Kristiina Rajaleid

High Hiv prevalence among injecting drug users in Estonia: implications for understanding the risk environment

We found a high prevalence of HIV among injecting drug users (IDU) 54% in Tallinn and 90% in Kohtla Jarve, Estonia. Risk factors for HIV in Tallinn included use of the drug ‘china white’, being registered as an IDU at a drug treatment clinic, and sharing injecting equipment with sex partners. Differences existed in risk behaviour between the cities. An urgent scale-up of HIV prevention is needed. It is also important to explore how local ‘risk environments’ mediate the risk of HIV transmission.

High-prevalence and high-estimated incidence of HIV infection among new injecting drug users in Estonia: Need for large scale prevention programs.

OBJECTIVE To examine HIV risk behavior and HIV infection among new injectors in Tallinn, Estonia. Design and methods Data from two cross-sectional surveys of injecting drug users (IDUs) recruited from a syringe exchange program (N = 162, Study 1) or using respondent driven sampling (N = 350, Study 2). Behavioral surveys were administered; serum samples were collected for HIV testing. Subjects were categorized into new injectors (injecting < or = 3 years) and long-term injectors (injecting > 3 years). RESULTS Twenty-eight of 161 (17%, Study 1) and 73/350 (21%, Study 2) of the study subjects were new injectors. HIV infection was substantial among the newer injectors: HIV prevalence was 50% (Study 1) and 34% (Study 2), and estimated HIV incidence 31/100 PY and 21/100 PY, respectively. In Study 2, new injectors were more likely to be female and ethnic Estonian and less likely to be injecting daily compared with long-term injectors. No significant difference was found among two groups on sharing injecting equipment or reported number of sexual partners. CONCLUSIONS A continuing HIV epidemic among new injectors is of critical public health concern. Interventions to prevent initiation into injecting drug use and scaling up HIV prevention programs for IDUs in Estonia are of utmost importance.

Estimating injection drug use prevalence using state wide administrative data sources: Estonia, 2004

Estonia has rapidly expanding injection drug use (IDU) driven HIV/AIDS epidemic with the highest reported incidence rate and prevalence (1.3%) of HIV in the European region. To evaluate the feasibility of IDU prevalence estimations based on routine nationwide data sources using capture-recapture methodology, and provide estimates of IDU prevalence. IDUs were identified from the Police, Health insurance fund, State HIV reference laboratory data sources. Poisson regression models were fitted to the observed data, with interactions between data sources fitted to replicate ‘dependencies’ between the data sources. There were 13,886 (95% CI 8132–34,443) IDUs in Estonia in 2004, which translates into a prevalence of 2.4% (95% CI 1.4–5.9%) among people aged 15–44 years. The estimate is in line with the estimate provided by the panel of experts and estimates from the neighbouring countries experiencing similar societal and economic challenges.

Knowledge of HIV serostatus and risk behaviour among injecting drug users in Estonia

Abstract We used the findings from two, cross-sectional studies of HIV serostatus and risk behaviours to assess the effects of knowledge of HIV serostatus and risk behaviours (relating to sex and injection drug use) among injecting drug users (IDUs). Respondent-driven sampling was used simultaneously at two sites in Estonia (the capital Tallinn, and the second-largest city of Ida-Virumaa County, Kohtla-Järve). The research tool was an interviewer-administered survey. Biological samples were collected for HIV testing. Participants were categorised into three groups based on HIV testing results and self-report on HIV serostatus: HIV-negative (n=133); HIV-positive unaware of their serostatus (n=75); and HIV-positive aware of their serostatus (n=168). In total, 65% of the participants tested positive for HIV. Of those 69% were aware of their positive serostatus. HIV-positive IDUs aware of their serostatus exhibited more risk behaviours than their HIV-positive counterparts unaware of their serostatus or HIV-negative IDUs. Effective prevention of HIV among IDUs should therefore, include programmes to reduce high-risk sexual and drug use behaviours at the public health scale and enhanced prevention efforts focusing on HIV-infected individuals.

