An extensive gastroenteritis outbreak after drinking-water contamination by sewage effluent, Finland.

An inappropriate cross-connection between sewage- and drinking-water pipelines contaminated tap water in a Finnish town, resulting in an extensive waterborne gastroenteritis outbreak in this developed country. According to a database and a line-list, altogether 1222 subjects sought medical care as a result of this exposure. Seven pathogens were found in patient samples of those who sought treatment. To establish the true disease burden from this exposure, we undertook a population-based questionnaire investigation with a control population, infrequently used to study waterborne outbreaks. The study covered three areas, contaminated and uncontaminated parts of the town and a control town. An estimated 8453 residents fell ill during the outbreak, the excess number of illnesses being 6501. Attack rates were 53% [95% confidence interval (CI) 49.5-56.4] in the contaminated area, 15.6% (95% CI 13.1-18.5) in the uncontaminated area and 6.5% (95% CI 4.8-8.8) in the control population. Using a control population allowed us to differentiate baseline morbidity from the observed morbidity caused by the water contamination, thus enabling a more accurate estimate of the disease burden of this outbreak.

Population-based surveillance study of Campylobacter infections in Finland.

The annual incidence in 14,361 campylobacteriosis cases reported in Finland in 2002-2005 varied between 61 and 76/100,000 population. The mean incidence was highest (148/100,000) in the 25-29 years age group and lowest (range 21-24/100,000) in children aged 5-14 years and patients aged ≥75 years. The number of domestic cases was low in winter and peaked in summer. A total of 622 strains isolated from domestic infections and 785 foreign travel-related strains were serotyped. Serotypes Pen 3 and Pen 37 had the strongest association with travel-related infections (96%, P<0·001), and Pen 6,7, Pen 12 and Pen 27 were significantly associated with domestic infections (>70% domestic within each serotype, P<0·001). Pen 2 and Pen 1,44 were less common in older than in younger patients. Of domestic strains, a higher proportion of Pen 2 strains was isolated in winter (18%) compared to the other serotypes (0-10%).

Factors associated to lifestyle and risk of adult onset asthma.

BACKGROUND: Asthma prevalence has been increasing especially in developed countries. The change seems to be associated with changes in lifestyle. We have made a prospective study to assess the effect of lifestyle factors, including smoking, educational level, physical activity and obesity on adult onset asthma. METHODS: A population of 10,597 adult twins, initially free of asthma was followed for 9 years. The main outcome measure was questionnaire-based report of physician diagnosed asthma. Logistic regression was used to estimate the risk of asthma predicted by lifestyle factors, with adjustment for atopy and respiratory symptoms. RESULTS: Obesity at baseline increased asthma risk (multivariable adjusted OR = 3.00, 95% CI: 1.64-5.50 for those with BMI > or = 30 compared to those with normal weight BMI: 20-24.99). Taller height was associated to lower asthma incidence. Leisure time physical activity had a slightly protective effect on asthma risk among men (P for trend = 0.037) while smoking and education did not have significant effects on the risk of adult onset asthma. CONCLUSIONS: Obesity was associated to the risk of adult onset asthma, while short height and low leisure time physical activity can be considered as other potential risk factors.

Asthma in relation to personality traits, life satisfaction, and stress: a prospective study among 11,000 adults.

BACKGROUND: While patients' personality has been thought to affect allergic diseases, the association of asthma and psychological factors is still debated. Stress is believed to predispose to asthma, but no clear evidence of causality has been found. We have studied the role of psychological factors in prevalent as well as in incident asthma cases among the adult population. METHODS: A total of 11540 adults initially aged 18-45 years responded to three questionnaires in 1975, 1981, and 1990, respectively. The association of psychological factors (including extroversion and neuroticism scales, subjective stress, and life satisfaction) and prevalent asthma was studied, as well as the predisposing effect of these factors on the risk of adult onset asthma. Logistic regression was used for risk calculations. RESULTS: Low life satisfaction was associated with asthma prevalence (age- and sex-adjusted OR=2.27: 1.04-4.93 for prevalent asthma among those with low life satisfaction compared to those with high life satisfaction), as was neuroticism (age and sex-adjusted OR=1.78:1.12-2.84 for those with a high neuroticism score compared to those with a low score). A high extroversion score was significantly associated with the risk of adult onset asthma among women (age-adjusted OR=2.72: 1.44-5.12 for new asthma among those with high score compared to those with a low extroversion score). CONCLUSION: No specific personality type is associated with adult onset asthma, but there is a significant sex difference in the effect of psychological factors in asthma risk. A high extroversion score is a strong predictor of incident asthma among women. Prevalent asthma decreases life satisfaction and is associated with a high neuroticism score.

