Varicella seroprevalence among health care workers in Korea: Validity of self-reported history and cost-effectiveness of prevaccination screening

• Published in: American journal of infection control 2014-08, Vol.42 (8), p.885-887
• Main Authors: Kang, Ji-Hea, RN, Park, Yoon Soo, MD, Park, Shin Young, RN, Kim, Sae Bom, RN, Ko, Kwang-Pil, MD, Seo, Yiel-Hea, MD
• Format: Article
• Language: English
• Subjects: Adult; Antibodies, Viral - blood; Bacteria; Biological and medical sciences; Chickenpox - epidemiology; Chickenpox - immunology; Cost-Benefit Analysis; Epidemiology. Vaccinations; Female; General aspects; Health Personnel; Herpesvirus 3, Human - immunology; History; Human viral diseases; Humans; Immunization; Infection Control; Infectious Disease; Infectious diseases; Male; Mass Screening - economics; Mass Screening - methods; Medical History Taking; Medical personnel; Medical sciences; Middle Aged; Prevaccination screening; Republic of Korea - epidemiology; Risk assessment; Seroepidemiologic Studies; Seroprevalence; Surveys and Questionnaires; Varicella; Viral diseases; Viral diseases with cutaneous or mucosal lesions and viral diseases of the eye; Young Adult
• ISSN: 0196-6553; 1527-3296
• DOI: 10.1016/j.ajic.2014.05.013

Background The validity of self-reported varicella history and cost-effectiveness of a prevaccination screening strategy have not been examined among health care workers (HCWs) living in Korea. Methods We investigated varicella-zoster virus immunity of all HCWs in high-risk departments. To determine the history of varicella, all applicants completed a standardized questionnaire at the time of blood sampling for serologic testing. Results Of the 550 HCWs, 526 (96%) were varicella seropositive. Although self-reported history was highly predictive of seropositivity (≥96%) among all age groups, the negative predictive value was extremely low (4%-5%) among all age groups. The prevaccination screening strategy was cheaper than vaccination without antibody screening if the varicella seroprevalence was >28%. Conclusion Seroprevalence was high (≥95%) among HCWs born in Korea before 1988. The self-reported varicella history did not accurately predict immunity, especially for individuals who have negative or uncertain varicella history. Given the high seroprevalence of varicella in Korean HCWs, serologic screening before vaccination was more cost-effective than universal vaccination.