Rickettsia prowazekii causes epidemic typhus. It is spread by lice. Brill-Zinsser disease is a mild form of epidemic typhus. It occurs when the bacteria re-activates in a person who was previously infected.It is more common in the elderly.t is spread by lice. Brill-Zinsser disease is a mild form of epidemic typhus. It occurs when the bacteria re-activates in a person who was previously infected. It is more common in the elderly.
In this article. When you look at your prescription for eyeglasses, you will see numbers listed under the headings of OS and OD. They are Latin abbreviations: OS (oculus sinister) means the left eye and OD (oculus dextrus) means the right eye. Occasionally, you will see a notation for OU, which means something involving both eyes.
It may look a bit daunting, but understanding your eyeglasses prescription is easier than you might have thought. The two most important of these mystery terms and abbreviations are OD (Oculus Dextrus) and OS (Oculus Sinister). These are Latin terms that mean right eye and left eye, respectively. Listed after these OD and OS abbreviations are numbers preceded by either a plus sign (+) or a minus sign (-).