Showing papers by "Centers for Disease Control and Prevention published in 1995"

Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: criteria for bacterial strain typing.

Abstract: FRED C. TENOVER,* ROBERT D. ARBEIT, RICHARD V. GOERING, PATRICIA A. MICKELSEN, BARBARA E. MURRAY, DAVID H. PERSING, AND BALA SWAMINATHAN National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333; Veterans Affairs Medical Center, Boston, Massachusetts 02130; Creighton University, Omaha, Nebraska 68178; Stanford University Medical Center, Stanford, California 94305; University of Texas Medical School, Houston, Texas 77030; and Mayo Clinic, Rochester, Minnesota 55905

Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trials.

Abstract: Objective. —To determine if inadequate approaches to randomized controlled trial design and execution are associated with evidence of bias in estimating treatment effects. Design. —An observational study in which we assessed the methodological quality of 250 controlled trials from 33 meta-analyses and then analyzed, using multiple logistic regression models, the associations between those assessments and estimated treatment effects. Data Sources. —Meta-analyses from the Cochrane Pregnancy and Childbirth Database. Main Outcome Measures. —The associations between estimates of treatment effects and inadequate allocation concealment, exclusions after randomization, and lack of double-blinding. Results. —Compared with trials in which authors reported adequately concealed treatment allocation, trials in which concealment was either inadequate or unclear (did not report or incompletely reported a concealment approach) yielded larger estimates of treatment effects ( P P =.01), with odds ratios being exaggerated by 17%. Conclusions. —This study provides empirical evidence that inadequate methodological approaches in controlled trials, particularly those representing poor allocation concealment, are associated with bias. Readers of trial reports should be wary of these pitfalls, and investigators must improve their design, execution, and reporting of trials. ( JAMA . 1995;273:408-412)

Prevalence of Hypertension in the US Adult Population: Results From the Third National Health and Nutrition Examination Survey, 1988-1991

Abstract: The purpose of this study was to estimate the current prevalence and distribution of hypertension and to determine the status of hypertension awareness, treatment, and control in the US adult population. The study used a cross-sectional survey of the civilian, noninstitutionalized population of the United States, including an in-home interview and a clinic examination, each of which included measurement of blood pressure. Data for 9901 participants 18 years of age and older from phase 1 of the third National Health and Nutrition Examination Survey, collected from 1988 through 1991, were used. Twenty-four percent of the US adult population representing 43 186 000 persons had hypertension. The age-adjusted prevalence in the non-Hispanic black, non-Hispanic white, and Mexican American populations was 32.4%, 23.3%, and 22.6%, respectively. Overall, two thirds of the population with hypertension were aware of their diagnosis (69%), and a majority were taking prescribed medication (53%). Only one third of Mexican Americans with hypertension were being treated (35%), and only 14% achieved control in contrast to 25% and 24% of the non-Hispanic black and non-Hispanic white populations with hypertension, respectively. Almost 13 million adults classified as being normotensive reported being told on one or more occasions that they had hypertension; 51% of this group reported current adherence to lifestyle changes to control their hypertension. Hypertension continues to be a common finding in the general population. Awareness, treatment, and control of hypertension have improved substantially since the 1976-1980 National Health and Nutrition Examination Survey but continue to be suboptimal, especially in Mexican Americans. Consideration should be given to revision of the criteria for classification of hypertension to reflect the widespread use of lifestyle modification for treatment of hypertension.

