It is the first known case of HIV transmission occurring between patients who have had surgery in a clinical setting where the surgeon practised recommended infection control procedures.
Scientists from the New South Wales Health Department in Sydney do not know how HIV transmission occurred, but believe that 'some failure' of the procedures on that one day, in November 1989, allowed transmission from one patient to another.
The doctor who treated the women, an experienced specialist surgeon who is not HIV positive, said his infection control procedures were no different in 1989 from those he used today. Most items were used once and thrown away, while reuseable scalpel handles were disinfected in accordance with accepted practice. However, sterilisation by autoclaving was not used (and is not mandatory).
The source of the virus is believed to have been a male patient in his early sixties who had a skin cyst removed on the same day as the women. He was not known to be HIV positive at the time and is believed to have been treated by the surgeon before the women.
According to a report in tomorrow's issue of the Lancet, Dr Kerry Chant and colleagues at the health department were alerted to the case after receiving two separate notifications of women, known as Case A and B, who were HIV positive but had no identifiable risk factors for infection. Painstaking detective work enabled Dr Chant to link the cases and trace others who were also infected by the same route.
Case A, a woman in her thirties, tested positive after giving blood in December 1992 and it was established that she had become infected between June 1989 and November 1990. Medical records showed that she had a cyst removed in November 1989 and suffered a brief feverish illness shortly after. This type of illness sometimes occurs after HIV infection and is associated with production of antibodies to the virus which led investigators to the surgeon who removed the cyst.
His patient records were examined and nine patients seen on the same day as Case A and who had had some form of skin surgery were identified. A search of New South Wales HIV and Aids database revealed that three of these patients were registered. They included Case B, a woman in her seventies already under investigation because she had no risk factors but until this point the researchers were unaware that she had attended the same surgeon as Case A.
The others were Case C, a woman in her thirties who had a mole removed and Case D, the man in his sixties. Of the five remaining cases, one woman in her eighties who had two skin lesions removed, tested positive.
Case D was subsequently identified as the probable source of infection. He reported that he had sexual intercourse with male partners and a blood test in September 1990 showed that he had a low white cell count, suggesting that he had been HIV positive for longer than any of the women. He died from an Aids-related illness a year ago.
Interviews with Cases B and E revealed that they had not had sexual contact for more than 10 years, while three partners of A and C since 1987 all tested negative. Genetic studies of viral samples from each patient are being studied which will confirm whether or not they are related to the strain carried by Case D.Reuse content