Viral Load In Breast Milk Research Articles

Breastfeeding in the United States Among Women With HIV: Con Viewpoint.

To breast feed or not has long been a difficult question for women with human immunodeficiency virus (HIV) in high-income countries, as undetectable HIV in maternal plasma does not translate to zero risk of transmission while breastfeeding, and clean water and formula are readily available. Recent, and more permissive, changes in US and other high-income-country guidelines regarding breastfeeding underscore this issue and acknowledge the information gaps that are essential for informed maternal choice and provider management. These include lack of guidance as to routine monitoring of mothers during lactation, type and length of prophylaxis for infants, and lack of data on factors associated with increased breast-milk viral load and risk of transmission. Ancillary to data are the education and staffing needs for providers participating in the management of breastfeeding individuals. Future studies of breast-milk transmission will need to evaluate these gaps so that we can move transmission to zero.

Frequencies of activated T cell populations increase in breast milk of HCMV-seropositive mothers during local HCMV reactivation.

Human cytomegalovirus (HCMV) can reactivate in the mammary gland during lactation and is shed into breast milk of nearly every HCMV-IgG-seropositive mother of a preterm infant. Dynamics of breast milk leukocytes during lactation, as well as blood leukocytes and the comparison between both in the context of HCMV reactivation is not well understood. Here, we present the BlooMil study that aimed at comparing changes of immune cells in blood and breast milk from HCMV-seropositive- vs -seronegative mothers, collected at four time ranges up to two months post-partum. Viral load was monitored by qPCR and nested PCR. Multiparameter flow cytometry was used to identify leukocyte subsets. CD3+ T cell frequencies were found to increase rapidly in HCMV-seropositive mothers' milk, while they remained unchanged in matched blood samples, and in both blood and breast milk of HCMV-seronegatives. The activation marker HLA-DR was more strongly expressed on CD4+ and CD8+ T cells in all breast milk samples than matched blood samples, but HCMV-seropositive mothers displayed a significant increase of HLA-DR+ CD4+ and HLA-DR+ CD8+ T cells during lactation. The CD4+/CD8+ T cell ratio was lower in breast milk of HCMV-seropositive mothers than in the blood. HCMV-specific CD8+ T cell frequencies (recognizing pp65 or IE1) were elevated in breast milk relative to blood, which might be due to clonal expansion of these cells during local HCMV reactivation. Breast milk contained very low frequencies of naïve T cells with no significant differences depending on serostatus. Taken together, we conclude that the distribution of breast milk leukocyte populations is different from blood leukocytes and may contribute to the decrease of breast milk viral load in the late phase of HCMV reactivation in the mammary gland.

Clinical presentation and transmission of postnatal cytomegalovirus infection in preterm infants.

Preterm infants are at greater risk of developing postnatal cytomegalovirus (CMV) infection with serious symptoms. Breast milk is the main route of CMV transmission in populations with a high seroprevalence. This study aimed to investigate the clinical presentation and transmission of postnatal CMV (pCMV) infection via breast milk in preterm infants under the specific setting of our neonatal intensive care unit (NICU). The medical records of 147 preterm infants were reviewed retrospectively, and their clinical characteristics and outcomes were analyzed. Breast milk and infant urine samples were collected every two weeks until discharge, and the kinetics of CMV loads were evaluated using a polymerase chain reaction assay. Seventeen infants (11.6%) were diagnosed with pCMV infection during the study period. In comparison between the pCMV and control groups, the mean birth weight was significantly lower in the pCMV group than in the control group (1084.1 ± 404.8 g vs. 1362.5 ± 553.8 g, P = 0.047). Four (23.5%) patients had leukocytopenia, six (35.3%) had neutropenia, three (17.6%) had thrombocytopenia, and two (11.8%) had hyperbilirubinemia in the pCMV group. Five patients were treated with antiviral agents, and their CMV load in the urine decreased after treatment. CMV loads peaked at 3-5 weeks in breast milk, whereas they peaked at 8-12 weeks of postnatal age in infants' urine. A comparison between the median CMV load in breast milk from the pCMV and control groups revealed a significant difference (P = 0.043). Most preterm infants with pCMV infection present a favorable clinical course and outcomes. A high CMV viral load in breast milk is associated with transmission. Further studies are warranted to prevent transmission and severe pCMV infections in preterm infants.