Youth Risk Behavior Surveillance-United States, 1993

Abstract: Priority health risk behaviors that contribute to the leading causes of mortality, morbidity, and social problems among youth and adults often are established during youth, extend into adulthood, and are interrelated. The Youth Risk Behavior Surveillance System (YRBSS) monitors six categories of priority health risk behaviors among youth and youth adults: behaviors that contribute to unintentional and intentional injuries, tobacco use, alcohol and other drug use, sexual behaviors, dietary behaviors, and physical activity. The YRBSS includes a national, school-based survey conducted by CDC and state and local school-based surveys conducted by state and local education agencies. This report summarizes results from the national survey, 24 state surveys, and nine local surveys conducted among high school students during February through May 1993. In the United States, 72% of all deaths among school-age youth and young adults are from four causes: motor vehicle crashes, other intentional injuries, homicide, and suicide. Results from the 1993 YRBSS suggest many high school students practice behaviors that may increase their likelihood of death from these four causes: 19.1% rarely or never use a safety belt, 35.3% had ridden during the 30 days preceding the survey with a driver who had been drinking alcohol, 22.1% had carried a weapon during the 30 days preceding the survey, 80.9% ever drank alcohol, 32.8% ever used marijuana, and 8.6% had attempted suicide during the 12 months preceding the survey. Substantial morbidity and social problems among adolescents also result from unintended pregnancies and sexually transmitted diseases including HIV infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Overweight Prevalence and Trends for Children and Adolescents: The National Health and Nutrition Examination Surveys, 1963 to 1991

Abstract: Objective: To examine prevalence of overweight and trends in overweight for children and adolescents in the US population. Design: Nationally representative cross-sectional surveys with an in-person interview and a medical examination, including measurement of height and weight. Participants: Between 3000 and 14000 youths aged 6 through 17 years examined in each of five separate national surveys during 1963 to 1965, 1966 to 1970, 1971 to 1974, 1976 to 1980, and 1988 to 1991 (Cycles II and III of the National Health Examination Survey, and the first, second, and third National Health and Nutrition Examination Surveys, respectively). Main Outcome Measures: Prevalence of overweight based on body mass index and 85th or 95th percentile cutoff points from Cycles II and III of the National Health Examination Survey. Results: From 1988 to 1991, the prevalence of over-weight was 10.9% based on the 95th percentile and 22% based on the 85th percentile. Overweight prevalence increased during the period examined among all sex and age groups. The increase was greatest since 1976 to 1980, similar to findings previously reported for adults in the United States. Conclusions: Increasing overweight among youths implies a need to focus on primary prevention. Attempts to increase physical activity may provide a means to address this important public health problem. (Arch Pediatr Adolesc Med. 1995;149:1085-1091)

Trends in the Prevalence, Awareness, Treatment, and Control of Hypertension in the Adult US Population: Data From the Health Examination Surveys, 1960 to 1991

Abstract: The objective of this study was to describe secular trends in the distribution of blood pressure and prevalence of hypertension in US adults and changes in rates of awareness, treatment, and control of hypertension. The study design comprised nationally representative cross-sectional surveys with both an in-person interview and a medical examination that included blood pressure measurement. Between 6530 and 13,645 adults, aged 18 through 74 years, were examined in each of four separate national surveys during 1960-1962, 1971-1974, 1976-1980, and 1988-1991. Protocols for blood pressure measurement varied significantly across the surveys and are presented in detail. Between the first (1971-1974) and second (1976-1980) National Health and Nutrition Examination Surveys (NHANES I and NHANES II, respectively), age-adjusted prevalence of hypertension at > or = 160/95 mm Hg remained stable at approximately 20%. In NHANES III (1988-1991), it was 14.2%. Age-adjusted prevalence at > or = 140/90 mm Hg peaked at 36.3% in NHANES I and declined to 20.4% in NHANES III. Age-specific prevalence rates have decreased for every age-sex-race subgroup except for black men aged 50 and older. Age-adjusted mean systolic pressures declined progressively from 131 mm Hg at the NHANES I examination to 119 mm Hg at the NHANES III examination. The mean systolic and diastolic pressures of every sex-race subgroup declined between NHANES II and III (3 to 6 mm Hg systolic, 6 to 9 mm Hg diastolic). During the interval between NHANES II and III, the threshold for defining hypertension was changed from 160/95 to 140/90 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

The level and tempo of children's physical activities: an observational study.

