Chickenpox-Shingles ( Varicella-Zoster Virus Infections ) : Prevention And Control

Publication: 01/07/2004  --
Last review: 26/11/2018  
Next review: 26/05/2022  
Clinical Guideline
INTERIM REVIEW DATE 
ID: 689 
Approved By: Trust Clinical Guidelines Group 
Copyright© Leeds Teaching Hospitals NHS Trust 2018  

 

This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Chickenpox-Shingles (Varicella-Zoster Virus Infections): Prevention And Control

Summary of Guideline

  • Hospital spread of chickenpox can be prevented by caring for patients with chickenpox, disseminated shingles or facial shingles using source isolation precautions (see LTHT Source Isolation Policy).
  • Varicella-Zoster Virus (VZV) susceptible patients who have had a significant exposure to chickenpox or shingles (Appendix B) should be placed in source isolation during the period when they may become infectious (usually 8 -21 days following exposure).
  • Susceptible, unvaccinated staff or patients, who are exposed to VZV, should avoid contact with high risk patients during the period when they may become infectious.
  • Staff who suspect that they may have chickenpox or shingles should avoid patient contact until they have sought advice from the Occupational Health Service and the Infection Prevention Team.

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Background

Varicella-Zoster virus is a herpes virus and primary infection results in chickenpox (varicella), an acute generalised disease with sudden onset of fever and a vesicular rash.  Infection usually confers life-long immunity, although the virus remains dormant in the sensory ganglia. Reactivation results in a localised rash known as shingles (zoster).

Chickenpox is endemic in the UK causing an epidemic every spring, although cases occur throughout the year.

About 95% of adults have had previous chickenpox and cannot acquire chickenpox a second time. They are however at risk of developing shingles.

Chickenpox is highly infectious with transmission by direct (person-to-person) contact, droplet or airborne spread.  While shingles is much less infectious than chickenpox, it can be spread by direct contact with the rash - causing chickenpox in susceptible contacts.  Shingles can become disseminated in the immunocompromised where it may be as infectious as chickenpox.

It is not possible to develop shingles from exposure to a person with chickenpox. It is possible, however, to develop chickenpox from exposure to a person with shingles.

Both chickenpox and shingles increase in severity with age.  Chickenpox is more likely to cause complications in adults aged over 20 years than in children.  Shingles is 20 times more likely to cause severe persistent pain in people over the age of 60 years than in those aged less than 50 years.

Chickenpox can be a severe, life-threatening illness in immunocompromised individuals and in neonates who are exposed in the first week of life. There is also a small risk of VZV affecting the foetus if maternal chickenpox occurs during the first 20 weeks of pregnancy.

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Diagnosis

Refer to the LTHT Varicella (chicken pox and shingles) guidelines

Investigation

Refer to the LTHT Varicella (chicken pox and shingles) guidelines

Treatment / Management

For treatment advice, refer to the LTHT Varicella (chicken pox and shingles) guidelines

What to do if you have a case of chickenpox or shingles on the ward

  • Contact the Infection Prevention and Control (IPC) Team for advice
  • Where patients have chickenpox, disseminated shingles or facial shingles (i.e. shingles on exposed areas of skin), they pose a significant infection risk and should be placed in source isolation until crusting of all lesions has occurred.
  • Effective hand hygiene is essential (ref. LTHT Hand Hygiene policy).  Those in direct contact with patients with chickenpox or shingles should wear disposable gloves and aprons.  Masks are not necessary.
  • Patients with VZV infections should be cared for by staff who are immune to chickenpox (i.e. have a past history of infection or are VZV IgG positive or have been vaccinated against VZV).
  • Only those visitors who have a past history of chickenpox or shingles should be allowed to visit patients who are isolated because of VZV infection.
  • Cases of chickenpox should, if possible, be placed on wards not containing at-risk patients (Appendix A).
  • In wards containing at-risk patients, all cases of shingles should be placed in source isolation unless otherwise agreed with IPC.
  • Patients attending outpatients, hospital departments, day-care units, etc. who have suspicious skin lesions should be asked to wait in an area separate from other patients until they can be assessed regarding a possible diagnosis of VZV infection.
  • Pregnant staff who are non-immune, uncertain of their immune status or immunocompromised should avoid contact with patients with VZV and seek advice from Occupational Health.

