Laboratory of Epidemiology and Biostatistics. Department of Preventive Veterinary Medicine and Animal Health. University of São Paulo, São Paulo, Brazil.|Physics Institute, University of São Paulo, São Paulo, Brazil.|Laboratory of Parasitic Diseases. Department of Preventive Veterinary Medicine and Animal Health. University of São Paulo, São Paulo, Brazil.|Laboratory of Epidemiology and Biostatistics. Department of Preventive Veterinary Medicine and Animal Health. University of São Paulo, São Paulo, Brazil.|Robert Koch-Institute, Berlin, Germany.