Abstract: We develop an observation system that quantifies the duration, intensity, and frequency of children's physical activities. We use this system to assess the level and tempo of energy expenditure under free-ranging, natural conditions experienced by 15 children aged 6-10 yr in southern California. Observations were recorded every 3 s during 4-h time blocks from 8:00 a.m.-8:00 p.m. Agreement among observers using the coding system was 91%. Using indirect calorimetry, calibration studies in the laboratory determined VO2 (ml.min-1.min-1) during each coded activity, and activities were categorized by intensity (low, medium, or high). Subjects were found to engage in activities of low intensity 77.1% of time and activities of high intensity 3.1% of time. The median duration of low and medium intensity activities was 6 s, of high intensity activities only 3 s with 95% lasting less than 15 s. Children engaged in very short bursts of intense physical activity interspersed with varying intervals of low and moderate intensity. These findings may be important for discovering how children's activity patterns under natural conditions influence physiological processes leading to growth and development. This study demonstrates the advantages of using an observational system that captures more than the intensity and frequency of children's activities to include duration and the length of intervals between activities of varying intensity.

Reliability of the Youth Risk Behavior Survey Questionnaire

Abstract: The Centers for Disease Control and Prevention's Youth Risk Behavior Survey (YRBS) has been used on a biennial basis since 1990 to measure health risk behaviors of high school students nationwide. The YRBS measures behaviors related to intentional and unintentional injury, tobacco use, alcohol and other drug use, sexual activity, diet, and physical activity. The authors present the results from a test-retest reliability study of the YRBS, conducted by administering the YRBS questionnaire to 1,679 students in grades 7 through 12 on two occasions 14 days apart. The authors computed a kappa statistic for each of 53 self-report items and compared group prevalence estimates across the two testing occasions. Kappas ranged from 14.5% to 91.1%; 71.7% of the items were rated as having "substantial" or higher reliability (kappa = 61-100%). No significant differences were found between the prevalence estimates at time 1 and time 2. Responses of seventh grade students were less consistent than those of students in higher grades, indicating that the YRBS is best suited for students in grade 8 and above. Except for a few suspect items, students appeared to report personal health risk behaviors reliably over time. Reliability and validity issues in health behavior assessment also are discussed.

Trends in Antimicrobial Drug Prescribing Among Office-Based Physicians in the United States

Abstract: Objective. —To assess changes in oral antimicrobial drug prescribing by office-based physicians from 1980 through 1992, with emphasis on the treatment of otitis media and sinusitis and on the possible impact of demographic variables on such use. Design. —The National Ambulatory Medical Care Survey is a sample survey of office-based physicians in the United States conducted by the National Center for Health Statistics, Centers for Disease Control and Prevention. Setting. —Physicians' offices. Patients or Other Participants. —Physicians sampled for the 1980,1985,1989, and 1992 National Ambulatory Medical Care Surveys, which included groups of 2959,5032,2540, and 3000 physicians, respectively. Sample physicians responding in 1980, 1985, 1989, and 1992 reported data for 46081, 71 594, 38384, and 34 606 sample office visits, respectively, including information on antimicrobial drug prescribing. Main Outcome Measure. —Trends in the antimicrobial drug prescription rates. Results. —From 1980 through 1992, increasing prescribing measured by the annual drug prescription rate per 1000 population, was found for the more expensive, broad-spectrum antimicrobial drugs, such as the cephalosporins; decreasing rates were observed for less expensive antimicrobial drugs with a narrower spectrum, such as the penicillins. No trend was found for trimethoprim-sulfamethoxazole, the erythromycins, or the tetracyclines. During the decade, an increasing trend in the visit rate to office-based physicians for otitis media was observed, while the visit rate for sinusitis among adults was found to be higher in 1992 than in each of the other study years. Conclusions. —The increased use of broader-spectrum and more expensive antimicrobial drugs have implications for all patients because of the impact on health care costs and the potential for the emergence of antimicrobial resistance. The data suggest that the incidence of otitis media and sinusitis is increasing. ( JAMA . 1995;273:214-219)

Dengue/dengue hemorrhagic fever: the emergence of a global health problem.

