Showing papers by "Centers for Disease Control and Prevention published in 1994"

The Chronic Fatigue Syndrome: A Comprehensive Approach to Its Definition and Study

Abstract: The complexities of the chronic fatigue syndrome and the methodologic problems associated with its study indicate the need for a comprehensive, systematic, and integrated approach to the evaluation, classification, and study of persons with this condition and other fatiguing illnesses. We propose a conceptual framework and a set of guidelines that provide such an approach. Our guidelines include recommendations for the clinical evaluation of fatigued persons, a revised case definition of the chronic fatigue syndrome, and a strategy for subgrouping fatigued persons in formal investigations.

Increasing Prevalence of Overweight Among US Adults: The National Health and Nutrition Examination Surveys, 1960 to 1991

Abstract: Objective. —To examine trends in overweight prevalence and body mass index of the US adult population. Design. —Nationally representative cross-sectional surveys with an in-person interview and a medical examination, including measurement of height and weight. Setting/Participants. —Between 6000 and 13000 adults aged 20 through 74 years examined in each of four separate national surveys during 1960 to 1962 (the first National Health Examination Survey [NHES I]), 1971 to 1974 (the first National Health and Nutrition Examination Survey [NHANES I]), 1976 to 1980 (NHANESII), and 1988 to 1991 (NHANES III phase 1). Results. —In the period 1988 to 1991,33.4% of US adults 20 years of age or older were estimated to be overweight. Comparisons of the 1988 to 1991 overweight prevalence estimates with data from earlier surveys indicate dramatic increases in all race/sex groups. Overweight prevalence increased 8% between the 1976 to 1980 and 1988 to 1991 surveys. During this period, for adult men and women aged 20 through 74 years, mean body mass index increased from 25.3 to 26.3; mean body weight increased 3.6 kg. Conclusions. —These nationally representative data document a substantial increase in overweight among US adults and support the findings of other investigations that show notable increases in overweight during the past decade. These observations suggest that the Healthy People 2000 objective of reducing the prevalence of overweight US adults to no more than 20% may not be met by the year 2000. Understanding the reasons underlying the increase in the prevalence of overweight in the United States and elucidating the potential consequences in terms of morbidity and mortality present a challenge to our understanding of the etiology, treatment, and prevention of overweight. ( JAMA . 1994;272:205-211)

Emerging Infectious Diseases

Abstract: Emerging infectious diseases , Emerging infectious diseases , کتابخانه دیجیتالی دانشگاه علوم پزشکی و خدمات درمانی شهید بهشتی

The decline in blood lead levels in the United States. The National Health and Nutrition Examination Surveys (NHANES)

Abstract: Objective. —To describe trends in blood lead levels for the US population and selected population subgroups during the time period between 1976 and 1991. Design. —Two nationally representative cross-sectional surveys and one cross-sectional survey representing Mexican Americans in the southwestern United States. Setting/Participants. —Participants in two national surveys that included blood lead measurements: the second National Health and Nutrition Examination Survey, 1976 to 1980 (n=9832), and phase 1 of the third National Health and Nutrition Examination Survey, 1988 to 1991 (n=12119). Also, Mexican Americans participating in the Hispanic Health and Nutrition Examination Survey, 1982 to 1984 (n=5682). Results. —The mean blood lead level of persons aged 1 to 74 years dropped 78%, from 0.62 to 0.14 μmol/L (12.8 to 2.8 μg/dL). Mean blood lead levels of children aged 1 to 5 years declined 77% (0.66 to 0.15 μmol/L [13.7 to 3.2 μg/dL]) for non-Hispanic white children and 72% (0.97 to 0.27 μmol/L [20.2 to 5.6 μg/dL]) for non-Hispanic black children. The prevalence of blood lead levels 0.48 μmol/L (10 μg/dL) or greater for children aged 1 to 5 years declined from 85.0% to 5.5% for non-Hispanic white children and from 97.7% to 20.6% for non-Hispanic black children. Similar declines were found in population subgroups defined by age, sex, race/ethnicity, income level, and urban status. Mexican Americans also showed similar declines in blood lead levels of a slightly smaller magnitude over a shorter time. Conclusions. —The results demonstrate a substantial decline in blood lead levels of the entire US population and within selected subgroups of the population. The major cause of the observed decline in blood lead levels is most likely the removal of 99.8% of lead from gasoline and the removal of lead from soldered cans. Although these data indicate major progress in reducing lead exposure, they also show that the same sociodemographic factors continue to be associated with higher blood lead levels, including younger age, male sex, non-Hispanic black race/ ethnicity, and low income level. Future efforts to remove other lead sources (eg, paint, dust, and soil) are needed but will be more difficult than removing lead from gasoline and soldered cans. (JAMA. 1994;272:284-291)

