5.2.2 Yersinia Yersinia is a genus of heterotrophic bacteria with 11 recognized species, some of which cause disease in humans, and both pathogenic and non-pathogenic strains of Yersinia have been found in surface water and unchlorinated drinking-water (Lassen 1972; Caprioli et al. 1978; Cafferkey et al. 1993)..2.2 Yersinia Yersinia is a genus of heterotrophic bacteria with 11 recognized species, some of which cause disease in humans, and both pathogenic and non-pathogenic strains of Yersinia have been found in surface water and unchlorinated drinking-water (Lassen 1972; Caprioli et al. 1978; Cafferkey et al. 1993).
1 When a woman ovulates, the egg is able to be fertilized for 12-24 hours (1 day). 2  When sperm enters the woman's body, it remains alive and able to fertilize an egg for 1-5 days. 3  It takes emergency contraception from 12-24 hours to be effective (1 day).  Emergency contraception remains effective for at least 10 days.
Research suggests that though it is recommended that you take it within 72 hours after sex, it is moderately effective up to 120 hours (or five days) after sex. However, even though it's referred to as the morning after pill, you don't have to wait for the sun to come up. The sooner it is taken, the more effective it is. Emergency contraception (EC) isn't to be confused with RU-486 (mifepristone), a pill that causes medical abortion in pregnant women within 49 days from the first day of their last menstrual period.