Breastfeeding, breast milk and viruses

We challenge this evidence because past breastfeeding studies did not determine "exposure" of newborn infants to colostrum and breast milk.We conducted a prospective review of 100 consecutive births of infants in the same centre to determine the proportion of newborn infants who were "exposed" to colostrum or breast milk, as distinct from being fully breast fed. We also report a review of the breastfeeding practices of mothers of over 87,000 newborn infants in the Australian State of New South Wales.This study was approved by the Human Research Ethics Committee of the University of New South Wales (Sydney, Australia). Approval 05063, 29 September 2005.Virtually all (97 of 100) newborn infants in this centre were "exposed" to colostrum or breast milk whether or not they were fully breast fed. Between 82.2% to 98.7% of 87,000 newborn infants were "exposed" to colostrum or breast milk.In some Western communities there is near universal exposure of new born infants to colostrum and breast milk. Accordingly it is possible for the transmission of human milk borne viruses. This is contrary to the widespread assumption that human milk borne viruses cannot be associated with breast cancer.Human immunodeficiency virus (HIV), cytomegalovirus (CMV), human T cell leukaemia virus (HTLV) and other viruses may be transmitted by human milk and cause infections and disease [1]. In animals, viruses, such as the mouse mammary tumor virus (MMTV), are transmitted by mouse milk to new born mouse pups and are a proven cause of mouse mammary tumours [2].Accordingly, the transmission of milk born viruses which may have a role in human breast cancer has long been postulated. However, there is extensive and consistent epidemiological evidence, which indicates that breastfeeding – and hence the opportunity to transfer viruses via human mothers milk to infants, is not related to breast cancer [3,4]. There also appears to be no association between risk of breast cancer and breastfeeding by daught