Showing papers by "Centers for Disease Control and Prevention published in 1991"

Genotypic identification of rickettsiae and estimation of intraspecies sequence divergence for portions of two rickettsial genes.

Abstract: DNA sequences from specific genes, amplified by the polymerase chain reaction technique, were used as substrata for nonisotopic restriction endonuclease fragment length polymorphism differentiation of rickettsial species and genotypes. The products amplified using a single pair of oligonucleotide primers (derived from a rickettsial citrate synthase gene sequence) and cleaved with restriction endonucleases were used to differentiate almost all recognized species of rickettsiae. A second set of primers was used for differentiation of all recognized species of closely related spotted fever group rickettsiae. The procedure circumvents many technical obstacles previously associated with identification of rickettsial species. Multiple amplified DNA digest patterns were used to estimate the intraspecies nucleotide sequence divergence for the genes coding for rickettsial citrate synthase and a large antigen-coding gene of the spotted fever group rickettsiae. The estimated relationships deduced from these genotypic data correlate reasonably well with established rickettsial taxonomic schemes.

Mycobacterium avium complex infection in the acquired immunodeficiency syndrome.

Abstract: ORGANISMS of the Mycobacterium avium complex have long been recognized as an uncommon cause of pneumonia in persons with chronic lung disease.1 2 3 4 Organisms of this complex, which comprises two closely related species, M. avium and M. intracellulare, appear to have little virulence in the normal host. Before the acquired immunodeficiency syndrome (AIDS) epidemic, disseminated infection with M. avium complex was extremely rare; by 1980, only 24 cases had been reported in the medical literature.5 Beginning in 1982, however, when the infection was recognized in patients with AIDS, the number of cases increased dramatically. At first, the minimal inflammatory response . . .

Smoking cessation and severity of weight gain in a national cohort.

Abstract: Background. Many believe that the prospect of weight gain discourages smokers from quitting. Accurate estimates of the weight gain related to the cessation of smoking in the general population are not available, however. Methods. We related changes in body weight to changes in smoking status in adults 25 to 74 years of age who were weighed in the First National Health and Nutrition Examination Survey (NHANES I, 1971 to 1975) and then weighed a second time in the NHANES I Epidemiologic Follow-up Study (1982 to 1984). The cohort included continuing smokers (748 men and 1137 women) and those who had quit smoking for a year or more (409 men and 359 women). Results. The mean weight gain attributable to the cessation of smoking, as adjusted for age, race, level of education, alcohol use, illnesses related to change in weight, base-line weight, and physical activity, was 2.8 kg in men and 3.8 kg in women. Major weight gain (>13 kg) occurred in 9.8 percent of the men and 13.4 percent of the women who qui...

Epidemiology of human listeriosis.

Abstract: During the 1980s, investigation of several large epidemics of listeriosis confirmed that transmission of L. monocytogenes in food causes human disease. Progress in laboratory detection and subtyping of the organism has enhanced our ability to compare human and environmental isolates of L. monocytogenes. Transmission by foodborne organisms is now recognized as causing both epidemic and sporadic listeriosis. Continued study of dietary risk factors associated with listeriosis is needed in order to develop dietary recommendations for the expanding population at increased risk of disease. Current research application of new molecular methods to the study of L. monocytogenes may improve the ability to diagnose pregnancy-associated disease and permit the rapid detection and control of L. monocytogenes in the food supply.

Nomenclature and research case definitions for neurologic manifestations of human immunodeficiency virus-type 1 (HIV-1) infection

Abstract: Infection with human immunodeficiency virus-type 1 (HIV-1) has been associated with avariety of neurologic disorders thought to be caused, directly or indirectly, by HIV-1.1-6 Although these disorders have been described clinically, there is no consensus terminology or criteria for diagnosis. To develop consensus nomenclature and case definitions for HIV-1-associated neurologic conditions for research purposes, the American Academy of Neurology AIDS Task Force convened a working group of neurologists, neuropsychologists, psychiatrists, and sociologists that included representatives of the American Neurological Association, the World Federation of Neurology, the International Neuropsychological Society, the National Academy of Neuropsychology, the American Psychological Association, the American Psychiatric Association, the World Health Organization, and the Centers for Disease Control (CDC). These definitions have been developed in conjunction with the International Classification of Diseases-10 (ICD-10, unpublished draft of the World Health Organization) and the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV, unpublished draft of the American Psychiatric Association). Although consistent with the ICD-10, the definitions are not identical. HIV-2 may cause similar disorders, but the neurologic manifestations of HIV-2 are unknown and are not addressed in this article.

