In Denmark 50 years later than in Paris, the prevalence of infection among children aged 5 to 9 years was still high, but below 20%.  The prevalence reached 80% only at the age of 50 years.

Among children, there were no differences by sex, but among adults, males had a slightly higher prevalence of infection than females.

The risk of becoming infected will depend on the risk of exposure, which is related to the extent of social interactions.  In countries, where women participate equally in public life as men, smaller differences in the prevalence of infection might be expected than in situations where this is not the case.

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