Abstract
Background
While measles vaccination is widely implemented in national immunisation programmes, measles incidence rates are increasing worldwide. Dutch inhabitants who were born between 1965–1975 may have fallen between two stools, lacking protection from a natural infection, and having missed the introduction of the measles vaccination schedule. With this study we aim to find the measles seroprevalence in travellers born between 1965 and 1975, compared to those born before 1965 and after 1975.
Methods
Families travelling to Eastern Europe or outside Europe during the preceding year were recruited via Dutch secondary schools between 2016 and 2018. Their vaccination status was assessed using questionnaires, vaccination records and measles serology in dried blood spot (DBS) eluates. Measles virus antibody concentrations were determined with an ELISA (EUROIMMUNE®) and a subset was retested with a focus reduction neutralization assay (FRNT).
Results
In 188 (79%) of the 239 available DBS eluates, the ELISA could detect sufficient measles virus-specific IgG antibodies. Of the negative samples that were retested with FRNT, 85% remained negative, resulting in an overall seroprevalence of 82% [95% CI 76–86]. Children had a lower seroprevalence (72%) than adults (87%). Travellers born between 1965 and 1975 were protected in 89%.
Conclusions
In this study, we report a measles seroprevalence of 82% among Dutch travelling families. Remarkably, seroprevalence rates were lowest in children (12–18 years) instead of travellers born between 1965 and 1975. Although a fraction of people without detectable antibodies may be protected by other immune mechanisms, these data suggest that measles (re)vaccination should be considered for travellers to endemic regions.
While measles vaccination is widely implemented in national immunisation programmes, measles incidence rates are increasing worldwide. Dutch inhabitants who were born between 1965–1975 may have fallen between two stools, lacking protection from a natural infection, and having missed the introduction of the measles vaccination schedule. With this study we aim to find the measles seroprevalence in travellers born between 1965 and 1975, compared to those born before 1965 and after 1975.
Methods
Families travelling to Eastern Europe or outside Europe during the preceding year were recruited via Dutch secondary schools between 2016 and 2018. Their vaccination status was assessed using questionnaires, vaccination records and measles serology in dried blood spot (DBS) eluates. Measles virus antibody concentrations were determined with an ELISA (EUROIMMUNE®) and a subset was retested with a focus reduction neutralization assay (FRNT).
Results
In 188 (79%) of the 239 available DBS eluates, the ELISA could detect sufficient measles virus-specific IgG antibodies. Of the negative samples that were retested with FRNT, 85% remained negative, resulting in an overall seroprevalence of 82% [95% CI 76–86]. Children had a lower seroprevalence (72%) than adults (87%). Travellers born between 1965 and 1975 were protected in 89%.
Conclusions
In this study, we report a measles seroprevalence of 82% among Dutch travelling families. Remarkably, seroprevalence rates were lowest in children (12–18 years) instead of travellers born between 1965 and 1975. Although a fraction of people without detectable antibodies may be protected by other immune mechanisms, these data suggest that measles (re)vaccination should be considered for travellers to endemic regions.
| Original language | English |
|---|---|
| Article number | 102194 |
| Journal | Travel Medicine and Infectious Disease |
| Volume | 44 |
| Early online date | 30 Oct 2021 |
| DOIs | |
| Publication status | Published - 2021 |
Bibliographical note
Funding Information:We would like to thank all travellers who participated in this study, all the schools that agreed to participate and gave their permission for us to visit them, as well as the students that helped to collect the necessary data at schools throughout the Netherlands: Merel te Marvelde, Saskia van Bergen, Elyke Visser, Jill Bollen, Miliaan Zeelenberg, Phoebe Otto. Finally, we would like to thank Tamara Kuhlemann for her technical assistance with the total human IgG assay.
Publisher Copyright:
© 2021 The Authors