A decline in the prevalence of injecting drug users in Estonia, 2005–2009

AIMS Here we report a study aimed at estimating trends in the prevalence of injection drug use between 2005 and 2009 in Estonia. BACKGROUND Descriptions of behavioural epidemics have received little attention compared with infectious disease epidemics in Eastern Europe. METHODS The number of injection drug users (IDUs) aged 15-44 each year between 2005 and 2009 was estimated using capture-recapture methodology based on 4 data sources (2 treatment data bases: drug use and non-fatal overdose treatment; criminal justice (drug related offences) and mortality (injection drug use related deaths) data). Poisson log-linear regression models were applied to the matched data, with interactions between data sources fitted to replicate the dependencies between the data sources. Linear regression was used to estimate average change over time. RESULTS There were 24305, 12,292, 238, 545 records and 8100, 1655, 155, 545 individual IDUs identified in the four capture sources (police, drug treatment, overdose, and death registry, accordingly) over the period 2005-2009. The estimated prevalence of IDUs among the population aged 15-44 declined from 2.7% (1.8-7.9%) in 2005 to 2.0% (1.4-5.0%) in 2008, and 0.9% (0.7-1.7%) in 2009. Regression analysis indicated an average reduction of about 1600 injectors per year. CONCLUSION While the capture-recapture method has known limitations, the results are consistent with other data from Estonia. Identifying the drivers of change in the prevalence of injection drug use warrants further research.

Does childhood trauma influence offspring's birth characteristics?

Abstract Background: A recent epigenetic hypothesis postulates that ‘a sex-specific male-line transgenerational effect exists in humans’, which can be triggered by childhood trauma during ‘the slow growth period’ just before puberty. The evidence is based on a few rather small epidemiological studies. We examine what response childhood trauma predicts, if any, in the birth size and prematurity risk of almost 800 000 offspring. Methods: Children of parity 1, 2 or 3, born 1976-2002 in Sweden, for whom we could trace both parents and all four grandparents, constituted generation 3 (G3, n = 764 569). Around 5% of their parents, G2, suffered parental (G1) death during their own childhood. The association of such trauma in G2 with G3 prematurity and birthweight was analysed, while controlling for confounders in G1 and G2. We examined whether the slow growth period was extra sensitive to parental loss. Results: Parental (G1) death during (G2) childhood predicts premature birth and lower birthweight in the offspring generation (G3). This response is dependent on G2 gender, G2 age at exposure and G3 parity, but not G3 gender. Conclusions: The results are compatible with the Pembrey-Bygren hypothesis that trauma exposure during boys’ slow growth period may trigger a transgenerational response; age at trauma exposure among girls seems less important, suggesting a different set of pathways for any transgenerational response. Finally, parental death during childhood was not important for the reproduction of social inequalities in birthweight and premature birth.

Impact of Maternal Obesity on Inhaled Corticosteroid Use in Childhood: A Registry Based Analysis of First Born Children and a Sibling Pair Analysis

Background It has been proposed that maternal obesity during pregnancy may increase the risk that the child develops allergic disease and asthma, although the mechanisms underpinning this relationship are currently unclear. We sought to assess if this association may be due to confounding by genetic or environmental risk factors that are common to maternal obesity and childhood asthma, using a sibling pair analysis. Methods The study population comprised a Swedish national cohort of term children born between 1992 and 2008 to native Swedish parents. Maternal body mass index (BMI) was measured at 8–10 weeks gestation. Unconditional logistic regression models were used to determine if maternal obesity was associated with increased risk of inhaled corticosteroid (ICS) in 431,718 first-born children, while adjusting for potential confounders. An age-matched discordant sib-pair analysis was performed, taking into account shared genetic and environmental risk factors. Results Maternal over-weight and obesity were associated with increased risk that the child would require ICS (for BMI≥35 kg/m2, aOR = 1.30, 95%CI = 1.10–1.52 compared with normal weight mothers) in children aged 6–12 years. Similar effects were seen in younger children, but in children aged 13–16 years, maternal obesity (BMI≥30) was related to increased risk of ICS use in girls (aOR = 1.28, 95%CI = 1.07–1.53) but not boys (OR = 1.05, 95%CI = 0.87–1.26). The sib-pair analysis, which included 2,034 sib-pairs older than six years who were discordant for both ICS use and maternal BMI category, failed to find any evidence that increasing maternal weight was related to increased risk of ICS use. Conclusion Maternal obesity is associated with increased risk of childhood ICS use up to approximately 12 years of age, but only in girls after this age. These effects could not be confirmed in a sib pair analysis, suggesting either limited statistical power, or the effects of maternal BMI may be due to shared genetic or environmental risk factors.

