Even before The New England Journal of Medicine reported last year that a three year old was in remission from HIV, it was one of the biggest medical stories of the year. Sadly however, the disease has only been delayed, and the “Mississippi Baby” once again has HIV.
The unnamed child was born prematurely in 2010. Her mother was HIV positive but was not diagnosed until the birth, and therefore did not receive antiretroviral medication during pregnancy. The risk of transmission was so high that the baby was started on triple drug treatment 30 hours after birth, even before testing confirmed that infection had occurred.
Treatment continued until the age of 18 months, at which point the family lost contact with the medical system. Five months later, when the toddler was seen again, HIV infection was either entirely gone, or below detectable levels, a situation that continued without treatment for more than two years.
When the case was announced there was much excitement about the possibility that antiretroviral treatment, given sufficiently soon after infection, might not only control HIV levels but eliminate them entirely. A second case reported earlier this year raised hopes further.
Sadly, this has turned out not to be the case. A routine blood test found HIV levels almost a thousand times above the detection threshold of 20 copies/mL, and this was confirmed three days later with a somewhat lower rate. Decreased T-cell counts and the presence of HIV antibodies put the findings beyond doubt.
Treatment through antiretroviral therapy is once again bringing the HIV levels down, and no side effects have been observed, so the prognosis for the child is hopeful. However, the wider possibility of quick treatment eliminating HIV forever now appears forlorn.
While it is of course possible that the child could have been infected independently since being declared virus free, the strain of HIV is the same as the mother has. With the mother's infection controlled through treatment, the chance of a second transmission seems small.
Nevertheless, the news is not all bad. “Typically, when treatment is stopped, HIV levels rebound within weeks, not years,” said Professor Deborah Persaud of the John Hopkins Children's Center. Professor Katherine Luzuriaga of the University of Massachusetts Medical School said, "The prolonged lack of viral rebound, in the absence of HIV-specific immune responses, suggests that the very early therapy not only kept this child clinically well, but also restricted the number of cells harboring HIV infection.”
Researchers studying the case are hoping to explore why the treatment had the success it did, and how this can be replicated in other cases.