Transcript Enteroviruses - KSU Faculty Member websites

Picornaviridae
By: Dr.Malak El-Hazmi
Assistant Professor &
Consultant Virologist
College of Medicine & KKUH
Picornaviruses
Nonenveloped , icosahedral , ss (+) RNA
Members of the Family Picornaviridae
Genus
Enterovirus
Hepatovirus
Parechovirus
Rhinovirus
Kobuvirus
Cardiovirus
Aphthovirus
Erbovirus
Teschovirus
Species
Poliovirus
Coxsackieviruses
Echoviruses
Enteroviruses ( 68-71)
Characteristics of Human Picornaviruses
Property
RhinoVs
ParechoVs
Enteroviruses
Polio
Coxsackie
A
1-3
1-24
Echo
Entero
B
1-6
Serotypes
>100
Acid pH (3.0)
Labile
Stable
Temp
33oC
37oC
Site
Nose
GIT
1-34
68 -71
1-4
Usual Host range of human enteroviruses:
animal and tissue culture spectruma
Cytopathic effect
Illness & Pathology
Antigenic
typesb
Monkey Kidney
tissue culture
Human
Tissue culture
1-3
+
+
-
+
Coxsackieviruses, gp A
1-24c
±
±
(+) flaccid
-
Coxsackieviruses, gp B
1-6
+
+
(+) spastic
-
Echoviruses
1-34d
+
±
-
-
Enteroviruses
68-71
+
+
-
-
Virus
Polioviruses
aMany
Suckling
mouse
Monkey
enteroviral strains have been isolated that do not conform to these categories
types, beginning with type 68, are now assigned enterovirus type numbers instead of coxsackievirus
or echovirus numbers. Types 68-71 have been identified.
CType 23 has been found to be the same as echovirus 9.
dEchovirus 8 was determined to be the same serotype as echovirus 1
; echovirus 10 has been reclassified as a reovirus type 1, echoviruses 22 & 23 as parechoviruses types 1& 2,
echovirus 28 as human rhinovirus 1 A, and echovirus 34 as coxsackievirus A24.
bNew
Epidemiology
 Reservoir : Human
Excreta from human
Spread :
 Fecal - oral route (mainly)
 Inhalation of Infectious aerosols
 Direct & indirect contact of
eye secretions
(Crowded, Poor hygiene &
Sanitation)
Hand
Sewage
Water Supply
Shellfish
Man
 Age : children > adults
 Seasonal distribution:
summer & fall
Solid waste
landfills
Pathogenesis
HFM
Echo,cox
Most EVs are cytolytic, some cause immunopath mech
Human enteroviruses & commonly associated clinical syndromes.1
Coxsackievirus
Syndrome
Neurologic
Aseptic meningitis
Paralysis
Encephalitis
Poliovirus
Types 1-3
1-3
1-3
Skin and mucosa
Herpangina
Hand-foot-and-mouth disease
Exanthems
Group A
Types 1-24
Group B
Types 1-6
Echovirus
Types 1-34
Enterovirus
Types 68-71
Many
7,9
2,5-7,9
1-6
2-5
1-5
Many
2,4,6,9,11,30
2,6,9,19
71
70,71
70,71
2-6,8,10
5,10,16
Many
Cardiac and muscular
Pleurodynia (epidemic myalgia)
Myocarditis, pericarditis
21,24
1,6,9
1,6,9,19
70
1,3,4,5
4,5
4,9,11,20,25
68
9,16
71
Gastrointestinal
Diarrhea
Hepatitis
2Causality
2,4,6,9,11,16,18
24
Respiratory
Colds
Pneumonia
Pneumonitis of infants
Pulmonary edema
1Examples
5
1-5
1-5
Ocular
Acute hemorrhagic conjunctivitis
Other
Undiff. Febrile illness
Generalized disease of infants
Diabetes mellitus
71
71
18,20-22,242
4,9
1-3
5
1-6
1-5
3,4
are not all-inclusive. Other enterovirus types may be associated with a given disease:
not established
Many2
4,9
11
Herpangina
Hand , Foot & Mouth disease
Human enteroviruses & commonly associated clinical syndromes.1
Coxsackievirus
Syndrome
Neurologic
Aseptic meningitis
Paralysis
Encephalitis
Poliovirus
Types 1-3
1-3
1-3
Skin and mucosa
Herpangina
Hand-foot-and-mouth disease
Exanthems
Group A
Types 1-24
Group B
Types 1-6
Echovirus
Types 1-34
Enterovirus
Types 68-71
Many
7,9
2,5-7,9
1-6
2-5
1-5
Many
2,4,6,9,11,30
2,6,9,19
71
70,71
70,71
2-6,8,10
5,10,16
Many
Cardiac and muscular
Pleurodynia (epidemic myalgia)
Myocarditis, pericarditis
21,24
1,6,9
1,6,9,19
70
1,3,4,5
4,5
4,9,11,20,25
68
9,16
71
Gastrointestinal
Diarrhea
Hepatitis
2Causality
2,4,6,9,11,16,18
24
Respiratory
Colds
Pneumonia
Pneumonitis of infants
Pulmonary edema
1Examples
5
1-5
1-5
Ocular
Acute hemorrhagic conjunctivitis
Other
Undiff. Febrile illness
Generalized disease of infants
Diabetes mellitus
71
71
18,20-22,242
4,9
1-3
5
1-6
1-5
3,4
are not all-inclusive. Other enterovirus types may be associated with a given disease:
not established
Many2
4,9
11
Pathogenesis of polio:
Pathway to CNS by:
 Blood
 Peripheral nerves
 Causing destruction of
motor neurons of AHCs
 Rarely affects brain stem
(bulber poliomyelitis)
Pathogenesis of Polio :
Immunity: IgA & IgG = Lifelong type-specific immunity
Poliovirus Infections
90-95%
No illness
4-8%
Asymptomatic
Minor Illness
1-2%
Abortive poliomyelitis (No CNS involvement)
Major Illness
1- Nonparalytic poliomyelitis (Aseptic meningitis)
2- Paralytic poliomyelitis: (Flaccid paralysis)
Poliovirus Infections :
 Bulber poliomyelitis
( brain stem)
 Post polio syndrome
Lab Diagnosis of Enteroviruses

