Varicella Zoster Immunity amongst New Health Personnel in a University Hospital in Northeastern Thailand
Wangsan K, MD1, Chaiear N, MD, MMedSc, PhD1, Krisorn P, MD1, Soonthornvinit W, MD1
Affiliation : 1 Division of Occupational Medicine, Department of Community Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
Background : Health personnel (HP) are at risk of varicella zoster virus (VZV) infection, thus varicella immunity is needed or
serious consequences to HP and patient care can result. A varicella immunity profile is not routinely checked in our pre-placement
program. The aim of the present study was to determine the proportion of new HP with varicella immunity.
Materials and Methods : The research design was a descriptive study. The study population was 258 HP who met the inclusion
criteria. The sample of 214 HP (82.9%) participated in the study. Varicella immunity history was obtained using a pre-placement
questionnaire. The HP who already had complete vaccination were concluded to be the immunized group without immunologic
blood test evidence. Only non vaccinated HP would get serologic test for varicella virus. A serological test for varicella virus was
performed using an enzyme-linked immunosorbent assay (Euroimmun, anti-VZV ELISA IgG, Hausen Bernstein Co., Ltd).The
proportion of positive immunity was used to describe overall immunity.
Results : Twenty-two percent (47/214) of HP reported having a complete history of varicella vaccination. History of varicella
infection was reported in 57.9% (124/214) of participants. The HP who had neither history of infection nor vaccination accounted
for 10.7% (23/214). Seven percent of the HP were unsure about their respective infection history (15/214). There were 167 HP
who did not have varicella vaccination, 89.2% (149/167) of them were positive to varicella IgG. The total proportion of immunized-
personnel was thus 91.6% (196/214).
Conclusion : The majority of new HP had varicella immunity; re-assessing immunity status serologically will prevent unnecessary
vaccinations and insure all HP have varicella immunity
Keywords : Varicella zoster, Health personnel, Health worker, Immunity, Fitness to work