Abstract: Dengue and dengue hemorrhagic fever (DHF) are caused by one of four closely related but antigenically distinct virus serotypes (DEN-1 DEN-2 DEN- 3 and DEN-4) of the genus Flavivirus. Infection with one of these serotypes does not provide cross-protective immunity so persons living in a dengueendemic area can have four dengue infections during their lifetimes. Dengue is primarily an urban disease of the tropics and the viruses that cause it are maintained in a cycle that involves humans and Aedes aegypti a domestic day-biting mosquito that prefers to feed on humans. Infection with a dengue virus serotype can produce a spectrum of clinical illness ranging from a nonspecific viral syndrome to severe and fatal hemorrhagic disease. Important risk factors for DHF include the strain and serotype of the virus involved as well as the age immune status and genetic predisposition of the patient. The first reported epidemics of dengue fever occurred in 1779-1780 in Asia Africa and North America; the near simultaneous occurrence of outbreaks on three continents indicates that these viruses and their mosquito vector have had a worldwide distribution in the tropics for more than 200 years. During most of this time dengue fever was considered a benign nonfatal disease of visitors to the tropics. Generally there were long intervals (10-40 years) between major epidemics mainly because the viruses and their mosquito vector could only be transported between population centers by sailing vessels. (excerpt)

Epidemiology of Nosocomial Fungal Infections, with Emphasis on Candida Species

Abstract: Currently, about 180 hospitals participate in the National Nosocomial Infections Surveillance (NNIS) system. From January 1980 through April 1990, 27,200 fungal isolates causing nosocomial infections were reported from these hospitals; Candida species accounted for 19,621 (72.1%) of these isolates. Immunocompromised patients are at particularly high risk for candidemia. In patients with acute lymphocytic leukemia, treatment with vancomycin and/or imipenem appears to be an independent risk factor for candidemia; colonization of stool by Candida species may be another important predisposing factor in these patients. Rapid detection of invasive candidemia in these high-risk patients is particularly important to the improvement of rates of survival. Methods for rapid detection, such as the measurement of mannan (the major cell-wall polysaccharide of Candida), may be useful for diagnosing invasive candidiasis and for monitoring the response of this infection to antifungal therapy. Further studies of risk factors and the development of new methods for rapid diagnosis and monitoring should help decrease the morbidity and mortality associated with nosocomial fungal infections.

Laboratory diagnosis and interpretation of tests for syphilis.

Abstract: The lack of a method for demonstrating the presence of Treponema pallidum by growth necessitates the use of alternative methods. Traditionally, these methods are divided into direct detection methods (animal inoculation, dark-field microscopy, etc.) and serologic tests for the presence of patient antibody against T. pallidum. Serologic methods are further divided into two classes. One class, the nontreponemal tests, detects antibodies to lipoidal antigens present in either the host or T. pallidum; examples are the Venereal Disease Research Laboratory and rapid plasma reagin and tests. Reactivity in these tests generally indicates host tissue damage that may not be specific for syphilis. Because these tests are easy and inexpensive to perform, they are commonly used for screening, and with proper clinical signs they are suggestive of syphilis. The other class of test, the treponemal tests, uses specific treponemal antigens. Confirmation of infection requires a reactive treponemal test. Examples of the treponemal tests are the microhemagglutination assay for antibodies to T. pallidum and the fluorescent treponemal antibody absorption test. These tests are more expensive and complicated to perform than the nontreponemal tests. On the horizon are a number of direct antigen, enzyme-linked immunosorbent assay, and PCR techniques. Several of these techniques have shown promise in clinical trials for the diagnosis of congenital syphilis and neurosyphilis that are presently difficult to diagnose.

