2. Enterovirus
Enteroviruses are a genus of the picornavirus family which replicate mainly in the gut.
Single stranded naked RNA virus with icosahedral symmetry
Unlike rhinoviruses, they are stable in acid pH
Capsid has 60 copies each of 4 proteins, VP1, VP2, VP3 and VP4 arranged with icosahedral symmetry
around a positive sense genome.
At least 71 serotypes are known: divided into 5 groups
◦ Polioviruses
◦ Coxsackie A viruses
◦ Coxsackie B viruses
◦ Echoviruses
◦ Enteroviruses (more recently, new enteroviruses subtype have been allocated sequential numbers (68-71))
3. Echoviruses
The first echoviruses were accidentally discovered in human faeces,
unassociated with human disease during epidemiological studies of
polioviruses. The viruses were named echoviruses (enteric,
cytopathic, human, orphan viruses).
These viruses were produced CPE in cell cultures, but did not
induce detectable pathological lesions in suckling mice.
Altogether, There are 32 echoviruses (types 1-34; echovirus 10 and
28 were found to be other viruses and thus the numbers are unused)
4. Echoviruses are found in the gastrointestinal tract (hence it being part
of the enterovirus genus) and exposure to the virus causes other
opportunistic infections and diseases.
The echovirus is among the leading causes of acute febrile illness in
infants and young children, and is the most common cause of aseptic
meningitis.
Infection of an infant with this virus following birth may cause severe
systemic diseases, and is associated with high infant mortality rates.
The echovirus can mimic symptoms caused by other
common bacterial and viral infections, so echovirus infections are
often treated with therapies aimed for other infections.
This can lead to the evolution of antibiotic-resistant bacteria.
5.
6. EXAMS AND TESTS
Because the illness is often mild and has no specific treatment, testing for echovirus is often not done.
If needed, ECHO virus can be identified from:
•Rectal culture
•Spinal fluid culture or PCR
•Stool culture
•Throat culture
Treatment
ECHO virus infections almost always clear up on their own. No specific medicines are available
to fight the virus. Immune system treatment called Intravenous immunoglobin may help
people with severe ECHO virus infections who have a weakened immune system. Antibiotics
are not effective against this virus, or any other virus.
7. Coxsackie virus infections
Coxsackie viruses are a group of RNA viruses with over 20 serotypes;
depending on specific viral characteristics, these serotypes are further divided
into groups A and B.
Infection is associated with a wide range of symptoms, which are dependent
on the exact serotype.
Hand, foot, and mouth disease (HFMD) and herpangina are commonly caused
by group A coxsackie viruses, while pleurodynia and myocarditis are caused by
group B coxsackie viruses.
Both groups may cause viral meningitis, conjunctivitis, or pneumonia.
Diagnostic procedures and treatment should be tailored to the specific disease
manifestation.
8. DISEASES
Coxsackie A
Herpangia
Hand Foot and mouth
disease
Pericarditis ,myocarditis
Aseptic meningitis
COXSACKIE B
Myocarditis
Dilated Cardiomyopathy
Bornholm disease
Pericarditis
Aseptic meningitis
9. Epidemiology
Worldwide distribution
Occur in all age groups
Highest incidence in infants and young children (< 10 years)
There is no evidence for complications associated with coxsackie
virus infection during pregnancy
10. Etiology
Pathogen : Coxsackie virus
oGenus :Enterovirus
oFamily: picornaviridae
o 20 serotypes, divided into group A and group B coxsackie viruses
oSingle-stranded RNA virus
Route of transmission
oAirborne droplets
oFecal-oral route
11. Hand, foot, and mouth disease
Hand, foot and mouth disease (HFMD) is an acute viral illness, which is usually mild
and self-limiting.
The disease is characterised by papulovesicular lesions on the distal limbs and
vesicular eruptions in the mouth.
HFMD occurs worldwide in temperate climates .It is most common in late
summer and early autumn.
It presents either in outbreaks or as sporadic cases. Outbreaks occur
frequently in schools and nurseries, and it often spreads within families.
It occurs most typically in children under 10 years of age, and most
commonly in those under 4 years of age.
12. Etiology &
pathophysiology
HFMD is most commonly caused by Coxsackie A16 virus, but can also be caused by other group A and B Coxsackie viruses.
HFMD may also be caused by Enterovirus 71, which can lead to a more serious clinical picture.
Importantly, HFMD is transmitted between humans and does not have an animal host. This means
it is not transmited from or to animals, and has no relation to foot and mouth disease.