A Multistate Outbreak of Escherichia coli O157:H7—Associated Bloody Diarrhea and Hemolytic Uremic Syndrome From Hamburgers: The Washington Experience

Abstract: Objective. —To determine the source of and describe a large outbreak of Escherichia coli O157:H7 infections in Washington State. Design. —Case-control study; environmental investigation; provider-based surveillance for E coli O157:H7 infections. Setting. —Chain of fast-food restaurants, hospitals, physician offices, local laboratories, and local health departments. Participants. —Patients with diarrhea and neighborhood controls. A case was defined as diarrhea with culture-confirmed E coli O157:H7 infection or postdiarrheal hemolytic uremic syndrome (HUS) occurring from December 1, 1992, through February 28, 1993, in a Washington State resident. Controls were age- and neighborhood-matched friends of the first 16 case patients. Interventions. —Announcement to the public; recall of implicated hamburger lots. Main Outcome Measure. —Abatement of outbreak due to E coli O157:H7. Results. —Infection was associated with eating at a fast-food chain (chain A) in the 10 days before symptoms began. Twelve (75%) of 16 case patients but no controls had eaten at chain A (matched odds ratio undefined; lower 95% confidence interval, 3.5; P E coli O157:H7 strains isolated from all regular hamburger lots of a single production date shipped to Washington was identical to that of the strains isolated from patients. Ten (63%) of 16 regular hamburgers cooked according to chain A policy had internal temperatures below 60°C. Public health action removed more than 250 000 potentially contaminated hamburgers, preventing an estimated 800 cases. Conclusions. —This E coli O157:H7 outbreak, the largest reported, resulted from errors in meat processing and cooking. Public health surveillance through state-mandated reporting of E coli O157:H7 infection as is carried out in Washington State was critical for prompt outbreak recognition and control. Measures should be developed to reduce meat contamination. Consumers and food service workers should be educated about cooking hamburger meat thoroughly. ( JAMA . 1994;272:1349-1353)

The medically important aerobic actinomycetes: epidemiology and microbiology.

Abstract: The aerobic actinomycetes are soil-inhabiting microorganisms that occur worldwide. In 1888, Nocard first recognized the pathogenic potential of this group of microorganisms. Since then, several aerobic actinomycetes have been a major source of interest for the commercial drug industry and have proved to be extremely useful microorganisms for producing novel antimicrobial agents. They have also been well known as potential veterinary pathogens affecting many different animal species. The medically important aerobic actinomycetes may cause significant morbidity and mortality, in particular in highly susceptible severely immunocompromised patients, including transplant recipients and patients infected with human immunodeficiency virus. However, the diagnosis of these infections may be difficult, and effective antimicrobial therapy may be complicated by antimicrobial resistance. The taxonomy of these microorganisms has been problematic. In recent revisions of their classification, new pathogenic species have been recognized. The development of additional and more reliable diagnostic tests and of a standardized method for antimicrobial susceptibility testing and the application of molecular techniques for the diagnosis and subtyping of these microorganisms are needed to better diagnose and treat infected patients and to identify effective control measures for these unusual pathogens. We review the epidemiology and microbiology of the major medically important aerobic actinomycetes. Images

Intersecting Epidemics -- Crack Cocaine Use and HIV Infection among Inner-City Young Adults

Abstract: Background and Methods The smoking of “crack” cocaine is thought to be associated with high-risk sexual practices that accelerate the spread of infection with the human immunodeficiency virus (HIV). We studied 2323 young adults, 18 to 29 years of age, who smoked crack regularly or who had never smoked crack. The study participants, recruited from the streets of inner-city neighborhoods in New York, Miami, and San Francisco, were interviewed and tested for HIV. This report presents the findings for the 1967 participants (85 percent) who had never injected drugs. Results Of the 1137 crack smokers, 15.7 percent were positive for HIV antibody, as compared with 5.2 percent of the 830 nonsmokers (prevalence ratio adjusted for the city, 2.4; 99 percent confidence interval, 1.7 to 3.6). The prevalence of HIV was highest among the crack-smoking women in New York (29.6 percent) and Miami (23.0 percent). In these two cities, of the 283 women who had sex in exchange for money or drugs, 30.4 percent were infected with...

