RSo far, no cases of yellow fever were reported in the State of Paraná where Foz do Iguaçu is located. Endemic areas are the States of São Paulo, Minas Gerais and Rio de Janeiro. Depending on the locations visited in Brazil, a yellow fever vaccination may be recommended. Foz do Iguaçu and Southern / South Eastern Brazil are not regions with malaria.
Please, inquire for further information at your local Institute of Tropical Medicine and International Health. Hiring an international health insurance is strongly recommended.