Postnatal Transmission Research Articles

Time to implement 9-month infant HIV testing in South Africa.

South Africa (SA) is likely to meet the National Strategic Plan target of <2% mother-to-child HIV transmission at 6 weeks of age in 2015. Children infected with HIV after 6 weeks often remain undiagnosed because of poor implementation of post-weaning and final outcome 18-month HIV testing. The World Health Organization recommends a screening HIV rapid test (HRT) in HIV-exposed infants at the 9-month immunisation visit to exclude postnatal infection, with a confirmatory HIV polymerase chain reaction (PCR) test if the HRT is positive. To evaluate the impact of substituting this recommendation for the post-weaning HIV testing recommended by SA guidelines. Rates of seroreversion and probability of infection at 9 months of age were applied to a theoretical population of 100 HIV-exposed infants, uninfected at birth and breastfed for 1 year with antiretroviral prophylaxis. Nine scenarios were developed and the number of HIV PCRs saved compared with current guidelines was calculated. Nine-month testing using the HRT reduced the number of follow-up PCR tests done in all scenarios by >50%, with differences ranging from 51% to 59% and 81% to 89% for low and high seroreversion rates, respectively. Nine-month testing using HRT would increase identification and early treatment of HIV-infected infants, improve monitoring of postnatal transmission rates, and reduce the number of HIV PCR tests done with resultant cost saving. Training of healthcare workers implementing HRT would be required. Ongoing efforts to improve implementation and monitoring of testing at 9 and 18 months will be essential.

Rapid Development of gp120-Focused Neutralizing B Cell Responses during Acute Simian Immunodeficiency Virus Infection of African Green Monkeys.

The initial phases of acute human immunodeficiency virus type 1 (HIV-1) infection may be critical for development of effective envelope (Env)-specific antibodies capable of impeding the establishment of the latent pool of HIV-1-infected CD4(+) T cells, preventing virus-induced immune hyperactivation to limit disease progression and blocking vertical virus transmission. However, the initial systemic HIV-1 Env-specific antibody response targets gp41 epitopes and fails to control acute-phase viremia. African-origin, natural simian immunodeficiency virus (SIV) hosts do not typically progress to AIDS and rarely postnatally transmit virus to their infants, despite high milk viral loads. Conversely, SIV-infected rhesus macaques (RMs), Asian-origin nonnatural SIV hosts, sustain pathogenic SIV infections and exhibit higher rates of postnatal virus transmission. In this study, of acute SIV infection, we compared the initial systemic Env-specific B cell responses of AGMs and RMs in order to probe potential factors influencing the lack of disease progression observed in AGMs. AGMs developed higher-magnitude plasma gp120-specific IgA and IgG responses than RMs, whereas RMs developed more robust gp140-directed IgG responses. These gp120-focused antibody responses were accompanied by rapid autologous neutralizing responses during acute SIV infection in AGMs compared to RMs. Moreover, acute SIV infection elicited a higher number of circulating Env-specific memory B cells in peripheral blood of AGMs than in the blood of RMs. These findings indicate that AGMs have initial systemic Env-specific B cell responses to SIV infection distinct from those of a nonnatural SIV host, resulting in more functional SIV-specific humoral responses, which may be involved in impairing pathogenic disease progression and minimizing postnatal transmission. Due to the worldwide prevalence of HIV-1 infections, development of a vaccine to prevent infection or limit the viral reservoir remains an important goal. HIV-1-infected humans, as well as SIV-infected nonnatural SIV hosts, develop pathogenic infections and readily transmit the virus to their infants. Conversely, natural SIV hosts do not develop pathogenic infections and rarely transmit the virus to their infants. The immunologic factors contributing to these favorable outcomes in natural SIV hosts could prove invaluable for directing HIV-1 vaccine and therapy design. This study identified distinctions in the specificity and function of the initial systemic SIV envelope-specific B cell response that developed during acute SIV infection in natural and nonnatural SIV host species. Identification of distinct acute B cell responses in natural SIV hosts may inform vaccine strategies seeking to elicit similar responses prior to or during the initial phases of acute HIV-1 infection.

Comparison of anti-retroviral therapy treatment strategies in prevention of mother-to-child transmission in a teaching hospital in Ethiopia.