Social predictors of adult asthma: a co-twin case-control study.

BACKGROUND: Environmental factors are needed to explain the observed increase in the prevalence of asthma during recent decades, despite the existence of a recognised genetic component in asthma. A co-twin case-control study was undertaken to examine possible social risk factors for asthma. METHODS: Asthma diagnoses were based on register data of reimbursed asthma medication. During 17 years follow up of the Finnish twin cohort, 262 twin pairs discordant for incident asthma were identified. Conditional logistic regression for 1-1 matched data was used for risk calculation. RESULTS: The atopic twin had an increased risk of asthma compared with the non-atopic co-twin (RR 2.91, 95% CI 1.81 to 4.68). The more educated twin had a decreased risk of asthma compared with his/her twin sibling with less education (RR 0.45, 95% CI 0.23 to 0.86), and the twin who participated in conditioning exercise had a decreased risk of asthma compared with the more sedentary co-twin (RR 0.55, 95% CI 0.34 to 0.88). CONCLUSIONS: In addition to allergic diseases, educational level and physical activity are associated with adult onset asthma, which indicates a role for factors associated with life style.

Incidence and prevalence of asthma among adult Finnish men and women of the Finnish Twin Cohort from 1975 to 1990, and their relation to hay fever and chronic bronchitis.

STUDY OBJECTIVES: To examine the prevalence of asthma and hay fever, and the incidence and temporal relationships of asthma, hay fever, and chronic bronchitis among adult twins during a 15-year period. DESIGN: Prospective cohort study. PARTICIPANTS: A population of 11,540 Finnish adult men and women, initially 18 to 45 years of age, who returned a health questionnaire in 1975, 1981, and 1990 as part of the Finnish Twin Cohort study. METHODS: Age-standardized prevalences and cumulative incidences among individuals were calculated for asthma, hay fever, and chronic bronchitis. The incidence of asthma among subjects with and without hay fever or chronic bronchitis was analyzed in the entire cohort as well as in twin pairs discordant for incident asthma. RESULTS: The prevalence of asthma increased slightly from 1975 (2.0% in men and 2.2% in women) to 1990 (2.9% in men and 3.1% in women). The prevalence of hay fever showed a larger increase in men and women (from 6.8% and 9.8% to 11.8% and 15.3%, respectively). Compared with figures for 1976 to 1981, no significant increase in asthma incidence occurred from 1982 to 1990, whereas the incidence of hay fever was lower during the latter period among men (incidence rate ratio, 0.7; 95% confidence interval, 0.6 to 0.9) as was the incidence of chronic bronchitis among women (incidence rate ratio, 0.7; 95% confidence interval, 0.6 to 0.9). Hay fever and chronic bronchitis were usually diagnosed before asthma. Both diseases increased the risk of asthma significantly on the basis of analyses of all individuals and of discordant twin pairs. CONCLUSIONS: The pattern of increase in asthma and hay fever prevalence with time was similar, and hay fever was a strong predictor of asthma. These diseases showed no significant increase in incidence.

Mortality of adults with asthma: a prospective cohort study.

BACKGROUND: Few studies have been published on the overall survival of adult patients with asthma. A cohort study was performed to assess the mortality from all causes, from chronic obstructive pulmonary disease, and from lung cancer among adult asthmatic subjects. METHODS: A population of 31,110 Finnish adult women and men, mostly twins, was studied to compare the 16 year mortality rates among asthmatic (n = 471) and non-asthmatic persons. A further 293 twin pairs, discordant for asthma, were also studied to determine whether the mortality of patients with asthma differs from that of their age matched siblings. RESULTS: Mortality from all causes was increased among asthmatic adults (age adjusted hazard ratios 1.49, 95% CI 1.09 to 2.05 for men and 1.53, 95% CI 1.10 to 2.13 for women), and mortality due to chronic obstructive pulmonary diseases was also significantly increased in asthmatic subjects. The risk of death due to lung cancer was increased in men with asthma (hazard ratio adjusted for smoking 3.19, 95% CI 1.39 to 7.31). The risk ratios found among twins discordant for asthma corresponded to those found in the whole cohort. CONCLUSIONS: Survival in adults with asthma is worse than in those without asthma. The excess deaths due to chronic obstructive pulmonary disease may explain some part of the increased mortality rates, but not all of it.