1999-2009 trends in prevalence, unawareness, treatment and control of hypertension in Geneva, Switzerland.

BACKGROUND: There are no time trends in prevalence, unawareness, treatment, and control of hypertension in Switzerland. The objective of this study was to analyze these trends and to determine the associated factors. METHODS/FINDINGS: Population-based study conducted in the Canton of Geneva, Switzerland, between 1999 and 2009. Blood pressure was measured thrice using a standard protocol. Hypertension was defined as mean systolic or diastolic blood pressure ≥140/90 mmHg or self-reported hypertension or anti-hypertensive medication. Unawareness, untreated and uncontrolled hypertension was determined by questionnaires/blood pressure measurements. Yearly age-standardized prevalences and adjusted associations for the 1999-2003 and 2004-2009 survey periods were reported. The 10-year survey included 9,215 participants aged 35 to 74 years. Hypertension remained stable (34.4%). Hypertension unawareness decreased from 35.9% to 17.7% (P<0.001). The decrease in hypertension unawareness was not paralleled by a concomitant absolute increase in hypertension treatment, which remained low (38.2%). A larger proportion of all hypertensive participants were aware but not treated in 2004-2009 (43.7%) compared to 1999-2003 (33.1%). Uncontrolled hypertension improved from 62.2% to 40.6% between 1999 and 2009 (P = 0.02). In 1999-2003 period, factors associated with hypertension unawareness were current smoking (OR = 1.27, 95%CI, 1.02-1.59), male gender (OR = 1.56, 1.27-1.92), hypercholesterolemia (OR = 1.31, 1.20-1.44), and older age (OR 65-74yrs vs 35-49yrs  = 1.56, 1.21-2.02). In 1999-2003 and 2004-2009, obesity and diabetes were negatively associated with hypertension unawareness, high education was associated with untreated hypertension (OR = 1.45, 1.12-1.88 and 1.42, 1.02-1.99, respectively), and male gender with uncontrolled hypertension (OR = 1.49, 1.03-2.17 and 1.65, 1.08-2.50, respectively). Sedentarity was associated with higher risk of hypertension and uncontrolled hypertension in 1999-2003. CONCLUSIONS: Hypertension prevalence remained stable since 1999 in the canton of Geneva. Although hypertension unawareness substantially decreased, more than half of hypertensive subjects still remained untreated or uncontrolled in 2004-2009. This study identified determinants that should guide interventions aimed at improving hypertension treatment and control.

The association between cigarettes smoking, cannabis use and alcohol consumption in a population of young men: results of a population-based survey.

BACKGROUND: Cigarette smoking is often initiated at a young age as well as other risky behaviors such as alcohol drinking, cannabis and other illicit drugs use. Some studies suggest that cigarette smoking may have an influence on other risky behaviors but little is known about the chronology of occurrence of those different habits. The aim of this study was to assess, by young men, what were the other risky behaviors associated with cigarette smoking and the joint prevalence and chronology of occurrence of those risky behaviors. METHODS: Cross-sectional analyses of a population-based census of 3526 young men attending the recruitment for the Swiss army, aged between 17 and 25 years old (mean age: 19 years old), who filled a self reported questionnaire about their alcohol, cigarettes, cannabis and other illicit drugs habits. Actual smoking was defined as either regular smoking (¡Ý1 cigarette/day, on every day) or occasional smoking, binge drinking as six or more drinks at least twice a month, at risk drinking as 21 drinks or more per week, recent cannabis use as cannabis consumption at least once during the last month, and use of illicit drugs as consumption once or more of illicit drugs other than cannabis. Age at begin was defined as age at first use of cannabis or cigarette smoking. RESULTS: In this population of young men, the prevalence of actual smoking was 51.2% (36.5% regular smoking, 14.6% occasionnal smoking). Two third of participamnts (60.1%) declared that they ever used cannabis, 25.2% reported a recent use of cannabis. 53.8% of participants had a risky alcohol consumption considered as either binge or at risk drinking. Cigarette smoking was significantly associated with recent cannabis use (Odds Ratio (OR): 3.85, 95% Confidence Interval (CI): 3.10- 4.77), binge drinking (OR: 3.48, 95% CI: 3.03-4.00), at risk alcohol drinking (OR: 4.04, 95% CI: 3.12-5.24), and ever use of illicit drugs (OR: 4.34, 95% CI: 3.54-5.31). In a multivariate logistic regression, odds ratios for smoking were increased for cannabis users (OR 3.10,, 95% CI: 2.48-3.88), binge drinkers (OR: 1.77, 95% CI: 1.44-2.17), at risk alcohol drinkers (OR 2.26, 95% CI: 1.52-3.36) and ever users of illicit drugs (OR: 1.56, 95% CI: 1.20-2.03). The majority of young men (57.3%) initiated smoking before cannabis and mean age at onset was 13.4 years old, whereas only 11.1% began to use cannabis before smoking cigarettes and mean age at onset was slightly older (14.4 years old). 31.6% started both cannabis and tobacco at the same age (15 years old). About a third of participants (30.5%) did have a cluster of risky behaviours (smoking, at risk drinking, cannabis use) and 11.0% did cumulate smoking, drinking, cannabis and ever use of illegal drugs. More than half of the smokers (59.6%) did cumulate cannabis use and at risk alcohol drinking whereas only 18.5% of non-smokers did. CONCLUSIONS: The majority of young smokers initiated their risky behaviors by first smoking and then by other psychoactive drugs. Smokers have an increased risk to present other risky behaviors such as cannabis use, at risk alcohol consumtion and illicit drug use compared to nonsmokers. Prevention by young male adults should focus on smoking and also integrate interventions on other risky behaviors.

