H. Blystad, G. Rimseliene
Department of Infectious Disease Epidemiology, Norwegian Institute of Public Health, Oslo, Norway
Citation: Blystad H, Rimseliene G. Incidence and trends in the epidemiology of bacterial sexually transmitted diseases in the Barents and Baltic Sea area, Ukraine, and Belarus, 1999-2010. EpiNorth 2011;12:102-8.
This surveillance report is a follow-up of three previous articles published in the EpiNorth Journal describing epidemiological trends for some important diseases in the Barents - and Baltic Sea region, Ukraine and Belarus (1-3). This report provides an overview of the current epidemiological situation and trends for bacterial sexually transmitted diseases in this region.
The EpiNorth project started as an international project for communicable disease control in Northern Europe in 1998. The project has from the beginning included several activities including collecting regional and national surveillance data (EpiNorthData). The data are collected directly from the national or regional centres for infectious disease control in the participating countries including Northwestern Federal Okrug of Russia. EpiNorth’s secretariat is located at the Norwegian Institute of Public Health.
The collaborating area (the “EpiNorth area”) countries include the Nordic countries: Denmark, Finland, Iceland, Norway and Sweden and the Baltic countries: Estonia, Latvia and Lithuania. It also includes the northwestern part of the Russian Federation (with a total of approximately 14.5 million people) comprising seven oblasts or regions (Murmansk, Arkhangelsk, Vologda, Kaliningrad, Leningrad, Novgorod, Pskov), two republics (Komi and Karelia), Nenets autonomous okrug and the city of St. Petersburg. In 2008, Belarus, Ukraine and Poland joined the EpiNorth project.
Epidemiological data presented in this report on incidence and trends in the epidemiology of bacterial sexual infections have been collected from the EpiNorthData (4). Incidence rates for 2010 for gonorrhoea, syphilis and genital chlamydial infections are presented as maps of the region, and trends in the incidence are presented as graphs with incidence curves covering the period 1999-2010. For gonorrhoea and syphilis, the region has been divided into groups of countries or areas, i.e. the Nordic countries, the Baltic countries and Northwest Russia as well as Belarus. Due to insufficient reported data on incidence rates prior to 2008, trend data from Poland, Ukraine, and Republic of Komi, Pskov, Novgorod, and Vologda are not included in this report.
In addition to a description of incidence trends, the general epidemiological situation for the three diseases in the EpiNorth region is briefly discussed.
Comparing epidemiologic data from national surveillance systems in different countries is a challenge since case definitions and methods of data collection often vary across countries. Surveillance systems in the various countries and regions are not measuring exactly the same things in exactly the same way. For this reason, some precaution is called for when interpreting the comparisons. The trend data may be considered more reliable than the figures for any one given year since no major changes have occurred in surveillance systems of participating countries during the reported period.
In the Nordic countries gonorrhoea is, compared with the situation in the 1970s and 1980s, not commonly diagnosed and reported mostly among men who have sex with men and in heterosexual males who are infected abroad, notably in South-East Asian countries and other popular tourist destinations (5). Among females, the infections are mainly domestically acquired.
In the Baltic countries, Northwest Russia, Ukraine, and Belarus heterosexual transmission dominates with a high number of cases among the young and unemployed. In the early 1990s the Baltic countries, Northwest Russia and Belarus experienced record high incidence rates of gonorrhoea. This may be attributed to political and social changes, resulting in changing sexual behaviour patterns and delays in treatment that caused patients to remain infectious for longer periods. In Northwest Russia, the incidence peaked around 1993-94. Although a significant decline in the incidence of gonorrhoea has been noted in the last decade in the Baltic countries, Belarus, Ukraine, and Northwest part of Russia, incidence is still high in these areas. Reported gonorrhoeal incidence in Poland is low compared with the rest of the region. This may be related to low notification rates, non-effective contact tracing and low testing activity (6).
