A woman in California’s decision to donate her breast milk raised some serious concerns—potentially life-altering ones at that. A recent case report from local health officials revealed that the woman tested positive for HIV after she began sharing her raw breast milk via informal social media groups. Luckily, despite at least one sample being positive for the virus, none of the children who received the milk contracted the infection. However, health authorities emphasize that this incident underscores the risks associated with unregulated breast milk donation.
“Educating patients about the health risks tied to unpasteurized breast milk from social media groups or private donors can help lessen potential exposures,” the authors noted in their paper, published in the Morbidity and Mortality Weekly Report, which is the primary journal from the Centers for Disease Control and Prevention.
A close call
HIV can be transmitted through certain bodily fluids, including breast milk, if the viral load is high enough. Although modern antiretroviral treatments can nearly eliminate transmission risks once the infection is managed, a woman who is unknowingly infected might still pass it on through breastfeeding.
The report outlines that the woman in question was a mother to a two-year-old and pregnant again. She had tested negative for HIV in a prenatal check-up in 2023. However, during her most recent prenatal screening on October 10, 2025, the results came back positive. At the time, she was breastfeeding her daughter and also donating her milk through two social media groups. Following this finding, the Santa Clara County Public Health Department was made aware of the situation and started investigating the potential spread.
This investigation faced some hurdles from the start. Initially, officials struggled to gain access to the private social media groups. And even after they were allowed in, it seems group administrators were reluctant to let any posts from the investigators circulate. Ultimately, as they interviewed the woman and reviewed posts about milk donations from May to October 2025, they found five infants who might have been exposed. They reached out to the families through direct messages on social media and other contact methods from public records. It’s worth noting that while the officials identified themselves as health department representatives, some families were hesitant to believe them at first.
One mother, who had kept the donated milk frozen and never fed it to her child, had her sample tested and it turned out positive for HIV, although seemingly at lower levels than would typically cause transmission. Whether it was infectious remains unclear. The investigators couldn’t confirm if the other four infants had actually consumed the donated milk, but fortunately, all tested negative for HIV.
The mother began antiretroviral treatment in late October. Yet, she also revealed she was still breastfeeding her daughter after her positive test. She was advised to stop, and the child received post-exposure prophylaxis, which thankfully prevented any infection.
The takeaway
Breast milk has numerous health advantages, though infant formula is, of course, a useful option as well. Many mothers who can’t breastfeed themselves might turn to donated milk out of necessity.
Health officials point out that accredited milk banks can safely handle donated milk. Families are urged to acquire their breast milk from these reputable sources rather than from unregulated social media outlets or individual donors. It’s crucial for parents to understand the heightened risks that come with using those less regulated avenues.
“Mothers who struggle to produce enough milk can safely obtain pasteurized donor milk from these banks, which screen donors for infectious diseases and medication use before pasteurizing the milk. This offers a secure alternative for parents wanting to provide their babies with breast milk,” the authors concluded.