A Meta-analysis of the Effect of Estrogen Replacement Therapy on the Risk of Breast Cancer

Abstract: To quantify the effect of estrogen replacement therapy on breast cancer risk, we combined dose-response slopes of the relative risk of breast cancer against the duration of estrogen use across 16 studies. Using this summary dose-response slope, we calculated the proportional increase in risk of breast cancer for each year of estrogen use. For women who experienced any type of menopause, risk did not appear to increase until after at least 5 years of estrogen use. After 15 years of estrogen use, we found a 30% increase in the risk of breast cancer (relative risk, 1.3; 95% confidence interval [CI], 1.2 to 1.6). The increase in risk was largely due to results of studies that included premenopausal women or women using estradiol (with or without progestin), studies for which the estimated relative risk was 2.2 (CI, 1.4 to 3.4) after 15 years. Among women with a family history of breast cancer, those who had ever used estrogen replacement had a significantly higher risk (3.4; CI, 2.0 to 6.0) than those who had not (1.5; CI, 1.2 to 1.7). (JAMA. 1991;265:1985-1990)

Isolation of Escherichia coli serotype O157:H7 and other Shiga-like-toxin-producing E. coli from dairy cattle.

Abstract: We examined 1,266 fecal specimens from healthy cattle during the investigations of two sporadic cases of hemolytic uremic syndrome associated with raw milk consumption and an outbreak of gastroenteritis and hemolytic uremic syndrome caused by Escherichia coli serotype O157:H7. We collected specimens from heifers, calves, and adult cows on 22 farms, in a stockyard, and in a packing house. We also collected 3 raw hamburger specimens from a restaurant and 23 raw milk samples from two farms. All specimens were examined for E. coli O157:H7 by using sorbitol-MacConkey agar, H immobilization, O157 agglutination, and tissue culture cytotoxicity. E. coli O157:H7 was isolated from 16 heifers or calves and 1 adult cow on 22 farms, 1 stockyard calf, 2 beef specimens, and 1 raw milk sample. Selected fecal specimens were also examined for the presence of other Shiga-like-toxin-producing E. coli (SLTEC) by testing polymyxin B extracts of colony sweeps and then testing individual colonies for toxin production. SLTEC other than O157 was isolated from 8 of 10 farms investigated and from the stockyard; 8% of adult cows and 19% of heifers and calves were positive for SLTEC. Several animals were positive for SLTEC by colony sweep only. This investigation demonstrates that dairy cattle are a reservoir of E. coli O157:H7 and other SLTEC.

Ehrlichia chaffeensis, a new species associated with human ehrlichiosis.

Abstract: The bacterial 16S rRNA genes from blood samples of two patients with human ehrlichiosis and from an isolate recovered from one of the patients were amplified by using the polymerase chain reaction. The amplimers were then cloned and sequenced. The 16S rRNA gene sequence was also determined for Ehrlichia canis (two strains), E. equi, E. phagocytophila (two strains), and E. sennetsu (two strains). These sequences, along with a previously published 16S rRNA gene sequence of E. risticii, were compared. The 16S rRNA gene sequences were identical for all three sources of the human ehrlichiosis agent. The sequence comparisons indicate that the human ehrlichiosis agent is a new species most closely related to E. canis (98.2%) and more distantly related to other Ehrlichia spp. We propose that this species be named Ehrlichia chaffeensis sp. nov., with the Arkansas strain as the type strain.

Hepatitis B: evolving epidemiology and implications for control.

