Two new mothers had to have their uteri removed after Streptococcus A bacteria was discovered in their wombs. They were apparently infected by a doctor at the Sheba Medical Center in Tel Hashomer who didn’t know he was carrying the bacterium.

The first infection was discovered 10 days ago, when a woman who had given birth at Sheba nine days earlier arrived at Beilinson Hospital in Petah Tikva with a raging infection. Doctors said they had to remove her womb to save her life.

The doctors informed Sheba of the infection, and Sheba said it immediately began testing both doctors and patients in its obstetrics ward. Yet a week later, a second new mother was diagnosed with the bacteria and also had to have her womb removed. Five other new mothers are suspected of being infected as well.

While strep throat is a common and usually mild infection, easily treated with antibiotics, Streptococcus A can cause severe infections in certain other organs and can even be fatal if not treated properly.