Infection Prevention and Control Team (IPCT) GUIDELINES FOR STAFF WHO COME INTO CONTACT WITH VARICELLA ZOSTER VIRUS (CHICKENPOX OR SHINGLES) WARNING This document is uncontrolled when printed. Check local intranet site for current version Page 1 of 8
Title of Policy: Guidelines for staff who come into contact with varicella zoster virus (chickenpox or shingles) Policy Reference: Issue no 5, October 2014 Scope: Controlled document: Organisation Wide This document shall not be copied in part or whole without the express permission of the author or the author's representative. Expiry Date: October 2014 Author: Policy application / Target Audience Policy Statement: Mr John Somerville, Lead Occupational Health Nurse Mrs Jan Bingham, Support Nurse - Occupational Health Throughout NHS Ayrshire and Arran It is the responsibility of all staff to ensure that they consistently maintain a high standard of infection control practice in accordance with this guidance to prevent the spread of infections from and between patients with varicella zoster virus. Last reviewed: October 2010 Agreed by: Electronic approval by: Infection Prevention and Control Policy Review Group Mrs Fiona McQueen Executive Nurse Director Date: Page 2 of 8
TABLE OF CONTENTS 1.0 INTRODUCTION...4 2.0 SIGNIFICANT EXPOSURE...5 3.0 HCWS WHO HAVE SIGNIFICANT EXPOSURE TO VZV INFECTED CASES...5 4.0 VARICELLA VACCINE...6 5.0 HUMAN VARICELLA-ZOSTER IMMUNOGLOBULIN (VZIG)...8 6.0 REFERENCES...8 Page 3 of 8
1.0 INTRODUCTION Chickenpox (Varicella) is an acute highly infectious disease, which is caused by infection with varicella zoster virus (VZV). It is transmitted directly by personal contact or droplet spread, and indirectly via fomites (any object e.g. towels, door handles, books etc that is capable of transmitting infection). It is most common in children below the age of ten in whom it is usually mild. Since chickenpox is so common in childhood, 90% of adults are immune. Shingles (Herpes zoster) is caused by the reactivation of the individual s VZV. It is transmissible to susceptible individuals who may develop chickenpox, by direct contact with Herpes zoster rash e.g. hand to mouth contact. Shingles has a much lower rate of transmission than chickenpox. 1.1 Immunocompromised patients VZ infection may be fatal in immunocompromised patients. 1.2 Pregnancy VZV infection in pregnancy may: affect the mother, with special risk of severe varicella pneumonitis, especially in the second and third trimesters increase the risk of congenital (foetal) varicella syndrome, which includes limb hypoplasia, microcephaly, cataracts, growth retardation and skin scarring. The mortality rate is high with the vast majority of congenital varicella syndrome cases occurring before 20 weeks gestation infect the foetus in-utero. The risks to the foetus and neonate from maternal chickenpox are related to the time of infection in the non-immune mother. When the mother is infected in the 2nd or 3rd trimester, the baby may be born with varicella. This is potentially life threatening if the baby is infected seven days before to two days after delivery 1.3 Determining the status of Health Care Workers (HCW) HCWs with a definite history of varicella can be considered protected. HCWs with patient contact, without a definite history of varicella/shingles should be routinely screened for VZV antibody, so that those susceptible are readily identified. Screening is normally undertaken once only, usually at the start of employment. Current HCWs with patient contact who do not have a definite history of varicella/shingles should contact Occupational Health (OH) for advice. A history of varicella from those individuals born and raised overseas is less reliable and routine testing should be considered. Varicella vaccine will be offered to susceptible HCWs by Occupational Health. Page 4 of 8
2.0 SIGNIFICANT EXPOSURE 2.1 Type of varicella-zoster infection in index case The risk of acquiring infection from an immunocompetent individual with nonexposed zoster lesions (e.g. thoraco-lumbar) is remote. Significant contact is therefore restricted to those in contact with chickenpox or who have had direct hand contact with herpes zoster lesions. 2.2 The timing of the exposure in relation to onset of rash in index case: The date of onset of symptoms in the case should be recorded. Exposure to a case of chickenpox potentially 48hrs before the onset of rash until cropping has ceased and crusting of all lesions For HCWs with exposure to a chickenpox case, the period of infectivity of the case should be regarded as being from two days before the onset of rash until all lesions have crusted. An exposure occurring three or more days before the rash develops in the index case (and not followed by further exposures) should be regarded as being of minimal risk with respect to VZV transmission Exposure to herpes zoster- clinical contact after rash has started For HCWs with direct exposure to a herpes zoster case, the period of infectivity of the case should be regarded as being from the onset of the rash until all lesions have crusted 2.2 Closeness and duration of exposure For chickenpox cases, the following should be used as a guide to the type of exposure, other than maternal/neonatal and continuous home contact. Exposure in the same room (e.g. in a house, classroom or hospital bay) for a significant period of time (15 minutes or more) Face to face exposure e.g. while having a conversation 3.0 HCWs WHO HAVE SIGNIFICANT EXPOSURE TO VZV INFECTED CASES If the HCW s immune status is unknown, a blood test should be taken for VZV status and antibody results should be documented in the HCW s notes If a VZV IgG positive result is obtained within seven days of the contact, this indicates previous exposure and immunity. Reassurance can be given and no further action is necessary Page 5 of 8