Abstract: Control and the possible elimination of transmission of HBV infection is possible with the appropriate use of hepatitis B vaccines. The prevention of chronic HBV infection has the potential of reducing the association burden of chronic liver disease and primary hepatocellular carcinoma. Worldwide, strategies for the effective use of hepatitis B vaccine have been developed and are being implemented in those areas where childhood transmission is the predominant source of chronic HBV infections. However, in the United States and other areas with "low" rates of HBV infection, current vaccination strategies have not been effective and have not fully taken into account the multifaceted epidemiology of HBV infection in those areas. Unfortunately, the majority of infections occur among adults who have been the most difficult to access, who acquire infection before they realize they are at risk, and where the changing epidemiology of HBV infections among the various risk groups only emphasizes the problems of vaccine delivery. In addition, the majority of persons receiving vaccine as a result of the current strategy to immunize adult high-risk groups have been persons who acquire HBV infection through occupational exposure, a group that accounted for no more than 5% of cases even before vaccine was introduced. The failure of the current immunization strategy to prevent a disease with significant health care and economic consequences is beginning to cause a reevaluation of this approach. A comprehensive approach to eliminating HBV transmission must address infections acquired during early childhood as well as those acquired by teenagers and adults.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for the effects of HIV antibody counseling and testing on risk behaviors.

Abstract: Objective. —To review published abstracts, journal articles, and presentations for evidence of the effects of human immunodeficiency virus (HIV) antibody counseling and testing on risk behaviors. Studies reviewed focused on homosexual men, intravenous drug users in treatment programs, pregnant women, and other heterosexuals. Data Sources. —Peer-reviewed journals (January 1986 through July 1990) and published abstracts and oral presentations from the second (1986) through the sixth (1990) International Conferences on AIDS. Study Selection. —We identified 66 studies that included data on the behavioral effects of HIV antibody counseling and testing. By consensus of the authors, 16 of these were excluded because of small sample size or inadequate study design. Data Extraction. —Studies were assessed by the authors according to methodological strength (sample selection, inclusion of appropriate comparison groups, and inclusion of statistical tests of significance). Data Synthesis. —All longitudinal studies of homosexual men reported reductions in risky behavior among both tested and untested men, and a few reported greater decreases among seropositive men than among seronegative men and those untested or unaware of their serostatus. For intravenous drug users in treatment, we found reductions in intravenous drug use and sexual risk behaviors regardless of counseling and testing experience. We found little evidence for the impact of counseling and testing on pregnancy and/or pregnancy termination rates for either seropositive or seronegative high-risk women. We noted substantial risk reduction among heterosexual couples with one infected partner. Findings among other heterosexuals at increased risk were scanty and mixed. Conclusions. —Further studies should specifically address the behavioral consequences of counseling and testing in various settings. (JAMA. 1991;266:2419-2429)

Factors affecting the immunogenicity of oral poliovirus vaccine in developing countries: review.

Abstract: Although rates of seroconversion following administration of trivalent oral poliovirus vaccine (TOPV) approach 100% in industrialized countries, only 73% (range, 36%-99%) and 70% (range, 40%-99%) of children in developing countries have detectable antibody to poliovirus types 1 and 3, respectively, after three doses. While factors accounting for these differences have not been fully elucidated, available data suggest that type 2 vaccine virus and enteric pathogens often interfere with responses to types 1 and 3 vaccine viruses but that this interference may be overcome by modifying the absolute and relative dosage of the three Sabin types. Increasing the interval between doses beyond 30 days may also be important, in view of the prolonged excretion of vaccine virus and the potential for interference with responses to subsequent doses. Although advances in molecular biology may ultimately lead to the development of more-immunogenic vaccine candidates, approaches such as increasing the number of doses of TOPV, mass vaccination campaigns, and combined use of oral and inactivated vaccines should also be considered.

Isolation and characterization of an Ehrlichia sp. from a patient diagnosed with human ehrlichiosis.

