13 - 15 % of reproductive age couples
||Human Homo sapiens
||Cools P. The role of Escherichia coli in reproductive health: state of the art. Res Microbiol. 2017 Feb 24. pii: S0923-2508(17)30037-2. doi: 10.1016/j.resmic.2017.02.002. p.1 left column 3rd paragraphPubMed ID28242352
|| Kim JY et al., Abnormal vaginal colonization by gram-negative bacteria is significantly higher in pregnancy conceived through infertility treatment compared to natural pregnancy. J Matern Fetal Neonatal Med. 2017 Mar30(5):556-561. doi: 10.1080/14767058.2016.1177819.PubMed ID27072161
||P.1 left column 3rd paragraph: "Infertility is defined as the lack of conception after at least one year of constant unprotected sexual intercourse [ref 94], and is a worldwide increasing medical problem seen in 13–15% of reproductive age couples [primary source]. E. coli can affect both female and male fertility."