Hantavirus Pulmonary Syndrome: A Clinical Description of 17 Patients with a Newly Recognized Disease

Abstract: Background In May 1993 an outbreak of severe respiratory illness occurred in the southwestern United States. A previously unknown hantavirus was identified as the cause. In Asia hantaviruses are associated with hemorrhagic fever and renal disease. They have not been known as a cause of human disease in North America. Methods We analyzed clinical, laboratory, and autopsy data on the first 17 persons with confirmed infection from this newly recognized strain of hantavirus. Results The mean age of the patients was 32.2 years (range, 13 to 64); 61 percent were women, 72 percent were Native American, 22 percent white, and 6 percent Hispanic. The most common prodromal symptoms were fever and myalgia (100 percent), cough or dyspnea (76 percent), gastrointestinal symptoms (76 percent), and headache (71 percent). The most common physical findings were tachypnea (100 percent), tachycardia (94 percent), and hypotension (50 percent). The laboratory findings included leukocytosis (median peak cell count, 26,000 per cu...

Emergence of Drug-Resistant Pneumococcal Infections in the United States

Abstract: Objective. —To estimate drug susceptibility patterns of Streptococcus pneumoniae in selected hospitals in the United States and to characterize the epidemiology of invasive drug-resistant pneumococcal infections. Design. —Minimum inhibitory concentrations (MICs) for a variety of commonly used antimicrobial drugs were determined for pneumococcal isolates submitted to the Centers for Disease Control and Prevention (CDC). Risk factors for drug-resistant pneumococcal infection were evaluated. Setting. —Hospital laboratories in the United States submitting pneumococcal isolates to the CDC between October 1, 1991, and September 30, 1992. Participants. —A total of 544 persons with pneumococci isolated from normally sterile sites. Results. —A total of 13 hospitals in 12 states actively participated in an ongoing pneumococcal surveillance study. Resistance to penicillin was detected in 6.6% of isolates, including 1.3% of isolates with MICs of 2.0 μg/mL or more (compared with Conclusions. —Emergence of drug-resistant pneumococcal infections will present critical challenges to clinicians for treating patients with pneumococcal disease. Widened and intensified surveillance is needed. These data suggest that current recommendations for use of 23-valent pneumococcal capsular polysaccharide vaccines should be aggressively promoted and that development and evaluation of new conjugate pneumococcal vaccines may be a crucial part of strategies for prevention. ( JAMA . 1994;271:1831-1835)

Magnetic separation techniques in diagnostic microbiology.

Abstract: The principles of magnetic separation aided by antibodies or other specific binding molecules have been used for isolation of specific viable whole organisms, antigens, or nucleic acids. Whereas growth on selective media may be helpful in isolation of a certain bacterial species, immunomagnetic separation (IMS) technology can isolate strains possessing specific and characteristic surface antigens. Further separation, cultivation, and identification of the isolate can be performed by traditional biochemical, immunologic, or molecular methods. PCR can be used for amplification and identification of genes of diagnostic importance for a target organism. The combination of IMS and PCR reduces the assay time to several hours while increasing both specificity and sensitivity. Use of streptavidin-coated magnetic beads for separation of amplified DNA fragments, containing both biotin and a signal molecule, has allowed for the conversion of the traditional PCR into an easy-to-read microtiter plate format. The bead-bound PCR amplicons can also easily be sequenced in an automated DNA sequencer. The latter technique makes it possible to obtain sequence data of 300 to 600 bases from 20 to 30 strains, starting with clinical samples, within 12 to 24 h. Sequence data can be used for both diagnostic and epidemiologic purposes. IMS has been demonstrated to be a useful method in diagnostic microbiology. Most recent publications describe IMS as a method for enhancing the specificity and sensitivity of other detection systems, such as PCR, and providing considerable savings in time compared with traditional diagnostic systems. The relevance to clinical diagnosis has, however, not yet been fully established for all of these new test principles. In the case of PCR, for example, the presence of specific DNA in a food sample does not demonstrate the presence of a live organism capable of inducing a disease. However, all tests offering increased sensitivity and specificity of detection, combined with reduced time of analysis, have to be seriously evaluated. Images