What to do if one or more patients are exposed to VZV

  • Where one or more patients have been exposed to an individual with confirmed chickenpox or shingles:
    • contact the IPC team
    • the infection prevention nurse will request a list of patients who have had significant exposure to chickenpox or shingles to be drawn up, together with their past history of chickenpox/shingles. Appendix B provides a definition of what constitutes significant exposure. The form can be found at Appendix D.
    • a list of staff who have had contact, as defined Appendix E, with a patient with VZV should be kept including the VZV history of each staff member.
  • Patients with an uncertain history of chickenpox or shingles should be tested for VZV antibody (IgG) (only about 30% of individuals without a history of chickenpox will be VZV susceptible, i.e. VZV IgG negative).
  • Immunocompromised individuals should be tested irrespective of past history of chickenpox unless this test has been performed in the recent past, i.e. three months ago.
  • Susceptible ‘at risk’ individuals (Appendix A) may require VZV immunoglobulin (ZIG) and /or aciclovir prophylaxis (please refer to Immunisation against infectious disease (”The Green Book’’) or contact the Consultant Virologist for advice).
  • All susceptible patients should be nursed in source isolation during the period when they may become infectious (days 8 -21 following exposure).
  • If transferred to another ward, or another hospital, the admitting ward should be informed of the situation and isolation should proceed as above.  If discharged home, appropriate advice on the need to seek medical advice within 24 hours of developing a rash should be given.

Management of staff who have VZV

  • Staff who are suspected to have chickenpox while at work should immediately cease patient contact and inform both the Occupational Health Department and the Infection Prevention Team. The same action should be taken for staff with shingles in contact with at-risk patients (Appendix C).
  • Staff with direct patient contact who suspect that they may have chickenpox or shingles while at home should remain there and contact Occupational Health and their line manager. They may need to be seen by their GP for diagnosis and treatment.
  • Staff at work who are suspected to have shingles but are not working in at-risk areas and lesions are covered by clothing, can continue to work, but should seek advice from the Occupational Health Service at the earliest opportunity.

Management of staff who have contact with chickenpox or shingles

  • Any members of staff (all staff groups) who have contact with patients should know their immune status (i.e. have a history of past chickenpox/shingles).  Otherwise, they should have VZV antibody testing by the Occupational Health Service (VZV IgG blood test). Those who are VZV IgG negative will be offered VZV vaccination (Appendix C).
  • Members of staff in contact with a case of chickenpox or shingles (be it in hospital or the community) who have not previously been screened and have an uncertain history of past chickenpox or shingles, should report this immediately to Occupational Health.
  • If found to be seronegative  (VZV IgG negative) the member of staff must avoid direct patient contact and contact with pregnant staff for 8-21 days after exposure.
  • Where pregnant and immunocompromised HCWs are exposed to VZV, they should report to Occupational Health to be assessed for the need for ZIG (zoster immune globulin). 
  • Pregnant staff without a positive history of chickenpox or shingles and those who are immunocompromised, regardless of their history of VZV infection, should be tested for VZV antibodies.  Pregnant staff with a positive history of chickenpox do not require VZIG.

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Provenance

Record: 689
Objective:

Aims
To prevent and control the transmission of infection with varicella-zoster virus

Objectives

  • To ensure that staff are aware of procedures associated with minimising the risk of infection when a patient or member of staff is suspected or diagnosed with VZV infection.
  • To ensure that patients or members of staff who are identified or suspected of VZV infection are appropriately placed within the clinical environment in order to prevent the transmission of infection.
Clinical condition:

Varicella Zoster Virus infections

Target patient group: All patients at LTHT
Target professional group(s): Secondary Care Doctors
Secondary Care Nurses
Adapted from:

Evidence base

  • Immunisation against infectious disease. (‘’The Green Book’’). Eds. Salisbury DM, Ramsay M, Noakes K. HMSO, London, 2006, 421-422.
  • Gray AM, Fenn P, Weinberg J, Miller E, McGuire A. An economic analysis of varicella vaccination for health care workers. Epidemiology and Infection 1997 119 (2):209-220.
  • Chickenpox (varicella) immunisation for health care workers. PL/CMO/2003/8.
  • Varicella zoster virus - Occupational aspects of management: A national guideline. Royal College of Physicians, NHS Plus, 2010.