More than 90% of Human immunodeficiency virus (HIV) infection in children is acquired due to mother-to-child transmission, which is spreading during pregnancy, delivery or breastfeeding. To determine the effectiveness of highly active antiretroviral and short course antiretroviral regimens in prevention of mother-to-child transmission of HIV and associated factors Jimma University Specialized Hospital (JUSH). A hospital based retrospective cohort study was conducted on HIV infected pregnant mothers who gave birth and had follow up at anti-retroviral therapy (ART) clinic for at least 6 months during a time period paired with their infants. The primary and secondary outcomes were rate of infant infection by HIV at 6 weeks and 6 months respectively. The Chi-square was used for the comparison of categorical data multivariate logistic regression model was used to identify the determinants of early mother-to-child transmission of HIV at 6 weeks. Cox proportional hazard model was used to analyze factors that affect the 6 month HIV free survival of infants born to HIV infected mothers. A total of 180 mother infant pairs were considered for the final analysis, 90(50%) mothers received single dose nevirapine (sdNVP) designated as regimen-3, 67 (37.2%) mothers were on different types of ARV regimens commonly AZT + 3TC + NVP (regimen-1), while the rest 23 (12.8%) mothers were on short course dual regimen AZT + 3TC + sdNVP (regimen-2). Early mother-to-child transmission rate at 6 weeks for regimens 1, 2 and 3 were 5.9% (4/67), 8.6% (2/23), and 15.5% (14/90) respectively. The late cumulative mother-to-child transmission rate of HIV at 6 months regardless of regimen type was 15.5% (28/180). Postnatal transmission at 6 months was 28.5% (8/28) of infected children. Factors that were found to be associated with high risk of early mother-to-child transmission of HIV include duration of ARV regimen shorter than 2 months during pregnancy (OR=4.3, 95%CI =1.38-13.46), base line CD4 less than 350 cells/cubic mm (OR=6.98, 95%CI=0.91-53.76), early infant infection (OR=5.4, 95%CI=2.04-14.4), infants delivered home (OR=13.1, 95%CI=2.69-63.7), infant with birth weight less than 2500 g (OR=6.41, 95%CI=2.21-18.61), and mixed infant feeding (OR=6.7, 95%CI=2.2-20.4). Antiretroviral regimen duration less than 2 months, maternal base line CD4 less than 350 cells/cubic mm and mixed infant feeding were also important risk factors for late infant infection or death. The effectiveness of multiple antiretroviral drugs in prevention of early mother-to-child transmission of HIV was found to be more effective than that of single dose nevirapine, although, the difference was not statistically significant. But in late transmission, a significant difference was observed in which infants born to mother who received multiple antiretroviral drugs were less likely to progress to infection or death than infants born to mothers who received single dose nevirapine.

Breastfeeding and the 2015 South African guidelines for prevention of mother-to-child transmission of HIV.

No abstract available

The experiences of HIV-positive mothers breastfeeding exclusively in Swaziland

In Swaziland, 41.1% of pregnant women live with HIV, while only 32% of Swazi mothers (including HIV negative mothers) currently practice exclusive breastfeeding among infants less than six months of age. The rate of exclusive breastfeeding decreases with an increase in the infant’s age, as only 17% of infants aged four to five months are reported to be exclusively breastfed. Exclusive breastfeeding is recommended by the ministry of health of Swaziland to reduce postnatal HIV transmission of HIV to the infant, through the prevention of mother-to-child transmission of HIV (PMTCT) strategy. However, little is known about HIV-positive mothers’ perspectives and experiences of exclusive breastfeeding in Swaziland. Therefore, a hospital-based explorative, descriptive qualitative study design was employed to describe the experiences of HIV-positive mothers in Swaziland breastfeeding exclusively. Seven exclusive breastfeeding, HIV-positive mothers, aged 21-41 years, married and unemployed, participated during two visits to the study site. Responses to semi-structured and in-depth interviews, through purposive sampling, were analyzed in order to generate themes. Five major themes emerged: (i) benefits of breast milk to the mother and the baby; (ii) social support factors; (iii) the role of healthcare workers in promoting exclusive breastfeeding; (iv) psychological relief from a baby’s negative test result; and (v) challenges faced by breastfeeding mothers. Despite pressure from relatives and in-laws for some of the participants, they continued to breastfeed exclusively for the first six months of the baby’s life, stating that breastfeeding benefited themselves and their infants. Continuous teaching and counseling offered by nurses during child-welfare clinic visits motivated the mothers to continue breastfeeding exclusively. In view of the challenges expressed by mothers, there is a need to develop and implement feasible interventions to improve support for HIV-positive mothers, in order to scale up exclusive breastfeeding practices in the country. Counseling on exclusive breastfeeding should also include the in-laws as they play a pivotal role in child feeding. This study contributes to the body of knowledge on infant feeding and provides insights to healthcare professionals and stakeholders working with HIV-positive breastfeeding women.