Blood lead levels in the US population. Phase 1 of the Third National Health and Nutrition Examination Survey (NHANES III, 1988 to 1991)

Abstract: Objective —To determine mean blood lead levels and their sociodemographic correlates in the US population Design —Nationally representative cross-sectional health examination survey that included measurements of venous blood lead Participants —A total of 13201 persons aged 1 year and older examined during phase 1 of the third National Health and Nutrition Examination Survey (1988 to 1991) Results —The overall mean blood lead level for the US population was 014 μmol/L (28 μg/dL) Blood lead levels were consistently higher for younger children than for older children, for older adults than for younger adults, for males than for females, for blacks than for whites, and for central-city residents than for non—central-city residents Other correlates of higher blood lead levels included low income, low educational attainment, and residence in the Northeast region of the United States National estimates for children 1 to 5 years of age indicate that 89%, or approximately 17 million children, have blood lead levels 048 μmol/L (10 μg/dL) or greater These levels are high enough to be of health concern under 1991 Centers for Disease Control and Prevention guidelines Conclusions —The low overall mean blood lead levels demonstrate a major public health success in primary prevention efforts However, exposure to lead at levels that may adversely affect the health of children remains a problem especially for those who are minority, urban, and from low-income families Strategies to identify the most vulnerable risk groups are necessary to further reduce lead exposure in the United States (JAMA 1994;272:277-283)

Comparison of traditional and molecular methods of typing isolates of Staphylococcus aureus.

Abstract: Fifty-nine Staphylococcus aureus isolates and 1 isolate of Staphylococcus intermedius were typed by investigators at eight institutions by using either antibiograms, bacteriophage typing, biotyping, immunoblotting, insertion sequence typing with IS257/431, multilocus enzyme electrophoresis, restriction analysis of plasmid DNA, pulsed-field or field inversion gel electrophoresis, restriction analysis of PCR-amplified coagulase gene sequences, restriction fragment length polymorphism typing by using four staphylococcal genes as probes, or ribotyping. Isolates from four well-characterized outbreaks (n = 29) and a collection of organisms from two nursing homes were mixed with epidemiologically unrelated stock strains from the Centers for Disease Control and Prevention. Several isolates were included multiple times either within or between the sets of isolates to analyze the reproducibilities of the typing systems. Overall, the DNA-based techniques and immunoblotting were most effective in grouping outbreak-related strains, recognizing 27 to 29 of the 29 outbreak-related strains; however, they also tended to include 3 to 8 epidemiologically unrelated isolates in the same strain type. Restriction fragment length polymorphism methods with mec gene-associated loci were less useful than other techniques for typing oxacillin-susceptible isolates. Phage typing, plasmid DNA restriction analysis, and antibiogram analysis, the techniques most readily available to clinical laboratories, identified 23 to 26 of 29 outbreak-related isolates and assigned 0 to 6 unrelated isolates to outbreak strain types. No single technique was clearly superior to the others; however, biotyping, because it produced so many subtypes, did not effectively group outbreak-related strains of S. aureus.

Surveillance for Legionnaires' Disease: Risk Factors for Morbidity and Mortality

Abstract: Background: To augment available information about the epidemiology of legionnaires' disease, we analyzed data reported to the passive surveillance system at the Centers for Disease Control and Prevention, Atlanta, Ga, from 1980 through 1989. Methods: Risk of disease associated with specific demographic characteristics and health conditions was calculated by comparing the surveillance group with the US population. Risk of death was calculated using multivariate logistic regression models. Results: A diagnosis of legionnaires' disease was confirmed on the basis of clinical and laboratory criteria for 3254 patients. Disease rates did not vary by year, but were higher in the northern states and during the summer.Legionella pneumophila, serogroup 1, constituted 71.5% of fully identified isolates. This study confirmed previously identified risk factors for legionnaires' disease. In addition, a markedly elevated risk was identified for persons with acquired immunodeficiency syndrome (rate ratio, 41.9; 95% confidence interval, 12.9, 71.0), or hematologic malignancy (rate ratio, 22.4; 95% confidence interval, 19.0, 25.9). Likelihood of death was increased in patients who were elderly or male; those with hospital-acquired infection, renal disease, malignancy, or immunosuppression; and those from whomL pneumophila, serogroup 6, was isolated. Conclusions: Infection withLegionellaremains an important cause of disease and death in the United States. Diagnosis and treatment of legionnaires' disease should be targeted at patients at increased risk for illness and complications due toLegionellainfection. Diagnostic tests for legionnaires' disease based on species other thanL pneumophila, serogroup 1, should be developed and tested. Recommendations for prevention of legionnaires' disease should be focused on settings where there are persons at greatest risk for illness or serious outcome. (Arch Intern Med. 1994;154:2417-2422)