Smoking, prevalence of disease and health service utilization among the Swiss population.

The data of the 1981-83 Swiss National Health Survey "SOMIPOPS", based on a randomly selected sample of 4,235 individuals aged 20 or over representative of the whole Swiss population, were used to investigate the relation between smoking, prevalence of disease and frequency of health care utilization. The risks of several conditions, including hypertension, myocardial infarction and other heart diseases, asthma, tuberculosis and kidney disease were elevated among ex-smokers. The diseases showing elevated risks among current smokers and significantly positive dose-risk trends included acute bronchitis (relative risk, RR = 3.2 for heavy cigarette smokers vs never smokers), chronic bronchitis or lung emphysema (RR = 2.0), gastro-duodenal ulcer (RR = 1.8) and bone fractures (RR = 1.6). For respiratory conditions, the risk of pipe or cigar smokers was comparable to that of moderate cigarette smokers, whereas for ulcer (RR = 4.1) or fractures (RR = 2.0) the point estimates were even higher than for heavy cigarette smokers. Smokers tended to consult more frequently general practitioners, used more other outpatients services, and were more frequently admitted to hospital during the year preceding the interview. These effects were consistent across strata of age, socio-economic indicators, and persisted after allowance for major identified potential distorting factors. Thus, the results of this survey confirm that smoking is an important cause of morbidity and a major contributory factor to the use of health services.

Prevalence of obesity and overweight and associated nutritional factors in a population-based Swiss sample: an opportunity to analyze the impact of three different European cultural roots.

PURPOSE: Obesity represents a growing public health concern worldwide. The latest data in Switzerland rely on self-reported body mass index (BMI), leading to underestimation of prevalence. We reassessed the prevalence of obesity and overweight in a sample of the Swiss population using measured BMI and waist circumference (WC) and explored the association with nutritional factors and living in different linguistic-cultural regions. METHODS: Data of 1,505 participants of a cross-sectional population-based survey in the three linguistic regions of Switzerland were analyzed. BMI and WC were measured, and a 24-h urine collection was performed to evaluate dietary sodium, potassium and protein intake. RESULTS: The prevalence of overweight, obesity and abdominal obesity was 32.2, 14.2 and 33.6 %, respectively. Significant differences were observed in the regional distribution, with a lower prevalence in the Italian-speaking population. Low educational level, current smoking, scarce physical activity and being migrant were associated with an higher prevalence of obesity. Sodium, potassium and protein intake increased significantly across BMI categories. CONCLUSIONS: Obesity and overweight affect almost half of the Swiss adolescents and adults, and the prevalence appears to increase. Using BMI and WC to define obesity led to different prevalences. Differences were furthermore observed across Swiss linguistic-cultural regions, despite a common socio-economic and governmental framework. We found a positive association between obesity and salt intake, with a potential deleterious synergistic effect on cardiovascular risk.

Prevalence and factors associated with use of smokeless tobacco in young Swiss men.

