TY - JOUR AU - Freuler, Michael AU - De Crom, Susan AU - Hatz, Christoph AU - Bühler, Silja PY - 2016/08/28 Y2 - 2024/03/29 TI - Varicella seroprevalence in individuals with a negative or unknown varicella history – results from a large travel clinic in Switzerland between 2008 and 2015 JF - Swiss Medical Weekly JA - Swiss Med Wkly VL - 146 IS - 3536 SE - Original article DO - 10.4414/smw.2016.14342 UR - https://smw.ch/index.php/smw/article/view/2217 SP - w14342 AB - <p><p>QUESTION UNDER STUDY: In Switzerland, vaccination against varicella is not recommended in the basic immunisation schedule. However, for individuals aged 11–40 years who do not have a reliable varicella history the Swiss Federal Office of Public Health recommends either (i) a vaccination or (ii) a serology test and vaccination of those with a negative result. In the Travel Clinic of the University of Zurich, the second strategy is followed. In this study we retrospectively assessed the overall percentage of individuals with varicella-specific antibodies despite a negative history and we examined the influence of age, number of siblings, order of siblings, age difference to siblings and nationality on varicella seropositivity.</p> <p>METHODS: Between December 2008 and August 2015, the sera of 1757 individuals with a negative varicella history were tested for varicella antibodies.</p> <p>RESULTS: A total of 1593 individuals (91%) had a positive result. We found an increasing trend for varicella seropositivity with increasing age. Those aged less than 40 years were significantly more often seronegative (9.5%) than those aged 40 years and above (6.0%, p = 0.049). Seropositivity was associated with nationality. The percentage of seropositives increased with the number of siblings.</p> <p>CONCLUSIONS: Our results indicate that, despite the significant varicella seropositivity differences between those aged below and above, the age of 40 may not be an ideal threshold for performing a varicella serology in individuals with a negative or unknown varicella history. In the age groups above 40, testing for varicella antibodies may be especially reasonable in individuals with no or a small number of siblings and in those of specific nationalities.</p></p> ER -