Hantavirus Pulmonary Syndrome: Pathogenesis of an Emerging Infectious Disease

Abstract: A recent outbreak of a severe pulmonary disease in the southwestern United States was etiologically linked to a previously unrecognized hantavirus The virus has been isolated from its major reservoir, the deer mouse, Peromyscus maniculatus, and recently named Sin Nombre virus Clinically, the disease has become known as the hantavirus pulmonary syndrome (HPS) Since May 1993, 44 fatal cases of HPS have been identified through clinicopathological review and immunohistochemical (IHC) testing of tissues from 273 patients who died of an unexplained noncardiogenic pulmonary edema In 158 cases for which suitable specimens were available, serological testing and/or reverse transcription-polymerase chain reaction (RT-PCR) amplification of extracted RNA was also performed IHC, serological, and PCR results were concordant for virtually all HPS and non-HPS patients when more than one assay was performed The prodromal illness of HPS is similar to that of many other viral diseases Consistent hematological features include thrombocytopenia, hemoconcentration, neutrophilic leukocytosis with a left shift, and reactive lymphocytes Pulmonary histopathological features were similar in most of the fatal HPS cases (40/44) and consisted of an interstitial pneumonitis with a variable mononuclear cell infiltrate, edema, and focal hyaline membranes In four cases, however, pulmonary features were significantly different and included diffuse alveolar damage and variable degrees of severe air space disorganization IHC analysis showed widespread presence of hantaviral antigens in endothelial cells of the microvasculature, particularly in the lung Hantaviral antigens were also observed within follicular dendritic cells, macrophages, and lymphocytes Hantaviral inclusions were observed in endothelial cells of lungs by thinsection electron microscopy, and their identity was verified by immunogold labeling Virus-like particles were seen in pulmonary endothelial cells and macrophages HPS is a newly recognized, often fatal disease, with a spectrum of microscopic morphological changes, which may be an important cause of severe and fatal illness presenting as adult respiratory distress syndrome

Pulsed-field gel electrophoresis as a replacement for bacteriophage typing of Staphylococcus aureus.

Abstract: Bacteriophage typing (BT) (World Health Organization method) has been used at the Centers for Disease Control and Prevention for over 30 years to type isolates of Staphylococcus aureus. Since studies have shown that BT patterns have poor reproducibility and because BT fails to type a high percentage (15 to 20%) of isolates, the Centers for Disease Control and Prevention has converted from using BT to using pulsed-field gel electrophoresis (PFGE) for strain typing S. aureus. We compared the results of BT with results of PFGE for typing 300 isolates of S. aureus, including strains from several well-characterized outbreaks. Ninety-six isolates were BT group I, 19 were group II, 82 were group III, 7 were group V, and 96 were nontypeable. PFGE identified subgroups within each phage group and thus was more discriminating than BT, which identified no subgroups. PFGE was able to type all isolates and distinguish related from unrelated strains of S. aureus. Our modified, standardized PFGE methodology should enable typing laboratories to obtain rapid, reliable results in 3 to 4 days when starting with an isolated colony on agar media.

Escherichia coli O157:H7 and the Hemolytic–Uremic Syndrome

Abstract: In the decade since its initial description in the Journal, 1 Escherichia coli O157:H7 has emerged as a major cause of both sporadic cases and outbreaks of diarrhea in North America. The first report described outbreaks of gastrointestinal illness that were associated with the consumption of undercooked ground beef from a chain of fast-food restaurants. At the time, little was known about the pathophysiology, epidemiology, or clinical sequelae of infection with E. coli O157:H7. Since that report, several studies have shown that infection with E. coli O157:H7 is responsible for most cases of the hemolytic–uremic syndrome, which is a major cause . . .

