Blood Tests Establish Early HIV Case
Seppa, Nathan, Science News
Exhaustive analyses of a blood sample taken from an African man in 1959 have confirmed the earliest known case of infection with HIV-1, the virus that causes most AIDS cases worldwide.
The finding establishes that HIV was present in people a decade or two earlier than scientists had thought, said Tuofu Zhu of the University of Washington in Seattle, speaking in Chicago this week at the 5th Conference on Retroviruses and Opportunistic Infections.
The man from whom the sample was taken lived in Leopoldville in the Belgian Congo, now Kinshasa in the Democratic Republic of the Congo. His fate is unknown. The man's blood had been preserved as part of a study of blood diseases and was first identified as HIV-positive in 1986, when researchers performed basic immunological tests on it and 1,212 other samples obtained from African patients between 1959 and 1982.
The information collected on the virus at that time was limited by several factors. Scientists then couldn't multiply tiny amounts of viral DNA many thousandfold, as they can today; they lacked knowledge of several HIV-1 subtypes; and they did not have extensive databases of viral DNA.
To find this blood sample's place in the evolution of HIV, Zhu and his colleagues converted viral RNA from the sample into DNA and then made thousands of copies ofthe DNA. The process yielded copies of a few strands of DNA consisting of about 300 nucleotides each. These sequences of HIV-1 found no perfect match among databases of modern HIV-1 sequences.
"The 1959 [viral DNA] sequence was not a mosaic of modern subtypes" of HIV-1, Zhu said at the meeting.
HIV has mutated many times since 1959, and this early sample may provide insights into that process, the researchers suggest in the Feb. …