Virus isolation:
•
Samples: Stool (best) .Rectal, throat swabs ,
conjunctival swab, CSF
•
Inoculate in MKC & HDF
All EVs grown except some strains of Cox A viruses
•
Observe for CPE
•
Identify the type by Neutralization Test

CSF in aseptic meningitis;
Glucose level N to slightly
Isolation rate is variable
lymphocytosis
, Protein level N or slightly
EV RNA detected in CSF by RT-PCR
 Serology (limited value)
•
IgM
•
≥ 4 fold rise in AB titer b/t Acute & Convalescent sera
Management
 Rx:
 No antiviral Rx
 Prevention:
 Sanitation & Hygienic measures
 Poliovirus vaccines
a- Inactivated polio vaccine
(IPV)
(Salk, Killed) (S/C or IM)
b- Live-attenuated polio vaccine
(OPV)
(Sabin, oral)
Important Features of Polio Vaccines
Attribute
Killed (IPV)
Live (OPV)
3 types (trivalent)
Prevents disease
Induces humoral IgG
Yes
Yes
Yes
Yes
Yes
Yes
Route of administration
Injection
Oral
Induces intestinal IgA
No
Yes
Interrupts transmission
No
Yes
Affords 2o protection by
spread to others
Reverts to virulance
No
Yes
No
Yes (rarely)
No
No
Yes
Yes
No
Yes
Causes disease in the immun
Co-infection with other EVs
ed
may impair immunization
Requires refrigeration
Duration of immunity
Shorter
Longer
Poliovirus Vaccine
 Adverse reactions ;
 local reactions (IPV)
 Vaccine -Associated Paralytic Poliomyelitis (OPV)
adult , immuno ed
4 doses of PV;
2, 4 , 6-18 ms
& 4 - 6 yrs
Pediarix contains IPV, DTaP & HB vaccines
Polio Vaccination of Adults
Indications:
 Travelers to polio-endemic countries
 Selected laboratory workers
 HCWs
IPV;
0, 1-2 ms, 6-12 ms
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