Hepatitis C is a chronic disease that is rarely symptomatic in the acute stage. It is therefore a disease that is difficult to monitor, particularly the incidence.
Hepatitis C surveillance and reporting varies within the region. Most countries report the number of diagnosed anti-HCV positive cases without differentiating between acute or chronic cases. The reported incidence rates of hepatitis C do therefore not always reflect the true incidence of the disease. This is especially the case in the Nordic counties where hepatitis C has been endemic among drug users since the 1970s. This is to a lesser extent true for Northwest Russia and the Baltic countries where the spread of hepatitis C probably started in the 1990s.
Norway is the only country in the region where only acute cases are reported. In Denmark, clinicians are asked to report acute cases and carriers separately. This leads probably to extensive underreporting of the disease. All the countries report only laboratory confirmed cases.
Figure 8. Number of persons with anti-HCV positive tests notified in 2003 per 100 000 population (1).
Intravenous drug users represent by far the highest risk group for hepatitis C in the entire region. Ever since hepatitis C serology was introduced in the late 1980s, an increasing number of anti-HCV positive cases have been diagnosed in this group in the entire region. In the Nordic countries, many of these cases have been diagnosed in older age groups who were infected while injecting drugs in the 1970s and 1980s. In contrast, most cases in the eastern part of the region have so far been diagnosed among young, active drug users often with hepatitis B co-infection. The number of reported cases of hepatitis C has been reduced drastically in Northwest Russia in the early 2000s (figure 9). A combination of effective preventive measures and decrease in numbers of susceptible drug users may have contributed to this improvement. The same is probably true for the Baltic countries.
Figure 9. Number of persons with positive anti-HCV tests notified 1999-2003 by groups of countries or regions (1). Denmark, Norway, Komi, Pskov, Novgorod and Vologda regions not included.
Seroprevalence studies among injecting drug users performed 2000-2002 in the region have shown the following prevalence of hepatitis C markers: Estonia 90%, Latvia 83%, Lithuania 79%, Norway 79%, Finland 30-52% and St. Petersburg 79%. (8, 9).
There are signs that the spread of hepatitis C is also slowing down in drug communities in the Nordic countries. Behavioural studies in drug users in Oslo, Norway have shown that about 50% of the drug users are anti-HCV positive 3-4 years after they started injecting drugs (10). The extent of sexual and nosocomial transmission of hepatitis C is mostly unknown.
The main measures to reduce the incidence of hepatitis C are to reduce intravenous drug abuse and implementing harm reduction by ensuring clean needles and syringes for the drug users. For prevention measures among injecting drug users, see HIV-infection.
An effective hospital infection control is considered important to prevent nosocomial infections and is of particular importance in the eastern part of the region.