8. enteroviruses including polio

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Enteroviruses

Prof. Mochammad Hatta. MD, PhD, SpMK (K)

Molecular Biology and Immunology Laoratory,

Ha!anuddin "ni#er!ity, Indone!ia


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Enteroviruses are a genus of the picornavirus family which replicatemainly in the gut.

Single stranded naked RNA virus with icosahedral symmetry Unlike rhinoviruses, they are stable in acid p !apsid has "# copies each of $ proteins, %&', %&(, %&) and %&$

arranged with icosahedral symmetry around a positive sensegenome.

At least *' serotypes are known+ divided into groups

&olioviruses

!o-sackie A viruses

!o-sackie viruses Echoviruses

Enteroviruses /more recently, new enteroviruses subtype have beenallocated se0uential numbers /"12*'33

Enteroviruses


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Enterovirus Particles

!ourtesy of 4inda 5. Stannard, University of !ape 6own, S.A.h


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&oliovirus 2 first identified in '7#7 by inoculation of specimens intomonkeys. 6he virus was first grown in cell culture in '7$7 which became

the basis for vaccines.

!o-sackieviruses 2 8n '7$1, a new group of agents were identified by

inoculation into newborn mice from two children with paralytic disease.

6hese agents were named co-sackieviruses after the town in New 9orkState. !o-sackieviruses A and were identified on the basis of the

histopathological changes they produced in Newborn mice and their

capacity to grow in cell cultures.

Echoviruses 2 were later identified which produced cytopathic changes in

cell culture and was nonpathogenic for newborn mice and subhuman

primates.

5ore recently, new enterovirus types have been allocated se0uential

numbers /"1 2 *'3.

History


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CPE in cell cultures

Monkey Human cell Pathology in

Group Virus types kidney culture newborn mice Major disease associations

Poliovirus 3 types + + - Paralytic poliomyelitis, aseptic

(1 - 3) meningitis, febrile illness.

Coxsackie 3 types - or ! - or ! + "septic meningitis, #erpangina,

group " ("1-, "$) febrile illness, con%unctivitis ("$), #an&, foot an& mout# &isease.

Coxsackie ' types + + + "septic meningitis, severe neonatal

group (1-') &isease, myopericar&itis, orn#olm

&isease, encep#alitis, febrile

illness.

!c#ovirus 31 types + ! - "septic meningitis, ras#, febrile

(1-, 11-* illness, con%unctivitis, severe

-33) generalie& neonatal &isease.

!nterovirus types + + - Polio-like illness, aseptic

('-*) meningitis, #an&, foot an& mout#

(!*1), epi&emic con%unctivitis (!*)

#epatitis " (!*)

Properties ofEnteroviruses


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) serotypes of poliovirus /', (, and)3 but no common antigen.

ave identical physical properties but only share )"2(: nucleotide

homology. umans are the only susceptible hosts.

&olioviruses are distributed globally. efore the availability of

immuni;ation, almost '##: of the population in developing countries

before the age of .

6he availability of immuni;ation and the poliovirus eradicationcampaign has eradicated poliovirus in most regions of the world

e-cept in the 8ndian Subcontinent and Africa.

&oliovirus is on course of being eradicated worldwide by the end of

(### or (##'.

Poliovirus


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6he incubation period is usually * 2 '$ days.


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6here are ) possible outcomes of infection+

Subclinical infection /7# 2 7:32 inapparent subclinical infection account

for the vast ma>ority of poliovirus infections.

Abortive infection /$ 2 1:3 2 a minor influen;a2like illness occurs,

recovery occurs within a few days and the diagnosis can only be made bythe laboratory. 6he minor illness may be accompanied by aseptic

meningitis

5a>or illness /' 2 (:32 the ma>or illness may present ( 2 ) days following

the minor illness or without any preceding minor illness. Signs of aseptic

meningitis are common. 8nvolvement of the anterior horn cells lead toflaccid paralysis. 8nvolvement of the medulla may lead to respiratory

paralysis and death.

Clinical Manifestations


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%irus 8solation

5ainstay of diagnosis of poliovirus infection

poliovirus can be readily isolated from throat swabs, faeces, and

rectal swabs. 8t is rarely isolated from the !S

8. enteroviruses including polio

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