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HIV in central and eastern Europe

We describe recent trends in the HIV epidemic and the differences between eastern and central Europe, using surveillance data, and published and unpublished reports. During the past 5 years, most countries of the former Soviet Union have been severely affected by HIV epidemics that continue to spread as a result of injecting drug use. With an estimated 1 million individuals already infected--mostly injecting drug users--and high rates of syphilis, the region may soon also face a large-scale epidemic of sexually-transmitted HIV infection. Indeed, data indicate that an HIV epidemic, fuelled by heterosexual transmission, is emerging; its expansion will depend on the size of so-called bridge populations that link high-risk groups with the general population. The lack of evidence to indicate increased rates of HIV as a result of homosexual transmission could indicate the social vulnerability of homosexual and bisexual men in the region rather than the true epidemiological picture. In view of the current levels of HIV prevalence, eastern Europe will soon be confronted with a major AIDS epidemic. By contrast, rates of HIV in central Europe remain low at present, but behaviours that promote HIV transmission are present in all countries. Improved measures to prevent further HIV spread are urgently needed.

The changing face of the HIV epidemic in western Europe: what are the implications for public health policies?

In this review, we describe changes in dynamics of HIV transmission and shifts in affected populations in western Europe using HIV/AIDS surveillance data and published and unpublished reports. Despite substantial reductions in HIV-related morbidity and mortality since the introduction of highly active antiretroviral treatment, HIV continues to pose a major public health problem in western Europe. More than half a million people are living with an infection that remains incurable and requires costly lifelong treatment; many people remain unaware of their infection, and thousands of new infections continue to occur every year. Migrants from countries with a high prevalence of HIV/AIDS, notably sub-Saharan Africa, bear a disproportionate and increasing share of HIV throughout western Europe and, in most countries, account for the majority of heterosexually acquired HIV infections diagnosed in recent years. Prevention, treatment, and care must be adapted to reach migrant populations. Following a resurgence of risky sexual behaviour, HIV transmission may now be increasing among homosexual and bisexual men, and renewed safer sex campaigns are urgently needed.

The HIV epidemic associated with injecting drug use in Europe: geographic and time trends.

Objectives:To evaluate the magnitude and trends of the HIV epidemic associated with injecting drug use in Europe. Methods:AIDS cases associated with injecting drug users (IDU) diagnosed through 1995 were analysed, including IDU, homo-/bisexual IDU, heterosexual partners of IDU and children whose mothers were IDU. HIV seroprevalence studies among IDU were reviewed. Results:Of the 171 932 cumulative AIDS cases, 73 119 (43%) were IDU-associated (IDU, 89.0%; homo-/bisexual IDU, 3.5%; heterosexual partners of IDU, 6.2%; children with IDU mothers, 1.4%). Over 90% of IDU-associated cases were concentrated in south-western European countries with considerably higher rates in Spain (124 cases per million in 1995) than elsewhere (Italy, 68 per million; Portugal, 42 per million; France, 38 per million). During 1990–1995, incidence increased at an average annual rate of 11% overall and > 23% in central and eastern Europe; overall, incidence increased in older persons (12%) while decreasing in those aged 13–24 years (by 6%). HIV prevalence in IDU showed considerable geographic variation across and within countries. In several countries of western Europe, prevalence decreased. In the former Soviet Union, large HIV outbreaks have recently been detected among IDU through systematic HIV testing (e.g., in Ukraine, 6750 HIV infections were diagnosed in IDU tested during 1995–1996). Conclusions:IDU have played a major role in the spread of HIV in Europe. In several western European countries, the incidence of HIV acquired through drug use has declined following high rates in mid-1980s. Studies to assess current transmission are needed and prevention efforts must be maintained. In eastern Europe, emerging epidemics reinforce the urgency for prevention.

Reconstruction and prediction of the HIV/AIDS epidemic among adults in the European Union and in the low prevalence countries of central and eastern Europe

Objectives:To reconstruct the HIV epidemic and to provide forecasts of AIDS incidence among adults in the European Union (EU) and in a group of low prevalence (LP) countries of central and eastern Europe (including the Asian republics of the former Soviet Union). Methods:An empirical Bayesian back-calculation method was applied to AIDS incidence data reported by 31 March 1994. The HIV-infection curve was modelled as a yearly step function and a seven-stage Markov model of disease progression, incorporating effects of pre-AIDS treatment, was used. Estimation was by penalized maximum likelihood with empirical Bayesian smoothing. Data were analysed by transmission group and, within the EU, by country. Predictions of AIDS cases to 1998 were made assuming constant annual HIV incidence from 1993 onwards. Results:Estimated HIV prevalences per 100 000 population aged 15–59 years were, at 31 December 1993, 198 (n = 447 800) in the EU and 2.7 (n = 6840) in the 22 LP countries, with increases of 41% (EU) and 71% (LP) between 1989 and 1993. Among homo/bisexual men in the EU, prevalence appears to have stabilized since 1989 and AIDS incidence appears to be reaching a peak. Among all prevalent HIV infections in the EU, 42% were estimated to be among injecting drug users, 25% among homo-/bisexual men and 18% among persons infected heterosexually, compared with 29%, 35% and 19%, respectively, in the LP countries. Without allowing for the 1993 revision of the case definition, annual AIDS incidence is predicted to increase, between 1994 and 1998, by 24% in the EU and by 48% in the LP countries, with the largest percentage increases among heterosexually-infected persons. Conclusion:The overall HIV prevalence rate is estimated to have been about 70-fold lower in the LP countries than in the EU in the early 1990s, but to be increasing much more rapidly in the former. Moreover, recent reports of rapidly increasing HIV infection rates suggest that back-calculation may seriously underestimate the size of the epidemic in the LP countries. Implementation of effective preventive measures is urgent if large-scale epidemics are to be avoided in the presently LP countries of the European region.