Serologic and Genetic Identification of Peromyscus maniculatus as the Primary Rodent Reservoir for a New Hantavirus in the Southwestern United States

Abstract: An outbreak of hantavirus pulmonary syndrome (HPS) in the southwestern United States was etiologically linked to a newly recognized hantavirus. Knowledge that hantaviruses are maintained in rodent reservoirs stimulated a field and laboratory investigation of 1696 small mammals of 31 species. The most commonly captured rodent, the deer mouse (Peromyscus maniculatus), had the highest antibody prevalence (30%) to four hantavirus antigens. Antibody also was detected in 10 other species of rodent and in 1 species of rabbit. Reverse transcriptase-polymerase chain reaction (RT-PCR) products of hantavirus from rodent tissues were indistinguishable from those from human HPS patients. More than 96% of the seropositive P. maniculatus were positive by RT-PCR, suggesting chronic infection. Antibody prevalences were similar among P. maniculatus trapped from Arizona (33%), New Mexico (29%), and Colorado (29%). The numeric dominance of P. maniculatus, the high prevalence of antibody, and the RT-PCR findings implicate this species as the primary rodent reservoir for a new hantavirus in the southwestern United States.

Measuring health-related quality of life for public health surveillance.

Abstract: In public health research and practice, quality of life is increasingly acknowledged as a valid and appropriate indicator of service need and intervention outcomes. Health-related quality of life measures, including objective and subjective assessments of health, are particularly useful for evaluating efforts in the prevention of disabling chronic diseases. Such data can inform health policy, planning, and practice. Mechanisms for routinely monitoring quality of life of populations at the State and local levels are currently lacking, however. This article discusses the rationale for and concepts measured by four quality of life questions developed for the 1993 Behavioral Risk Factor Surveillance System, a State-based telephone surveillance system. To encourage quality of life surveillance by States, the Centers for Disease Control and Prevention's National Center for Chronic Disease Prevention and Health Promotion held two related workshops, one in December 1991 and the other in June 1992. The workshops convened experts in quality of life and functional status measurement and resulted in the formulation of items for the Behavioral Risk Factor Surveillance System on self-perceived health, recent physical and mental health, and recent limitation in usual activities. The criteria, including feasibility and generalizability, considered by the Centers for Disease Control and Prevention and the workshop participants in the selection and development of these items are discussed. A model that conceptualizes the relationship of quality of life domains measured by the four survey items is presented and validated with preliminary data from the 1993 Behavioral Risk Factor Surveillance System. Finally, how States can use these measures to track progress towards the Year 2000 goal of improving quality of life is discussed.

Dietary intake of vitamins, minerals, and fiber of persons ages 2 months and over in the United States: Third National Health and Nutrition Examination Survey, Phase 1, 1988-91.

Abstract: Intervention strategies aimed at reducing the prevalence of nutrition-related diseases, including designing nutrition policies and nutrition education and assistance programs, require effective monitoring of what Americans are eating. Nutrient reference data from the third National Health and Nutrition Examination Survey provide essential information to achieve these goals. Mean and median iron intakes were adequate in males of all race-ethnic groups but were generally low in females and young children. Mean and median calcium intakes were also higher in males than in females and were lower than recommendations in adolescents and in women of all ages. Mean sodium intakes for all age, sex, and race-ethnic groups exceeded the minimum requirements of healthy persons and were higher in non-Hispanic black children and adolescents than in non-Hispanic white and Mexican American children and adolescents. Mean fiber intakes also did not meet recommendations in most subgroups and were higher in Mexican American adults followed by non-Hispanic white adults and non-Hispanic black adults. Further research is planned to compare the food sources of energy and nutrients consumed by different population groups in NHANES III to similar results from earlier nation surveys. NHANES III, Phase 2 (1991-94) recalls were collected using the same dietary method as those collected in Phase 1 (1988-91), and other analyses will compare findings from both phases of NHANES III.