If the IgG is negative, the HCW will be contacted by OH and will be excluded from duty. Exclude from day eight following 1st infective contact to day twenty-one following last infective contact, or until day twenty eight if VZIG has been administered to the HCW in the following risk groups: - maternity and paediatrics - oncology, especially units treating cases of leukaemia and lymphoma - intensive care and renal dialysis - bone marrow transplant - immunosuppressed patients - patients with symptomatic HIV infection and AIDS HCWs working in other areas, including community settings, should also be assessed by OH regarding the need for exclusion. HCWs who may have contracted varicella will either be swabbed or diagnosed clinically. If swabbed, the test required is PCR from a swab of vesicle/fluid in Virus Transport Medium (VTM). If swabbing is not done then varicella is a clinical diagnosis (i.e. GP or out of hours NHS 24). If varicella has occurred, the HCW can be regarded as non-infectious once all lesions have crusted. 4.0 VARICELLA VACCINE Varicella vaccine is now available. Non-immune HCWs with patient contact will be offered vaccination and, if they decline, will be asked to sign a Disclaimer Form, which will be kept in their OH record. HCWs should receive two doses of varicella vaccine, four to eight weeks apart. If the HCW has any concern for personal reasons e.g. partner is pregnant/immunocompromised, this should be discussed on an individual basis prior to vaccination. Consideration should be given to checking the IgG status of the partner or immunocompromised potential contact prior to immunising the HCW. HCWs should be told at the time of vaccination that they may experience a local rash around the site of injection, or a more generalised rash in the month after vaccination. In either case, they should report to their Occupational Health Department (OHD) for assessment before commencing work. If the rash is generalised and consistent with a vaccine associated rash (papular or vesicular), the HCW should avoid patient contact until all the lesions are crusted. HCWs with localised vaccine rashes that can be covered with a bandage and/or clothing, should be allowed to continue working unless in contact with immunocompromised, neonates or pregnant patients. In the latter situation, an individual risk assessment should be made. Page 6 of 8
Post vaccination serological testing is not routinely recommended but is advisable for HCWs dealing with highly vulnerable patients in the risk groups specified above (see 3.0). Where this testing has been done post vaccination for HCWs working in any of these areas and the result is negative, a serology sample should be sent for the more sensitive reference time-resolved fluorescence immunoassay (TRFIA) test. The procedure for vaccinating health care workers is demonstrated in the following flowchart: The procedure for vaccinating health care workers is demonstrated in the following flowchart: Definite history of VZ virus infection? No Yes Consider immune VZ virus antibody test Positive Consider immune Negative Evaluate for VZ virus vaccine Contraindication (immunocompromised, pregnant) VZIG prophylaxis if significant exposure to VZ virus Informed consent for vaccination, advice to avoid salicylates for six weeks, pregnancy for three months and to consult occupational health if postvaccine rash appears First dose then second dose four to eight weeks later No VZ virus compatible rash: may continue working Outcome Generalised rash exclude from patient contact until lesions crusted Localised rash cover lesions and allow to work (those working in close contact with high-risk patients should be reviewed on a case-by-case basis) Page 7 of 8
5.0 HUMAN VARICELLA-ZOSTER IMMUNOGLOBULIN (VZIG) VZIG prophylaxis is recommended for individuals who fulfil all of the following criteria: A clinical condition which increases the risk of severe varicella; this includes immunosuppressed patients, neonates and pregnant women No antibodies to Varicella-zoster virus Significant exposure to chickenpox or herpes zoster VZIG should be given as soon as possible when indicated; it may however, be given up to ten days after the exposure. If individuals antibody status is not known and the test can be done and results given within 7 days of exposure then the administration of VZIG should be delayed pending the results. If the results are not going to be available within 7 days of exposure VZIG should be given. If individuals antibody status known and negative give VZIG providing it can still be given within 10 days of exposure (ideally given within 7 days but may attenuate up to 10 days). 6.0 REFERENCES 1. Department of Health. (2010) Immunisation against infectious diseases HMSO. Also available at http://www.dh.gov.uk/en/publicationsandstatistics/publications/publicati onspolicyandguidance/dh_079917 (last accessed 12/5/10) 2. Varicella Zoster Reference Service, Barts and the London NHS Trust Vaccine related serology algorithm Available from: http://www.clinicalvirology.org/pages/vzrl/vzrl_summary.html#algorithm (last accessed 10/02/2010) (230610 JS / JB) Page 8 of 8