Alternative modified infant-feeding practices to prevent postnatal transmission of human immunodeficiency virus type 1 through breast milk: past, present, and future

Oropharyngeal mucosal transmission of Zika virus in rhesus macaques

Zika virus is present in urine, saliva, tears, and breast milk, but the transmission risk associated with these body fluids is currently unknown. Here we evaluate the risk of Zika virus transmission through mucosal contact in rhesus macaques. Application of high-dose Zika virus directly to the tonsils of three rhesus macaques results in detectable plasma viremia in all animals by 2 days post-exposure; virus replication kinetics are similar to those observed in animals infected subcutaneously. Three additional macaques inoculated subcutaneously with Zika virus served as saliva donors to assess the transmission risk from contact with oral secretions from an infected individual. Seven naive animals repeatedly exposed to donor saliva via the conjunctivae, tonsils, or nostrils did not become infected. Our results suggest that there is a risk of Zika virus transmission via the mucosal route, but that the risk posed by oral secretions from individuals with a typical course of Zika virus infection is low.

Zika virus (ZIKV) is present in body fluids, including saliva, but transmission risk through mucosal contact is not well known. Here, the authors show that oropharyngeal mucosal infection of macaques with a high ZIKV dose results in viremia, but that transmission risk from saliva of infected animals is low.

HIV-1 and breastfeeding: biology of transmission and advances in prevention

Breastfeeding accounts for about 40% of mother-to-child transmission of HIV-1 worldwide and carries an estimated risk of transmission of 0.9% per month after the first month of breastfeeding. It is recommended that HIV-1-infected women completely avoid breastfeeding in settings where safe feeding alternatives exist. However, as replacement feeding is not safely available in many parts of the world, and because breastfeeding provides optimal nutrition and protection against other infant infections, there is intense ongoing research to make breastfeeding safe for HIV-1-infected mothers in resource-limited settings. More research is needed to determine the optimal duration of breastfeeding, optimal weaning practices, and which individual antiretroviral prophylactic regimen is best for HIV-1-infected mothers and their infants in a particular setting.

MUC1 in human milk blocks transmission of human immunodeficiency virus from dendritic cells to T cells

Mother-to-child transmission of human immunodeficiency virus-1 (HIV-1) occurs frequently via breast-feeding. HIV-1 targets DC-SIGN+ dendritic cells (DCs) in mucosal areas that allow efficient transmission of the virus to T cells. Here, we demonstrate that the epithelial mucin MUC1, abundant in milk, efficiently bound to DC-SIGN on DC. The O-linked glycans within the mucin domain contained Lewis X structures, that were specifically recognized by the receptor. Interestingly, MUC1 prevented DC-SIGN-mediated transmission of HIV-1 from DCs to CD4+ T cells. We hypothesize that repetitive units of Lewis X, within the mucin domain, play an important role in inhibiting transmission of HIV-1 from mother to child.

Prevention of human immunodeficiency virus-1 transmission to the infant through breastfeeding: new developments

Breastfeeding accounts for up to half of all infant human immunodeficiency virus (HIV) infections worldwide and carries an estimated transmission risk of about 15% when continued into the second year of life. Because replacement feeding is not safely available, culturally acceptable, or affordable in many parts of the world and because breastfeeding provides protection against other causes of infant mortality, approaches that reduce breastfeeding mother-to child transmission of HIV are being explored. These include exclusive breastfeeding for the infant's first few months of life followed by rapid weaning, treatments of expressed milk to inactivate the virus, and antiretroviral prophylaxis taken by the infant or mother during breastfeeding, which are strategies currently being tested in clinical trials. Passive (antibodies) and active (vaccine) immunoprophylaxis will also soon begin to be tested. This paper focuses on current and planned research on strategies to prevent breastfeeding transmission of HIV.

Humanizing infant milk formula to decrease postnatal HIV transmission

There are currently no safe methods for feeding babies born from the 16 million HIV-infected women living in resource-constrained countries. Breast milk can transmit HIV, and formula feeding can lead to gastrointestinal illnesses owing to unsanitary conditions and the composition of milk formulations. There is therefore a need to ensure that breast milk substitutes provide optimal health outcomes. Given that the immune properties of several breast milk proteins are known, transgenic food crops could facilitate inexpensive and safe reconstitution of the beneficial breast milk proteome in infant formulae, while keeping the HIV virus at bay. At least seven breast milk immune proteins have already been produced in food crops, and dozens more proteins could potentially be produced if fortified formula proves effective in nursing newborns born to HIV-infected mothers.

International perspectives, progress, and future challenges of paediatric HIV infection

Paediatric HIV infection is a growing health challenge worldwide, with an estimated 1500 new infections every day. In developed countries, well established prevention programmes keep mother-to-child transmission rates at less than 2%. However, in developing countries, where transmission rates are 25-40%, interventions are available to only 5-10% of women. Children with untreated natural infection progress rapidly to disease, especially in resource-poor settings where mortality is greater than 50% by 2 years of age. As in adult infection, antiretroviral therapy has the potential to rewrite the natural history of HIV, but is accessible only to a small number of children needing therapy. We focus on the clinical and immunological features of HIV that are specific to paediatric infection, and the formidable challenges ahead to ensure that all children worldwide have access to interventions that have proved successful in developed countries.

Biochemical analysis of human milk treated with sodium dodecyl sulfate, an alkyl sulfate microbicide that inactivates human immunodeficiency virus type 1

Reduction of transmission of human immunodeficiency virus type 1 (HIV-1) through human milk is needed. Alkyl sulfates such as sodium dodecyl sulfate (SDS) are microbicidal against HIV-1 at low concentrations, have little to no toxicity, and are inexpensive. The authors have reported that treatment of HIV-1-infected human milk with < or = 1% (10 mg/mL) SDS for 10 minutes inactivates cell-free and cell-associated virus. The SDS can be removed with a commercially available resin after treatment without recovery of viral infectivity. In this article, the authors report results of selective biochemical analyses (ie, protein, immunoglobulins, lipids, cells, and electrolytes) of human milk subjected to SDS treatment and removal. The SDS treatment or removal had no significant effects on the milk components studied. Therefore, the use of alkyl sulfate microbicides to treat milk from HIV-1-positive women may be a simple, practical, and nutritionally sound way to prevent or reduce transmission of HIV-1 while still feeding with mother's own milk.