1. Postgraduate Program in Health Sciences, University of Pernambuco (UPE), Recife, Brazil
2. Department of Parasitology, Institute Aggeu Magalhães (IAM), Foundation Oswaldo Cruz (FIOCRUZ), Recife, Brazil
3. Postgraduate Program in Biometrics and Applied Statistics, University Federal Rural de Pernambuco (UFRPE), Recife, Brazil