1. Swansea University Medical School, Singleton Park, Swansea, Wales, SA2 8PP, UK
2. Health Protection, Public Health Wales NHS Trust, Temple of Peace, Cathays Park, Cardiff, Wales, CF10 3NW, UK
3. Cryptosporidium Reference Unit, Public Health Wales Microbiology, Singleton Hospital, Swansea, Wales, SA2 8QA, UK
4. Communicable Disease Surveillance Centre, Public Health Wales NHS Trust, Temple of Peace, Cathays Park, Cardiff, Wales, CF10 3NW, UK