51.   Normally, when a virus infects a cell, the cell displays bits of viral proteins on its surface like red flags to alert the immune system.

52.   State officials say they have no idea how the virus infected the Texas shrimp farms.

53.   The idea is to let the virus infect the cells in the airways so that the cells carry in the needed gene.

54.   The virus infected the bone marrow, carrying the normal gene into each of the blood-making cells.

55.   The virus usually infects the skin, causing a cold sore, and then works its way into the nerves of the face where it remains for life.

56.   The virus commonly infects birds and poultry but had never been found in humans, according to health officials.

57.   The virus infected computer networks at businesses and government offices, besides affecting thousands of individual users, mainly in Dhaka and in the southeastern port city of Chittagong.

58.   The virus can infect the intestinal system and other organs, including the heart.

59.   The virus had infected the entire networks of some organizations, the Television Corporation of Singapore news report said.

60.   When it was injected into mouse muscle, the altered virus quickly infected nearby cells, delivering the growth factor gene but causing no other infection.