Southern Derbyshire Shared Care Pathology Guidelines. Varicella Zoster Virus (VZV)

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1 Southern Derbyshire Shared Care Pathology Guidelines Varicella Zoster Virus (VZV) Purpose of guideline This guideline provides information about the definition of significant exposure to VZV and management of exposure in immuno-suppressed patients, neonates and pregnant women. Definitions Significant contact with chickenpox is defined as any person who is not immune to varicella- Zoster Virus (VZV) (i.e. not had chickenpox before) who has had: Contact with a case of chickenpox from the onset of the rash (if a household contact) or 48 hours prior to rash onset, until all the lesions are crusted and there is no further cropping Face to face contact In the same room as the index case for more than 15 minutes Contact with clothing and bedding soiled by discharge from blisters Significant contact with Shingles is defined as any person who is not immune to varicella- Zoster Virus (VZV) (i.e. not had chickenpox before) who has had: Contact with case of disseminated/wide-spread shingles or exposed area of shingles from the day of on set of rash until crusted Contact with clothing and bedding soiled by discharge from blisters Confirmation of chickenpox or shingles in a patient Confirmation of the presence of VZV can be: Clinical Microbiological swab from newly burst blister for VZV PCR. Use any sterile swab placed in a sterile Universal tube (a swab from a charcoal swab pack may be used if it is snapped off in a sterile Universal and the charcoal tube is discarded) Checking for previous immunity serum (red top tube) for VZV IgG Authorised by Julia Forsyth Page 1 of 5

2 Management of VZV Exposure in Immuno-suppressed Patients Is the Patient Immuno-suppressed? e.g. All types of primary immunodeficiency syndromes Having or within 6 months of chemotherapy/radiotherapy On immuno-suppressive therapy following an organ transplant Bone marrow transplant recipients up to 12 months after immuno-suppressive therapy Child who in previous 3 months has had Prednisolone therapy for over 1 week Adult who in previous 3 months has had 40mg Prednisolone a day for <1 week Patients on lower doses of steroids in combination with cytotoxic drugs See the Green Book for Group A and B immunosuppression ( Does the index case have definite chickenpox/shingles? Was contact during infectious period? VZIG * not normally given Is current Vz IgG status positive? UNKWN *Offer acyclovir prophylaxis from day 7-14 Test VZ IgG urgently Negative Positive *For advice on prescribing acyclovir prophylaxis see later section (page 4) Authorised by Julia Forsyth Page 2 of 5

3 Management of VZV Exposure During Pregnancy Confirm diagnosis of chickenpox/shingles in index case Does contact constitute significant exposure? required What is the VZ immune status? History of chickenpox/shingles OR Known VZ IgG positive UNKWN Test blood for VZ IgG immediately required POSITIVE VZ IgG NEGATIVE VZ IgG Too late to test *Consultant Virologist will arrange VZIG to be issued by the Colindale Rabies and Immunoglobulin service; this will then either be delivered direct to the GP practice for administration or Derby Royal Hospital Pharmacy for administration by antenatal services. Give VZIG* Within 10 days of exposure if <20 weeks pregnant. If >20 weeks offer acyclovir prophylaxis Authorised by Julia Forsyth Page 3 of 5

4 Management of VZV Exposure in Neonates Is mother the index case and has she got chickenpox? (if shingles and unexposed, no ) Was the contact in the first 7 days of life? Full-term infant no further. Advise against signs of infection Was onset of rash between 7 days before and 7 days after delivery? If it is significant exposure Prem/LBW infant. Born <28 weeks or <1000g. In hospital since birth. Give VZIG* to neonate Consider Acyclovir if rash occurred between 4 days before and 2 days after delivery *Consultant Virologist will arrange VZIG to be issued by the Colindale Rabies and Immunoglobulin service; this will then be delivered direct to Derby Royal Hospital Pharmacy for administration by the neonatal team. Full term and mother is immune no further If VZ IgG positive no further required Full term infant but no history of chickenpox in mother and antibody status unknown Check maternal or infant blood for VZ IgG as soon as possible If prem/lbw and still in NICU/SCBU give VZIG* even if contact >7 days after birth If VZ IgG negative give VZIG * within 7 days of initial exposure Acyclovir Prophylaxis is recommended in the following settings: Pregnant women over 20 weeks gestation are advised to take oral acyclovir at 800mg four times a day or oral valaciclovir 1000mg three times a day from days 7 to 14 after exposure. Immunosuppressed individuals are advised the following: o Children under 2 years of age Acyclovir 10mg/kg four times a day, days 7-14 after exposure. o Children 2-17 years of age Acyclovir 10mg/kg (upto a maximum of 800 mg) four times a day, days 7-14 after exposure. Valaciclovir 20mg/kg (upto a maximum of 1000 mg) three times a day, days 7-14 after exposure. o Adults - Acyclovir 800 mg four times a day, days 7-14 after exposure. Valaciclovir 1000 mg) three times a day, days 7-14 after exposure. Authorised by Julia Forsyth Page 4 of 5

5 Useful Contacts On-call consultant Virologist (10am - 5pm Mon to Fri) On-call consultant Virologist out of hours - via switchboard Microbiology Manager Main Microbiology Lab Serology Lab Author: Dr Deboarah Gnanarajah, November 2014 Reviewed by: Date: Expiry date: Dr Cariad Evans, Dr P Blackwell, Mrs H Seddon July st July 2019 Dr Cariad Evans updated VZIG treatment information Sept th Sep 2020 Authorised by Julia Forsyth Page 5 of 5