Clinical, Virologic and Immunologic Correlates of Breast Milk Acquired Cytomegalovirus (CMV) Infections in Very Low Birth Weight (VLBW) Infants in a Newborn Intensive Care Unit (NICU) Setting.

Cytomegalovirus (CMV) infections acquired by very-low-birthweight (VLBW) infants are incompletely characterized. To examine CMV transmission in VLBW infants, we evaluated maternal DNAlactia, infant DNAemia, and presence of clinical disease in a blinded study in VLBW infants in our newborn intensive care unit (NICU). To examine these issues, 200 VLBW infants were enrolled in a surveillance study, with weekly breast milk and infant whole blood samples collected, as available. Virologic (breast milk and infant whole blood real time PCR) and immunologic (IgG, IgM, and IgG avidity) correlates were evaluated. A chart review examined whether infants had symptoms compatible with CMV disease. DNAlactia was identified in 65/150 (43%) of lactating mothers. Nine CMV infections were identified in 9/75 CMV-exposed infants (12% of exposed infants). A higher median breast milk viral load (DNAlactia) correlated with an increased likelihood of DNAemia (p = 0.05). Despite potential symptoms compatible with CMV infection, clinicians had not considered the diagnosis of CMV in 6/9 cases (66%). All of these infants had chronic lung disease at discharge. There was no correlation between IgG antibody titer or IgG avidity index and the likelihood of transmission or CMV disease. In conclusion, in VLBW infants receiving milk from seropositive mothers, CMV infections are commonly acquired, and are frequently unrecognized. Future studies are needed to determine whether routine surveillance for CMV of either breast milk or infant plasma is beneficial in preventing or recognizing infection.

High prevalence of breastmilk-acquired cytomegalovirus infection in jaundiced infants.

BackgroundOur objective was to evaluate the prevalence and different diagnostic methods of breastmilk (BM)‐acquired cytomegalovirus (CMV) infection in a pathologically jaundiced cohort.MethodsA total of 400 infants confirmed with pathological jaundice at The People's Hospital of Qingyang City were screened for BM‐acquired CMV infection between February 2018 and February 2019. A total of 300 infants were finally enrolled in our study. CMV infection was confirmed by detecting both CMV‐DNA in various samples using FQ‐PCR and CMV‐IgM with chemiluminescence. Clinical and other laboratory data were collected from these infants during their hospitalization or regular visits.ResultsNinety‐eight (32.67%) subjects were confirmed to be BM CMV‐DNA–positive, and 18 (18.37%) were diagnosed with a BM‐acquired CMV infection. All 18 (100%) infants with a BM‐acquired CMV infection were CMV‐DNA–positive in urine, while 5 (27.78%) cases and 11 (61.11%) cases were confirmed in plasma and peripheral blood mononuclear cells (PBMCs), respectively. Only 6 (33.33%) infants were CMV‐IgM–positive. Birthweight, direct bilirubin, aspartate aminotransferase, and the viral load in BM of the BM‐acquired CMV group were higher than those in the non‐infected group (P < .05). Low birthweight and viral load in BM were risk factors for BM‐acquired CMV infection. Detecting CMV‐DNA in urine samples exhibited better performance than the other methods for screening BM‐acquired CMV infections.ConclusionsOur study found a high prevalence of BM‐acquired CMV infection in jaundiced infants, and detecting CMV‐DNA in a urine sample was the most sensitive method for disease screening.

Observational study of cytomegalovirus from breast milk and necrotising enterocolitis

ObjectiveTo evaluate the relationship between cytomegalovirus (CMV) exposure from breast milk and risk of necrotising enterocolitis (NEC).DesignSecondary analysis of a multicentre, observational cohort study. Maternal breast milk and infant serum...

Simultaneous quantification of four antiretroviral drugs in breast milk samples from HIV-positive women by an ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method.