USPHS/IDSA Guidelines for the Prevention of Opportunistic Infections in Persons Infected with Human Immunodeficiency Virus: Introduction

Abstract: The USPHS/IDSA Prevention of Opportunistic Infections Working Group has recently formulated disease-specific recommendations for 17 opportunistic infections (OIs) or groups of OIs in HIV-infected persons [1]. The purpose of this article is to synthesize these recommendations and to offer the health care provider an organized approach to the prevention of OIs in this population. The authors recognize that preventing all exposures to opportunistic pathogens or all disease due to these pathogens is not possible. The avoidance of all behaviors and environments that can result in exposure to opportunistic pathogens would excessively restrict the patient's lifestyle. Furthermore, drugs active against many opportunistic pathogens are not available; even if they were, the multitude of agents required to reduce the risk of all OIs-with the attendant problems of toxicities, interactions, cost, and adherence to chemoprophylactic regimens-would render a complete preventive strategy impossible. This article is therefore intended to guide the provider in establishing priorities for the various preventive measures available.

The prevalence of drug-resistant Streptococcus pneumoniae in Atlanta.

Abstract: Background Streptococcus pneumoniae is a major cause of illness, and the emergence of drug-resistant strains threatens to complicate the management of pneumococcal infections. We conducted a laboratory-based surveillance for drug-resistant S. pneumoniae among patients with invasive pneumococcal infections in Atlanta. Methods From January through October 1994, pneumococcal isolates from 431 patients with invasive disease in metropolitan Atlanta were serotyped and tested to determine their susceptibility to various antimicrobial agents. Susceptibility to the antimicrobial agents was defined according to guidelines established by the National Committee for Clinical Laboratory Standards. Results The annual incidence of invasive pneumococcal infection was 30 cases per 100,000 population. Isolates from 25 percent of the patients were resistant to penicillin (7 percent were highly resistant), and isolates from 26 percent were resistant to trimethoprim–sulfamethoxazole (7 percent highly resistant). Fifteen percen...

Prospective Study of Intentional Weight Loss and Mortality in Never-Smoking Overweight US White Women Aged 40–64 Years

Abstract: Although 40% of US women indicate they are currently trying to lose weight, the association between intentional weight loss and longevity is unknown. The authors analyzed prospective data from 43,457 overweight, never-smoking US white women aged 40-64 years who in 1959-1960 completed a questionnaire that included questions on weight change direction, amount, time interval, and intentionality. Vital status was determined in 1972. Proportional hazards regression was used to estimate mortality rate ratios for women who intentionally lost weight compared with women who had no change in weight. Women who died within the first 3 years of follow-up were excluded. Analyses were stratified by preexisting illness and adjusted for age, beginning body mass index, alcohol intake, education, physical activity, and health conditions. In women with obesity-related health conditions (n = 15,069), intentional weight loss of any amount was associated with a 20% reduction in all-cause mortality, primarily due to a 40-50% reduction in mortality from obesity-related cancers; diabetes-associated mortality was also reduced by 30-40% in those who intentionally lost weight. In women with no preexisting illness (n = 28,388), intentional weight loss of > or = 20 lb (> or = 9.1 kg) that occurred within the previous year was associated with about a 25% reduction in all-cause, cardiovascular, and cancer mortality; however, loss of or = 1 year was generally associated with small to modest increases in mortality. The association between intentional weight loss and longevity in middle-aged overweight women appears to depend on their health status. Intentional weight loss among women with obesity-related conditions is generally associated with decreased premature mortality, whereas among women with no preexisting illness, the association is equivocal.

Postoperative infections traced to contamination of an intravenous anesthetic, propofol

Abstract: Background Between June 1990 and February 1993, the Centers for Disease Control and Prevention conducted investigations at seven hospitals because of unusual outbreaks of bloodstream infections, surgical-site infections, and acute febrile episodes after surgical procedures. Methods We conducted case–control or cohort studies, or both, to identify risk factors. A case patient was defined as any patient who had an organism-specific infection or acute febrile episode after a surgical procedure during the study period in that hospital. The investigations also included reviews of procedures, cultures, and microbiologic studies of infecting, contaminating, and colonizing strains. Results Sixty-two case patients were identified, 49 (79 percent) of whom underwent surgery during an epidemic period. Postoperative complications were more frequent during the epidemic period than before it. Only exposure to propofol, a lipid-based anesthetic agent, was significantly associated with the postoperative complications at a...