BACKGROUND: Smokeless tobacco is of increasing interest to public health researchers and policy makers. This study aims to measure prevalence of smokeless tobacco use (nasal dry snuff, snus and chewing tobacco) among young Swiss men, and to describe its correlates. METHODS: We invited 13 245 young men to participate in this survey on socio-economic and substance use data. Response rate was 45.2%. We included 5720 participants. Descriptive statistics and multivariable-adjusted logistic regression were performed. RESULTS: Mean age of participants was 19.5 years. Self-reported use once a month or more often was 8% for nasal dry snuff, 3% for snus and negligible for chewing tobacco. In multivariable-adjusted logistic regression, the odds for nasal dry snuff use increased in non daily smokers [odds ratio (OR) 2.41, 95% confidence interval (CI) 1.90-3.05], compared with non smokers, participants reporting risky weekly drinking volume (OR 3.93, 95% CI 1.86-8.32), compared with abstinents, and binge drinking once a month or more often (OR 7.41, 95% CI 4.11-13.38), compared with never binge drinking. Nasal dry snuff use was positively associated with higher BMI, average or above family income and German language, compared with French, and negatively associated with academic higher education, compared with non higher education, and occasional cannabis use, compared with no cannabis use. Correlates of snus were similar to those of nasal dry snuff. CONCLUSION: One in 12 young Swiss men use nasal dry snuff and 3% use snus. Consumption of smokeless tobacco is associated with a cluster of other risky behaviours, especially binge drinking.

High prevalence of peripheral atherosclerosis in a rapidly developing country.

Cardiovascular disease is rapidly increasing in developing countries experiencing epidemiological transition. We investigated the prevalence of peripheral atherosclerosis in a rapidly developing country and compared our findings with data previously reported in Western populations. A cardiovascular risk factor survey was conducted in 1067 individuals aged 25-64 randomly selected from the general population of Seychelles. High-resolution ultrasonography of the right and left carotid and femoral arteries was performed in a random subgroup of 503 subjects (245 men and 258 women). In each of the four arteries, arterial wall thickness (in plaque-free segments) and atherosclerotic plaques (i.e. focal wall thickening at least 1.0 mm thick) were measured separately. The prevalence of peripheral atherosclerosis was high in this population. For instance, at least one plaque > or =1.0 mm was found in, respectively, 34.9 and 27.5% of men and women aged 25-34 and at least one plaque > or =2.5 mm was found in, respectively, 58.2 and 36.9% of men and women aged 55-64. With reference to data found in the literature, the prevalence of carotid atherosclerosis appeared to be significantly higher in Seychelles than in Western populations. This study provides further evidence for the importance of cardiovascular disease in developing countries. Determinants should be identified and relevant prevention and control programs implemented.

Prevalence of overweight and obesity among migrants in Switzerland: association with country of origin.

Migrants tend to present higher overweight and obesity levels, but whether this relationship applies to all nationalities has seldom been studied. The present study aimed to assess the prevalence of overweight and obesity according to nationality in adults. Cross-sectional population-based samples. Five-year nationwide interview surveys (Swiss Health Surveys - SHS) from 1992 to 2007 (n 63 766) and a local examination survey (CoLaus Study in Lausanne 2004-2006, n 6743). Participants were separated into Swiss, French, German, Italian, Portuguese, Spanish nationals, those from the former Republic of Yugoslavia and from other European and other countries. Compared with Swiss nationals, German and French nationals presented a lower prevalence of overweight and obesity, whereas nationals from Italy, Spain, Portugal and the former Republic of Yugoslavia presented higher levels. Adjusting the SHS data for age, gender, education, smoking, leisure-time physical activity and survey year, a lower risk for overweight and obesity was found for German (OR = 0·80, 95 % CI 0·70, 0·92) and French (OR = 0·74, 95 % CI 0·61, 0·89) nationals, whereas higher risks were found for participants from Italy (OR = 1·45, 95 % CI 1·33, 1·58), Spain (OR = 1·36, 95 % CI 1·15, 1·61), Portugal (OR = 1·25, 95 % CI 1·06, 1·47) and the former Republic of Yugoslavia (OR = 1·98, 95 % CI 1·69, 2·32). Similar findings were observed in the CoLaus Study for Italian (OR = 1·63, 95 % CI 1·29, 2·06), Spanish (OR = 1·54, 95 % CI 1·17, 2·04) and Portuguese (OR = 1·49, 95 % CI 1·16, 1·91) participants and for those from the former Republic of Yugoslavia (OR = 5·34, 95 % CI 3·00, 9·50). Overweight and obesity are unevenly distributed among migrants in Switzerland. Migrants from Southern Europe and from the former Republic of Yugoslavia present higher prevalence rates. This suggests that preventive messages should be tailored to these specific populations.

