Sequencing of virus isolates from the patient and his wife revealed that the HIV strains were closely related to each other. True seroreversion - seroreversion or loss of antibodies together with loss of infection has been described in a small number of cases of infants who were demonstrated to have been infected with HIV and then were able to clear the infection. This has not been convincingly demonstrated in adults. The reason for this seronegativity is still not understood. False negative test results are rare.
Blood bank screening The implications of false negativity on blood bank screening are profound.
The patient described above had donated 33 units of plasma to a plasmapheresis centre. Fortunately all plasma was inactivated before being used. The risk of transmission of infection can be reduced by requesting potential donors to reply to a questionnaire which elicits information about high risk behaviour. In addition, more and more blood banks are currently supplementing serological screening with p24 antigen screening. A 49 year old man presented with a diagnosis of PUO and night sweats over the past few months.