The influence of smoking cessation on the prevalence of overweight in the United States.

Abstract: Background The proportion of U.S. adults 35 to 74 years of age who were overweight increased by 9.6 percent for men and 8.0 percent for women between 1978 and 1990. Since the prevalence of smoking declined over the same period, smoking cessation has been suggested as a factor contributing to the increasing prevalence of overweight. Methods To estimate the influence of smoking cessation on the increase in the prevalence of overweight, we analyzed data on current and past weight and smoking status for a national sample of 5247 adults 35 years of age or older who participated in the third National Health and Nutrition Examination Survey, conducted from 1988 through 1991. The results were adjusted for age, sociodemographic characteristics, level of physical activity, alcohol consumption, and (for women) parity. Results The weight gain over a 10-year period that was associated with the cessation of smoking (i.e., the gain among smokers who quit that was in excess of the gain among continuing smokers) was 4.4 k...

Epidemiology of hepatitis C in the West

Abstract: Most hepatitis C occurs among young adults with high-risk behaviors or lifestyles. Although the most efficient transmission of HCV is through large or repeated percutaneous exposures to infectious blood, transmission also seems to occur through occupational exposure, sexual activity, household contact, and perinatal exposure. The risk of transmission in these settings is most likely dependent on the titer of virus as well as the type and size of the inoculum and the route of transmission. The apparent inconsistency of results between studies is probably a result of the small sample sizes, in that insufficient numbers of infectious persons are included, as well as the variations in methodology and serologic testing. Although HCV may be inefficiently transmitted by inapparent parenteral or mucosal exposures, the high rate of persistent infection with HCV creates a large reservoir of persons who are infectious to others. Current preventive measures, such as donor screening, prevent only a small proportion of the disease. Epidemiologic studies to define the risk of, and the factors facilitating transmission of HCV in other settings, still need to be conducted to develop measures to prevent most disease acquisition.

Special article the economic cost and social and psychological impact of musculoskeletal conditions

Abstract: Objective. To provide an indication of the economic, social, and psychological impact of musculoskeletal conditions in the United States. Methods. Review of the literature combined with estimates of data concerning health care utilization and acute and chronic disability due to musculoskeletal conditions, from the 1990–1992 National Health Interview Survey. Results. The cost of musculoskeletal conditions was $149.4 billion in 1992, of which 48% was due to direct medical care costs and the remainder was due to indirect costs resulting from wage losses. This amount translates to ˜2.5% of the Gross National Product, a sharp rise since the prior studies, even if part of the increase is an artifact of improved accounting methods. Each year, persons with musculoskeletal conditions make 315 million physician visits, have more than 8 million hospital admissions, and experience ˜1.5 billion days of restricted activity. Approximately 42% of persons with musculoskeletal conditions–more than 17 million in all–are limited in their activities. Conclusion. The economic and social costs of musculoskeletal conditions are substantial. These conditions are responsible for a sizable amount of health care use and disability, and they significantly affect the psychological status of the individuals with the conditions as well as their families.

Relation of Serum Uric Acid to Mortality and Ischemic Heart Disease The NHANES I Epidemiologic Follow-up Study

Abstract: Although hyperuricemia is frequently found among persons with ischemic heart disease, its importance as a risk factor remains uncertain. The authors examined this relation among 5,421 persons in the First National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-up Study; baseline data were collected in 1971-1975 and follow-up was through 1987. No associations were seen among men, but, among women, the serum uric acid level was predictive of mortality from all causes and from ischemic heart disease. These associations persisted even after excluding the first 10 years of follow-up and were independent of use of antihypertensive agents and diuretics, diastolic blood pressure, overweight, and other characteristics. A dose-response relation was evident for mortality from ischemic heart disease: each 1-mg/dl change in uric acid (about two thirds of the standard deviation) among women increased the rate by 1.48 (95% confidence interval 1.3-1.7). Furthermore, as compared with women who had a uric acid level <4 mg/dl, those with a level ≥7 mg/dl had a 4.8-fold (95% confidence interval 1.9-12) higher rate of ischemic heart disease mortality. In contrast, the uric acid level showed a weaker relation with disease incidence among women, with a rate ratio of 1.14 for each 1-mg/dl change. Although the biologic mechanism is unclear, further investigation into the possible role of uric acid in the development of ischemic heart disease is needed

