Yvonne Edna Cossart AO (14 August 1934 – 16 December 2014)^[1] was an Australian virologist, who discovered the parvovirus B19 in 1975.^[2] Parvovirus B19, or Fifth Disease, causes a mild illness in children.^[3]

Cossart graduated from the University of Sydney with a Bachelor of Science in 1957 and MBBS in 1959.^[4]

The majority of Cossart's work was on hepatitis, starting in 1967. She was key in testing, survey, and prevention of hepatitis in hospitals and communities.^[5] She was appointed an Officer of the Order of Australia in the 1998 Queen's Birthday Honours for "service to medicine as a specialist in infectious diseases, especially in the areas of virological research, epidemiology and disease prevention, and to education".^[6]

Towards the latter part of her life, Cossart dedicated efforts to developing teaching programs for medical curriculum, involvement in university affairs, and supervising post-graduate research students.^[7] In 1986, she was appointed as a Bosch Professor of Infectious Diseases and Immunology until she retired in 2006.^[8]

Cossart died at Greenwich Hospital on 16 December 2014, aged 80.^[9]

• Cossart, Yvonne E (1977), Virus hepatitis and its control, Baillière Tindall, ISBN 978-0-7020-0651-7
• Department of Infectious Diseases; Cossart, Yvonne E (1990), History and philosophy of medicine for medical students, Department of Infectious Diseases, University of Sydney
• Cossart, Yvonne E; Pegler, Mollie; University of Sydney. Faculty of Medicine (1993), Doctor! Look behind you : a companion for medical students, History & Philosophy of Medicine Unit, University of Sydney
• Sefton, Ann Jervie; Cossart, Yvonne E; Freckelton, Louise; University of Sydney (2006), 150 years of the Faculty of Medicine, Sydney University Press, ISBN 978-1-920898-35-9