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Up to 40% of all mother-to-child transmission of HIV occurs by means of breast-feeding; yet in developing countries infant formula may not be a safe option. The World Health Organization recommends heat-treated breast milk as an infant-feeding alternative. We investigated the ability of a simple method flash-heat to inactivate HIV in breast milk from HIV-positive mothers. Ninety-eight breast milk samples collected from 84 HIV-positive mothers in a periurban settlement in South Africa were aliquoted to unheated control and flash-heating. Reverse transcriptase (RT) assays (lower detection limit of 400 HIV copies/mL) were performed to differentiate active versus inactivated cell-free HIV in unheated and flash-heated samples. We found detectable HIV in breast milk samples from 31% (26 of 84) of mothers. After adjusting for covariates multivariate logistic regression showed a statistically significant negative association between detectable virus in breast milk and maternal CD4+ T-lymphocyte count (P = 0.045) and volume of breast milk expressed (P = 0.01) and a positive association with use of multivitamins (P = 0.03). All flash-heated samples showed undetectable levels of cell-free HIV-1 as detected by the RT assay (P less than 0.00001). Flash-heat can inactivate HIV in naturally infected breast milk from HIV-positive women. Field studies are urgently needed to determine the feasibility of in-home flash-heating breast milk to improve infant health while reducing postnatal transmission of HIV in developing countries. (authors)

Although heat treatment of human milk is an official infant-feeding recommendation for human immunodeficiency virus (HIV)-positive mothers in Zimbabwe, its implementation has not been adequately addressed, because knowledge about the safety of this method is rudimentary and its acceptability is poorly understood. To address this knowledge gap, the authors conducted focus group discussions among mothers, grandmothers, midwives, and husbands in various regions of Zimbabwe. Although the practice of heat treating expressed human milk was initially met with skepticism because of potential obstacles, including time constraints and social and cultural stigma, a pattern of opinion reversal emerged in all groups. By the end of each discussion, participants believed that, given its affordability and its potential to protect infants from HIV infection, heat-treated human milk may be a feasible infant-feeding option for HIV-positive mothers in Zimbabwe. These findings merit further investigation so that appropriate behavioral strategies can be designed.

Background: Transmission of HIV via breast milk is a primary cause of pediatric HIV infection in developing countries. Reliable methods to detect breast milk viral load are important. Objective: To correlate the ability of the VERSANT HIV 3.0 (bDNA) assay to real-time (RT) TaqMan PCR in quantifying breast milk HIV-1 RNA. Study design: Forty-six breast milk samples that had been spiked with cell-free HIV-1 and eight samples spiked with cell-associated HIV-1 were assayed for HIV-1 RNA by both VERSANT HIV 3.0 and TaqMan RNA assays. Results: Only assays on the cell-free samples were statistically compared. Both a Deming regression slope and a Bland–Altman slope indicated a linear relationship between the two assays. TaqMan quantitations were on average 2.6 times higher than those of HIV 3.0. A linear relationship was observed between serial dilutions of spiked cell-free HIV-1 and both the VERSANT HIV 3.0 and the TaqMan RNA assays. Conclusion: The two methods correlated well although the VERSANT HIV 3.0 research protocol quantified HIV-1 RNA slightly lower than TaqMan.

Allyson Sage, RN, MPH,¶ and Barbara Abrams, DrPH# Background: Heat-treated breast milk of HIV-positive mothers has potential to reduce vertical transmission. This study compared the impact of flash-heating (FH) and Pretoria pasteurization (PP) on HIV, nutrients, and antimicrobial properties in human milk. Methods: Milk samples were spiked with 1 3 10 8 copies/mL of clade C HIV-1 and treated with FH and PP. We measured HIV reverse transcriptase (RT) activity before and after heating (n = 5). Heat impact on vitamins A, B6 ,B 12, and C; folate, riboflavin, thiamin, and antimicrobial proteins (lactoferrin and lysozyme) was assessed. Storage safety was evaluated by spiking with Escherichia coli or Staphylococcus aureus. Results: Both methods inactivated $3 logs of HIV-1. FH resulted in undetectable RT activity. Neither method caused significant decrease in any vitamin, although reductions in vitamins C and E were noted. Heat decreased immunoreactive lactoferrin (P , 0.05) but not the proportions of lactoferrin and lysozyme surviving digestion. FH seems to retain more antibacterial activity. Both treatments eliminated spiked bacteria. Conclusions: FH may be superior to PP in eliminating all viral activity; both methods retained nutrients and destroyed bacterial contamination. Heat-treated breast milk merits further study as a safe and practical infant feeding option for HIV-positive mothers in developing countries.