Evaluation of cytomegalovirus infection in low-birth weight children by breast milk using a real-time polymerase chain reaction assay.

Human Cytomegalovirus (CMV) is the most common cause of intrauterine and perinatal infections worldwide. Postnatal CMV transmission has usually no consequences, but in some cases it may produce disease in preterm infants. Literature reports a broad range of breast milk-acquired CMV infections (5.7-58.6%), which depends on the study's design and the treatment of the milk. To evaluate CMV transmission via breast milk, a prospective study using a real-time PCR assay was performed. One hundred and thirty-one mothers (accounting for 160 children) accepted the participation in the study. Urine samples from the infants and breast milk samples from their mothers were collected at 3, 15, 30, 60, and 90 days after delivery. CMV-DNA in breast milk was analysed by quantitative real-time PCR assay Affigene® CMV Trender (Cepheid, Bromma, Sweden). The breast milk samples from 92 mothers (92 of 131, 70.2%) were positive for CMV by PCR. CMV infection was detected in thirteen children by PCR, and four of them (30.7%) had clinical symptoms. There were not significant differences in morbidity between symptomatic and non- symptomatic patients; nonetheless, the average length of hospitalization in symptomatic children was higher than that of non-symptomatic children (P < 0.05). The rtPCR technique is useful for detection of mothers with high viral loads of CMV-DNA in milk, and might be of help to decide whether to freeze the breast milk in preterm children less than 28 weeks.

Efficacy of WHO recommendation for continued breastfeeding and maternal cART for prevention of perinatal and postnatal HIV transmission in Zambia.

IntroductionTo prevent mother-to-child transmission (MTCT) of HIV in developing countries, new World Health Organization (WHO) guidelines recommend maternal combination antiretroviral therapy (cART) during pregnancy, throughout breastfeeding for 1 year and then cessation of breastfeeding (COB). The efficacy of this approach during the first six months of exclusive breastfeeding has been demonstrated, but the efficacy of this approach beyond six months is not well documented.MethodsA prospective observational cohort study of 279 HIV-positive mothers was started on zidovudine/3TC and lopinavir/ritonavir tablets between 14 and 30 weeks gestation and continued indefinitely thereafter. Women were encouraged to exclusively breastfeed for six months, complementary feed for the next six months and then cease breastfeeding between 12 and 13 months. Infants were followed for transmission to 18 months and for survival to 24 months. Text message reminders and stipends for food and transport were utilized to encourage adherence and follow-up.ResultsTotal MTCT was 9 of 219 live born infants (4.1%; confidence interval (CI) 2.2–7.6%). All breastfeeding transmissions that could be timed (5/5) occurred after six months of age. All mothers who transmitted after six months had a six-month plasma viral load >1,000 copies/ml (p<0.001). Poor adherence to cART as noted by missed dispensary visits was associated with transmission (p=0.04). Infant mortality was lower after six months of age than during the first six months of life (p=0.02). The cumulative rate of infant HIV infection or death at 18 months was 29/226 (12.8% 95 CI: 7.5–20.8%).ConclusionsMaternal cART may limit MTCT of HIV to the UNAIDS target of <5% for eradication of paediatric HIV within the context of a clinical study, but poor adherence to cART and follow-up can limit the benefit. Continued breastfeeding can prevent the rise in infant mortality after six months seen in previous studies, which encouraged early COB.

