A genus of the picornavirus family
Naked ssRNA virus
Are stable in acidic pH
Enter the body mainly via ingestion
Primary site of replication is lymphoid
tissue in the gut.
Spread to blood and into lumen of gut to
be excreted in feces
Courtesy of Linda M. Stannard, University of Cape Town, S.A.h
At least 71 serotypes are known:
divided into 5 groups
Coxsackie A viruses
Coxsackie B viruses
First identified in 1909
First grown in cell culture in 1949 which
became the basis for vaccines.
3 serotypes of poliovirus (1, 2, and 3)
but no common antigen.
Humans are the only susceptible hosts.
Polioviruses are distributed globally.
Immunization has eradicated poliovirus
in most regions of the world except in
the Indian Subcontinent and Africa.
Incubation period : 7 - 14 days.
After ingestion, the virus multiplies
in the tonsils and Peyer's patches of
Transient viraemia occurs
In few cases, involves the CNS
Spreads along axons of peripheral
nerves to involve anterior horn cells
of spinal cord, intermediate grey
ganglia and even posterior horn cells
Subclinical infection (90 - 95%)
A minor influenza-like illness
Recovers within a few days
May be accompanied by aseptic meningitis
Major illness (1 - 2%)
Signs of aseptic meningitis.
Infection of anterior horn cells: flaccid paralysis.
Infection of medulla: respiratory paralysis and death.
Mainstay of diagnosis
Can be readily isolated in cell culture
from throat swabs, feces, rectal swabs
Very rarely used
No specific antiviral therapy is available.
Intramuscular Poliovirus Vaccine (IPV)
Formalin inactivated virus of all 3 serotypes.
Oral Poliovirus Vaccine (OPV)
Consists of live attenuated virus of all 3 serotypes.
Produces local immunity through the induction of
an IgA response as well as systemic immunity.
The normal response rate to OPV is
close to 100%.
OPV is used for the WHO poliovirus
Poliovirus was targeted for eradication
by the WHO by the end of year 2005
Eradicated from most regions of the
world except the Indian subcontinent
and sub-Saharan Africa.
Current Status of Wild Poliovirus Transmission
Properties of Enteroviruses
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 23 types - or E - or E + Aseptic meningitis,
group A (A1-22, A24) febrile illness, conjunctivitis
(A24), hand, foot and mouth disease.
Coxsackie 6 types + + + Aseptic meningitis, severe neonatal
group B (B1-6) disease, myopericarditis,
Echovirus 31 types + E - Aseptic meningitis, rash, febrile
(1-9, 11-27 illness, conjunctivitis, severe
29-33) generalized neonatal disease.
Enterovirus 5 types + + - Polio-like illness, aseptic
(68-72) meningitis, hand, foot and mouth
(E71), epidemic conjunctivitis (E70)
hepatitis A (E72)
Coxsackieviruses are distinguished from other
enteroviruses by their pathogenicity for suckling rather
than adult mice.
Two groups on the basis of the lesions in suckling mice.
Group A: diffuse myositis with acute inflammation
and necrosis of fibers of voluntary muscles. Has 23
Group B: focal areas of degeneration in the brain,
necrosis in the skeletal muscles, and inflammatory
changes in the dorsal fat pads, the pancreas and
occasionally the myocardium. Have 6 serotypes
Were accidentally discovered in human
feces, unassociated with human disease
during epidemiological studies of
polioviruses. The viruses were named
echoviruses (enteric, cytopathic, human,
Altogether, There are 32 echoviruses
(types 1-9, 11-27, 29-34
Newly identified picornaviruses that are not
polioviruses, coxsackie, and echovirus : 5
types (68 - 72).
Enterovirus 70 causes acute haemorrhagic
Enterovirus 71 has been associated with
epidemics of aseptic meningitis, encephalitis,
paralytic poliomyelitis-like disease and
Mainstay of diagnosis of enterovirus infection
Coxsackie B and Echoviruses can be readily grown in cell culture from
throat swabs, feces, and rectal swabs. They can also be isolated from the
Coxsackie A viruses cannot be easily isolated in cell culture. Can be
isolated readily in suckling mice. Molecular techniques may provide a
Very rarely used for diagnosis since cell culture is efficient.
Neutralization tests or EIAs
Management and Prevention
No specific antiviral therapy available
IVIG in the treatment of neonatal
infections or severe infections in
HNIG to prevent outbreaks of
neonatal infection with good results.
No vaccine available