The primary strategy to avoid mother-to-child transmission of human immunodeficiency virus (HIV) through breastfeeding is administration of highly active antiretroviral therapy (HAART) to HIV-positive pregnant women. Because significant changes in the pharmacokinetics of antiretroviral (ARV) drugs occur during pregnancy, quantifying HAART and the viral load in breast milk in this population is essential. Here, we developed an analytical assay for the simultaneous quantification of four ARV drugs in breast milk using ultra-performance liquid chromatography coupled to tandem mass spectrometry. We validated this method following Mexican and international guidelines. ARV drugs. We extracted the ARV drugs from 200 μL samples of breast milk and detected these drugs in a triple quadrupole mass spectrometer with positive electrospray ionization. The validated concentration ranges (ng/mL) for zidovudine, lamivudine, lopinavir, and ritonavir were 12.5–750, 50–2500, 100–5000 and 5 to 250, respectively. Additionally, the absolute recovery percentages (and matrix effects) were 91.4 (8.39), 88.78 (28.75), 91.38 (11.77) and 89.78 (12.37), respectively. We determined that ARV drugs are stable for 24 h at 8°C and 24°C for 15 days at –80°C. This methodology had the capacity for simultaneous detection; separation; and accurate, precise quantification of ARV drugs in human breast milk samples according to Mexican standard laws and United States Food and Drug Administration guidelines.

Maternal and Breastmilk Viral Load: Impacts of Adherence on Peripartum HIV Infections Averted-The Breastfeeding, Antiretrovirals, and Nutrition Study.

Antiretroviral (ARV) interventions are used to reduce HIV viral replication and prevent mother-to-child transmission. Viral suppression relies on adherence to ARVs. A 2-phase study was conducted using data from the Breastfeeding, Antiretrovirals, and Nutrition study. We included mothers randomized to 28 weeks of postpartum ARVs with ≥1 plasma or breastmilk specimen. All mothers who transmitted HIV to their infants from 2-28 weeks (n = 31) and 15% of mothers who did not (n = 232) were included. Adherence was measured by pill count [categorized as poor (0%-80%), partial (81%-98%), and near perfect (>98%)]. Associations between adherence and breastmilk RNA were assessed using mixed-effects models. Cox models were used to estimate associations between breastmilk RNA and HIV transmission. Using Monte Carlo simulation, we estimated the number of transmissions that would occur had everyone randomized to maternal ARVs been 90% and 100% adherent. Partial or near perfect ARV adherence significantly reduced the odds of having detectable (≥40 copies/mL) breastmilk RNA, compared with poor adherence (Odds Ratio (OR) 0.23, 95% CI: 0.08 to 0.67; OR 0.36, 95% CI: 0.16 to 0.81, respectively). Detectable breastmilk RNA was associated with increased breastmilk transmission compared with undetectable breastmilk RNA (hazard ratio 3.8, 95% CI: 1.2 to 12.1). All transmitting mothers had ≥1 plasma viral load specimen >100 copies per milliliter. An estimated similar number of transmissions would occur with 90% adherence compared with 100%. Helping patients adhere to ARVs throughout breastfeeding is important for realizing the full potential of recommended ARV interventions to prevent mother-to-child HIV transmission. Maintaining plasma viral load <100 copies per milliliter may prevent breastmilk transmission.

Correlation between serum hepatitis B virus DNA load, status of hepatitis B e antigen and viral load in breast milk of hepatitis B virus-infected parturients

Objective To study the correlation between hepatitis B virus (HBV) DNA load, hepatitis B e antigen (HBeAg) status and the viral load in breast milk of HBV-infected parturients. Methods A total of 370 HBV-infected parturients who delivered in the Second People′s Hospital of Tianjin between January 2010 and July 2013 were selected. Patients with hepatitis B surface antigen (HBsAg) positive, HBeAg (+ ) and hepatitis B core antibody (+ ) were put in HBeAg-positive group, those with HBsAg (+ ), hepatitis B e antibody (+ ) and hepatitis B core antibody (+ ) were included in HBeAg-negative group. HBV DNA levels in serum and breast milk within 24 hours postpartum were detected. Count data between groups were compared by chi-square test. Measurement data were compared by using t test. Correlation analysis was conducted by Pearson correlation analysis. Results 174 out of 370 parturients (47.0%) were included in HBeAg-positive group with serum HBV DNA load of (6.03 + 0.86) lg copies/mL. And 196 cases (53.0%) were included in HBeAg-negative group with serum HBV DNA (4.04 + 0.61) lg copies/mL. The difference between the two groups was statistically significant (t=25.883, P 1×105 copies/mL. Among them, 86 cases (72.9%) had HBV DNA>500 copies/mL in milk. The viral load in breast milk increased with that in serum. The comparison of detection rates of HBV DNA >1×105 - 1×107 copies/mL and>1×107 copies/mL in both HBeAg-positive and HBeAg-negative groups were both statistically significant (χ2=16.238 and 6.453, respectively, both P 1×105 - 1×107 copies/mL between HBeAg-positive group and HBeAg-negative group did not reach statistical significance (χ2=0.029, P=0.864). And there was no statistically significant differences between HBeAg-positive group and HBeAg-negative group for HBV DNA >1×107 copies/mL (χ2=0.002, P=0.965). Conclusions The transmission risk through breast milk in HBeAg-positive HBV-infected parturients is significantly higher than HBeAg-negative patients. HBV DNA load in breast milk depends on the viral load in serum. HBV DNA load in breast milk is not correlated with the status of HBeAg. Key words: Carry the maternal HBV; Hepatitis B e antigen; HBV DNA loads; Breast milk

