A response to readers comments and questions Karleen Gribble, University of Western Sydney 29 January 2012 After the publication of our paper ¿Emergency preparedness for those who care for infants in developed country contexts¿ the authors received questions, helpful comments and suggestions for possible modification of emergency kits for babies. We would like to respond. Several health professionals and mothers questioned whether there was a place for a chemical sterilisation process in emergencies. Chemical sterilisation could be used in an emergency situation however, there would be little benefit to doing so. Thorough washing using hot water of feeding and preparation implements is required before sterilisation. Furthermore the water used for chemical sterilisation needs to be renewed every 24 hours. Thus, avoiding sterilisation by boiling by using chemical sterilisation would only save a small amount of water and fuel. Some have questioned the volume of water required for hand washing, suggesting that much less water is required. The authors allowed 500 mL for each hand washing. This figure was chosen after discussion with Water, Sanitation and Hygiene (WASH) specialists in the humanitarian sector. It should be recognised that in an emergency situation, contamination of surfaces with waste is common and hands can become very soiled. Five hundred millilitres to thoroughly clean dirty hands is a conservative estimate based on field experience. However, the authors recognise that there is no research to indicate how much water is needed to thoroughly clean hands and that such research would be welcome. Reducing the volume of water required to be stored in the ready-to-use infant formula kit is possible if disposable knifes can be used to open the containers of ready-to-use infant formula. This would reduce the amount of water required to be stored to 56L. Disposable knifes might be either high quality plastic knives that are intended to be disposable or metal knifes that are intended to be reusable but are disposed of after a single use. Care needs to be taken to ensure that the knives are sharp enough and strong enough to open the containers. The authors have been made aware that in some locations it is possible to purchase ready-to-use infant formula in disposable bottles and with disposable teats. This option may be more cost effective and take less space to store than purchasing ready-to-use infant formula and bottles and teats separately. However, use of this product still requires the opening of the bottle before assemblage with the teat. Therefore water to clean hands and a preparation area are still required. This option does not materially change the requirements for the ready-to-use infant formula kit. Some mothers expressed confusion about the amount of ready-to-use infant formula that needs to be stored, stating that they believed that the volume suggested was excessive. It should be understood that the amount of ready-to-use formula stored needs to be based both on the anticipated volume of milk that the infant would be expected to consume and the number of feeds per day that the infant is expected to need. This is because once a package of formula is opened it must be fed immediately to the infant and any leftover formula discarded; left over infant formula cannot be saved to be fed to the infant later. Thus, if an infant requires frequent small feeds (most likely in a very young infant), the amount of formula that needs to be stored may be much greater than the volume that the infant will actually consume because of the number of feeds required each day. One mother suggested to the authors that it would be possible to reconstitute powdered infant formula with stored water in disposable bottles, negating the need for heating water for cleaning and sterilisation. This would require storage of the same number of bottles and teats as for the ready-to-use infant formula kit but also make it more feasible to use powdered infant formula in an emergency situation. This option has some risks. In particular, reconstitution of powdered infant formula with cool water does not deactivate any bacteria present in the infant formula. Whilst intrinsic contamination of powdered infant formula is common , infection causing illness as a result, is rare. However, it should be noted that medical resources required to treat infections may not be readily available during emergencies. It should also be noted that the risk of infection differs depending on characteristics of the infant with newborns, premature or low birth weight infants and infants otherwise immunocompromised over represented amongst those infected . Mothers with healthy older infants may decide that the risk posed by intrinsic contamination of powdered infant formula is acceptable and that they are willing to reconstitute infant formula with water at ambient temperature. The other factor to consider is the quality of water for reconstitution. Ordinary bottled water is not sterile and can contain levels of microbes greater than that in tap water . Tap water itself can be contaminated with disease causing organisms [4-6]. Long-term storage of water can allow bacterial proliferation . Guidelines for the safe storage of water for emergency use are available and include practices such as rinsing storage containers with bleach prior to use, limiting storage to six months and chlorination of water [8, 9]. In some locations it is possible to purchase sterile water for reconstitution of infant formula. Given that the option of reconstituting powdered infant formula in disposable bottles involves practices that are more likely to result in the infant formula containing higher levels of bacterial contamination than is usually the case, it is even more important that the formula be fed immediately to the infant and the unused portion discarded immediately. If considering using powdered infant formula with disposable bottles in an emergency kit, caregivers should ensure that the volumetric measurements on the feeding bottle are accurate. Clinical experience has shown that volumetric measurements on feeding bottles can be inaccurate and if the bottle is used to measure water for reconstitution, errors resulting in over or under-dilution of the infant formula can occur Thus, while reconstitution of powdered infant formula in disposable bottles is certainly feasible, the risks associated with it require careful consideration. It is unlikely that this option would be recommended by health authorities because of these risks. If individual caregivers decide that this option is one that they wish to use, ensuring that they understand how to minimise the risks is important. The risks of this option are decreased if the infant is older, has no history of low birth weight, prematurity or immunocompromise, if sterile water is used for reconstituting the powdered infant formula and if the formula is fed immediately to the infant. Some concerns were raised about the cost of the emergency kits for formula fed infants. The figures provided were based on the cost of purchasing the products at one of Australia¿s major supermarkets. The cost is likely to vary widely depending upon location and the ability of the individual to source the cheapest possible products. It should be recognised however, that in the event of an approaching emergency (such as a cyclone or hurricane) that caregivers will have limited options for sourcing the items in the kits and costs may be much greater than those provided in the paper. The authors would welcome further comment and questions from health professionals and parents. Karleen D Gribble Nina J Berry 1. Forsythe SJ: Enterobacter sakazakii and other bacteria in powdered infant milk formula. Maternal and Child Nutrition 2005, 1:44-50. 2. WHO, FAO: Enterobacter sakazakii and other microorganisms in powdered infant formula. Geneva: WHO; 2004. 3. Lalumandier JA, Ayers LW: Fluoride and bacterial content of bottled water vs tap water. Archives of Family Medicine 2000, 9:246-250. 4. Almeida A, Moreira MJ, Soares S, Delgado ML, Figueiredo J, Silva E, Castro A, Cosa JM: Presence of Cryptosporidium spp. and Giardia duodenalis in drinking water samples in the north of Portugal. Korean Journal of Parasitology 2010, 48:43-48. 5. Rudi K, Tannaes T, Vatn M: Temporal and spatial diversity of the tap water microbiota in a Norwegian hospital. Applied and Environmental Microbiology 2009, 75:7855-7857. 6. Xi C, Zhang Y, Marrs CF, Ye W, Simon C, Foxman B, Nriagu J: Prevalence of antibiotic resistance in drinking water treatment and distribution systems. Applied and Environmental Microbiology 2009, 75:5714-5718. 7. Morais PV, Da Costa MS: Alterations in the major heterotrophic bacterial populations from a still bottled mineral water. Journal of Applied Bacteriology 1990, 69:750-757. 8. Food and Water Concerns [http://www.bt.cdc.gov/disasters/earthquakes/food.asp] 9. Water [http://www.fema.gov/plan/prepare/water.shtm] Competing interests The authors declare that they have no competing interests.