feces w/o causing GI diseases. Adenoviruses is a family and causes GI infections
Adenovirus
-most common disorders
-most common isolated
-most common cause
-URT, eye, GI infections, epidemic Keratoconjunctivitis (EKG)
-isolated in children and infants from pharynx and stools
-most common cause
Most common cause of viral conjunctivitis
Adenoviruses
Adenovirus transmission
-aerosols
-fecal
-direct contact (fomites, fingers, swimming pools)
*can usually last for up to 5 weeks on inanmiate objects) this is fairly common on naked viruses
Adenovirus pathogenesis
-virus infects mucoepithelial cells (URT, GI, conjunctiva)
-virus Persists in lymph nodes (Peyer patches, adenoids, tonsils)
-Latent infection (reactivation on immunosuppressed patients)
URT infection caused by adenovirus
-symptoms
-caused by adenovirus
-fever
-sore throat
-cough
-headache
-NO conjunctivitis
Adenoviral conjunctivitis
-serotypes
-symptoms
-types 1-11
-Adenovirus infection can cause both
-palpebral and bulbar conjunctiva
Pharyngoconjuctival fever
-caused by and what type of
-symptoms
-combo of adenovirus URT infection and Conjunctivitis
-caused by type 3 of adenovirus
-fever, malaise, cough, sore throat, nasal congestion, follicular conjunctivitis (one or both eyes)
Epidemic Keratoconjunctivitis (EKC)
-caused by what serotypes of what virus
-initial symptoms & others
-heals?
-Adenoviruses serotypes 8,9,19,37
-MULTIFOCAL SUBEPITHELIAL INFILTRATES pathognomonic for adenoviral infections scene in chronic phase of EKC after initial symptoms present
-acute onset of watery discharge. (Initial)
-pain (initial)
-conjunctival injection (red eyes) (initial)
-photophobia
-SUBCONJUNCTIVAL HEMORRHAGE (broken blood vessel in the eye)
-keratitis (corneal inflammation)
-heals after 2 months w/o scaring
** important to note: Acute hemorrhagic conjunctivitis vs. subconjunctival hemorrhage: acute hemorrhagic conjunctivitis (pink eye- caused by CAV which is from the genus of enteroviruses which is from the family of Picornaviruses) Subconjunctival hemorrhage (broken vessel in the eye) is an initial symptom from epidemic Keratoconjunctivitis (EKC) which can be caused by the family of adenoviruses**
Pathognomonic for adenoviral infections of Keratoconjunctivitis
Multifocal subepithelial infiltrates (SEIs)
-hallmark for a chronic phase of EKC
can be seen in EKC - epidemic Keratoconjunctivitis
Respiratory and GI infections
-what virus
-what serotypes
-causes
-adenovirus- serotypes 4 and 7 most common
-URT - bronchitis = atypical walking pneumonia = ARDS
ARDS = respiratory distress syndrome = fluid in the lungs at a chronic level vs. pneumonia
atypical pneumonia is caused by a different bacteria than pneumonia and its also a milder form
-GI - enteric adenoviral infection = infant diarrhea also known as gastroenteritis (watery diarrhea)
enteric adenoviral infection is 3rd common cause of gastroenteritis. 1st= rotavirus & norovirus
common causes of most serious URT infections
Adenovirus diagnosis
-clinically
-LFA= test eyes for conjunctivitis
-PCR = typing of serotypes, and only after symptoms are present
Adenovirus treatment AND prevention
Treatment
*Supportive care
-lubricating the eyes
-topical steroids to reduce eye swelling
-fluids (GI)
Prevention
- Vaccine w/ types 4 and 7 (used in for military personnel ONLY)
common causes of most serious URT infections
What serotypes of the adenovirus causes URT and GI infections?
Serotypes 4 and 7
