1. Department of Clinical Chemistry, Bispebjerg Hospital, Copenhagen, Denmark, and Department of Toxoplasmosis and Viral Diseases, Statens Seruminstitut, Copenhagen, Denmark.
2. Research Fellow, University of Copenhagen.
3. Department of Clinical Chemistry, Bispebjerg Hospital, Copenhagen.
4. Department of Toxoplasmosis and Viral Diseases, Statens Seruminstitut, Copenhagen.
5. Department of Medicine, Country Hospital, Kalundborg, Denmark.