TY - JOUR T1 - Pneumococcal lactational mastitis in a healthy woman JF - BMJ Case Reports JO - BMJ Case Reports DO - 10.1136/bcr-2022-250277 VL - 15 IS - 11 SP - e250277 AU - Ayaka Ujita AU - Hikohaku Ryu AU - Hiroyuki Kobayashi AU - Mikiro Kato Y1 - 2022/11/01 UR - http://casereports.bmj.com/content/15/11/e250277.abstract N2 - We report a case of lactational mastitis complicated by Streptococcus pneumoniae bacteraemia in a breast feeding, healthy woman in her 20s. Numerous investigations showed that mastitis was the probable source of S. pneumoniae bacteraemia. While S. pneumoniae is known to cause non-lactational mastitis in patients with underlying diseases, such as systemic lupus erythematosus, reports of lactating mastitis in healthy individuals are scarce, with only six cases reported in the scientific literature published in English since 1995. Similar to previous reports, our patient had a good clinical course with antimicrobial therapy, and the infection was presumably transmitted from the asymptomatic child to the mother. Although the exact mechanisms that establish transmission from a child remain unclear, both host and pathogen factors, such as stagnant milk or bacterial virulence factors, are thought to play a key role. Caution should be exercised because serotypes not currently covered by pneumococcal vaccines are emerging. ER -