Subverting Randomization in Controlled Trials

Abstract: Recent empirical evidence supports the importance of adequate randomization in controlled trials. Trials with inadequate allocation concealment have been associated with larger treatment effects compared with trials in which authors reported adequate allocation concealment. While that provides empirical evidence of bias being interjected into trials, trial investigators rarely document the sensitive details of subverting the intended purpose of randomization. This article relates anonymous accounts of deciphering assignment sequences before allocation based on experiences acquired from epidemiologic workshops for physicians. These accounts run the gamut from simple to intricate operations, from transillumination of envelopes to searching for code in the office files of the principal investigator. They indicate that deciphering is something more frequent than a rare occurrence. These accounts prompt some methodological recommendations to help prevent deciphering. Randomized controlled trials appear to annoy human nature—if properly conducted, indeed they should. ( JAMA . 1995;274:1456-1458)

Identification, classification, and clinical relevance of catalase-negative, gram-positive cocci, excluding the streptococci and enterococci.

Abstract: Several new genera and species of gram-positive, catalase-negative cocci that can cause infections in humans have been described. Although these bacteria were isolated in the clinical laboratory, they were considered nonpathogenic culture contaminants and were not thought to be the cause of any diseases. Isolation of pure cultures of these bacteria from normally sterile sites has led to the conclusion that these bacteria can be an infrequent cause of infection. This review describes the new bacteria and the procedures useful for clinical laboratories to aid in their identification. The clinical relevance and our experience with the various genera and species are reviewed and discussed.

Detection and differentiation of antigenically distinct small round-structured viruses (Norwalk-like viruses) by reverse transcription-PCR and southern hybridization.

Abstract: Application of reverse transcription (RT)-PCR to detect small round-structured viruses (SRSVs) from fecal specimens of patients with gastroenteritis has been insensitive because of the tremendous sequence heterogeneity between strains. We have designed two RT-PCR primer sets (G-1 and G-2) based on the nucleotide sequence diversity in the RNA polymerase gene of SRSVs belonging to two distinct genogroups represented by Norwalk virus (primers G-1) and Snow Mountain agent (primers G-2). All 22 SRSV strains examined that had been classified previously by solid-phase immune electron microscopy into four antigenic types (UK1, UK2, UK3, and UK4) could be detected by RT-PCR with these two primer sets. The G-1 primer set detected 6 UK2 strains, and the G-2 primers detected 16 strains, including 7 UK1, 5 UK3, and 4 UK4 strains. On the basis of nucleotide sequences of 81-bp fragments of the RT-PCR products from 13 strains determined in this study, together with those previously reported for 17 SRSV strains, we designed four sets of internal oligonucleotide probes (P1-A, P1-B, P2-A, and P2-B) for Southern hybridization, using chemiluminescent detection. The P1-A probe hybridized with PCR products from the UK2 strains; the P1-B probe, with products from two of the seven UK1 strains; the P2-A probe, with four of the remaining five UK1 strains; and the P2-B probe, with products from both UK3 and UK4 strains, as well as with one strain originally typed as UK1 which showed cross-reactivity with UK4 upon retesting by solid-phase immune electron microscopy. RT-PCR with both the G-1 and the G-2 primer sets can increase the detection rate of the many antigenically distinct SRSVs and, when combined with Southern hybridization, may predict the antigenic type of the SRSV associated with infection.