Maternal and Breastmilk Viral Load: Impacts of Adherence on Peripartum HIV Infections Averted—The Breastfeeding, Antiretrovirals, and Nutrition Study

Maternal and Breastmilk Viral Load: Impacts of Adherence on Peripartum HIV Infections Averted—The Breastfeeding, Antiretrovirals, and Nutrition Study

Why is Breast-feeding a risk factor for HIV-1 transmission despite HIV-1 infected mothers receiving combination ART (cART)?

Mother-to-child transmission (MTCT) of human immunodeficiency virus type 1 (HIV-1) is an important source of HIV-1 infection in infants, and can occur at any point, including in utero, at the time of delivery, and via breastfeeding. In the absence of intervention, such as the use of antiretroviral therapy (ART), MTCT of HIV-1 during pregnancy or delivery can affect approximately 15–25% of infants, with a further 5–20% of infants becoming infected postnatally during breastfeeding. The use of maternal ART while breastfeeding reduces the MTCT risk from 35% without any intervention to less than 5%. Although a significant improvement, 5% of infants continue to be infected.i Maternal factors that contribute to this continued risk of transmission despite taking ART include the method of feeding, breast health, RNA and DNA viral load in breast milk and plasma, and maternal nutrition. Infantfactors such as the disruption in the integrity of the gastrointestinal mucosal surfaces also contribute to an increased rate of MTCT.Aims: This literature review aimed to investigate why breastfeeding is still a risk factor despite HIV-1-infected mothers being on effective combination ART (cART)? This review will explore the associated factors that contribute to the increased risk of HIV-1 transmission to the infant via breastfeeding.

Live neonates born to mothers with Ebola virus disease: a review of the literature.

Ebola virus disease (EVD) is associated with a high mortality, especially among neonates. There is a paucity of literature on live neonates born to pregnant women with EVD, and therefore, our understanding of their clinical illness and outcomes is extremely limited. A literature search was conducted to identify descriptions of live neonates born to pregnant women with EVD. To date, five known reports have provided limited information about 15 live neonates born to pregnant women with EVD. All 15 neonates died, and of those with information, death was within 19 days of birth. Of the 12 neonates with information on signs and symptoms, 8 (67%) were reported to have fever; no other signs or symptoms were reported. There are no published data describing the clinical course or treatments provided for these neonates. Potential modes of Ebola virus transmission from mother to neonate are through in utero transmission, during delivery, direct contact or through breast milk. There is an urgent need for more information about neonates with EVD, including clinical course (for example, onset and presentation of illness, symptomatology and course of illness) and treatments provided as well as information on Ebola viral load in breast milk from Ebola-positive and convalescing mothers.

Human Alpha-Defensin HNP1 Increases HIV Traversal of the Epithelial Barrier: A Potential Role in STI-Mediated Enhancement of HIV Transmission.

