Evaluation of varicella immune status in an obstetric population in relation to place of birth.

Obstetric populations born in tropical or subtropical regions are likely to be seronegative for varicella virus; obstetric populations containing a large proportion of women born in tropical or subtropical regions will benefit greatly from being screened for varicella immunity. Physicians should therefore know the geographic origin of the community they serve and should consider testing varicella immunity in their obstetric patients born in tropical or subtropical regions. To ensure that passive immunization is received when indicated, physicians should obtain serostatus without relying on patients' recollection of their exposure to varicella virus.