Fig. 1. Reported number of gonorrhoea cases per 100,000 inhabitants in the EpiNorth project area, 2010
Fig. 2. Gonorrhoea incidence in Nordic countries, Baltic countries, Northwest Russia, and Belarus, 1999-2010
As in many western European countries, syphilis has re-emerged in the Nordic countries. This is primarily caused by an increase in incidence among men who have sex with men (7,8,9) and in heterosexual males who are infected abroad, notably in South-East Asia and other popular tourist destinations. A high proportion of men who have sex with men who have contracted syphilis during the last few years have also been HIV-positive (8).
In the early 1990s Northwest Russia, the Baltic countries, Belarus and Ukraine experienced record high incidence rates of syphilis. This was probably due to political and social changes, resulting in changing sexual behaviour and delays in treatment that caused patients remaining infectious for longer periods. The syphilis epidemic in the eastern part of the region reached its peak around 1995-96, and the incidence has fallen markedly over the past decade. Data on transmission routes among men (i.e. heterosexual or homosexual) are unavailable in most parts of the eastern region (10). A tendency is that syphilis cases in the eastern part of the EpiNorth project area more common among the young, the unemployed, substance users and sex workers compared with syphilis cases in the western part of region.
Fig. 3. Reported number of syphilis cases per 100 000 inhabitants in the EpiNorth project area, 2010
Fig. 4. Syphilis incidence in Nordic countries, Baltic countries, Northwest Russia, and Belarus, 1999-2010
Genital chlamydial infections
Chlamydia is the most commonly reported bacterial sexually transmitted infection in Europe (11). While testing for genital chlamydial infections is common practise in the Nordic countries and some parts of the Baltic countries, routine or clinical testing is not widely practised in Northwest Russia, Poland, Ukraine and Belarus. Therefore, little is known about the true incidence of genital chlamydial infections these areas.
Up till 2007, a marked increase in the incidence of Chlamydia was reported in all the Nordic countries (4). However, the same countries have during the past few years reported a slight decline in chlamydia rates. Chlamydia infections are mainly diagnosed in young heterosexuals, especially young women. The highest incidence is reported in the age group 15–24 years (11).
Fig. 5. Reported number of genital chlamydia cases per 100,000 inhabitants in the EpiNorth cooperation area, 2010
Fig. 6. Genital chlamydia infection incidence in the Nordic countries, 1999-2010
Data collected through the EpiNorth project show that a marked decline in incidence of bacterial sexually transmitted disease has been noted over the past decade in most of the regions in the Barents- and Baltic Sea area and Belarus. The decrease in gonorrhoea and syphilis rates have be more marked in the Baltic countries and in Northwest Russia, but rates remain high in most regions of Northwest Russia, Ukraine and Belarus compared with many other European countries. The increase in gonorrhoea and syphilis rates observed in in the Nordic countries during the last decade is primarily due to transmission among men who have sex with men. Chlamydial infections are the most common bacterial sexually transmitted infection diagnosed in the Nordic countries and are most prevalent among younger heterosexuals. Little is known about the true incidence of chlamydia in most Baltic countries, Northwest Russia, Ukraine, Belarus, and Poland.
The authors would like to thank the EpiNorth collaborative partners for their valuable input to the EpiNorth project providing the annual data on infectious diseases to the EpiNorthData module (in alphabetical order): Centre for Communicable Diseases and AIDS in Lithuania, Directorate of Health of Iceland, Directorates of the Federal Service for Surveillance on Consumer Rights Protection and Human Well-being (Rospotrebnadzor) in Arkhangelsk oblast, in the city of St. Petersburg, in Kaliningrad oblast, in Leningrad oblast, in Murmansk oblast, in Nenets okrug, in Novgorod oblast, in Pskov oblast, in the Republic of Karelia, in the Republic of Komi and in Vologda oblast (Russian Federation), Health Board, Estonia, Institute for Communicable Disease Control, Sweden, Ministry of Health, Belarus, Ministry of Health, Ukraine, National Institute for Health and Welfare, Finland, National Institute of Public Health, Poland, State Agency "Latvian Infectology Centre", Latvia, State Serum Institute, Denmark, and Norwegian Institute of Public Health.
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4. EpiNorthData (http://www.epinorth.org )
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