Alpha-defensins, including human neutrophil peptides 1-3 (HNP1-3) and human defensin 5 (HD5), are elevated at the genital mucosa in individuals with sexually transmitted infections (STIs). The presence of STIs is associated with an increased risk of human immunodeficiency virus (HIV) transmission, suggesting there may be a role for defensins in early events of HIV transmission. HD5 has been demonstrated to contribute to STI-mediated increased HIV infectivity in vitro. HNPs exhibit anti-HIV activity in vitro. However, increased levels of HNPs have been associated with enhanced HIV acquisition and higher viral load in breast milk. This study found that HNP1, but not HD5, significantly disrupted epithelial integrity and promoted HIV traversal of epithelial barriers. Linear HNP1 with the same charges did not affect epithelial permeability, indicating that the observed effect of HNP1 on the epithelial barrier was structure dependent. These results suggest a role for HNP1 in STI-mediated enhancement of HIV transmission.

Nevirapine, sodium concentration and HIV-1 RNA in breast milk and plasma among HIV-infected women receiving short-course antiretroviral prophylaxis.

IntroductionRisk factors for breast milk transmission of HIV-1 from mother to child include high plasma and breast milk viral load, low maternal CD4 count and breast pathology such as mastitis.ObjectiveTo determine the impact of nevirapine and subclinical mastitis on HIV-1 RNA in maternal plasma and breast milk after intrapartum single-dose nevirapine combined with either 1-week tail of Combivir (zidovudine/lamivudine) or single-dose Truvada (tenofovir/emtricitabine).MethodsMaternal plasma and bilateral breast milk samples were collected between April 2008 and April 2011 at 1, 4 and 6 weeks postpartum from HIV-infected Tanzanian women. Moreover, plasma samples were collected at delivery from mother and infant.ResultsHIV-1 RNA was quantified in 1,212 breast milk samples from 273 women. At delivery, 96% of the women and 99% of the infants had detectable nevirapine in plasma with a median (interquartile range, IQR) of 1.5 μg/mL (0.75–2.20 μg/mL) and 1.04 μg/mL (0.39–1.71 μg/mL), respectively (P < 0.001). At 1 week postpartum, 93% and 98% of the women had detectable nevirapine in plasma and breast milk, with a median (IQR) of 0.13 μg/mL (0.13–0.39 μg/mL) and 0.22 μg/mL (0.13–0.34 μg/mL), respectively. Maternal plasma and breast milk HIV-1 RNA correlated at all visits (R = 0.48, R = 0.7, R = 0.59; all P = 0.01). Subclinical mastitis was detected in 67% of the women at some time during 6 weeks, and in 38% of the breast milk samples. Breast milk samples with subclinical mastitis had significantly higher HIV-1 RNA at 1, 4 and 6 weeks (all P < 0.05).ConclusionAfter short-course antiretroviral prophylaxis, nevirapine was detectable in most infant cord blood samples and the concentration in maternal plasma and breast milk was high through week 1 accompanied by suppressed HIV-1 RNA in plasma and breast milk.

Effect of breastfeeding on infant cytomegalovirus viral load

Objective Follow-up monitoring was carried out in infants infected with cytomegalovirus(CMV) so as to find out whether breastfeeding could bring about changes of CMV viral load. Methods Saliva of the neonates born in Changzhou Maternal and Child Health Hospital from Nov.2010 to Feb.2012, was collected for CMV scree-ning.Premature infants, or the infants with seriously infectious diseases and deformities were excluded, such as severe intrauterine infection, congenital immune deficiency disease and so on.The full-term infants with aymptomatic infection were divided into the artificial feeding group and the breastfeeding group, and followed up for 6 months.During the 1st, the 3rd and the 6th month after their birth, their saliva and their mother's breast milk were collected.The method of real-time fluorescent quantitative PCR was adopted to test the changes in the viral load of CMV-DNA in the saliva and breast milk.Meanwhile, head B-ultrasound test, otoacoustic emission hearing screening, liver function test, blood routine analysis and so on were performed. Results Among infants from both artificial feeding group and breastfeeding group, during the 1st, the 3rd and the 6th month after birth, no significant changes in the DNA viral load of saliva and breast milk cytomegalovirus were found(t=2.832, 3.161, 3.475, all P>0.05). And in breastfeeding group, the cytomegalovirus DNA viral load in breast milk were 3.125×103±2.017×102(the 1st month), 2.688×103±2.251×102(the 3rd month), 3.016×103±2.613×102(the 6th month), also no significance during the time(F=1.725, P=0.667). Meanwhile, the head B-ultrasound, otoacoustic emission hearing screening, liver function test, blood routine analysis, etc showed no clinical significance(F=1.725, P=0.667). Conclusions In the CMV-infected neonates, even if CMV in breast milk is tes-ted to be positive, breastfeeding can continue without causing secondary symptoms of infection. Key words: Cytomegalovirus; Breast milk; Viral load; Infant

