1 Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, New South Wales, Australia. Electronic address: jan.slapeta@sydney.edu.au.
2 Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel St, London, UK.
3 Institute of Parasitology, University of Veterinary Medicine Vienna, Vienna, Austria.