HA Guideline on
2nd revision - 7 August, 1998
|Dear fellows & members of the college, |
Hospital Authority has recently issued a revised set of guidelines concerning
enterovirus infection after a visit to Taiwan by a group of paediatricians
and microbiologists. The Professional and General Affairs Committee
considers it appropriate to share this information with you. I hope you will
find this information useful.
Enquiry : Please contact the hospital Infection Control Unit or
Causative agents :
Enterovirus belongs to a group of small RNA viruses within the family
Picornaviridae. It comprises four species, namely Polioviruses (3 serotypes),
Coxsackieviruses (group A: 23 serotypes, group B: 6 serotypes), Echoviruses (31
serotypes) and Enteroviruses (4 serotypes).
enter the body via ingestion. They are shed in the faeces and from the
oropharynx. Enteroviral infections tend to peak in summer in temperate regions.
Outbreaks of infections have been reported world-wide. Young children are its
main target and reservoir but adults can also be infected. The viruses are
mainly transmitted by the faecal-oral route but can also be spread by direct
contact with respiratory secretions. The incubation period is 3 to 6 days for
Hand-Foot-Mouth Disease (HFMD).
Clinical Manifestation :
Enteroviral infections are mostly subclinical. The same virus can cause several
different clinical syndromes. Conversely, the same clinical picture can be
caused by different enteroviruses, such as meningoencephalitis (Echoviruses,
Enterovirus 71); acute flaccid paralysis (Polioviruses; Enterovirus 71;
Coxsackievirus A7); myocarditis/pleurodynia (Coxsackievirus B); herpangina
(Coxsackievirus A), HFMD (Coxsackievirus A9, A16; Enterovirus 71); acute
haemorrhagic conjunctivitis (Enterovirus 70); respiratory infections
(Coxsackievirus A21, A24).
- Enterovirus infections in Taiwan have been associated with HFMD and
neurological complications in some of the cases. A distinct and new clinical
pattern of brain stem failure was described which progressed from the mild early
phase (with symptoms of fever, poor appetite, oral/skin manifestations, cough )
lasting up to 3 days to the more severe phase (with symptoms of irritability,
insomnia, panic attack, abdominal distension, vomiting, photophobia) followed by
the toxic manifestations including apathetic look, sleepiness, myoclonic jerks,
hallucinations, shortness of breath, cold sweating, poor peripheral circulation,
tachycardia (>160/min), limb weakness, ataxia, conjugated ocular
disturbance, and cranial nerve paresis. Further deterioration could result in
hypothermia, respiratory disturbance, neurogenic shock, haemorrhagic crisis,
cardiopulmonary failure, and ARDS.
- In Hong Kong, most of the EV/EV-71 infections to date were simple
uncomplicated cases. However, we believe that the clinical experience from
Taiwan could facilitate our early detection of complicated cases.
Laboratory Diagnosis :
- Standard methods
- Virus Isolation : Enteroviruses can be isolated by cell culture but
this is of variable sensitivity. Specimens (as stated above), except CSF, should
be put in viral transport medium (T/M) and kept in low temperature
during transport to the laboratory. Serological test is also available
for diagnosis but of limited value. Paired serum samples (acute and
convalescent) should be taken at least 14 days apart.
- Viral studies for enteroviruses should focus on hospitalised patients with
any of the following conditions :
- HFMD/Enterovirus infection with rapid clinical deterioration or
- Children with fever and rapid clinical deterioration;
- aseptic meningitis / encephalitis;
- acute flaccid paralysis;
- Specimens should be taken in the early phase of the disease. The
specimens of choice include :
- faeces (shedding continues up to a few weeks);
- NPA / throat swab (within the first few days of onset of illness);
- others as appropriate - vesicle fluid, CSF, eye swab and tissue;
- paired serum samples.
- Specimens should be sent to the Government Virus Unit or Virology
Laboratory of PWH, following existing arrangement.
- Rapid Methods
- Refer to Information on rapid diagnosis for enteroviral infections
provided by HA designated centres (appendix 1) for the details.
- The primary aim of these tests is to provide prompt enteroviral diagnosis
for management of patients with severe complications.