Prevalence and Health Impact of Developmental Disabilities in US Children

Abstract: Objective. Data from the 1988 National Health Interview Survey—Child Health Supplement were used to examine the prevalence of selected developmental disabilities and their impact among children ages 0 through 17 years. Design. The following conditions, identified through a structured in-person interview with a parent or other adult household member, were examined: deafness or trouble hearing, blindness, epilepsy or seizures, stammering and stuttering, other speech defects, cerebral palsy, delay in growth or development, learning disabilities, and emotional or behavioral problems. The impact was defined by measures of perceived health status, school performance and attendance, and health care utilization. Results. Seventeen percent of children in the United States were reported to have ever had a developmental disability. The prevalence of the individual disabilities ranged from 0.2% for cerebral palsy to 6.5% for learning disabilities. These conditions taken together had a substantial impact on the health and educational functioning of affected children: 1.5 times more doctor visits, 3.5 times more hospital-days, twice the number of school-days lost, and a 2.5-fold increase in the likelihood of repeating a grade in school compared with children without these conditions. The extent of this impact was much greater among children with multiple disabilities or with either cerebral palsy, epilepsy or seizures, delays in growth and development, or emotional or behavioral problems. The impact on school performance was most pronounced for children reported to have learning disabilities. Conclusions. Future research efforts should be focused on ways to reduce the impact of these developmental disabilities on quality of life.

The public health burdens of sedentary living habits: theoretical but realistic estimates.

Abstract: Quantitative estimates indicate that sedentary living is responsible for about one-third of deaths due to coronary heart disease, colon cancer, and diabetes--three diseases for which physical inactivity is an established causal factor. Presumably, if everyone were highly active the death rate from these three disease would be only two-thirds of the current rate. Not everyone will become highly active, however. Assuming smaller increases in physical activity practices, mortality from these three conditions combined could be reduced by as much as 5-6%, or 30,000-35,000 deaths per year. Overall mortality in the United States might be reduced about 1-1.5%. The greatest gains would accrue from strategies that encourage those who report no leisure-time physical activity to do some and that encourage those who are irregularly active to participate in 30 or more minutes of light to moderate activity for 5 or more d.wk-1. Mortality is only one aspect of public health burdens that would be reduced by greater participation in regular physical activity. Quality of life, which we have not attempted to quantify, would also improve.

Cost-effectiveness of a routine varicella vaccination program for US children

Abstract: Objective. —To evaluate the economic consequences of a routine varicella vaccination program that targets healthy children. Methods. —Decision analysis was used to compare the costs, outcomes, and cost-effectiveness of a routine vaccination program with no intervention. Clinical outcomes were based on a mathematical model of vaccine efficacy that relied on published and unpublished data and on expert opinion. Medical utilization rates and costs were collected from multiple sources, including the Kaiser Permanente Medical Care Program and the California Hospital Discharge Database. Results. —A routine varicella vaccination program for healthy children would prevent 94% of all potential cases of chickenpox, provided the vaccination coverage rate is 97% at school entry. It would cost approximately $162 million annually if one dose of vaccine per child were recommended at a cost of $35 per dose. From the societal perspective, which includes work-loss costs as well as medical costs, the program would save more than $5 for every dollar invested in vaccination. However, from the health care payer's perspective (medical costs only), the program would cost approximately $2 per chickenpox case prevented, or $2500 per life-year saved. The medical cost of disease prevention was sensitive to the vaccination coverage rate and vaccine price but was relatively insensitive to assumptions about vaccine efficacy within plausible ranges. An additional program for catch-up vaccination of 12-year-olds would have high incremental costs if the vaccination coverage rate of children of preschool age were 97%, but would result in net savings at a coverage rate of 50%. Conclusions. —A routine varicella vaccination program for healthy children would result in net savings from the societal perspective, which includes work-loss costs as well as medical costs. Compared with other prevention programs, it would also be relatively cost-effective from the health care payer's perspective. (JAMA. 1994;271:375-381)

Prediction of Long-Term Mortality in Patients with Rheumatoid Arthritis according to Simple Questionnaire and Joint Count Measures

Abstract: Objective: To describe mortality over 15 years in a cohort of patients with rheumatoid arthritis, according to a simple questionnaire and joint count. Design: A cohort study with 15 years of follow...