Breast milk cellular HIV-specific interferon γ responses are associated with protection from peripartum HIV transmission

Breast milk is a major route of infant HIV infection, yet the majority of breast-fed, HIV-exposed infants escape infection by unknown mechanisms. This study aimed to investigate the role of HIV-specific breast milk cells in preventing infant HIV infection. A prospective study was designed to measure associations between maternal breast milk HIV-specific interferon-γ (IFN-γ) responses and infant HIV-1 detection at 1 month of age. In a Kenyan cohort of HIV-infected mothers, blood and breast milk HIV-gag IFN-γ ELISpot responses were measured. Logistic regression was used to measure associations between breast milk IFN-γ responses and infant HIV infection at 1 month of age. IFN-γ responses were detected in breast milk from 117 of 170 (69%) women. IFN-γ responses were associated with breast milk viral load, levels of macrophage inflammatory protein (MIP) 1α, MIP-1β, regulated upon activation, normal T-cell expressed, and secreted and stromal-cell derived factor 1 and subclinical mastitis. Univariate factors associated with infant HIV infection at 1 month postpartum included both detection and breadth of breast milk IFN-γ response (P = 0.08, P = 0.04, respectively), breast milk MIP-1β detection (P = 0.05), and plasma (P = 0.004) and breast milk (P = 0.004) viral load. In multivariate analyses adjusting for breast milk viral load and MIP-1β, breast milk IFN-γ responses were associated with an approximately 70% reduction in infant HIV infection [adjusted odds ratio (aOR) 0.29, 95% confidence interval (CI) 0.092-0.91], and each additional peptide pool targeted was associated with an approximately 35% reduction in infant HIV (aOR 0.65, 95% CI 0.44-0.97). These data show breast milk HIV-gag-specific IFN-γ cellular immune responses are prevalent and may contribute to protection from early HIV transmission. More broadly, these data suggest breast milk cellular responses are potentially influential in decreasing mother-to-child transmission of viruses.

Kinetics of Nevirapine and Its Impact on HIV-1 RNA Levels in Maternal Plasma and Breast Milk Over Time After Perinatal Single-Dose Nevirapine

To determine kinetics after single-dose nevirapine and the impact on HIV RNA [viral load (VL)] in maternal plasma and breast milk (BM). Cohort of 120 HIV-1-infected pregnant Ugandan women received perinatal single-dose nevirapine alone and followed up with their infants through 24 weeks postdelivery. We assessed the relationship of nevirapine concentration (tandem mass spectroscopy) and HIV-1 VL (Roche AMPLICOR HIV-1 Kit, version 1.5) in maternal plasma and BM over time. At week 1 postpartum, NVP (≥10 ng/mL) was detected in all 53 plasma and 47 of 51 (92.2%) BM samples with median (interquartile ranges) of, respectively, 171 (78-214) ng/mL and 112 (64-158) ng/mL, P = 0.075, which decreased subsequently with traces persisting through week 4 in plasma. Plasma and BM VL dropped by week 1 and were highly correlated at delivery (R = 0.71, P < 0.001) and week 1 (R = 0.69, P < 0.001) but not thereafter. At week 1, VL correlated inversely with NVP concentration in plasma (R = 0.39, P = 0.004) and BM (R = 0.48, P = 0.013). There was a VL rebound in both compartments, which peaked at week 4 to levels greater than those at week 1 [significantly in plasma (P < 0.001) but not in BM] and remained stable thereafter. Median VL was consistently greater (11- to 50-fold) in plasma than BM at all time points (all P < 0.001). After single-dose nevirapine, NVP concentration was comparably high through week 1, accompanied by suppression of plasma and BM VL. A longer "tail" (>1 week) of potent postnatal antiretroviral drugs is warranted to minimize the observed VL rebound and potential for NVP resistance as a result of persistent NVP traces.

