BACKGROUND: Varicella zoster infection can be spread by infected healthcare workers (HCWs) to coworkers and patients. A self-reported history of chickenpox infection is sometimes taken as proof of immunity. AIM: To establish the relationship between positive recall history and serological immunity against varicella zoster virus (VZV) amongst healthcare workers in a tertiary hospital in Taiwan. METHODS: Between May 2008 and April 2009, all HCWs in a Taiwanese tertiary care hospital were tested for VZV immunoglobulin G (IgG), and completed a self-administered questionnaire to determine their history of varicella infection or vaccination. Those who were seronegative were vaccinated. FINDINGS: All HCWs (N=3733) at the hospital participated in this study. Their mean age was 34.6 years, and the seroprevalence of VZV was 91.1%. Sensitivity, specificity, and positive and negative predictive values of a self-reported history of varicella infection were 82.3%, 48.6%, 96.3% and 14.4%, respectively. Corresponding figures for a history of varicella vaccination were 23.4%, 69.4%, 90.9% and 6.5%, respectively. The recall history of younger HCWs and medical professionals (doctors, nurses and paramedical staff) to varicella had higher sensitivity. However, only the recall history of medical professionals had a significantly higher positive predictive value. CONCLUSION: A positive recall history of varicella infection and vaccination did not ensure the presence of protective VZV IgG, and a negative history was not predictive of a lack of immunity. For effective prevention of nosocomial infection, VZV IgG status should be documented for all HCWs, and susceptible HCWs should be vaccinated.
BACKGROUND:Varicella zoster infection can be spread by infected healthcare workers (HCWs) to coworkers and patients. A self-reported history of chickenpox infection is sometimes taken as proof of immunity. AIM: To establish the relationship between positive recall history and serological immunity against varicella zoster virus (VZV) amongst healthcare workers in a tertiary hospital in Taiwan. METHODS: Between May 2008 and April 2009, all HCWs in a Taiwanese tertiary care hospital were tested for VZV immunoglobulin G (IgG), and completed a self-administered questionnaire to determine their history of varicella infection or vaccination. Those who were seronegative were vaccinated. FINDINGS: All HCWs (N=3733) at the hospital participated in this study. Their mean age was 34.6 years, and the seroprevalence of VZV was 91.1%. Sensitivity, specificity, and positive and negative predictive values of a self-reported history of varicella infection were 82.3%, 48.6%, 96.3% and 14.4%, respectively. Corresponding figures for a history of varicella vaccination were 23.4%, 69.4%, 90.9% and 6.5%, respectively. The recall history of younger HCWs and medical professionals (doctors, nurses and paramedical staff) to varicella had higher sensitivity. However, only the recall history of medical professionals had a significantly higher positive predictive value. CONCLUSION: A positive recall history of varicella infection and vaccination did not ensure the presence of protective VZV IgG, and a negative history was not predictive of a lack of immunity. For effective prevention of nosocomial infection, VZV IgG status should be documented for all HCWs, and susceptible HCWs should be vaccinated.
Authors: Nikki M Turner; Jayden MacRae; Mary L Nowlan; Lynn McBain; Maria H Stubbe; Anthony Dowell Journal: BMJ Open Date: 2018-05-31 Impact factor: 2.692
Authors: Alexander Wilhelm Gorny; Chikul Mittal; Sharon Saw; Indumathi Venkatachalam; Dale Andrew Fisher; Paul Anantharajah Tambyah Journal: BMC Res Notes Date: 2015-11-10