Diagnostic methods for mastitis in cows are not appropriate for use in humans: commentary

Linda J. Kvist

Healthcare workers are now being targeted for marketing of diagnostic tools for mastitis that were developed for the dairy industry and which aim to provide information regarding choice of antibiotic treatment. Meanwhile, scientists are striving to understand how the human microbiome affects health and wellbeing and the importance of maintenance of bacterial balance in the human body. Breast milk supplies a multitude of bacteria to populate the baby's intestinal tract and kick-start the immune system. Researchers propose a paradigm shift in the understanding of bacterial content in breast milk and an alternative paradigm for the understanding of lactational mastitis: there is the beginning of evidence that many cases of lactational mastitis will resolve spontaneously. An international group of researchers is attempting to answer how dietary habits, birth mode, genetics and environmental factors may impact the bacterial content of breast milk. Until we have more comprehensive knowledge about the human milk microbiome, diagnostic aids for identification of women in need of antibiotic therapy for mastitis remain unreliable. Diagnostic aids could lead to the injudicious use of antibiotic therapy, which in turn may rob the infant of bacteria valuable for development of its immune system. The marketing of diagnostic aids for use in human medicine, that were originally developed for use in cows, is neither evidence-based nor good ethical practice.