Lecture 90: Enteroviruses Flashcards
what are the Examples of Picornaviruses?
Describe their virology
what is the surface protein trimer of picornaviruses ?
Hepatovirus
Rhinovirus
Enterovirus
Non enveloped, Positive Sense ss RNA
cytoplasmic replication
cytolytic
Surface protein trimer = VP 1, 2, 3
Describe the pathogenesis of enteroviruses
what are some clinical manifesations?
Replicate in the orpharynx and gut
primary viremia
stopped by immune system, but if not …
Major viremia –
different enteroviruses with different tropisms for different tissues lead to different manifestations
Aspectic meningitis Encephalitis Myocarditis Pericarditis Myositis, Pluerodynia Hand/foot/mouth Herpangina
what is the division of the enteroviruses ?
enterovirus transmission and seasonality ?
Poliovirus
Non polioviruses – such as coxsackie, Echovirus, enterovirus (numbered)
Transmission: person to person via fecal oral; respiratory droplets; fomites
Low infectious dose
Temperate climates - summer and fall
Tropical – year round
Poliovirus -
what is the common tropism for poliovirus?
- describe the cliincal manifestations
CNS:
Anterior Horn of the Spinal cord
Manifestations: asymmetric flaccid paralysis without sensory loss
1) Fever, myalgia, loss of DTRs
2) Sudden onset of asymmetric paralysis/paresis
Proximal muscles are more affected than distal (eg muscles of respiration)
Lower extremities > upper extremities
Polio virus:
Diagnosis
Dx:
Clinical suspicion
Imaging with ventral horn lesions
Throat and stool cultures
PCR
Polio virus: Describe the different vaccines; advantanges and disadvantages for each
Salk Virus == Killed virus
- good systemic immunity
- Given IM
- can combine with other vaccines
- poor mucosal immunit
Sabin Virus == Live attenuated
- Given Oral
- good systemic and local immunity
- Immunizes contacts in areas of poor sanitation
- disad: can mutate and cause paralysis
What are the non polio enteroviruses?
coxsackieviurus
ECHOvirus (enteric cytopathic human orphan virus)
Enterviruses (numbered)
What are the exanthems/enanthems caused by non polio enteroviruses?
what causes them?
1) herpangina, stomatitis – painful vesicles on the soft palate and posterior pharynx + Fever, HA, sore throat
- Coxsackie A
2) Hand, Foot, Mouth:
- Painful Vesicular, papular lesions on hands, feed groin, tongue, throat
== Coxsackie A16, other coxsackie A, B
What are the non polio enterovirus infections of the CNS and what causes them ?
Asepctic Meningitis – often asymptomatic. All types of enteroviruses
Encephalitis- 10-20% enteroviruse (coxsackie A - benign);
Poliomyelitis
Other: Guillane Barre; acute transverse myelitis
what causes the most severe form of encephalitis
what are the CSF findings of the encephalitis:
Enterovirus 71
Elevated WBC
Elevated Protien
Normal Glucose
Gram Stain Negative
What are the non polio enterovirus skeletal muscle infections ? what causes them?
Pleurodynia – coxsackie B (inflammation of the chest wall and abd muscles)
Myositis - -infection of the muscle
Fevers, chills, local or general
Coxsakie B
Other manifestations of non polio enteroviruses:
- eyes
- heart
- vertical trans
- chronic
- Eyes: Acute Hemorrhagic conjunctivitis: Coxsackie A24, Enterovirus 70
- Heart: Myocarditis (myopericarditis)
- Severe Neonatal Infection: Sepsis Like, multi system failure; Fatal
- ## Chronic infection in the immunodeficient:
Dx of Non polio enteroviruses:
Sample will depend on where the virus is replicating
Testing is available for some enterovirus, but no coxsackie A
stool, respiratory tract
PCR
Treatment of non polio enterovirsues
(what therapy has been phased out)
Prevention
IV IG - some benefit for myopericardiits
Oxadiazoles – block attachment and uncoating (no longer in use)
Immunomodulators like IFN
Prevent: Wash hands
No vaccine
