• Type of varicella-zoster infection in the index case:
• Exposure is significant if contact with: chickenpox, disseminated zoster, immunocompetent people with exposed lesions (e.g. ophthalmic zoster), or immunosuppressed people with localized zoster on any part of the body.
• Timing of exposure in relation to the rash onset in the index case — exposure is significant if in contact with:
• Chickenpox — between 48 hours before onset of rash to crusting of lesions.
• Disseminated zoster — from 48 hours before onset of rash to crusting of lesions.
• Localized zoster — day of onset of rash until crusting of lesions.
• Closeness of contact:
• Exposure is significant if: maternal/neonatal contact, continuous home contact, contact in the same room (e.g. house or classroom, or 2- to 4-bed hospital bay) for 15 minutes or more, contact on large open wards (particularly paediatric wards), or face-to-face contact (e.g. having a conversation).

• If the exposure to chickenpox is not significant, or the person has a definite history of chickenpox or herpes zoster, reassure.
• If the person has no definite history and exposure is significant, warn them that they may develop chickenpox.
• For healthcare workers:
• If the person is vaccinated or has a definite history of chickenpox or herpes zoster, they can continue working, but advise them to contact their occupational health department if they feel unwell or develop a rash.
• If there is a negative or uncertain history of chickenpox or herpes zoster, test to determine immunity and advise that the person may develop chickenpox. Advise to avoid contact with high-risk patients for 8–21 days after contact with chickenpox and to report to occupational health before patient contact if they feel unwell or develop a fever or rash.
• Healthcare workers without varicella-zoster antibody should be offered varicella vaccine to reduce the risk of exposing patients to the varicella-zoster virus in the future.

In depth

• If the woman has a definite history of chickenpox or shingles, assume immunity.
• If the woman has no history of chickenpox or shingles (or is uncertain) and has a history of significant contact:
• Establish the stage of gestation (weeks from the last menstrual period).
• Test for varicella-zoster immunoglobulin G (IgG) antibodies in primary care if test results can be available within 2 working days of first exposure. If this is not possible, urgently seek specialist advice because testing in secondary care and/or varicella-zoster immunoglobulin prophylaxis may be needed.
• If the test shows varicella-zoster IgG, reassure the woman that she is immune.
• If the woman's antibody status is negative, urgently seek specialist advice.
• Advise the woman to promptly seek medical advice if she develops a rash and has had contact with chickenpox, regardless of whether she has received varicella-zoster immunoglobulin.

In depth

• Seek urgent specialist advice regarding the need for testing and further management, and whether the mother should continue to breastfeed if she has chickenpox.
• All neonates exposed to chickenpox must be followed up and monitored for signs of infection for 14–16 days by a GP, midwife, or health visitor, or in hospital.

In depth

• Establish whether the person fulfils the criteria for immunosuppression (if in doubt, seek specialist advice).
• Urgently seek specialist advice regarding further management.
• People who have had a significant exposure to chickenpox and who are immunocompromised should be tested for varicella-zoster antibody, regardless of their history of chickenpox. Test for varicella-zoster immunoglobulin G (IgG) antibodies in primary care if test results can be available within 2 working days of first exposure. If this is not possible, urgently seek specialist advice because testing in secondary care and/or varicella-zoster immunoglobulin prophylaxis may be needed.

In depth