A covalent bond forming H 2 (right) where two hydrogen atoms share the two electrons. A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms.
C. difficile bacteria and their spores are found in feces. People can get infected if they touch surfaces contaminated with feces, and then touch their mouth. Healthcare workers can spread the bacteria to their patients if their hands are contaminated. For healthy people, C. difficile does not pose a health risk. The elderly and those with other illnesses or who are taking antibiotics, are at a greater risk of infection.
1 Legionella bacteria are not transmitted from person to person. 2  People get Legionnaires' disease or Pontiac fever when they breathe in a mist or vapor (small droplets of water in the air) that has been contaminated with Legionella bacteria.