If Hannah Gay had wanted to be a world-famous scientist, she would probably not have chosen to make a career at the Blair E Batson Hospital for Children in Jackson, Mississippi, but with her desire to help the underprivileged sick, underpinned by a strong Christian faith, that is where she was working in the summer of 2010. It says much about the many problems that HIV (or human immunodeficiency virus) has caused researchers over some decades that a single decision taken by Gay when confronted with a possibly infected newborn baby propelled her into a limelight she had never sought. For 27 months, she was the HIV paediatrician who might have stumbled across the cure for Aids (acquired immune deficiency syndrome—the disease caused by HIV).
Gay, an associate professor of paediatrics and an HIV specialist at the University of Mississippi Medical Center, of which Batson is part, was called to see a baby brought in from a rural hospital because the mother had tested positive for HIV in labour. It is not a situation that so often occurs anymore in the United States or Europe. If antenatal tests pick up the virus, a pregnant woman is put on drugs that suppress it to very low levels in her blood, safeguarding the baby from infection at birth. Relatively few babies are now born with HIV in affluent countries. But this mother had not attended an antenatal clinic. She did not know she had HIV.
It can take weeks or months of testing and re-testing to confirm that a baby has the virus. Knowing early treatment is best, Gay decided not to wait. Within 30 hours of her birth, the Mississippi baby, as she became known, was on not one or two antiretroviral drugs, as would be more usual in these circumstances, but the full three-drug cocktail. And so she would have remained, had not mother and child disappeared, 18 months later.
When they made contact with the hospital again, after a five-month absence, tests showed no trace of…