Molecular evolution and epidemiology of dengue-3 viruses

Abstract: The nucleic acid sequences of the pre-membrane/membrane and envelope protein genes of 23 geographically and temporally distinct dengue (DEN)-3 viruses were determined. This was accomplished by reverse transcriptase-PCR amplification of the structural genes followed by automated DNA sequence analysis. Comparison of nucleic acid sequences revealed that similarity among the viruses was greater than 90%. The similarity among deduced amino acids was between 95% and 100%, and in many cases identical amino acid substitutions occurred among viruses from similar geographical regions. Alignment of nucleic acid sequences followed by parsimony analysis allowed the generation of phylogenetic trees, demonstrating that geographically independent evolution of DEN-3 viruses had occurred. The DEN-3 viruses were separated into four genetically distinct subtypes. Subtype I consists of viruses from Indonesia, Malaysia, the Philippines and the South Pacific islands; subtype II consists of viruses from Thailand; subtype III consists of viruses from Sri Lanka, India, Africa and Samoa; subtype IV consists of viruses from Puerto Rico and the 1965 Tahiti virus. Phylogenetic analysis has also contributed to our understanding of the molecular epidemiology and worldwide distribution of DEN-3 viruses.

Laboratory investigation of a multistate food-borne outbreak of Escherichia coli O157:H7 by using pulsed-field gel electrophoresis and phage typing.

Abstract: Two hundred thirty-three isolates of Escherichia coli O157:H7 were analyzed by both pulsed-field gel electrophoresis (PFGE) and bacteriophage typing All 26 isolates from persons whose illness was associated with a recent multistate outbreak of E coli O157:H7 infections linked to the consumption of undercooked hamburgers and all 27 isolates from incriminated lots of hamburger meat had the same phage type and the same PFGE pattern Twenty-five of 74 E coli O157:H7 isolates from Washington State and 10 of 27 isolates from other states obtained during the 6 months before the outbreak had the same phage type as the outbreak strain, but only 1 isolate had the same PFGE pattern PFGE thus appeared to be a more sensitive method than bacteriophage typing for distinguishing outbreak and non-outbreak-related strains The PFGE patterns of seven preoutbreak sporadic isolates and five sporadic isolates from the outbreak period differed from that of the outbreak strain by a single band, making it difficult to identify these isolates as outbreak or non-outbreak related Phage typing and PFGE with additional enzymes were helpful in resolving this problem While not as sensitive as PFGE, phage typing was helpful in interpreting PFGE data and could have been used as a simple, rapid screen to eliminate the need for performing PFGE on unrelated isolates

Epidemiology of Tuberculosis in the United States, 1985 Through 1992

Abstract: Objective. —To examine the distribution and sources of increased tuberculosis (TB) morbidity in the United States from 1985 through 1992. Design. —Review of TB surveillance data. Participants. —All incident TB cases in the United States reported to the Centers for Disease Control and Prevention from 1980 through 1992. Main Outcome Measures. —Changes in reported number of TB cases from 1985 through 1992 were analyzed by sex, race/ethnicity, age, country of birth (1986 through 1992), site of disease, geographic location, and socioeconomic status (through 1991). From 1985 through 1992, reported number of cases was compared with expected number of cases, extrapolated from 1980 through 1984 trends, to estimate excess cases by sex, race/ethnicity, and age. Results. —Increases in number of cases from 1985 through 1992 were concentrated among racial/ethnic minorities, persons 25 to 44 years of age, males, and the foreign-born. Excess cases occurred in both sexes, all racial/ethnic groups, and all age groups. Foreign-born cases accounted for 60% of the total increase in the number of US cases from 1986 through 1992 and had the greatest impact among Asians, Hispanics, females, and persons other than those 25 to 44 years of age. Human immunodeficiency virus infection had the greatest impact on TB morbidity among whites, blacks, males, and persons 25 to 44 years of age. From 1985 through 1992, the number of cases among children 4 years old or younger increased 36%, suggesting that transmission of TB increased during this period. Conclusions. —Multiple factors contributed to the recent increases in the number of TB cases. The effectiveness of TB screening in immigrants needs further evaluation. Intensified efforts to determine the human immunodeficiency virus status of persons with TB are needed. Screening of subpopulations at increased risk for tuberculous infection or TB should be expanded. (JAMA. 1994;272:535-539)