PO-0569 Pasteurisation Of Human Breast Milk: A Neonatal Dilemma

Background Preterm infants are at risk of postnatal transmission of cytomegalovirus (CMV) via breast milk. Although most infants remain asymptomatic in the neonatal period, doubts about adverse effects on neurodevelopmental outcome have been raised. Pasteurisation prevents transmission of CMV via breast milk, which concomitantly inactivates immune and bioactive components. Data indicate that necrotizing enterocolitis (NEC) and late-onset sepsis (LOS) are less common in preterm infants fed with breast milk, as compared to infants fed with formula or pasteurised breast milk. Aim To assess whether feeding preterm infants with unpasteurized breast milk i) decreases the rate of LOS and NEC and ii) increases the rate of postnatally acquired CMV infections. Methods Between January 2008 and July 2013 preterm infants Results The number of infants diagnosed with postnatally acquired CMV infections was significantly higher in the non-pasteurised group as compared to the pasteurised group (6.7% vs. 0.6%, p = 0.006). There was no significant difference regarding rate of LOS (15.9% vs. 15.1%, p = 0.486) or NEC (2.4% vs. 4.4%, p = 0.254). Conclusion Feeding preterm infants with unpasteurized breast milk increases the rate of CMV infections. Of interest, we also show a non-significant trend to decreased rates of NEC, but this needs to be confirmed in larger studies.

Restricted isotype, distinct variable gene usage, and high rate of gp120 specificity of HIV-1 envelope-specific B cells in colostrum compared with those in blood of HIV-1-infected, lactating African women.

A successful HIV-1 vaccine must elicit immune responses that impede mucosal virus transmission, though functional roles of protective HIV-1 Envelope (Env)-specific mucosal antibodies remain unclear. Colostrum is a rich source of readily accessible mucosal B cells that may help define the mucosal antibody response contributing to prevention of postnatal HIV-1 transmission. To examine the HIV-1 Env-specific colostrum B cell repertoire, single B cells were isolated from 17 chronically HIV-infected, lactating women, producing 51 blood and 39 colostrum HIV-1 Env-specific B cell antibodies. All HIV-1 Env-specific colostrum-derived antibodies were IgG1 isotype and had mean heavy chain complementarity-determining region 3 (CDR3) lengths and mutation frequencies similar to those isolated from blood. However, variable heavy chain (VH) gene subfamily 1~69 usage was higher among colostrum than blood HIV-1 Env-reactive antibodies (49% versus 20%, p = 0.006, Fisher’s exact test). Additionally, more HIV-1 Env-specific colostrum antibodies were gp120-specific than those isolated from blood (44% versus 16%, p = 0.005, Fisher’s exact test). One cross-compartment HIV-1 Env-specific clonal B cell lineage was identified. These unique characteristics of colostrum B cell antibodies suggest selective homing of HIV-1-specific IgG1-secreting memory B cells to the mammary gland and have implications for targeting mucosal B cell populations by vaccination.

Immune-based interventions to prevent postnatal HIV-1 transmission

Despite global scale-up in antiretroviral-based prevention of mother-to-child transmission services, more than 250 000 infants become infected with HIV-1 each year. Breast milk transmission is responsible for almost half of these infections. The development of alternative strategies to prevent postnatal HIV-1 transmission is imperative to achieve a generation free of HIV-1.

The association between maternal hepatitis B e antigen status, as a proxy for perinatal transmission, and the risk of hepatitis B e antigenaemia in Gambian children.

BackgroundEarly age at infection with hepatitis B virus (HBV) increases the risk of chronic HBV infection. In addition early age at infection may further increase the risk of persistent viral replication beyond its effect on chronicity. The effects of perinatal and early postnatal transmission on the risk of prolonged hepatitis B e antigenaemia in children with chronic HBV infection are not well documented in Africa. We examine these associations using maternal HBV sero-status and the number of HBV-positive older siblings as proxy measures for perinatal and early postnatal transmission, respectively.MethodsHepatitis B e antigen (HBeAg)-positive mothers were identified in six population-based HBV sero-surveys conducted in The Gambia between 1986 and 1990. For every HBeAg-positive mother, a hepatitis B surface antigen (HBsAg)-positive HBeAg-negative mother and HBsAg-negative mother were randomly selected from the population surveyed. These mothers and their family members were tested for HBV sero-markers in a subsequent survey conducted between 1991 and 1993.ResultsThirty-eight HBeAg positive mothers and the same number of HBsAg-positive HBeAg-negative mothers and HBsAg-negative mothers participated in the study. Sixty-nine percent of their children also participated. There was a non-significant positive association between HBeAg prevalence in children and the number of HBeAg-positive older siblings (64.1%, 69.2% and 83.3% in children with 0, 1 and ≥2 HBeAg-positive older siblings, respectively). After adjusting for confounders, having an HBeAg-positive mother was a risk factor for HBeAg positivity in children carrying HBsAg (adjusted OR 4.5, 95% CI: 1.0-19.5, p = 0.04), whilst the number of HBeAg-positive older siblings was not.ConclusionsMaternal HBeAg was associated with positive HBeAg in children with chronic HBV infection. This suggests that interrupting mother-to-infant transmission in sub-Saharan Africa might help reduce the burden of liver disease. A timely dose of HBV vaccine within 24 hours of birth, as recommended by WHO, should be implemented in sub-Saharan Africa.

