Bacillus Pre-Pasteurization Screening Protocol Reduces Donor Human Milk Loss

Abstract

Introduction:

Human milk is the optimal source of nutrition and bioactives for infants, particularly preterm infants, who are at higher risk of morbidity and mortality. Many premature infants require pasteurized donor human milk (PDHM) to supplement their diet. Given the increased susceptibility of preterm infants to infections, PDHM is strictly regulated to ensure safety. Pasteurization of human milk eliminates most pathogens. However, spore-forming bacteria, notably Bacillus cereus and other Bacillus species, are capable of surviving pasteurization. These bacteria contribute significantly to PDHM discard rates, which average approximately 5–10% of the final donor milk products, making it a leading cause of contamination-related waste.

Objective:

The University of California Health Milk Bank adopted at their inception in 2020, a novel pre-pasteurization screening protocol with the aim to reduce discard rates. This study examines 3 years of data to assess the protocol’s effectiveness and cost efficiency.

Results:

Ninety-eight percent of post-pasteurization positive cultures were Bacillus species. Following a pre-pasteurization screening protocol, the total discard rate due to Bacillus contamination was 3.1%—1.9% pre-pasteurization and 1.2% post-pasteurization. Without pre-pasteurization screening, 10.7% of PDHM could have potentially been discarded due to Bacillus contamination. The cost of pre-pasteurization screening of donor milk was $60,069 over 3 years, and the potential reduction in discard-related losses was 1,942,800 mL (64,760 ounces), with a value of approximately $323,800 for a return on investment of $4.39 per dollar spent.

Conclusions:

The findings highlight the role of pre-pasteurization screening cultures as a cost-effective method of reducing product loss.