The HIV infection rate was low in Estonia until 1999. In 2000-2001 the infection rate increased sharply and in 2001 an HIV epidemic was declared. The spread of HIV in Estonia is associated mainly with injecting drug use. The epidemic is characterized by high infection rate, young age, male gender, marginalisation, non-Estonian ethnic background, increasing heterosexual transmission and an increasing proportion of women.
The HIV epidemic started in Estonia in late 2000 and early 2001 as witnessed by a sudden increase in the number of HIV-infected persons. In February 2001 the situation reached an epidemic level among injecting drug users (IDUs). In 1988-1999 hetero- and homosexual transmission were the main modes of HIV transmission. Since 2000, the virus has been mainly transmitted through the sharing of contaminated needles and syringes. There is some evidence of increasing heterosexual transmission from IDUs to their sexual partners. HIV infection is predominantly among people under 25 years of age. The proportion of women among newly infected persons has been increased year by year. The prevalence of HIV infection among IDUs depends on the study sample and the region, and ranges between 40%-90%. Estonia has the highest number of newly diagnosed cases of HIV infection per million population among EU/EEA countries and in Europe.
Materials and Methods
Data on HIV infection incidence and prevalence were obtained from the official HIV/AIDS database managed by the Estonian Health Board.
The first case of HIV in Estonia was confirmed by laboratory analysis in 1988. In 2001, 1474 new cases were notified (107.8 per 100,000). In February 2001 the Ministry of Social Affairs declared an HIV epidemic among IDUs. During the following years, the numbers of new HIV cases has slowly but steadily decreased; in 2005, 2008 and 2009 the number of reported cases was 46.1, 40.6 and 30.7 cases per 100,000, respectively (Fig. 1).
Fig.1 HIV and AIDS in Estonia, 1995-2009
The regional spread of the HIV epidemic in 2001 was characterized by the concentration of new cases in three areas, Tallinn (35.8% of total cases), Ida-Viru county (30.8%) and Narva City (27.7%). The incidence of HIV infection was 132.0 for Tallinn, 422.3 for Ida-Viru county and 572.1 for Narva City. Though in Tallinn there is a slight increase in the number of cases (36.5%) in 2009, the regional spread of HIV over the years has shown a decreasing trend; of the new cases reported in 2009, 27.7% in Ida-Viru county and 18.2% in Narva City (Fig. 2).
Fig. 2. Cumulative incidence of HIV in Estonia by counties, 2001 – 2009
HIV infection by age groups
In 2001 men 15-19 (23.8%) and 20-29 (44.1%) years old and women 15-19 (12.0%) and 20-29 (9.5%) years old were most affected. In 2009 men 20-29 (28.7%) and 30-39 (19.7%) years old and women 20-29 (21.0%) and 30-39 (9.3%) years old were most affected. The proportion of new HIV-positive cases among men 15-19 years old decreased to 1.5% and among women 15-19 years old to 4.6% (Fig. 3, 4).
Fig.3. HIV infection by age groups, 2000-2009
Fig .4. Distribution of male and female HIV cases by age groups in Estonia, in 2001 and 2009
Trend among women
The growing trend of HIV infection among women is evident. The proportion was 20% in 2000, 23.5% in 2001, 37% in 2005 and 42.2% in 2008 (Fig. 5). The HIV infection rate among women has doubled in ten years.
Fig. 5. Proportion of HIV positive females among all HIV cases, 2000-2009
Incidence among pregnant women
The first case of HIV infection in a pregnant woman was diagnosed in 1993. In 2000-2005 there was an increasing trend of new cases from 6 to 132 cases annually (twelve-fold increase). During the last four years the number of annually diagnosed new cases (42-45 cases) has been stable. The total number of HIV-positive pregnant women and the proportion among all HIV cases is shown in Figure 6.
Fig. 6. Number of HIV cases among pregnant women and proportion of pregnant women among all HIV cases, 2000-2007
Incidence among prisoners
The first case of HIV infection in a prisoner was diagnosed in 2000. In 2000-2001 the number of new cases among HIV-positive prisoners increased from 80 to 420 (five-fold increase) (Fig. 7). During the last three years 61-68 new cases have been diagnosed annually. The proportion of new HIV cases among prisoners detected annually has decreased from 16.4% in 2001 to 1.4% in 2009.
Fig.7. Number of HIV cases among prisoners and proportion of prisoners’ cases among all HIV cases, 2000-2007
Prevalence among blood donors
During last ten years 43,000-62,000 blood donors’ samples have been tested annually for HIV. The highest HIV prevalence rate among blood donors, 0.05%, was notified in 2002. During 2004-2009 the prevalence rate of HIV among blood donors has been less than 0.02%.
