Annie Porter, parasitologist, studied at University College, London, and was awarded the degree Doctor of Science (DSc) in zoology by the University of London in 1910. From 1908 to 1916 she was a researcher at the Quick Laboratory, University of Cambridge. In 1915 she married the zoologist Harold B. Fantham*. The next year, during World War 1 (1914-1918), she began a period of special war research in animal parasitology at the Liverpool School of Tropical Medicine. In 1917 she came to Johannesburg to establish a Department of Parasitology at the South African Institute for Medical Research (SAIMR). She was subsequently also appointed as a part-time senior lecturer in parasitology at the University of the Witwatersrand.
During the nineteen-twenties Porter was particularly involved in public health projects. From 1923 to 1928 she studied the parasites in the street dust of Johannesburg, finding many human and animal parasites in the form of cysts, eggs, larvae and pupae. She also studied the effect of freezing on meat infested with tapeworms, using herself as a test subject (SAIMR Publications, No. 16, 1923). Though she had a wide interest in parasitology, the study of bilharzia remained her major objective during her entire stay in South Africa and she made many contributions to knowledge of the ecology of the disease. For example, she confirmed the conclusion reached by Dr J.G. Becker* that the snail now known as Bulinus africanus is an intermediate host of the parasite Schistosoma haematobium; proved that the snail Planorbus pfeiferi is an intermediate host of another human schistosome, S. mansoni; and described the life cycles of both organisms. This work was reported in 'The experimental determination of the vertebrate hosts of some South African cercariae from the molluscs Physopsis Africana and Limnaea natalensis' (Medical Journal of South Africa, 1920, Vol. 15, pp. 128-133). Outside the field of bilharzia research she showed that the snail Limnaea natalensis is an intermediate host of two species of liver flukes [parasitic flatworms], and worked out the life cycles of other flukes, one of which parasitizes the clawed frog (Medical Journal of South Africa, 1920, Vol. 16, pp. 75-76; South African Journal of Science, 1921, Vol. 18, pp. 156-163). In Chinese patients in Johannesburg she found the Chinese liver fluke, which had presumably entered the country in imported dried fish (Medical Journal of South Africa, 1922, Vol. 17, pp. 240-244). She reported the first infection due to Schistosoma spindalis in humans, and the occurrence of S. bovis in sheep in the Eastern Cape (South African Journal of Science, 1926, Vol. 23, pp. 661-666), though both infections were later ascribed to S. mattheei. Later she compiled a detailed monograph on the bilharzia parasites and other helminthic parasites in mammals (including humans) and birds, and their intermediate hosts: 'The larval Trematoda found in certain South African Mollusca with special reference to schistosomiasis (bilharziasis)' (SAIMR Publications No. 42, 1938, 492 p).
Porter collaborated with her husband on some research, including two papers on the biology of race crossings (South African Journal of Science, 1927, 1930). She was a Fellow of the Linnean Society (FLS) and in 1920 was elected a Fellow of the Royal Society of South Africa. In 1918 she became a member of the South African Association for the Advancement of Science, served as joint secretary of Section D from 1920 to 1932 and as its president for 1922, as honorary librarian of the Association during 1926-1932, and was awarded its South Africa Medal (gold) in 1927. She was a member also of the South African Geographical Society, served on its council from 1920 to 1932 and as president for 1924. In 1933 she resigned her position when her husband accepted an appointment in Montreal, Canada. She became a research associate at McGill University there, but after Professor Fantham's death in 1937 returned to England. There she worked as a parasitologist for the Zoological Society of London until just before her death. She bequeathed several sums of money to institutions with which she had been associated during her career, including the University of the Witwatersrand.