Survey of potential sharpshooter and spittlebug vectors of Xylella fastidiosa to grapevines at the São Francisco River Valley, Brazil

Survey of potential sharpshooter and spittlebug vectors of Xylella fastidiosa to grapevines at the São Francisco River Valley, Brazil. Pierce's disease of grapevines, caused by Xylella fastidiosa, is a serious problem in some regions of North America, not yet reported in Brazil. In this study, a survey of potential sharpshooter (Hemiptera, Cicadellidae, Cicadellinae) and spittlebug (Hemiptera, Cercopidae) vectors of X. fastidiosa was conducted in vineyards at the São Francisco River Valley, a major grape growing region in Brazil. Four vineyards of Vitis vinifera L. were sampled fortnightly from June/2005 to June/2007, using yellow sticky cards, each placed at two different heights (45 cm aboveground and 45 cm above the crop canopy) in 10 sampling localities. A total of 4,095 specimens of sharpshooters were collected, nearly all from 3 Proconiini species, Homalodisca spottii Takiya, Cavichioli & McKamey, 2006 (96.8% of the specimens), Tapajosa fulvopunctata (Signoret, 1854) (3.1%), and Tretogonia cribrata Melichar, 1926 (1 specimen). Hortensia similis (Walker, 1851) (2 specimens) was the only Cicadellini species. Only 1 cercopid specimen, belonging to Aeneolamia colon (Germar, 1821), was trapped. Even though they are not considered potential Xylella vectors, 2 Gyponini leafhoppers were collected: Curtara samera DeLong & Freytag, 1972 (11 specimens) and Curtara inflata DeLong & Freytag, 1976 (1 specimen). Homalodisca spottii was observed feeding and mating on green branches of grapevines, in addition to egg masses. Because of its prevalence on the crop canopy, occurrence throughout the year (with peaks from February to August), and ability to colonize grapevines, H. spottii could be an important vector if a X. fastidiosa strain pathogenic to grapevines becomes introduced at the São Francisco River Valley.

Female genital mutilation in Switzerland: a survey among gynaecologists.

QUESTION UNDER STUDY: To evaluate the situation of Female Genital Mutilation (FGM) in Switzerland. METHODS: Through a questionnaire, Swiss gynaecologists were asked if they have been confronted to FGMs, if they have been asked to perform infibulations and FGMs. The health representatives (Kantonsärzte/médecins cantonaux) were interviewed on FGM activity at the Canton level. Swiss Medical Schools were asked if FGM was included in the pregraduate curriculum, and an estimated prevalence rate for FGMs in Switzerland was gathered. RESULTS: Among Swiss gynaecologists, 20% reported having been confronted with patients presenting with FGM and among them 40% had been asked about reinfibulation. Gynaecologists are occasionally asked about the possibility of performing FGMs in Switzerland. No activity concerning FGM is reported by health authorities in the Cantons. Teaching about FGM is not included in the curriculum of any of the Swiss medical schools. Approximately 6,700 girls at risk and women who have undergone FGM live in Switzerland. CONCLUSION: The extent to which gynaecologists are confronted to women with FGM may justify further action to try to better understand the situation in Switzerland. Improvement of care by better education of health care providers (guidelines) and prevention of new cases by women's education should also be considered.

Prevalence of hyperuricemia and relation of serum uric acid with cardiovascular risk factors in a developing country.

BACKGROUND: The prevalence of hyperuricemia has rarely been investigated in developing countries. The purpose of the present study was to investigate the prevalence of hyperuricemia and the association between uric acid levels and the various cardiovascular risk factors in a developing country with high average blood pressures (the Seychelles, Indian Ocean, population mainly of African origin). METHODS: This cross-sectional health examination survey was based on a population random sample from the Seychelles. It included 1011 subjects aged 25 to 64 years. Blood pressure (BP), body mass index (BMI), waist circumference, waist-to-hip ratio, total and HDL cholesterol, serum triglycerides and serum uric acid were measured. Data were analyzed using scatterplot smoothing techniques and gender-specific linear regression models. RESULTS: The prevalence of a serum uric acid level >420 micromol/L in men was 35.2% and the prevalence of a serum uric acid level >360 micromol/L was 8.7% in women. Serum uric acid was strongly related to serum triglycerides in men as well as in women (r = 0.73 in men and r = 0.59 in women, p < 0.001). Uric acid levels were also significantly associated but to a lesser degree with age, BMI, blood pressure, alcohol and the use of antihypertensive therapy. In a regression model, triglycerides, age, BMI, antihypertensive therapy and alcohol consumption accounted for about 50% (R2) of the serum uric acid variations in men as well as in women. CONCLUSIONS: This study shows that the prevalence of hyperuricemia can be high in a developing country such as the Seychelles. Besides alcohol consumption and the use of antihypertensive therapy, mainly diuretics, serum uric acid is markedly associated with parameters of the metabolic syndrome, in particular serum triglycerides. Considering the growing incidence of obesity and metabolic syndrome worldwide and the potential link between hyperuricemia and cardiovascular complications, more emphasis should be put on the evolving prevalence of hyperuricemia in developing countries.

