41.   If so, would such a clue explain why it can cause severe infection in humans as well as birds?

42.   If you have a cut or scrape, germs can more easily cause infection.

43.   If the attachment contains one of these macro viruses, opening the file can cause the infection.

44.   In meningococcemia, N. meningitidis multiplies in the blood, causing so much infection that the immune response can swerve out of control.

45.   In severe cases, the bacteria can slip into the bloodstream and cause systemic infections.

46.   It can also seep into the eye or brain, where, in rare cases, it can cause life-threatening infections.

47.   Knowing that, scientists may one day be able to block those signals, prevent their powerful formation and leave the little guys that cause infection more vulnerable.

48.   Microorganisms that cause chronic infections also kill cells and stimulate cell division, he said, and high rates of cell division are associated with increased mutagenesis and carcinogenesis.

49.   Most E. coli infections are caused by tainted food, often hamburger.

50.   None of them have caused infection, but none have been shown to prevent it, either.