Heat-treated expressed breast milk is recommended by the World Health Organization as an option to reduce vertical HIV transmission in resource-poor regions. Flash-heat (FH) is a low technology pasteurization method developed for home use, but its effect on quantity and quality of breast milk immunoglobulins is unknown.To evaluate FH's effect on breast milk immunoglobulin levels and antigen-binding capacity.Fifty HIV+ mothers in South Africa provided breast milk. Part of each sample served as an unheated control; the remainder was flash-heated. Total and antigen-specific immunoglobulin A (IgA) and immunoglobulin G (IgG) were measured by enzyme-linked immunosorbent assay. Paired t test was performed on log-transformed data.FH significantly decreased total IgA and IgG concentrations [geometric mean (geometric SD) 318.0 (1.9) vs. 398.2 (1.9) microg/mL and 89.1 (2.7) vs. 133.3 (2.5) microg/mL, P0.001 each]. Similar decreases in anti-HIV-1 gp120 IgG, anti-pneumococcal polysaccharide, and anti-poliovirus IgA occurred (P0.001 each). Although the latter was most affected, FH retained 66% of the antigen-binding ability. In contrast, binding capacity of IgA and IgG to influenza increased after FH (P = 0.029 and 0.025, respectively).Most breast milk immunoglobulin activity survives FH, suggesting flash-heated breast milk is immunologically superior to breast milk substitutes. Clinical significance of this decreased immunoglobulin activity needs evaluation in prospective trials.

Background World Health Organization advocates heat treatment of expressed breastmilk (EBM) as one method to reduce postnatal transmission of human immunodeficiency virus (HIV) in developing countries. Flash-heat is a simple heat treatment method shown to inactivate cell-free HIV. Objective To determine the effect of flash-heat on vitamin content of milk. Methods Fresh EBM was collected from 50 HIV+ mothers in Durban, South Africa. Mothers washed their hands and then manually expressed 75-150 mL EBM into sterile jars. Milk was aliquoted to unheated controls or flash-heat (50 mL EBM in a glass jar heated in a 450-mL water jacket in an aluminum pan until water boiled, then EBM removed) simulating field conditions with an open flame. Samples were stored at -70 degrees C and then analyzed for the effect of flash-heat on vitamins [A, ascorbic acid, riboflavin (B2), pyridoxal-5-phosphate (B6), folate, and B12]. Results Vitamin A was not significantly affected by flash-heat and vitamins B12 and C and folate increased significantly. Vitamins B2 and B6 were decreased to 59% (95% confidence interval 44 to 81) and 96% (95% confidence interval 92 to 99), respectively, of that found in unheated milk. Conclusions The percentage remaining after flash-heat suggests that most vitamin concentrations are retained after heating. Flash-heat may be a practical and nutritious infant feeding method for mothers in developing countries.

Heat-treated breastmilk is one infant-feeding option recommended by the WHO to reduce mother-to-child transmission of HIV in developing countries. Flash-heat, a simple pasteurization method that a mother could perform in her home, has been shown to inactivate cell-free HIV-1. Since heating may affect the naturally occurring antimicrobial properties found in breastmilk, storing heated breastmilk may present a safety issue in resource-poor settings due to lack of refrigeration and potential contamination. To address this, we investigated the ability of flash-heat to eliminate bacteria and to prevent growth over time compared with unheated breastmilk. We collected breastmilk samples from 38 HIV positive mothers in South Africa and aliquoted them to flash-heated and unheated controls. Samples were stored at room temperature for 0, 2, 6 and 8 h and then plated and incubated for 24 h at 37 degrees C in CO(2). We performed total colony counts and identified Escherichia coli, Staphylocuccus aureus and Group A and Group B streptococci. Unheated samples had a significantly higher number of samples positive for bacterial growth at each time point (p < 0.0001), as well as mean colony-forming units (CFU)/ml in those samples that were positive at each time point (p < 0.0001). In addition, unheated samples had a significantly higher rate of bacterial propagation over time than flash-heated samples when comparing log values of CFU/ml across 0-8 h (p < 0.005). No pathogenic growth was observed in the flash-heated samples, while the unheated samples showed growth of E. coli (n = 1) and S. aureus (n = 6). Our data suggest that storage of flash-heated breastmilk is safe at room temperature for up to 8 h.

