1 Visa - Digits two through six are the bank number, digits seven through 12 or seven through 15 are the account number and digit 13 or 16 is a check digit.  MasterCard - Digits two and three, two through four, two through five or two through six are the bank number (depending on whether digit two is a 1, 2, 3 or other). The digits after the bank number up through digit 15 are the account number, and digit 16 is a check digit.
AIDS is the acronym for acquired immunodeficiency syndrome. 1  It is the stage of HIV infection where a person's immune system is fully compromised, leaving the body open to a wide range of potentially deadly diseases known as opportunistic infections.
What is HIV Infection? Once the Human Immunodeficiency Virus (HIV) has entered the body, the immune system comes under attack. The HIV virus multiplies and slowly begins to destroy the CD4 lymphocytes (T-cells), which are the white blood cells that are important for fighting off infections.