Immuniteit tegen infectieziekten bij asielzoekers*

Objective

To gain insight in the seroprevalence of 9 vaccine-preventable infectious diseases among adult asylum seekers in the Netherlands.

Design

Cross-sectional seroprevalence survey.

Method

In 2016, adult asylum seekers aged 18 to 45 from Syria, Iran, Iraq, Afghanistan and Eritrea, living in reception centres, were invited to participate in the study. Participants received a short questionnaire and blood samples were taken. We then measured the seroprevalence of protective antibodies to the following infectious diseases: measles, mumps, rubella, diphtheria, tetanus, polio, varicella and hepatitis A and B.

Results

The median age of the 622 participants was 28; 81% were male and 48% were born in Syria. Average seroprevalence was: 88% for measles (range between countries: 83%-93%), 91% for mumps (81%-95%), 94% for rubella (84%-98%), 96% for varicella (92%-98%), 82% for diphtheria (65%-88%), 98% for tetanus (86%-100%), 91% for type 1 polio (88%-94%), 95% for type 2 polio (90%-98%), 82% for type 3 polio (76%-86%), 84% for hepatitis A (54%-100%) and 27% for hepatitis B (8%-42%; anti-HBs). Seven participants (1%) had a chronic HBV infection.

Conclusion

The seroprevalence of protective antibodies against the infectious diseases investigated is generally high among adult asylum seekers and does not differ significantly from that in the general Dutch population, with the exception of the seroprevalence of measles. However, it is not deemed necessary to adjust vaccination policy since the seroprevalence of measles in the general Dutch population is sufficient to provide herd immunity to non-immune asylum seekers.

Conflict of interest and financial support: potential conflicts of interest have been reported for this article. ICMJE forms provided by the authors are available online along with the full text of this article.