Enteroviruses

Polioviral replication in tonsil and intestinal epithelial cells, lymphoid tissueInfection of draining lymph nodesPrimary viremiaSeeding of reticuloendothelial organs and target organ (CNS in polio)Viral infection of cells =>lytic deathSome symptoms may be caused by host immune response to tissue injuryMolecular mimicry: virus-induced autoimmune response

Joint painFatigueDifficulty swallowingWeakness in certain muscle groupsDecreased endurance

Unlike ALS

4-fold Ab increase

Complete Eradication?Virulent poliovirus "replaced" with attenuated strain; risk of VAPP (vaccine-associated paralytic polio)Still endemic in developing countriesGoal to eradicate worldwide within decadeHard to justify cost ($250 million per year) when few children get itMust be cooperative effort worldwideDelays will lessen urgencyTotal eradication needed before vaccination can safely be stopped, otherwise further epidemics possible

Preferred

Can be good or bad

Some risk of contracting mutated virusCDC panel now advises return to Salk vaccine

Untranslated regions at both termini1st third of polyprotein is P1 (capsid)No easy way to summarize:Multiplication mechanism:Attachment via VP1 to specific host cell surface receptorsGenome immediately translated to yield polyproteinFirst 1/3 of polyprotein is P1 (capsid), remainder (P2, P3) for replicationP1 cleaved into VP0, VP1, VP3 with viral proteaseVP0 cleaved to VP2 and VP4 =>maturation and infectivityRNA-directed RNA polymerase makes (-) strand intermediate, template for genome copiesCapsid assembly, genome insertionProtease (protein 2A) cleaves host cap binding protein complex => host shutoffExits host cells by lysis

PicornaviridaePico for small

Infection time course1-2 h: host shutoff2.5-3 h: viral protein synthesis, vacuolation of cytoplasm\3-4 h: permeabilization of host plasma membrane4-6 h: virus assembly6-10 h: virus release

Bornholm disease"Devil's Grip"

Herpangina: an infectious disease, esp. of children, characterized by a sudden occurrence of fever, loss of appetite, and throat ulcerations, caused by a Coxsackie virus.

Eradicated in U.S.

What route?What is the reservoir?

Contaminated water

No known animal reservoirs

DCC = Day care centers

Seasonality?

Due to water exposure