We read the recent article “Breast milk pasteurization in developed countries to reduce HIV transmission. Do the benefits outweigh the risks?” in Infectious Diseases in Obstetrics and Gynecology with great concern. The authors tested two paired specimens of heated and unheated breast milk using HIV RNA quantification (NASBA and Roche ULTRA PCR). They found no decrease in HIV RNA levels between the heated and unheated samples and thus concluded there to be insufficient data to recommend heat treatment as a safe alternative in resource-rich countries. We are particularly concerned that they have misinterpreted their results and that this confusion may be perpetuated in discussions and policies around the globe, most importantly in resource-poor regions. We strongly encourage the authors, editors, and readership of your journal to reinterpret the results presented since the HIV detection method used by Giles and Mijch does not differentiate between active (infectious) and inactive (noninfectious) HIV in breast milk. Our team has been investigating the safety of heat-treated breast milk as an infant feeding option for mothers in developing countries and have recently published the results of pilot safety data [2]. We have designed a simple “flash-heat” treatment method that a mother could use in her home or over a fire, similar to commercial high-temperature, short-time (HTST) pasteurization. Although the study published by Chantry et al [3] used a similar heating method and demonstrated destruction of HIV proviral DNA in HIV-infected breast milk cells [3], the method used in that report achieved higher milk temperatures due to smaller milk volumes and Pyrex glass. In designing a more gentle heating method, we also found, as reported by Giles and Mijch, no decrease in HIV RNA. We ascertained, however, that assaying for presence of viral RNA, as performed by Giles in the above article, is not an adequate technique for detecting infectious virus in heated breast milk. Nucleic acid is very resistant to heating, up to the boiling point of water. It is to be expected that viral nucleic acid will remain postheating and will be detected by PCR-based assays even after the virus itself is rendered totally incapable of replication due to destruction of vital enzyme activities, structural proteins, and membrane structures due to the heat. We acknowledge that RNA detection is commonly used for quantification of HIV in both plasma and unheated breast milk. In order to determine the effect of heat on HIV in breast milk, however, the assay must effectively distinguish between live versus inactivated virus. We have demonstrated this in our recent pilot work comparing the flash-heat method with Pretoria pasteurization, another simple technique mentioned by Giles and Mijch [4, 5] . We found no decrease in cell-free HIV RNA as determined by TaqMan Real-time RNA PCR in breast milk (Log HIV RNA (SD) in unheated milk = 8.00(0.03) versus heated milk = 7.95(0.03)). We recognized the need for an alternative assay to accurately assess virus viability and, as traditional coculture methods are difficult with breast milk due to the innate antiviral properties of the milk, we chose quantitative measurement of reverse transcriptase (RT) as a marker for viable HIV (ExaVir Quantitative Reverse Transcriptase Load Kit, Cavidi, Uppsala Sweden). In contrast to our TaqMan PCR data from the same samples, we found inactivation of ≥ 3 logs of HIV-1 as detected by enzymatic activity of RT in postheated samples, with the flash-heat method more effectively eliminating RT than Pretoria pasteurization. We have subsequently confirmed these results by directly assaying for infectivity using transactivation of a green fluorescent protein (GFP) reporter group (data unpublished). Although we acknowledge that detection of HIV activity in breast milk can be challenging, we would encourage the authors to repeat their work using an appropriate assay. We recognize the concerns mentioned by the authors regarding the impact of heat on vitamins, proteins, immunoglobulins, and the antimicrobial properties of breast milk. Low-temperature, long-time (LTLT) heat treatments, for example, Holder pasteurization, typically preserve nutrients less than HTST methods do. We reported pilot data suggesting limited impact on vitamins and proteins using flash-heat [2]. Our ongoing study is investigating the above concerns in-depth and we hope to have this data available in the near future. We agree that it is not currently justifiable to recommend heat treatment of HIV-infected breast milk in resource-rich countries. However, we are concerned that the results, presented by Giles and Mijch of two heated breast milk samples demonstrating persistent HIV RNA being interpreted as “persistent HIV” without further exploration of viral infectivity, may have unwarranted repercussions. We strongly urge re-consideration of the results in light of our findings that HIV RNA is detectable after heating with no demonstrable activity of RT, which is necessary for virus to replicate. Heat treatment of breast milk is a recognized infant feeding option by the World Health Organization for HIV positive mothers who live in areas where no other alternatives are available. While we acknowledge that further research is needed, caution should be used when stating conclusions that may negatively impact policy makers' decisions regarding what may be appropriate in such communities.