Trichomonas vaginalis infection and risk of advanced prostate cancer.

BACKGROUND: The epidemiologic evidence for an association of Trichomonas vaginalis (Tv) with overall prostate cancer is mixed, but some studies suggest Tv may increase risk of more aggressive disease. The aim of this study was to assess whether Tv serostatus is associated with advanced or fatal prostate cancer. METHODS: A total of 146 men with advanced (metastatic or fatal) prostate cancer and 181 age-matched controls were selected from two prior population-based, case-control studies. Tv serostatus was determined with the same laboratory methods used in previous epidemiologic studies. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariable logistic regression to compare Tv serostatus in prostate cancer cases and controls adjusted for potential confounders. RESULTS: The seroprevalence of Tv in controls was 23%. Tv serostatus was not associated with an increased risk of metastatic or fatal prostate cancer (ORs < 1). CONCLUSIONS: Our study does not support an increased risk of advanced or fatal prostate cancer in men seropositive for Tv.

Hepatitis B vaccine and risk of autoimmune thyroid disease: a Vaccine Safety Datalink study.

PURPOSE: Hepatitis B vaccine has been postulated as a possible cause of autoimmune disorders, including autoimmune thyroid diseases (ATD). Cases of Graves' disease and Hashimoto's thyroiditis, following hepatitis B vaccine have been reported to the Vaccine Adverse Events Reporting System (VAERS). To test the hypothesis that hepatitis B vaccine increases the risk of ATD, we conducted a case-control study, within the Vaccine Safety Datalink project. METHODS: We identified potential cases of Graves' disease and Hashimoto's thyroiditis, among persons aged 18-69 years from administrative data recorded by three health maintenance organizations (HMOs) and verified cases by medical record review. Controls were frequency-matched to cases by birth year, sex, and study site. Vaccine information was collected from administrative records, chart review, and telephone interviews with study subjects. We enrolled 355 Graves' disease cases, 418 Hashimoto's thyroiditis cases, and 1102 controls. We assessed the association between ever-receipt of hepatitis B vaccine, as well as receipt of hepatitis B vaccine less than 1 year, 1-5 years and at least 5 years prior to the index date, and the risk of ATD. RESULTS: Ever-receipt of hepatitis B vaccine was not associated with risk of Graves' disease (odds ratio (OR), 0.90; 95% confidence interval (CI), 0.62-1.32) or Hashimoto's thyroiditis (OR, 1.23; 95%CI, 0.87-1.73). There was also no association between the time interval since receipt of hepatitis B vaccination and either outcome. CONCLUSIONS: We did not observe an increased risk of Graves' disease or Hashimoto's thyroiditis, following receipt of hepatitis B vaccine.

The burden of community-acquired pneumonia in seniors: results of a population-based study.

BACKGROUND: Pneumonia is recognized as a leading cause of morbidity in seniors. However, the overall burden of this disease--and, in particular, the contribution of ambulatory cases to that burden--is not well defined. To estimate rates of community-acquired pneumonia and to identify risk factors for this disease, we conducted a large, population-based cohort study of persons aged >or=65 years that included both hospitalizations and outpatient visits for pneumonia. METHODS: The study population consisted of 46,237 seniors enrolled at Group Health Cooperative who were observed over a 3-year period. Pneumonia episodes presumptively identified by International Classification of Diseases, Ninth Revision, Clinical Modification codes assigned to medical encounters were validated by medical record review. Characteristics of participants were defined by administrative data sources. RESULTS: The overall rate of community-acquired pneumonia ranged from 18.2 cases per 1000 person-years among persons aged 65-69 years to 52.3 cases per 1000 person-years among those aged >or=85 years. In this population, 59.3% of all pneumonia episodes were treated on an outpatient basis. In multivariate analysis, risk factors for community-acquired pneumonia included age, male sex, chronic obstructive pulmonary disease, asthma, diabetes mellitus, congestive heart failure, and smoking. CONCLUSIONS: On the basis of these data, we estimate that roughly 915,900 cases of community-acquired pneumonia occur annually among seniors in the United States and that approximately 1 of every 20 persons aged >or=85 years will have a new episode of community-acquired pneumonia each year.

Effectiveness of pneumococcal polysaccharide vaccine in older adults.

BACKGROUND: Streptococcus pneumoniae is the chief cause of pneumonia in older adults, but it remains unclear whether use of the pneumococcal polysaccharide vaccine alters the overall risk of community-acquired pneumonia. In a large population of older adults, we assessed the effectiveness of the pneumococcal vaccine. METHODS: In this retrospective cohort study, 47,365 Group Health Cooperative members 65 years of age or older were assessed over a three-year period. The primary outcomes were hospitalization because of community-acquired pneumonia (validated by chart review), pneumonia in patients who were not hospitalized ("outpatient pneumonia," determined from administrative data sources), and pneumococcal bacteremia. The association between pneumococcal vaccination and the risk of each outcome was evaluated by means of multivariate Cox proportional-hazards models, with adjustment for age, sex, nursing-home residence or nonresidence, smoking status, medical conditions, and receipt or nonreceipt of influenza vaccine. RESULTS: During the study period, 1428 cohort members were hospitalized with community-acquired pneumonia, 3061 were assigned a diagnosis of outpatient pneumonia, and 61 had pneumococcal bacteremia. Receipt of the pneumococcal vaccine was associated with a significant reduction in the risk of pneumococcal bacteremia (hazard ratio, 0.56; 95 percent confidence interval, 0.33 to 0.93) but a slightly increased risk of hospitalization for pneumonia (hazard ratio, 1.14; 95 percent confidence interval, 1.02 to 1.28). Pneumococcal vaccination did not alter the risk of outpatient pneumonia (hazard ratio, 1.04; 95 percent confidence interval, 0.96 to 1.13) or of any case of community-acquired pneumonia, whether or not it required hospitalization (hazard ratio, 1.07; 95 percent confidence interval, 0.99 to 1.14). CONCLUSIONS: These findings support the effectiveness of the pneumococcal polysaccharide vaccine for the prevention of bacteremia, but they suggest that alternative strategies are needed to prevent nonbacteremic pneumonia, which is a more common manifestation of pneumococcal infection in elderly persons.