Marilyn Parsons, Ph.D.

Professor and Director of Professional Development, Seattle Biomedical Research Institute
Affiliate Professor, Department of Global Health, University of Washington
Area of Expertise: African sleeping sickness, toxoplasmosis, leishmaniasis

Dr. Parsons’ research uses molecular approaches to identify important cellular differences between parasites and their human hosts that could lead to new therapies. As U.S. Co-Director of the Global Infectious Diseases Training Grant on Intracellular Pathogens, she is actively involved in training young scientists from India.


Among different disease agents, parasites are the most similar to their human hosts. This has made the search for drugs and vaccines highly challenging. Scientists in Dr. Parsons’ laboratory are interested in identifying differences in cell structure and function between parasites and humans.

The lab studies several parasites including Trypanosoma brucei (African trypanosomes), Leishmania, and Toxoplasma gondii. These pathogens are the causative agents of African sleeping sickness (human African trypanosomiasis), leishmaniasis, and toxoplasmosis, respectively. While the number of people suffering from sleeping sickness is probably less than 100,000, left untreated the disease is invariably fatal. The World Health Organization estimates that 12 million people are infected with Leishmania parasites, with some showing little sign of disease and others dying from its effects. Co-infection with HIV can lead to severe, often fatal, leishmaniasis. T. gondii infects approximately 50 million Americans, and causes encephalitis in the immunocompromised. It also is a significant cause of birth defects if the mother becomes infected early in pregnancy.

Dr. Parsons’ interest in these parasites stems from both an interest in their role as important pathogens worldwide and in their basic biology as evolutionarily divergent eukaryotes. Her long-term goal is to identify differences between host and parasite that would be appropriate targets for drug development. Currently, Dr. Parsons’ two focal areas of research are protein phosphorylation and organelle biogenesis and function in parasitic protozoa. Her lab uses technologies ranging from fluorescence microscopy to molecular genetics to study the functional attributes of these processes. The links below provide further information on these projects.

Dr. Parsons’ research is currently supported by the National Institutes of Health (NIH).