- The tests provided are rapid (Shell vial) culture and molecular technique
(RT-PCR) for direct detection.
- These tests are available at three HA designated centres, namely QMH, QEH
- Doctor in-charge or the hospital microbiologist should consult the medical
microbiologist/virologist of the designated centre before ordering any such
Patient Management :
- At Accident & Emergency Department (AED) / Out-Patient Clinic :
- Most cases of HFMD/enterovirus infection are mild and do not require
- Cases showing the severe symptoms/signs, especially when they are secondary
cases in the household, should be considered for hospitalization for
investigation and treatment. The following are important warning signs :
- irritability, insomnia, panic attack, abdominal distension, repeated
vomiting, photophobia, sleepiness, myoclonic jerks, hallucinations, shortness
of breath, cold sweating, poor peripheral circulation, tachycardia (>160/min),
limb weakness, unsteady gait, conjugated ocular disturbance, and cranial nerve
- The "Advice on Enterovirus Infection" (see
appendix 2) should be given to parents of patients
who are discharged with HFMD or fever.
- In-patient Management :
- Specific anti-enteroviral agents are not available. Prompt supportive
treatment is the mainstay of patient management.
- Secondary cases from household contact could be more severe and require
- Early detection of signs of CNS involvement (especially brain stem) is
- Patients should be closely monitored for cardiopulmonary decompensation
(HR, RR, BP, SaO2).
- Careful monitoring and assessment of fluid balance and left ventricular
function are important.
- When deterioration is noted, early intubation is desirable since the
patient might progress to pulmonary edema rapidly.
- Consider left ventricular failure and perform early echocardiogram if
patient fails to respond to fluid resuscitation.
- The use of intravenous immune globulin (IVIG) for the treatment of severe
enteroviral infections has been suggested for patients showing signs of
encephalitis/myelitis or carditis based on the assumption that it might exert
either an immunomodulation effect or anti-viral effect. However, it efficacy has
not been fully established. Its use should therefore be regarded as empirical
and the patient should be clearly informed.
- Upon discharge;
- the "Advice on Enterovirus Infection" should also
be given to parents/patients.
- Remind parents that recovery from HFMD does not necessarily confer
protection against other enteroviruses and the patient should therefore maintain
personal hygiene and observe precautions especially hand-washing when in contact
with other children suffering from HFMD.
- Inform parents/patients (even if discharged) when the diagnosis of
Enterovirus infection is confirmed by the Department of Health.
Infection Control Measures :
- Contact Precautions is the key in preventing hospital
outbreak and should be strictly observed.
- Wash hands immediately and thoroughly after handling patients
secretions or excretions irrespective of whether or not gloves are worn.
- Wear gloves and gown during patient-care activities that are likely
to involve contact with patient's secretions or excretions.
- Put on personal protection (as in Universal Precautions) when
carrying out procedures that will generate splashes to mucous membranes.
- Place the patient in a private room or cohorting (i.e. in a room
with other patients who has active infection with the same organism) with other
- Restrict the direct contact of patients suffering from HFMD/enterovirus
infection with other patients.
- Disinfect the patient items properly by following existing guideline on
- Health care workers could also contract the disease from patients and
strict compliance to the above recommendations is therefore important. If
infected, they should avoid direct patient care especially for infants, neonates
or immunocomprised patients, until symptoms resolve.
Reporting of Cases :
- Ward Staff
- Inform the hospital's Infection Control Unit of any patients admitted
- Hand-Foot-Mouth disease (HFMD)/herpangina;
- Febrile illness in children with rapid clinical deterioration;
- Aseptic meningitis or encephalitis;
- Acute flaccid paralysis (AFP);
- Myocarditis / Cardiomyopathy.
- For in-patients under category 2-5 who also has HFMD (i.e. severe
complications associated with HFMD), please also fill in the DH report form and
send it to the hospital's Infection Control Unit.
- Inform the hospital's Infection Control Unit of any reported patients whose
clinical condition become "critical" (among the four categories of
clinical conditions for case reporting).
- Infection Control Staff
- Inform Duty Microbiologist daily on cases under categories 2-5 and weekly