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.
Using the morning-after pill may delay your period by up to one week after you normally expect it. If you don't get your period within three to four weeks of taking the morning-after pill, take a pregnancy test. Normally, you don't need to follow up with your health care provider after using the morning-after pill. Don't have sex until you start another method of birth control. 2  The morning-after pill doesn't offer lasting protection from pregnancy. 3  If you have unprotected sex in the days and weeks after taking the morning-after pill, you're at risk of becoming pregnant. 4  Be sure to begin using or resume use of birth control.