Infant Feeding Practices were not Associated with Breast Milk HIV-1 RNA Levels in a Randomized Clinical Trial in Botswana

Exclusive breastfeeding has been associated with a reduced risk of late vertical HIV transmission as compared to an infant diet composed of breast milk mixed with supplemental foods or liquids. Hypothesized mechanisms include increased infectivity of breast milk from mothers who practice mixed breastfeeding (MBF), or mechanisms such as increased gastrointestinal permeability in the infant caused by mixed feeding. It has been proposed that MBF may result in subclinical mastitis and higher breast milk HIV titers. However, little is known about the relationship between feeding strategy and breast milk viral load. We measured the HIV-1 concentration in breast milk in a sub-cohort of women enrolled in a mother-to-child HIV transmission prevention trial (the "Mashi" study). We report no observed relationship between MBF and measured breast milk viral RNA load. Our findings suggest that the increased transmission risk associated with higher breast milk HIV-1 RNA during MBF is unlikely.

Cumulative Exposure to Cell-Free HIV in Breast Milk, Rather Than Feeding Pattern per se, Identifies Postnatally Infected Infants

We quantified the relationship between human immunodeficiency virus (HIV) RNA shedding in breast milk, cumulative RNA exposure, and postnatal transmission, relating timing of infection in the infant to estimated total volume of milk exposure. Nested case-control study of 36 infants of HIV-infected mothers. Case patients were infants who acquired HIV infection through breastfeeding from age 6 through 28 weeks, and control subjects were uninfected infants matched on age at obtainment of a breast milk sample. Mothers and infants received peripartum single-dose nevirapine prophylaxis. Feeding data were collected daily; breast milk samples were collected and infant anthropometry was performed at 6 weeks and monthly thereafter. Volume of milk ingested was estimated using infant weight and feeding pattern. Before HIV acquisition in case patients, feeding pattern (exclusive breastfeeding; median duration, 65 vs 70 days; P = .6) and daily milk intake (mean volume, 638 vs 637 mL; P = .97) did not differ significantly between case patients and control subjects. Case mothers were more likely to shed virus (64% vs 9% always, 22% vs 20.5% intermittently, 14% vs 70.5% never shed; overall, P < .001). Case patients ingested ~15 times more HIV-1 RNA particles than did control subjects (196.5 vs 13 × 10⁶ copies; P < .001). Allowing for maternal antenatal CD4 cell count and plasma HIV-1 load, child sex and duration of mixed breastfeeding, the association between HIV RNA exposure and infection remained statistically significant (P < .001). Postnatal acquisition of HIV-1 is more strongly associated with cumulative exposure to cell-free particles in breast milk than with feeding mode. Reducing breast milk viral load through antiretroviral therapy to mother or child can further decrease postnatal transmission in exclusively breastfed infants.

Effect of vitamin supplements on HIV shedding in breast milk

Supplementation in lactating HIV-1-infected women with preformed vitamin A and β-carotene (VA/BC) increases the risk of mother-to-child transmission of HIV through breastfeeding. Identifying a biological mechanism to explain this unexpected finding would lend support to a causal effect. The aim of the study was to evaluate the effect of VA/BC or multivitamin (B complex, vitamin C, and vitamin E) supplementation of HIV-infected women on HIV shedding in breast milk during the first 2 y postpartum. We quantified viral (cell-free) and proviral (cell-associated) HIV loads in breast-milk samples collected ≤15 d after delivery and every 3 mo thereafter from 594 Tanzanian HIV-1-infected women who participated in a randomized trial. Women received 1 of the following 4 daily oral regimens in a 2 × 2 factorial fashion during pregnancy and throughout the first 2 y postpartum: multivitamin, VA/BC, multivitamin including VA/BC, or placebo. The proportion of breast-milk samples with detectable viral load was significantly higher in women who received VA/BC (51.3%) than in women who were not assigned to VA/BC (44.8%; P = 0.02). The effect was apparent ≥6 mo postpartum (relative risk: 1.34; 95% CI: 1.04, 1.73). No associations with proviral load were observed. The multivitamin had no effects. In observational analyses, β-carotene but not retinol breast-milk concentrations were significantly associated with an increased viral load in milk. VA/BC supplementation in lactating women increases the HIV load in breast milk. This finding contributes to explaining the adverse effect of VA/BC on mother-to-child transmission. β-Carotene appears to have an effect on breast-milk viral load, independent of preformed vitamin A. This trial was registered at clinicaltrials.gov as NCT00197756.