A rare case of streptococcus mitis infective endocarditis complicated by heart failure in a lactating mother with recurrent breast engorgement

• Main Authors: Mohammad Sallehuddin, Hakimah, Zakariah, Siti Zulaikha, Inche Mat, Liyana Najwa, Wan Zukiman, Wan Zul Haikal Hafiz, Hoo, Fan Kee, Ming, Tan Wei
• Format: Article
• Language: English
• Published: Academy of Family Physicians of Malaysia 2019
• Online Access: http://psasir.upm.edu.my/id/eprint/80457/1/MITIS.pdf; http://psasir.upm.edu.my/id/eprint/80457/; https://pubmed.ncbi.nlm.nih.gov/31827735/

Infective endocarditis during breastfeeding is rare. To the best of the authors’ knowledge, this is the second recorded case of infective endocarditis in a lactating mother. It is known that women of child-bearing age are susceptible to infective endocarditis during pregnancy when the immune system is compromised. Nevertheless, past cases were also exposed to a systemic infection via milk infected by their infant's oral commensal. Streptococcus mitis (S.Mitis) endocarditis in pregnancy has also been reported, whereby a lady delivered via caesarean section and underwent mitral valve reconstruction and annuloplasty. S. mitis is considered a pioneer streptococci commensal in human oral mucosa, appearing as early as 1-3 days after delivery. As a child grows, their oral mucosa will be colonized by more viridans streptococci, including the teeth, oropharynx and nasopharynx. In a mother who breastfeeds, a crack in the nipple and breast engorgement can be predisposing factors for systemic infection stemming from an infant's oral commensal. Both cases of breastfeeding-related infective endocarditis caused by pioneer streptococcus viridans, S.mitis in our report and S.salivarius3 in the previous report, affected the left-sided valves.