The impact of reduced worktime on sleep and perceived stress: A group randomized intervention study using diary data

Objective Insufficient time for recovery between workdays may cause fatigue and disturbed sleep. This study evaluated the impact of an intervention that reduced weekly working hours by 25% on sleep, sleepiness and perceived stress for employees within the public sector. Method Participating workplaces (N=33) were randomized into intervention and control groups. Participants (N=580, 76% women) worked full-time at baseline. The intervention group (N=354) reduced worktime to 75% with preserved salary during 18 months. Data were collected at baseline and after 9 and 18 months follow-up. Sleep quality, sleep duration, sleepiness, perceived stress,and worries and stress at bedtime were measured with diary during one week per data collection. Result A multilevel mixed model showed that compared with the control group, at the 18-month follow-up, the intervention group had improved sleep quality and sleep duration (+23 minutes) and displayed reduced levels of sleepiness, perceived stress, and worries and stress at bedtime on workdays (P<0.002). The same effects were shown for days off (P<0.006), except for sleep length. Effect sizes were small (Cohens f2<0.08). Adding gender, age, having children living at home, and baseline values of sleep quality and worries and stress at bedtime as additional between-group factors did not influence the results. Conclusion A 25% reduction of weekly work hours with retained salary resulted in beneficial effects on sleep, sleepiness and perceived stress both on workdays and days off. These effects were maintained over an 18-month period. This randomized intervention thus indicates that reduced worktime may improve recovery and perceived stress.

Total workload and recovery in relation to worktime reduction: a randomised controlled intervention study with time-use data

Objectives A 25% reduction of weekly work hours for full-time employees has been shown to improve sleep and alertness and reduce stress during both workdays and days off. The aim of the present study was to investigate how employees use their time during such an intervention: does total workload (paid and non-paid work) decrease, and recovery time increase, when work hours are reduced? Methods Full-time employees within the public sector (n=636; 75% women) were randomised into intervention group and control group. The intervention group (n=370) reduced worktime to 75% with preserved salary during 18 months. Data were collected at baseline, after 9 months and 18 months. Time-use was reported every half-hour daily between 06:00 and 01:00 during 1 week at each data collection. Data were analysed with multilevel mixed modelling. Results Compared with the control group, the intervention group increased the time spent on domestic work and relaxing hobby activities during workdays when worktime was reduced (P≤0.001). On days off, more time was spent in free-time activities (P=0.003). Total workload decreased (−65 min) and time spent in recovery activities increased on workdays (+53 min). The pattern of findings was similar in subgroups defined by gender, family status and job situation. Conclusions A worktime reduction of 25% for full-time workers resulted in decreased total workload and an increase of time spent in recovery activities, which is in line with the suggestion that worktime reduction may be beneficial for long-term health and stress.

Transgenerational response and life history theory: a response to Peeter Hõrak

We are grateful to Peeter H~ orak for his careful reading of our paper on the transgenerational response to childhood trauma. We reported that grandparental (generation 1, G1) death during generation 2 (G2) childhood predicted birthweight and prematurity in generation 3 (G3). The major point in H~ orak’s response is that our results can be explained by ‘life history theory’, derived from evolutionary biology or evolutionary ecology. Our major conclusion, that the observed transgenerational response along the male line may well be epigenetic and triggered during the slow growth period, is hardly touched on by H~ orak. Finally, H~ orak states that human population data, like ours, can be used to test theories derived from evolutionary biology, such as life history theory. We disagree on H~ orak’s first point but agree on the last. All three points are elaborated below.