1 Department of Microbiology and Parasitology, Faculty of Pharmacy and Bioanalyses, University of Los Andes, Mérida, Venezuela.
2 Parasitology Service, National Centre for Microbiology, Carlos III Institute of Health, Majadahonda, Madrid, Spain.
3 Parasitology Service, National Centre for Microbiology, Carlos III Institute of Health, Majadahonda, Madrid, Spain. Electronic address: dacarmena@isciii.es.