Was a baby cured of HIV?
At the annual Conference on Retroviruses and Opportunistic Infections (CROI) held in the U.S. in March 2013, researchers presented details of the case of a baby that was apparently cured of HIV infection. Claims of apparent cures of HIV are rare and because of their potential importance they deserve a high level of scrutiny and critical thinking.
Case details
The research team reported on a mother in the southern U.S. who sought care because she was about to give birth. They stated that “she had not been engaged in prenatal care” and so doctors did not know that she was HIV positive until she prematurely entered labour, when they performed rapid HIV testing. Her HIV viral load was low (2,423 copies/ml) and her CD4+ count was relatively high (644 cells). Analysis of her HIV suggested that it had not encountered anti-HIV drugs.
Assuming that the baby was also infected, doctors sent the infant to a major hospital for care. There, 31 hours after birth, researchers found that the baby had HIV-infected cells in its blood and its viral load was 19,812 copies/ml. Doctors immediately began anti-HIV therapy with nevirapine (Viramune), AZT (Retrovir, zidovudine) and 3TC (lamivudine). After a week, nevirapine was replaced with lopinavir-ritonavir (Kaletra). The baby responded well to treatment and a month after birth its viral load was less than 48 copies/ml.
After 18 months, hospital staff lost track of the child and its family. The reasons for this lapse were not disclosed.
When the infant was nearly two years old, researchers stated that hospital staff resumed contact with the baby and its “caretaker.” This adult disclosed to healthcare providers that they had stopped giving ART to the baby at about 18 months of age. Again, the reasons for this were not disclosed.
Extensive virologic, immunologic and genetic testing was performed on the baby’s blood. The reason for the genetic testing was to confirm that the baby was indeed the same infant that had been previously cared for at the hospital. At this point, the hospital laboratory’s experimental single copy assay confirmed that the infant’s viral load was 1 copy/ml. The baby is clinically well and at the time the results were reported at the conference has not taken ART for almost a year.
Points to consider
1. This case is stark reminder about what can happen when pregnant women are not linked to prenatal care, offered HIV testing and given ART during pregnancy. The risk of HIV transmission from mother to child in untreated HIV infection ranges between 25% and 30%. In high-income countries such as Canada and the U.S., giving HIV-positive pregnant women prenatal care, counselling and ART, along with temporary treatment of the baby with anti-HIV drugs just after birth, and using formula instead of breast milk has reduced the risk of mother-to-child transmission to less than 2%. That the baby is now apparently HIV negative is an extremely lucky outcome. Still, this case underscores serious gaps in the healthcare and social service systems in the mother’s region.
2. How a major hospital in a high-income country could lose contact for several months with a family having an HIV-positive baby seems, at best, highly unusual. This also points to another apparent gap in the healthcare system, particularly for this baby and its mother.
3. Although researchers associated with this case have suggested that early initiation of ART for nearly 18 months apparently cured the baby, talk of a cure is premature. This arises because the baby’s ART could have acted as PEP—post-exposure prophylaxis. PEP is routinely used in high-income countries in healthcare settings because of needle-stick injuries when healthcare workers inadvertently become exposed to HIV. PEP is also used to help prevent HIV infection after possible sexual exposure. Given within 72 hours after exposure, PEP has a high probability of working. The ART given to the baby within this timeframe could have acted as a form of PEP, helping to greatly restrict and limit HIV infection.
4. The virus that the mother had was a strain (or clade) that is relatively common in North America, Australia, Japan and Western Europe: subtype B. Moreover, the mother’s viral load seemed unusually low, so perhaps she was infected with a weakened strain of HIV. This would have made it easier for the baby’s immune system, fortified with ART, to control and perhaps ultimately get rid of the virus.
5. According to the research team, the mother did not breastfeed her infant. This is important because breastfeeding can transmit HIV.
6. Analyses of lymph nodes and tissues need to be done to ensure that the baby is truly free from HIV.
7. There may be other possible explanations for the baby’s ability to have low levels of HIV without continued treatment that have not yet been advanced by researchers.
Implications
It is premature to suggest that routine use of prolonged ART in HIV-infected babies born to HIV-positive mothers will cure the infants. Today most babies born to HIV-positive mothers are born in low- and middle-income countries. The reasons that some of these babies in those countries are born infected are that their mothers received limited or no prenatal care, had little or no access to ART and breast fed the babies. International agencies, local governments and NGOs are working hard to bring the rate of mother-to-child transmissions of HIV to zero.
In Canada and other high-income countries, the vast majority of HIV-positive women who become pregnant receive prenatal care and ART and give birth to healthy babies. There are, of course, cases where mothers in high-income countries may not receive prenatal care. The reasons for this are complex and vary from one woman to another but are usually related to one or more of the following factors:
- living in a remote community
- having poor mental and emotional health
- addiction
- recent migration from a country where HIV is relatively common
By making the offer of a routine HIV test much more widely available, expanding health and addiction prevention and treatment services, prenatal care and other social services to populations in need, and engaging communities in strengthening their health, Canada, the U.S. and other high-income countries can help to bring an end to babies born with HIV.
Resources
Society of Obstetricians and Gynaecologists of Canada
Canadian HIV Pregnancy Planning Guidelines
Information for Women who are Diagnosed with HIV during Pregnancy
Pregnancy Planning Information for HIV+ Women and Their Partners
Pregnancy Planning Information for HIV+ Men and Their Partners
—Sean R. Hosein
REFERENCES:
- Mark S, Murphy KE, Read S, et al. HIV mother-to-child transmission, mode of delivery, and duration of rupture of membranes: experience in the current era. Infect Dis Obstet Gynecol. 2012;2012:267969.
- Persaud D, Gay H, Ziemniak C, et al. Functional cure after very early ART of an HIV-infected infant. In: Program and abstracts of the 20th Conference on Retroviruses and Opportunistic Infections, 3-6 March 2013, Atlanta, U.S. Abstract 48 LB.