1. Department of Microbiology and Immunology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, 412 96 Gothenburg, Sweden
2. Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, 412 96 Gothenburg, Sweden
3. Department of Surgery, Sahlgrenska University Hospital, Region Västra Götaland, 413 45 Gothenburg, Sweden
4. Department of Surgery, Massachusetts General Hospital, Boston, MA 02114, USA
5. Department of Surgery, Uganda Christian University School of Medicine, Mukono P.O. Box 4, Uganda