Current situation and regional perspective on HIV/AIDS surveillance in europe.

&NA; AIDS reporting has been the principal means of monitoring the HIV/AIDS situation in Europe since 1989. HIV reporting was set up at the European level in 1999, although it has existed in most European countries since the 1980s. Anonymous individual data on AIDS and, if available, new HIV diagnoses, and data on HIV prevalence in various populations are reported from the 51 countries of the WHO European Region to EuroHIV. Aggregate data on HIV prevalence in various populations. Data are presented after grouping the 51 countries into three geographic areas: the West, Center, and East. At end of 2000, in the West, AIDS incidence continued to decline except among those infected heterosexually; numbers of newly diagnosed HIV infections are relatively stable, but rising among heterosexually infected persons, many of whom originate from countries with generalized HIV epidemics. In the East, numbers of newly diagnosed HIV cases (mostly injection drug users) continue to rise steeply, particularly in the Russian Federation, Latvia, and Estonia. In the Center, levels of HIV and AIDS remain low. HIV reporting is becoming a central element of HIV/AIDS surveillance in Europe. Heterogeneity between countries in health care systems, HIV testing patterns and surveillance systems remain challenging for data standardization at the European level. Efforts should be made to use surveillance data for evaluating the effectiveness of HIV/AIDS prevention interventions.

Back-calculation by birth cohort, incorporating age-specific disease progression, pre-AIDS mortality and change in European AIDS case definition.

ObjectivesTo adapt and improve methodology for back-calculation of AIDS in Europe and to examine the feasibility of estimating past HIV incidence by birth cohort. MethodsEmpirical Bayesian back-calculation (EBBC) used Markov disease progression models, modified to allow for three diseases added to the AIDS case definition in 1993 and for pre-AIDS mortality, and estimation by penalized maximum likelihood with a neighbour prior. EBBC by 5-year birth cohort assumed a minimum age at infection and age-dependent progression rates; three versions, with varying age effects, were investigated using AIDS cases diagnosed prior to the introduction of highly active antiretroviral therapies (HAART). ResultsCompared with the no age-effect version, EBBC by birth cohort tended to produce flattened HIV incidence curves in country-exposure groups with < 1000 AIDS cases, reflecting effects of the neighbour prior when data become sparse. Otherwise, birth cohort analysis, with moderate effects of age on progression, gave initially increasing incidence curves and consistent patterns across countries, with the 1960–1964 cohort most affected. In the European Union, incidence is estimated to have peaked in 1983 among homosexual men and in 1988 among injecting drug users; 460 000 persons were estimated to be living with HIV/AIDS at the end of 1995. ConclusionsOur improved methodology deals effectively with the change in AIDS case definition and has allowed quantitative assessments of the HIV epidemic by birth cohort using all AIDS cases diagnosed before 1996, thus providing a sound basis for public health policy at a time when estimation of more recent prevalence is compromised by the effects of HAART.

Trends in HIV prevalence in blood donations in Europe, 1990-2004.

Introduction:The comparison of HIV prevalence among blood donations in European countries provides an indication of the relative safety of the blood supply in different countries and over time. Methods:Data between 1990 and 2004 on annual numbers of blood donations and HIV prevalence in blood donations were collected from national correspondents in the 52 countries of the World Health Organization European Region. Data are presented for three geographic areas: West, Centre and East. Results:Since 1990, the number of blood donations has declined by 43% in the East and by 26% in the Centre, while remaining relatively stable in the West. In 2004, the number of blood donations was more than twice as high in the West in comparison with the East and the Centre. Over the same period, HIV prevalence among blood donations increased dramatically in the East, remained stable in the Centre and declined in the West. Since 2001, HIV prevalence levels of more than 10 per 100 000 donations were reported from six countries in the East (with a high of 128/100 000 in Ukraine), whereas in the rest of Europe the reported national HIV prevalence levels were lower than 10/100 000 donations. The prevalence of HIV was much lower among donations from repeat donors than from first-time donors. Conclusion:In some eastern European countries public health interventions, such as deferring individuals at risk of HIV infection from donating blood and constituting a pool of regular donors, are urgently needed to assure the safety of the blood supply.