Constance Schultsz conducts research into antimicrobial resistance and emerging infectious diseases. She focuses on bacterial infections which are transmitted from animals to humans, diagnostic and epidemiological research, specifically in the area of antibiotic resistance, and healthcare interventions in low and middle income countries.

Schultsz is a physician specialised in medical microbiology at the Academic Medical Center (AMC) in Amsterdam. She is deputy head of the department of Global Health and also works at the Medical Microbiology department. She is a member of the Board of the Amsterdam Institute for Global Health and Development (AIGHD), the interdisciplinary network organisation of the University of Amsterdam, AMC and VU Amsterdam, which focuses on research, education, training and policy in the area of Global Health and development. Schultsz previously worked at the International Centre for Diarrhoeal Disease Research, Bangladesh in Dhaka and at the Oxford University Clinical Research Unit in Ho Chi Minh City, Vietnam. She is an honorary visiting research fellow for Tropical Medicine/Vaccinology at the Nuffield Department of Medicine of the University of Oxford.

Schultsz co-founded MOSO (Medische OnderwijsStages in Ontwikkelingslanden) in 1985, an internship exchange programme for medical students in the Netherlands and in developing countries (now known as IFMSA-Amsterdam). She is currently also involved in the Bachelor's and Master's programmes in Global Health for students of Medicine and Biomedical Sciences and in the Research Master's programme in Global Health at VU Amsterdam.