Abstract: A new disease was recognized in the United States in 1986. The etiologic agent, although not previously isolated from a human, appeared to be serologically related to Ehrlichia canis, a canine leukotropic rickettsia. We obtained blood specimens from 27 febrile patients with a history of tick exposure. Leukocytes from 24 patients not treated with tetracycline were placed onto a monolayer of DH82 cells. We performed indirect immunofluorescence on sera from all 27 febrile patients as well as sera from 12 patients with previously diagnosed ehrlichiosis. Intractoplasmic inclusions were first observed in culture 35 days after the addition of infected blood from one patient. Partial sequencing of the rRNAs from the human isolate and E. canis indicated that they are 98.7% related. Positive indirect immunofluorescence reactions to the human isolate were obtained for all 12 previously diagnosed patients and for 33% of the 27 febrile patients. Two patients were seropositive for the human isolate but not for E. canis. No sera were positive for E. canis and negative for the human isolate. We report the isolation of a previously unrecognized Ehrlichia sp. that appears to be the etiologic agent of human ehrlichiosis. Serologic data (range of antibody titers, 256 to 32,768) in combination with rRNA sequencing indicated that the newly isolated Ehrlichia sp. is similar, but not identical, to E. canis.

HIV-associated disease of the nervous system: review of nomenclature and proposal for neuropathology-based terminology.

Abstract: Herbert Budka 1, Clayton A. Wiley 2, Paul Kleihues 3, Juan Artigas 4, Arthur K. Asbury 5, Eun-Sook Cho 6, David R. Cornblath 7, Mauro C. Dal Canto 8, Umberto DeGirolami 9, Dennis Dickson 10, Leon G. Epstein 11, Margaret M. Esiri 12, Felice Giangaspero 13, Georg Gosztonyi 14, Francoise Gray 15, John W. Griffin 7, Dominique Henin 16, Yuzo lwasaki 17, Robert S. Janssen '8, Richard T. Johnson 7, Peter L. Lantos 19, William D. Lyman 10, Justin C. McArthur 7, Kazuo Nagashima 20, Nancy Peress 21, Carol K. Petito 22, Richard W. Price 23, Roy H. Rhodes Z4, Marc Rosenblum 25, Gerard Said 26, Francesco Scaravilli 27, Leroy R. Sharer 6, Harry V. Vinters 28

Physical Activity Behaviors in Lower and Higher Socioeconomic Status Populations

Abstract: Few data on physical activity habits among populations of low socioeconomic status have been published. The authors studied physical activity habits--leisure-time physical activity, job-related physical activity, household physical activity, and walking--among 172 lower socioeconomic status women and 84 lower socioeconomic status men and compared their habits with those of 208 higher socioeconomic status women and 95 higher socioeconomic status men. All subjects resided in the greater Pittsburgh, Pennsylvania, area. Data collection occurred throughout 1986. Lower socioeconomic status women, the least active group, averaged 1,536 +/- 1,701 minutes/week (+/- standard deviation) of total physical activity, whereas higher socioeconomic status women, the most active group, averaged 2,079 +/- 1,807 minutes/week (p less than 0.0001). Higher socioeconomic status men averaged 1,952 +/- 1,799 minutes/week, and lower socioeconomic status men averaged 1,948 +/- 1,916 minutes/week. Higher socioeconomic status women spent significantly more time each week in leisure-time physical activity, job-related physical activity, and household physical activity than did lower socioeconomic status women. Lower socioeconomic status men spent significantly more time each week walking and doing household chores, whereas higher socioeconomic status men tended to be more active in leisure-time physical activity. These data suggest important quantitative and qualitative differences in physical activity among population subgroups. In view of the important role of physical activity in promoting physical and mental health, reasons for the differences among groups of varying socioeconomic status must be examined and elucidated.

Clinical evaluation of the cysticercosis enzyme-linked immunoelectrotransfer blot in patients with neurocysticercosis.