Practices and recommendations in infant feeding and HIV prevention: the child's perspective

Although the attainment of Millennium Development Goal 4 (MDG 4), reducing under-five mortality by two-thirds by the year 2015, depends on optimizing breast-feeding practices in resource-limited settings, there are some conditions in which breast-feeding is impossible, contraindicated, or not recommended. The overall impact of involuntary nonbreast-feeding on the attainment of MDG 4 has not been documented. In industrialized and many middle-income countries replacement feeding is affordable, feasible, acceptable, sustainable, and safe and complete avoidance of breast-feeding is the norm to prevent postnatal transmission of HIV. The situation is very different in many low-income countries affected by the HIV epidemic where infants are exposed to HIV and antiretroviral (ARV) mediation through breast milk for long periods with risk of acquiring HIV infection, development of multidrug resistant HIV and short and long term toxicity associated to ARV medications. Despite the obvious needs, there is no specific research on how to make replacement feeding safer for infants with no access to breast-feeding and for whom replacement feeding is justified. Orphans, abandoned and infants of severely ill mothers unable to breast-feed, won't benefit from the research done on making breast-feeding safer for HIV exposed infants. A child rights perspective illuminates societal obligations to provide replacement feeding with infant formula milk to such infants, and to support research to make it safer at the same time that breast-feeding is promoted and protected for the general population.

Tuberculosis Congénita en el Hospital Dos de Mayo

Se presenta un caso de tuberculosis congénita con desenlace fatal. Se demostró la presencia de lesiones tuberculosas a nivel pulmonar y del tracto genital materno, por medio de biopsia de endometrio y luego por sucesivas bisterosalpingografías. El niño nacido pretérmino, 36 semanas de gestación, con peso de 2760 gr. luego de una evolución que incluía hiperbilirrubinemia de 15,12 mgr%, hidrocele, pie equino varo, diastasis de los rectos abdominales, piodermitis y onfalitis, presenta a los 27 días de nacido un cuadro severo de dificultad respiratoria con marcada cianosis, diagnosticándose TBC mi liar y sepsis con desenlace fatal. Tomando en cuenta la propuesta de Cantwell y col. en 1994, sobre criterios diagnósticos revisados para la tuberculosis congénita, el presente caso cumple con los criterios señalados: La tuberculosis probada en el niño y la infección genital materna, corroborado por el examen anatomopatológico de los restos obtenidos por legrado uterino, así como exclusión completa de la posibilidad de contagio postnatal por el aislamiento del niño de la madre, además de la existencia de lesiones desde las primeras semanas de vida.

Efficacy and Safety of an Extended Nevirapine Regimen in Infants of Breastfeeding Mothers With HIV-1 Infection for Prevention of HIV-1 Transmission (HPTN 046)

HPTN 046 compared the efficacy and safety of infant nevirapine (NVP) among HIV-exposed breastfed infants randomized at 6 weeks to 6 months to t NVP or placebo to prevent postnatal infection: we report final 18-month outcomes. Randomized, placebo-controlled trial in 4 African countries. Infant diagnostic HIV testing was performed regularly from birth through 18 months. Kaplan-Meier analysis was used to assess 18-month cumulative infant HIV infection, HIV infection/or death, and mortality rates. Between 6 weeks and 6 months, postnatal HIV infection rates were significantly lower among infants receiving daily NVP from 6 weeks to 6 months 1.1% [95% confidence interval (CI): 0.2% to 1.8%], compared with placebo 2.4% (95% CI: 1.3% to 2.6%), P = 0.049, but not significantly lower thereafter. Eighteen-month postnatal infection rates were low: 2.2% (95% CI: 1.1% to 3.3%) versus 3.1% (95% CI: 1.9% to 4.4%), respectively, P = 0.28. Mortality and HIV infection/death did not differ between arms at any age. Infants of women receiving antiretroviral therapy (ART) for their own health had the lowest 18-month postnatal infection rates (0.5%, 95% CI: 0.0% to 1.1%). However, HIV infection/death rates at 18 months were not significantly different for infants of mothers on ART (3.7%, 95% CI: 1.9% to 5.5%), and infants of mothers with CD4 counts of ≥ 350 cells per cubic millimeter not receiving ART (4.8%, 95% CI: 2.7% to 6.8%; P = 0.46). There were no differences in adverse events between study arms. This trial demonstrated early but not late differences in postnatal HIV transmission among infants randomized at age 6 weeks to extended NVP or placebo, underscoring the importance of continued prophylaxis throughout breastfeeding.