Evidence levels:
A. Meta-analyses, randomised controlled trials/systematic reviews of RCTs
B. Robust experimental or observational studies
C. Expert consensus.
D. Leeds consensus.

Approved By

Trust Clinical Guidelines Group

Document history

LHP version 1.0

Related information

Appendix A

At-risk individuals (who are at-risk of severe chickenpox) include:

  • Immunocompromised individuals
  • Neonates (during the first week of life or beyond if premature)
  • Pregnant women (at any stage of pregnancy)

For the purposes of this policy at-risk areas include:

  • Liver transplant
  • Renal transplant
  • Oncology
  • Haematology
  • Rheumatology
  • OPD in these areas
  • Genito-urinary medicine
  • Infectious diseases (excluding negative pressure rooms)
  • All paediatric areas
  • Maternity units          
  • Obstetric and Neonatal Intensive Care Units

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Appendix B

Significant exposure depends upon:

  1. Type of VZV infection in index case
    • There is significant risk of acquiring infection from individual with chickenpox, disseminated zoster, immunocompetent person with exposed herpes zoster (eg ophthalmic zoster).
    • Contact with zoster in an immunocompetent individual where lesions are covered by clothing eg thoraco-lumbar) is not considered a significant exposure.
  2. Timing of the exposure in relation to onset of rash in index case
    • A person with chickenpox or disseminated zoster is capable of transmitting the infection from 2 days before the appearance of the rash and, continuously, until complete crusting of all vesicles has occurred.
    • Those with localised herpes zoster may transmit infection from the day of onset of rash until complete crusting of all lesions.
  3. Closeness and duration of contact
    • Household contact i.e. living in the same household as a case;
    • Face-to-face contact for > 5 minutes;
    • Contact for > 15 minutes in the same room/bay as a case.

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Appendix C

Immunisation

VZV immunisation offers greater than 70% protection against infection and comprises two doses of a live vaccine given 4-8 weeks apart.

Some individuals will develop mild symptoms (vesicles) following vaccination which typically occurs 1 – 2 weeks following administration of the first dose. If working with at-risk patients, staff will need to remain off work until all lesions have crusted over.  If continuing to work staff should ensure that this area is covered.

There is a 2-3% annual breakthrough rate of chickenpox although the illness is usually milder than normal. If infection does occur then action should be taken as per a case of chickenpox. However, no action needs to be taken if an immunised person is in contact with VZV.

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Appendix D

Please Note:
All people who were born or have lived in tropical regions, and have been resident in the United Kingdom or other temperate regions for less than three years should have a blood test for Varicella Zoster Virus immunity. The exception being that they have had Varicella Zoster Virus Infection (Chickenpox/Shingles) whilst residing in a temperate region or they have had a course of Varicella Zoster Virus vaccination.

Tropical regions are sub-Saharan Africa, South East Asia, Caribbean, Central America and parts of India.

Temperate (non-tropical) regions are United Kingdom, rest of Europe, North America, Antipodes, Middle East and Indian sub-continent.

IF IN DOUBT TEST

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Appendix E

Please Note:
All people who were born or have lived in tropical regions, and have been resident in the United Kingdom or other temperate regions for less than three years should have a blood test for Varicella Zoster Virus immunity. The exception being that they have had Varicella Zoster Virus Infection (Chickenpox/Shingles) whilst residing in a temperate region or they have had a course of Varicella Zoster Virus vaccination.

Tropical regions are sub-Saharan Africa, South East Asia, Caribbean, Central America and parts of India.

Temperate (non-tropical) regions are United Kingdom, rest of Europe, North America, Antipodes, Middle East and Indian sub-continent.

IF IN DOUBT TEST

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Equity and Diversity

The Leeds Teaching Hospitals NHS Trust is committed to ensuring that the way that we provide services and the way we recruit and treat staff reflects individual needs, promotes equality and does not discriminate unfairly against any particular individual or group.