1. Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
2. Department of Infectious Diseases, Christchurch Hospital, Christchurch, New Zealand
3. Department of Biochemistry, Canterbury Health Laboratories, Christchurch, New Zealand
4. Department of Microbiology, Canterbury Health Laboratories, Christchurch, New Zealand
5. Department of Population Health, University of Otago, Christchurch, New Zealand