Chronic illness, life style and emotional health in adolescence: results of a cross-sectional survey on the health of 15-20-year-olds in Switzerland.

The objective was to evaluate the prevalence of chronic conditions (CC) in adolescents in Switzerland; to describe their behaviour (leisure, sexuality, risk taking behaviour) and to compare them to those in adolescents who do not have CC in order to evaluate the impact of those conditions on their well-being. The data were obtained from the Swiss Multicentre Adolescent Survey on Health, targeting a sample of 9268 in-school adolescents aged 15 to 20 years, who answered a self-administered questionnaire. Some 11.4% of girls and 9.6% of boys declared themselves carriers of a CC. Of girls suffering from a CC, 25% (versus 13% of non carriers; P=0.007) and 38% of boys (versus 25%; P=0.002) proclaimed not to wear a seatbelt whilst driving. Of CC girls, 6.3% (versus 2.7%; P=0.000) reported within the last 12 months to have driven whilst drunk. Of the girls, 43% (versus 36%; P=0.004) and 47% (versus 39%; P=0.001) were cigarette smokers. Over 32% of boys (versus 27%; P=0.02) reported having ever used cannabis and 17% of girls (versus 13%; P=0.013) and 43% of boys (versus 36%; P=0.002) admitted drinking alcohol. The burden of their illness had important psychological consequences: 7.7% of girls (versus 3.4%; P=0.000) and 4.9% of boys (versus 2.0%; P=0.000) had attempted suicide during the previous 12 months. CONCLUSION: experimental behaviours are not rarer in adolescents with a chronic condition and might be explained by a need to test their limits both in terms of consumption and behaviour. Prevention and specific attention from the health caring team is necessary.

Transmission of HIV-1 drug resistance in Switzerland: a 10-year molecular epidemiology survey.

OBJECTIVES: Representative prevalence data of transmitted drug-resistant HIV-1 are essential to establish accurate guidelines addressing resistance testing and first-line treatments. METHODS: Systematic resistance testing was carried out in individuals in Switzerland with documented HIV-1 seroconversion during 1996-2005 and available samples with RNA > 1000 copies/ml obtained within 1 year of estimated seroconversion. Resistance interpretation used the Stanford list of mutations for surveillance of transmitted drug resistance and the French National Agency for AIDS Research algorithm. RESULTS: Viral sequences from 822 individuals were available. Risk groups were men having sex with men (42%), heterosexual contacts (32%) and intravenous drug users (20%); 30% were infected with non-B subtype viruses. Overall, prevalence of transmitted resistance was 7.7% [95% confidence interval (CI), 5.9-9.5] for any drug, 5.5% (95% CI, 3.9-7.1) for nucleoside reverse transcriptase inhibitors, 1.9% (95% CI, 1.0-2.8) for non-nucleoside reverse transcriptase inhibitors and 2.7% (95% CI, 1.6-3.8) for protease inhibitors. Dual- or triple-class resistance was observed in 2% (95% CI, 0.8-2.5). No significant trend in prevalence of transmitted resistance was observed over years. There were no differences according to ethnicity, risk groups or gender, but prevalence of transmitted resistance was highest among individuals infected with subtype B virus. CONCLUSIONS: The transmission rate of drug-resistant HIV-1 has been stable since 1996, with very rare transmission of dual- or triple-class resistance. These data suggest that transmission of drug resistance in the setting of easy access to antiretroviral treatment can remain stable and be kept at a low level.

