In 1990 in the whole world were known to exist 170 million of people infected with hepatitis C virus, and World Health Organization said that every year there appear 3-4 million new patients. The prevalence of the HCV is higher in Southeast Asia and the Indian subcontinent, northern and central Africa, the eastern Mediterranean, and the Ukraine.

In many countries there is a lack of screening and testing for HCV among people and so there might be more infected people than we are aware of.

In Western Europe and US, Hepatitis C is more frequent than Hepatitis B and is the most common cause of end-stage liver disease, patients requiring a liver transplant after some years of chronic hepatitis C.

It is believed that in US, 1.8% of the population carries the virus, meaning that 4.9 million US citizens are infected.

Relying on demographic studies, it seems that most people infected with HCV are now 30 to 50 years old, meaning that most infections occurred between 1960 and 1985, when the test for HCV were not discovered yet.

The current incidence of HCV is less than 20 per 100,000 people per year in US.

Even though in 1995 only 25,000 new cases have been discovered, mathematical models suggest that the world will not get rid off HCV so easily, and only by 2030 the prevalence will decline to 1%. Until then there will appear new cases every year of chronic hepatitis C and of cirrhosis, which will require liver transplant.

HCV transmission began in the era of blood transfusions. Using contaminated blood, needles, acupuncture and hemodialysis contributed to the virus's transmission. Also, using drugs and practicing non-protected sex was a way of getting the infection. Transmission from infected mothers to the baby during pregnancy is also possible. It was also observed that HIV infected people got HCV more easily than others.

The virus that causes Hepatitis C is part of the Flaviviridae family; it is small, measuring about 40 to 60 nm in diameter and is composed of proteins. The scientists have sequenced the genome and identified the functions of the proteins.

The virus has the ability to mutate quickly and that is why scientists have a problem in developing an efficient vaccine against it.

For Hepatitis C virus the period of incubation is 2 to 26 weeks, and 75% to 85% do not recover well and develop chronic hepatitis, cirrhosis, even liver cancer. They can also spread the virus to other healthy persons. Symptoms of infection are jaundice and fatigue for 20-30% of the patients; for the rest of the infected ones, symptoms are usually mild and nonspecific.

The fact that HCV patients develop HCC is not a good thing for the country's economic, because this means giving more money for hospitalization, treatment and day care.