The  National Institute of Infectious Diseases (NIID) , formerly known as the National Institute of Health (NIH) and established in 1947, is a research institute attached to the Ministry of Health, Labour and Welfare for conducting researches on infectious diseases. The mission of the Department of Medical Entomology include basic and applied researches for taxonomy, ecology, physiology, biochemistry, vector-parasite relationship, molecular mechanisms of insecticide resistance, and developing control strategies for vector insects of diseases and other arthropods for public health importance.

Dr. Kyoko Sawabe is leading the Department of Medical Entomology and is working on the survey and control of vector-borne diseases and their vectors (arthropods) in Japan. Her research focuses on the relationship between pathogens and vectors. Another interest is to clarify the mechanisms of overwintering, hibernation and long–distance migration of Japanese encephalitis vector mosquitoes by the physiological approach.

Dr. Shinji Kasai is a senior research scientist of the Department of Medical Entomology. His research focuses on the molecular mechanisms of insecticide resistance of medically important arthropods and development of new tools to overcome insecticide resistance. He is especially interested in association of insecticide resistance with detoxification enzymes and target site modifications.