It broke Sunday, the big news that a baby with HIV had apparently been cured by intensive anti-retroviral therapy immediately after birth. NPR's Richard Knox did a bang-up job on the story here, including our local angle, contributions by pediatric AIDS researcher Dr. Katherine Luzuriaga of the University of Massachusetts.
But given that pediatric HIV and AIDS are — thankfully — rare, in American babies at least, the news seemed to beg the question: So what implications does this have for adults? I put it to Dr. Daniel Kuritzkes, chief of infectious diseases at Brigham and Women's Hospital. He's currently at the Atlanta conference where the baby's case was presented. His response, lightly edited:
I think the implication for adults are not certain, because the difference with children is that we know exactly when they may have been exposed, and have an opportunity to test them immediately after birth or very shortly after birth. Whereas the typical adult may be exposed to HIV and not know it, and come in later when they start having symptoms. So the opportunities to intervene very, very early are much harder to produce in adults.
'We continue to see evidence that it is possible to eradicate HIV from infected patients — maybe still in very unique and unusual circumstances, but the more of these cases we see, the more impetus it provides for ongoing research.'
Strikingly, there was a presentation just before [the baby's case] by a Thai investigator working with the US military research program, where they were doing pooled HIV testing of people coming in to testing centers in Thailand, and had the opportunity to identify some people very early on, and show that those who did get on treatment very early on subsequently had either undetectable or very, very low levels of HIV. That suggests that if you could get to people early enough, you might in fact prevent the establishment of the reservoir. [NPR's Knox explains that viral reservoirs are "hideouts for the virus within the immune cells."]
Those patients all remain on antiretroviral therapy, so they're not claiming that the patients are cured, but the timing here is really critical. Between the first group, who are really within the first week or so of infection, and the next group, who were a few days beyond, there was a big difference in what happened with the reservoir.
Babies are most commonly infected with HIV during birth as they transit the birth canal. A small number of kids get infected because the virus actually passes through the placenta. And unfortunately, what happens in resource-limited settings is that kids not initially infected may be infected post-natally from breast milk.
In this kid, because the virus was initially detected at 30 hours after birth, it argues that probably infection had to have occurred before birth, or you wouldn't have had detectable virus at birth. But exactly when it happened before birth is debatable, because virus levels weren't that high. Yet if it had been one or two months earlier, it seems highly unlikely the prompt initiation of antiretroviral therapy would have had this result.
There are some unique features about the timing here that are very hard to tease apart. So there's still a possibility that this wasn't actually a full-blown infection. There's no question there was virus in the baby and treatment prevented the baby from becoming fully infected. And no question the baby is now clear of HIV. But there are some unusual features to the transmission of the virus.
So, I asked, what would you hope the public takeaway would be from this news?
First of all, from the perspective of the health of HIV-infected mothers and their children, it's really important that women be tested and, if they're infected, they get on to antiretroviral therapy, because we can effectively prevent the transmission. There were 150 cases of HIV infection in infants in the last year the CDC reported, which is still 150 too many but it's a remarkable accomplishment.
Second, we continue to see evidence that it is possible to eradicate HIV from infected patients — maybe still in very unique and unusual circumstances, but the more of these cases we see, the more impetus it provides for ongoing research toward an HIV cure that would be more broadly applicable. So I think it provides a strong sense of optimism to those of in the field who are working on it....
This program aired on March 4, 2013. The audio for this program is not available.