HFMD can be transmitted in the following ways:
•Direct contact with infected respiratory secretions (coughing and sneezing)
•Direct contact with fluid from the blisters
•Faeco-oral transmission. The virus can be faecally shedded for 4-8 weeks after
the onset of the initial viral illness, therefore asymptomatic individuals can
continue to infect others
•Vertical transmission from mother to foetus
13. CLINICAL FEATURES
Not all clinical features are present in every case, and not all
children get lesions on their hand, feet or in their mouths.
It has an incubation period of 3-7 days.
There is a prodromal period (12-36 hours) of fever (38-39°C),
malaise, decreased appetite, cough, abdominal pain and myalgia.
If HFMD is caused by enterovirus 71, there may rarely be vomiting.
14. There are two types of lesion in HFMD - mouth
lesions and distal limb lesions.
MOUTH LESIONS
These generally appear first as 2-8
mm diameter erythematous macules
and papules (commonly on hard
palate, tongue and buccal mucosa).
These progress rapidly to vesicles,
which easily erode.
The eroding vesicles leave shallow
yellow-grey ulcers with an
erythematous halo.
DISTAL LIMB LESIONS
The limb lesions appear soon after the oral lesions as 2-5
mm diameter erythematous macules and papules, often
with a central grey coloured vesicle.
The vesicles found on the limbs are often elliptical with
the long axis running in parallel with the skin lines.
The limb lesions most commonly affect the sides of the
fingers, dorsum of the hands and the margins of the heels.
Less frequently they are seen on the heals and palms with
the buttocks and groins occassionally being affected.
15. Atypical HFMD
Atypical hand foot and mouth disease results in a more
widespread rash .
● Red, crusted papules
● No blisters or very large ones
● Targetoid lesions
● Involvement of unusual sites such as the ear.
Atypical hand foot and mouth disease due to Coxsackie A6 results
in a more widespread rash, larger blisters and subsequent skin
peeling and/or nail shedding ( Onychomadesis) .
_____________________________________________________
16. Soles of the feet of a child
Macular, vesicular lesions on an
erythematous base are visible on
the toes and the soles of the feet.
This rash is typical in hand, foot, and
mouth disease.
17. Images of a 12-month-old infant
There are white-grey blisters on the
fingers with a diameter of approx. 3–5
mm that are surrounded by an
erythematous halo and are rather typical
of the disease. In some cases, such as
the present one, there is a disseminated
maculopapular rash on the upper and
lower legs. There are also several,
partially crusted papulovesicles in the
perioral region. The eponymous
involvement of the mouth, however,
refers to the most painful aphthous
enanthem of the oral mucosa, which is
not shown here.
18. Area around the mouth and
the tongue of a child
There is an ulcer on the tip of
the tongue, which is, however,
not specific in hand, foot, and
mouth disease, but may occur.
19. Investigations & diagnosis
Diagnosis of HFMD is almost always clinical, based upon thorough history taking and
recognition of clinical signs.
In ill children, blood tests may show:
o Raised white cell count
o Atypical lymphocytes
o Raised serum C-reactive protein (CRP)
o Positive serology for the causative virus, which may be isolated from swabs of
vesicles, mucosal surfaces, or stool specimens, which confirms the infection but is
rarely necessary.
● Skin biopsy of a blister is rarely considered .
20. Management
Management is limited to offering supportive treatment and treatment of complications.
Signs and symptoms of hand-foot-and-mouth disease usually clear up in seven to 10 days.
Medications other than aspirin, such as acetaminophen (Tylenol, others) or ibuprofen (Advil,
Motrin, others) may help relieve general discomfort.
HOW LONG IT’S CONTAGIOUS ?
The blisters remain infective until they have dried up, which is usually
within a few days. The stools are infective for up to a month after the
illness.
21. ● Keep the blisters clean and apply non-adherent
dressings to erosions.
● Maintain adequate fluid intake.
● Drink cold beverages, such as milk or ice water.
● Rinse your mouth with warm water after meals.
● Eat soft foods that don't require much chewing.
● The blisters should not be ruptured, to reduce
contagion.
● Avoid acidic foods and beverages, such as citrus
fruits, fruit drinks and soda.
● Avoid salty or spicy foods.
DO ‘ S
DON’TS
22. COMPLICATIONS
•Dehydration due to inadequate fluid
intake
•Fingernail and toenail changes are
often noted about 2 months after
CVA6 infection:
• Transverse lines that slowly move
outwards
• Nail shedding (onychomadesis)
about 2 months after the illness.
• Eventually, the nails return to
normal.
Serious enteroviral infection can lead to:
•Widespread vesicular rash
•Enteritis
•Myocarditis
•Meningoencephalitis
•Acute flaccid paralysis
•Pulmonary oedema and pneumonia
•In pregnancy, first-trimester spontaneous abortion or
fetal growth retardation.