Postnatal cytomegalovirus exposure in infants of antiretroviral-treated and untreated HIV-infected mothers.

HIV-1 and CMV are important pathogens transmitted via breastfeeding. Furthermore, perinatal CMV transmission may impact growth and disease progression in HIV-exposed infants. Although maternal antiretroviral therapy reduces milk HIV-1 RNA load and postnatal transmission, its impact on milk CMV load is unclear. We examined the relationship between milk CMV and HIV-1 load (4–6 weeks postpartum) and the impact of antiretroviral treatment in 69 HIV-infected, lactating Malawian women and assessed the relationship between milk CMV load and postnatal growth in HIV-exposed, breastfed infants through six months of age. Despite an association between milk HIV-1 RNA and CMV DNA load (0.39 log10 rise CMV load per log10 rise HIV-1 RNA load, 95% CI 0.13–0.66), milk CMV load was similar in antiretroviral-treated and untreated women. Higher milk CMV load was associated with lower length-for-age (−0.53, 95% CI: −0.96, −0.10) and weight-for-age (−0.40, 95% CI: −0.67, −0.13) Z-score at six months in exposed, uninfected infants. As the impact of maternal antiretroviral therapy on the magnitude of postnatal CMV exposure may be limited, our findings of an inverse relationship between infant growth and milk CMV load highlight the importance of defining the role of perinatal CMV exposure on growth faltering of HIV-exposed infants.

Human Milk Galectin-3 Binding Protein and Breast-feeding–associated HIV Transmission

Analysis of milk from 247 HIV-infected Zambian mothers showed that galectin-3 binding protein concentrations were significantly higher among HIV-infected mothers who transmitted HIV through breast-feeding (6.51 ± 2.12 μg/mL) than among nontransmitters but were also correlated with higher milk and plasma HIV RNA copies/mL and lower CD4+ cell counts. The association between galectin-3 binding protein and postnatal transmission was attenuated after adjustment for milk and plasma HIV load and CD4+ cell counts. This suggests that although milk galectin-3 binding protein is a marker of advanced maternal disease, it does not independently modify transmission risk.

Neutralization of HIV subtypes A and D by breast milk IgG from women with HIV infection in Uganda

Among HIV-exposed infants in resource-limited countries, 8-12% are infected postnatally by breastfeeding. However, most of those uninfected at birth remain uninfected over time despite daily exposure to HIV in breast milk. Thus, we assessed the HIV-inhibitory activity of breast milk. We measured cross-clade neutralization in activated PBMC of Ugandan subtype A (92UG031) and D (92UG005) primary HIV by breast milk or purified milk IgG and IgA from 25 HIV-infected Ugandan women. Isotype-specific antigen recognition was resolved by immunoblot. We determined HIV subtype from envelope population sequences in cells from 13 milk samples by PCR. Milk inhibited p24 production by ≥50% (dose-dependent) by subtype A (21/25; 84%) and subtype D (11/25; 44%). IgG consistently reacted with multiple HIV antigens, including gp120/gp41, but IgA primarily recognized p24 alone. Depletion of IgG (n=5), not IgA, diminished neutralization (mean 78±33%) that was largely restored by IgG repletion. Mothers infected with subtype A more effectively neutralized subtype A than D. Breast milk from HIV-infected women showed homotypic and cross-subtype neutralization of HIV by IgG-dependent and -independent mechanisms. These data direct further investigations into mechanisms of resistance against postnatal transmission of HIV to infants from their mothers.