Incidence among tuberculosis patients
The first case of HIV in a TB patient was diagnosed in 1997. Proportion of HIV-positive among primary tuberculosis patients has increased from 1.3% (seven cases) in 2001 to 14.8% (41 cases) in 2009 (Fig. 8). 55% of the HIV+TB cases have been diagnosed in male patients aged 25-34 years old. Of the total number of persons with HIV/TB co-infection, 53% reside in Ida-Viru county, one of the regions with the highest prevalence of HIV.
Fig. 8. Number of HIV cases among tuberculosis patients and proportion of tuberculosis patients among all HIV cases, 2000-2009
Prevalence and incidence among IDUs
In 2005, a study revealed that there are 13,886 IDUs in Estonia or 2.4% of the adults aged 15-44 years old. The majority of IDUs (72%) reside in the capital Tallinn and the surrounding county, and 18% in the Northeastern region (1). The prevalence of HIV among IDUs depends on the study sample and region. In a cross-sectional study conducted in 2005, the prevalence of HIV among IDUs in Tallinn was 54% (2). In another study among IDUs in Tallinn and Kohtla-Järve, the overall HIV prevalence was 62.1%; in Tallinn 54.2% and in Kohtla-Järve 89.9%. The highest HIV prevalence (66.7%) was reported among IDUs 20-24 years old. Among sexual partners sharing syringes with IDUs, 72.2% were HIV-positive. The proportion of HIV among IDUs in prisons was 65.6%. HIV prevalence among IDUs who had used injecting drugs for 6-9 years was 72.2% (3). The prevalence of HIV was 6.2%-18.7% among IDUs during 2000-2007 according to laboratory test results (Fig. 9).
Fig.9. Number of HIV cases among IDUs and proportion of IDU cases among all HIV cases,2000-2007
In 1988-1999 sexual contacts were the main routes of HIV transmission. Since 2000, HIV has primarily been transmitted through the sharing of virus-contaminated needles and syringes. There is some evidence of increasing sexual transmission from IDUs to their sexual partners during the past years.
A seroprevalence study including 191 commercial sex workers reported a total HIV prevalence of 7.3%. The prevalence according to age groups was 95% among ≤24 years, 8.7% among 25-34 years and 2.2% among ≥35 years (4). There are approximately 3,000-5,000 commercial sex workers in Estonia according to a UNAIDS estimate (2002).
Little is known about the prevalence of HIV among men who have sex with men (MSM). In a small study conducted during 2007 in Tallinn and Harju county, the HIV prevalence among MSM was 1.7%. According to reports from AIDS counselling centres in 2005, 7.2% of all HIV-positive men were MSM (5).
Mother-to-child transmission (MTCT) has been notified since 2,000 and the first three cases were reported in 2001. The proportion of HIV among newborns of HIV-positive mothers was 2.2%-15.0% in 2001-2007 (Fig. 10).
Fig.10. HIV cases among newborns of HIV positive mothers and proportion of HIV cases among newborns of HIV positive mothers among all HIV cases, 2000-2007
In 2009 the following transmission routes were notified: heterosexual (5.6%), UDUs (20.5%), MTCT (0.7%) and unknown (73.2%).
Estonia has the highest rate of new HIV cases in the EU/EAA and Europe. Since the HIV epidemic peak in 2001 the number of new cases has declined and reached a steady level. The proportion of women with HIV has been steadily increasing while the number of new cases among men has decreased. Women diagnosed with HIV are almost always the sex partners of male IDUs. The IDU-driven HIV epidemic in Estonia started with injecting drug users who were young, male and sexually active, and spread through sexual transmission to female and male partners as well as to children through MTCT. Commercial sex involving the exchange of sex for drugs or to support drug use, could create a transmission bridge between the drug-using and non-using populations.
- Uusküla A, Rajaleid K, Talu A, Abel K, Rüütel K, Hay G. Estimating injection drug use prevalence using state wide administrative data sources: Estonia, 2004. Addict Res Theory 2007, 15: 411-24.
- Platt L, Bobrova N, Rhodes T, Uusküla A, Parry JV, Rüütel K, et al. High HIV prevalence among injecting drug users in Estonia: implications for understanding the risk environment. AIDS 2006; 20:2120–3.
- Uusküla A, Abel K et al. HIV levimuse ja riskikäitumise uuring Eesti kahe linna süstivate narkomaanide seas. Tallinn, 2005.
- Trummal A, Fischer K, Raudne R. HIV-nakkuse levimus ning riskikäitumine prostitutsiooni kaasatud naiste hulgas Tallinnas. Tallinn 2006.
- Trummal A, Johnson LG, Lõhmus L. HIV-nakkuse levimus ja riskikäitumine MSM seas Tallinnas ja Harjumaal. Tallinn, 2007.