Prevalence of bacterial contamination of powdered infant feeds in a hospital environment.

BACKGROUND The study arose as part of a best-practice nutrition model regarding the introduction of ready-to-use (RTU) infant feeds in place of powdered infant feeds (PIFs) as a standard formula for infants under the age of 1 year who are unable to be breastfed. Internationally and locally there is grave concern regarding the safety and efficacy of mixing PIFs, especially in a hospital setting, and the resultant bacterial contamination causing enteric infections, especially in premature, immunocompromised and sick infants. OBJECTIVE To evaluate the prevalence of bacterial contamination of PIFs given to infants at Red Cross War Memorial Children's Hospital, Cape Town. METHODS Quantitative levels of bacterial contamination were determined and were expressed as colony-forming units (CFUs) per millilitre of sample. Aliquots of milk were inoculated onto agar, and the milk samples were then incubated at 25 degrees C overnight (N = 10), 30 degrees C overnight (N = 48) and 30 degrees C for 6 hours (N = 34). Post-incubation milk samples were cultured again. Contamination was defined as any positive culture before administration (i.e. pre incubation) or > 10(2) CFU/ ml after administration (i.e. post incubation). RESULTS Fifty samples of PIFs (N = 82) were contaminated pre incubation, with 25/82 samples (30.4%) being heavily contaminated ( >or= 10(4) CFU/ml). Post incubation, 43/92 samples (46.7%) were contaminated with > 102 CFU/ml. The acidified PIFs appeared to have some bactericidal effect against some of the organisms, but not all. CONCLUSIONS RTU infant feeds are sterile and are recommended for use in all hospitalised infants. The results of this study indicate that even when milk is prepared in a controlled environment there is significant bacterial contamination of PIFs post production. As RTU feeds are now readily available in South Africa every attempt should be made to use a sterile RTU system for hospitalised infants.