Abstract:
In addition to providing life-giving nutrients and other substances to the breastfed infant, human milk can also
represent a vehicle of pathogen transfer. As such, when an infectious disease outbreak, epidemic, or pandemic
occurs—particularly when it is associated with a novel pathogen—the question will naturally arise as to
whether the pathogen can be transmitted through breastfeeding. Until high-quality data are generated to answer
this question, abandonment of breastfeeding due to uncertainty can result. The COVID-19 pandemic, which was
in full swing at the time this document was written, is an excellent example of this scenario. During these times
of uncertainty, it is critical for investigators conducting research to assess the possible transmission of pathogens through milk, whether by transfer through the mammary gland or contamination from respiratory
droplets, skin, breast pumps, and milk containers, and/or close contact between mother and infant. To promote
the most rigorous science, it is critical to outline optimal methods for milk collection, handling, storage, and
analysis in these situations, and investigators should openly share their methods in published materials.
Otherwise, the risks of inconsistent test results from preanalytical and analytical variation, false positives, and
false negatives are unacceptably high and the ability to provide public health guidance poor. In this study, we
provide ‘‘best practices’’ for collecting human milk samples for COVID-19 research with the intention that this
will also be a useful guide for future pandemics.
