1. Institute of Tropical Medicine, Antwerp, Nationalestraat 155, 2000
Antwerpen, Belgium
2. The General Hospital of Athens, Messogeion 156, Athens 11527,
Greece
3. Med. Poliklinik der Universität München, Immunambulanz MP 118,
München, Germany
4. North Manchester General Hospital, Delaunay's Road, Crumpsall,
Manchester, UK