Epstein-Barr virus reactivation associated with diminished cell-mediated immunity in antarctic expeditioners

Epstein-Barr virus (EBV) reactivation and cell-mediated immune (CMI) respon ses were followed in 16 Antarctic expeditioners during winter-over isolatio n at 2 Australian National Antarctic Research Expedition stations. Delayed- type hypersensitivity (DTH) skin testing was used as an indicator of the CM I response, that was evaluated 2 times before winter isolation and 3 times during isolation. At all 5 evaluation times, 8 or more of the 16 subjects h ad a diminished CMI response. Diminished DTH was observed on every test occ asion in 4/16 subjects; only 2/16 subjects exhibited normal DTH responses f or all 5 tests. A polymerase chain reaction (PCR) assay was used to detect EBV DNA in saliva specimens collected before, during, and after the winter isolation. EBV DNA was present in 17% (111/642) of the saliva specimens; al l 16 subjects shed EBV in their saliva on at least 1 occasion. The probabil ity of EBV shedding increased (P = 0.013) from 6% before or after winter is olation to 13% during the winter period. EBV appeared in saliva during the winter isolation more frequently (P < 0.0005) when DTH response was diminis hed than when DTH was normal. The findings indicate that the psychosocial, physical, and other stresses associated with working and living in physical isolation during the Antarctic winter result in diminished CMI and an acco mpanying increased reactivation and shedding of latent viruses. Published 2 000 Wiley-Liss, Inc.