Burnout levels among Portuguese family doctors: a nationwide survey

AIM: To characterise the prevalence of burnout syndrome in a sample of family doctors (FDs) working in the Portuguese National Health System. DESIGN: Cross-sectional survey. SETTING: Primary healthcare centres from the 18 continental districts and two archipelagos of Portugal. METHOD: The Portuguese version of the Maslach Burnout Inventory-Human Services Survey was sent to 40 randomly selected healthcare centres and distributed to the FDs employed. Socio-demographic and work-related data were also collected. Participants were classified as having high, average or low levels of emotional exhaustion (EE), depersonalisation (DP) and personal accomplishment (PA) dimensions of burnout. RESULTS: 371 questionnaires were sent, of which 153 (83 women, age range 29-64 years; response rate 41%) returned. One-quarter (25.3%, 95% CI 18.6% to 33.1%) of FDs scored high for EE, 16.2% (10.7% to 23.2%) for DP and 16.7% (11.1% to 23.6%) for lack of PA. On multivariate analysis, being married, of older age, having many years of practice or working in a personalised healthcare unit tended to be associated with increased burnout components. Men tended to present higher EE and DP but lower lack of PA than women. Finally, the prevalence (95% CI) of burnout ranged between 4.1% (1.5% to 8.6%) and 32.4% (25.0% to 40.6%), depending on the definition used. CONCLUSIONS: High burnout is relatively common among Portuguese FDs. Burnout relief measures should be developed in order to prevent a further increase of burnout syndrome among Portuguese FDs.

Descriptive epidemiology of isolated anal anomalies: a survey of 4.6 million births in Europe.

The prevalence of anal anomalies among 4,618,840 births recorded in 33 EUROCAT registries between 1980 and 1994 was 4.05 per 10,000 births. Of the 1,846 recorded cases, 672 (36.4%) were isolated anal anomalies while 1,174 (63.6%) occurred together with other anomalies. Only isolated anal anomalies were analyzed in this study: 75.5% were atresias, 10.1% of which were above and 89.9% were below the level of the levator ani muscle. Fistula occurred in 53% of supralevator and 37% of infralevator atresia. Other anal anomalies were ectopic anus (3.4%), congenital anal fistula (14.7%), and persistent cloaca (0.9%). There was a predominance of males in anal atresia without fistula (male to female (M:F) ratio was 6.7 for supralevator and 2.3 for infralevator atresia), but no significant sex difference in atresias with fistula. There was a predominance of females in ectopic anus and congenital anal fistula (M:F = 0.11 and 0.36 respectively). High frequencies of fetal deaths were recorded in supralevator atresia without fistula (8.3%) and in persistent cloaca (11.1%). Mean gestational length and mean birth weights were reduced for persistent cloaca but were within normal limits for other isolated anal anomalies. Odds ratios (ORs) for mothers above 35 years were increased for supralevator atresia without fistula, supralevator atresia with fistula, and congenital anal fistula. ORs for mothers below 30 years were slightly increased for supralevator atresia without fistula and decreased for persistent cloaca. There were marked differences in prevalence and distribution of anal anomalies among the EUROCAT registries. The results indicated that there are epidemiological differences among the various types of anal anomalies which might reflect different embryological origins.

Decrease in the prevalence of hepatitis B and a low prevalence of hepatitis C virus infections in the general population of the Seychelles.

A serological survey of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections was carried out on a random sex- and age-stratified sample of 1006 individuals aged 25-64 years in the Seychelles islands. Anti-HBc and anti-HCV antibodies were detected using commercially available enzyme-linked immunosorbent assays (ELISA), followed by a Western blot assay in the case of a positive result for anti-HCV. The age-adjusted seroprevalence of anti-HBc antibodies was 8.0% (95% CI: 6.5-9.9%) and the percentage prevalence among males/females increased from 7.0/3.1 to 19.1/13.4 in the age groups 25-34 to 55-64 years, respectively. Two men and three women were positive for anti-HCV antibodies, with an age-adjusted seroprevalence of 0.34% (95% CI: 0.1-0.8%). Two out of these five subjects who were positive for anti-HCV also had anti-HBc antibodies. The seroprevalence of anti-HBc was significantly higher in unskilled workers, persons with low education, and heavy drinkers. The age-specific seroprevalence of anti-HBc in this population-based survey, which was conducted in 1994, was approximately three times lower than in a previous patient-based survey carried out in 1979. Although there are methodological differences between the two surveys, it is likely that the substantial decrease in anti-HBc prevalence during the last 15 years may be due to significant socioeconomic development and the systematic screening of blood donors since 1981. Because hepatitis C virus infections are serious and the cost of treatment is high, the fact that the prevalence of anti-HCV antibodies is at present low should not be an argument for not screening blood donors for anti-HCV and eliminating those who are positive.