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About 100 new prescription or over-the-counter drugs come into the U.S. market every year.
Over time, chronic hepatitis B virus and hepatitis C virus infections can progress to advanced liver disease, liver failure, and hepatocellular carcinoma. Unlike other forms, more than 80% of hepatitis C infections become chronic and lead to liver disease. When combined with hepatitis B, hepatitis C now accounts for 75% percent of all cases of liver disease around the world. Liver failure caused by hepatitis C is now leading cause of liver transplants in the United States.
Since 1988, the CDC has reported a 99% reduction in bacterial meningitis caused by Haemophilus influenzae, due to the introduction of the vaccine against it.
Warfarin was developed as a consequence of the study of a strange bleeding disorder that suddenly occurred in cattle on the northern prairies of the United States in the early 1900s.
During the twentieth century, a variant of the metric system was used in Russia and France in which the base unit of mass was the tonne. Instead of kilograms, this system used millitonnes (mt).