Elevated Concentrations of Milk β2-Microglobulin Are Associated with Increased Risk of Breastfeeding Transmission of HIV-1 (Vertical Transmission Study)

There is increasing evidence to support a relationship between human immunodeficiency virus (HIV-1) transmission through breastfeeding and milk host factors. We analyzed skim milk proteome to further determine the contribution of host factors to the risk of mother-to-child transmission of HIV-1. Quantitative mass spectrometry analysis was performed on nine case-control pairs of HIV+ transmitter/nontransmitter mothers, and specific biochemical assays on two selected proteins were assessed in an independent validation set of 127 samples. 33 identified proteins were differentially expressed between HIV+ transmitter and nontransmitter mothers. Among them, β2-microglobulin was significantly higher in the maternal transmitter than in the nontransmitter groups (p value = 0.0007), and S100A9 was significantly higher in the early maternal transmitter cases (before 4 months of age) compared with the nontransmitters (p value = 0.004). β2-Microglobulin correlated with milk and plasma HIV viral load and CD4+ cell count, whereas S100A9 correlated with the estimated timing of infection of the infant through breastfeeding. Finally, β2-microglobulin concentration in milk could accurately predict the risk of HIV-1 postnatal transmission by breastfeeding (p value < 0.0001, log-rank test). In conclusion, milk β2-microglobulin and S100A9 are host factors that are found to be associated with mother-to-child transmission of HIV-1.

Challenges in infant and young child nutrition in the context of HIV

There is consensus on the benefits for all infants of exclusive breastfeeding for 6 months and introduction of appropriate complementary foods at 6 months, followed by continued breastfeeding. However, guidelines on infant and young child feeding (IYCF) for HIV-positive mothers have changed continually since 2000. This article explores issues and evidence related to IYCF for the prevention and care of paediatric HIV in resource-limited settings in light of new HIV treatment guidelines, implementation challenges and knowledge gaps.In 2010 the impact of antiretroviral drugs (ARVs) on reducing the risk of mother-to-child transmission of HIV moved WHO to urge countries to endorse either avoidance of all breastfeeding or exclusive breastfeeding for the first 6 months while taking ARVs, depending on which strategy could give their infants the greatest chance of HIV-free survival. Implementation of the 2010 recommendations is challenged by lack of healthcare provider training, weak clinic-community linkages to support mother/infant pairs and lack of national monitoring and reporting on infant feeding indicators.More evidence is needed to inform prevention and treatment of malnutrition among HIV-exposed and HIV-infected children. Knowledge gaps include the effects of prolonged ARV exposure, the cause of HIV-associated growth faltering, the effects of early infant testing on continuation of breastfeeding and specific nutrition interventions needed for HIV-infected children.Significant progress has been made toward keeping mothers alive and reducing paediatric HIV infection, but sustained political, financial and scientific commitment are required to ensure meaningful interventions to eliminate postnatal transmission and meet the nutritional needs of HIV-exposed and HIV-infected children.

Tenascin-C is an innate broad-spectrum, HIV-1–neutralizing protein in breast milk

Achieving an AIDS-free generation will require elimination of postnatal transmission of HIV-1 while maintaining the nutritional and immunologic benefits of breastfeeding for infants in developing regions. Maternal/infant antiretroviral prophylaxis can reduce postnatal HIV-1 transmission, yet toxicities and the development of drug-resistant viral strains may limit the effectiveness of this strategy. Interestingly, in the absence of antiretroviral prophylaxis, greater than 90% of infants exposed to HIV-1 via breastfeeding remain uninfected, despite daily mucosal exposure to the virus for up to 2 y. Moreover, milk of uninfected women inherently neutralizes HIV-1 and prevents virus transmission in animal models, yet the factor(s) responsible for this anti-HIV activity is not well-defined. In this report, we identify a primary HIV-1-neutralizing protein in breast milk, Tenascin-C (TNC). TNC is an extracellular matrix protein important in fetal development and wound healing, yet its antimicrobial properties have not previously been established. Purified TNC captured and neutralized multiclade chronic and transmitted/founder HIV-1 variants, and depletion of TNC abolished the HIV-1-neutralizing activity of milk. TNC bound the HIV-1 Envelope protein at a site that is induced upon engagement of its primary receptor, CD4, and is blocked by V3 loop- (19B and F39F) and chemokine coreceptor binding site-directed (17B) monoclonal antibodies. Our results demonstrate the ability of an innate mucosal host protein found in milk to neutralize HIV-1 via binding to the chemokine coreceptor site, potentially explaining why the majority of HIV-1-exposed breastfed infants are protected against mucosal HIV-1 transmission.