Tuberculosis is a notifiable disease in all countries in the region. Case definitions vary slightly. Most countries report both laboratory confirmed cases and cases with typical clinical picture without laboratory confirmation. In Northwest Russia, cases epidemiologically linked to a laboratory confirmed case are also reported.
For regions in Northwest Russia, cases diagnosed in military and penitentiary settings are not included in the officially supplied data.
Figure 2. Number of cases of tuberculosis (all types) notified in 2003 per 100 000 population (1)
Incidence rates for tuberculosis have for many years remained low and relatively stable in the Nordic countries. In these countries, the decrease in incidence among persons born in these countries is offset by an increase in cases detected in persons immigrating from other areas that have a higher burden of the disease. In Finland, however, the proportion of foreign born patients is much lower than in the other Nordic countries. Therefore, the two main defined risk groups for developing tuberculosis are elderly persons born in the Nordic countries with a reactivation of endogenous foci of infection acquired earlier in life, and younger persons immigrating from highly endemic areas. Tuberculosis is rarely spread among native citizens in the Nordic countries except Denmark, and most newly diagnosed cases occur in the immigrant population. In Denmark in 2000, native Danes with open, infectious tuberculosis made up a larger group than the equivalent immigrant group, both in relative and absolute numbers (2). The few cases of multi-drug resistant tuberculosis (MDR-TB) so far diagnosed in the Nordic countries have mostly been seen in the immigrant population.
Figure 3. Number of cases of tuberculosis (all types) notified per 100 000 population 1999-2003 by groups of countries or regions (1). Saint Petersburg, Komi, Pskov, Novgorod and Vologda regions not included.
The epidemiologic situation of tuberculosis in Northwest Russia and the Baltic countries is different compared to the Nordic countries. Since the early 1990s the deteriorating health situation in this part of the region has resulted in a growing number of tuberculosis cases, especially among males. Several factors have contributed to this increase; economic recession and malnutrition, poor living conditions and overcrowding in prisons. Disruption of the health services, severe shortages of drugs and laboratory supplies also contributed to inadequate tuberculosis control. The majority of newly diagnosed tuberculosis patients in Northwest Russia are unemployed. Through institutional infection control programs and prison reforms, the situation has now improved in many areas. The direct observed therapy, short course (DOTS) strategy has been introduced in most regions and laboratory facilities have improved. Reforms in the penitentiary systems have resulted in a reduction in number of prisoners, regular supplies of anti-tuberculosis medication and better living conditions for inmates.
Incidence rates have now decreased in the Baltic countries, while they remain high in Northwest Russia. In some areas like Kaliningrad, a marked increase has even been observed during the last few years. There may be many reasons for this increase. Tuberculosis cases diagnosed in prisons as well as re-treatment cases have been increasingly included in the notifications. In addition, more effective services have resulted in more case detections.
MDR-TB has been and continues to be a serious public health problem in the Baltic countries and Russia and presents a major challenge of treatment at the individual level and in the infection control at the population level. In these regions, the proportions of MDR among tuberculosis patients are some of the highest in the world. Drug resistance surveillance has shown that 17%-26% of tested tuberculosis isolates are MDR (3). Recent surveys have shown a decrease in newly diagnosed MDR-TB patients in Estonia and Latvia. Current data from Lithuania and Northwest Russia are not sufficient to describe the trends in MDR-TB epidemiology. In order to obtain the more complete picture on the MDR-TB in this region, several reference laboratories testing for drug susceptibility have been set up in the Baltic countries and in some parts of Russia.
Co-infection with HIV is an increasing problem among tuberculosis patients in both the Baltic states and Northwest Russia. 2.5 % of notified tuberculosis cases in Latvia in 2003 were HIV positive (4). Less is known about co-infection with HIV in Northwest Russia, but some data indicate that it is a serious problem in Kaliningrad.
A number of measures are taken to prevent the further spread of tuberculosis in the eastern part of the region. Control programmes have actively been reoriented according to recent WHO recommendations. The most important measures are increased cooperation between reference laboratories for better diagnostics, implementation of directly observed therapy to ensure higher cure rate, secured availability of anti-tuberculosis drugs and reforms in the penitentiary systems. Among Nordic countries, Norway is the only one that has implemented since 2003 obligatory directly observed treatment for all tuberculosis patients throughout the full treatment period.
On the individual level, contact tracing is important to prevent further spread. The importance of BCG vaccination is more disputed. BCG vaccination is a part of the national immunisation programmes in all the countries in the region, except in Denmark, Iceland and Sweden. In Russia, Estonia, Latvia, Lithuania and Finland, BCG vaccination is provided to all newborns, and an additional dose is given to tuberculin negative persons at 7 and 14 years of age in Russia. In Norway, the single BCG vaccination is provided at 14 years of age. The BCG coverage is very high (approx. 98%) in all the countries that have included the vaccine in their national immunisation programme.
Tuberculosis screening policy using tuberculin testing and/or chest X-ray varies within the region. In the Nordic countries, screening is usually limited to immigrants and other high risk groups such as drug and other substance abusers. In other parts of the region, large proportions of children and young people are screened yearly. Non-governmental organisations (NGOs) play a major part in many tuberculosis control projects in Northwest Russia and the Baltic countries.