Abstract: During the 3 years that the enzyme-linked immunoelectrotransfer blot (EITB) assay for the diagnosis of human cysticercosis has been in use at the Centers for Disease Control, 50 patients with both pathologically confirmed neurocysticercosis and computed tomographic (CT) or magnetic resonance imaging (MRI) scan results were identified. Of 32 patients with two or more lesions, 94% had detectable antibodies by EITB compared with 28% of 18 patients with single lesions. Patients with only calcified cysts (single or multiple) were less likely to have EITB-positive results than were those with noncalcified, enhancing lesions. Antibody was detectable more frequently in serum than in cerebrospinal fluid, regardless of the number or apparent condition of the cysts. These findings confirm that the EITB assay for cysticercosis antibodies is highly sensitive in patients with multiple, enhancing intracranial lesions but is less sensitive in patients with single lesions and in those with calcified lesions.

Unintentional carbon monoxide-related deaths in the United States, 1979 through 1988.

Abstract: Objective.— To describe the epidemiology of recent unintentional carbon monoxide poisoning deaths in the United States. Design.— Descriptive analysis of carbon monoxide—related deaths in the United States from 1979 through 1988, based on death certificate reports compiled by the National Center for Health Statistics. Population Studied.— All US deaths, 1979 through 1988. Results.— We reviewed data from 56 133 death certificates that contained codes implicating carbon monoxide as a contributing cause of death. Of these, 25 889 were suicides, 210 were homicides, 15 523 were associated with severe burns or house fires, and 11 547 were classified as unintentional. The number of unintentional deaths decreased steadily by about 63 deaths per year, from 1513 in 1979 to 878 in 1988. The highest death rates occurred in winter and among males, blacks, the elderly, and residents of northern states. Motor vehicle exhaust gas caused 6552 (57%) of the unintentional deaths; 5432 (83%) of these were associated with stationary automobiles. Conclusions.— The rate of unintentional death from carbon monoxide poisoning is decreasing. This may be attributable to improvements in automobile pollution control systems and improved safety of cooking and heating appliances. Prevention programs should target young drivers, males, and the elderly. ( JAMA . 1991;266:659-663)

Comparison of the E Test to agar dilution, broth microdilution, and agar diffusion susceptibility testing techniques by using a special challenge set of bacteria.

Abstract: The E Test (AB Biodisk, Solna, Sweden) is a new method for performing antimicrobial susceptibility tests. It consists of an impervious carrier (5- by 50-mm strip) with a predefined antimicrobic gradient which is placed on an inoculated agar plate and processed like a disk diffusion test. Results are generated directly as MICs from a continuous concentration gradient covering 15 twofold dilutions, and MICs are read where the edge of the inhibition zone intersects the strip. We compared the E Test with disk diffusion, broth microdilution, and agar dilution tests by using a challenge set of 195 gram-positive and gram-negative bacteria for 14 antimicrobial agents. Also, disk diffusion, broth microdilution, and agar dilution tests were compared with each other. All test method comparisons gave greater than 94% agreement for the category of susceptibility. The E Test category agreement with disk diffusion and broth microdilution was 95.1%, and with agar dilution it was 95.2%. The E Test results were as reliable as the results obtained by the standard antimicrobial susceptibility testing methods.

Threshold of detection of Cryptosporidium oocysts in human stool specimens: evidence for low sensitivity of current diagnostic methods.

Abstract: To determine the minimum number of Cryptosporidium oocysts that can be detected in stool specimens by diagnostic procedures, stool samples seeded with known numbers of Cryptosporidium parvum oocysts were processed by the modified Formalin-ethyl acetate (FEA) stool concentration method. FEA concentrates were subsequently examined by both the modified cold Kinyoun acid-fast (AF) staining and fluorescein-tagged monoclonal antibody (immunofluorescence [IF]) techniques. Oocysts were more easily detected in watery diarrheal stool specimens than they were in formed stool specimens. For watery stool specimens, a 100% detection rate was accomplished at a concentration of 10,000 oocysts per g of stool by both the AF staining and IF techniques. In formed stool specimens, 100% of specimens seeded with 50,000 oocysts per gram of stool were detected by the IF technique, whereas 500,000 oocysts per g of stool were needed for a 100% detection rate by AF staining. Counting of all oocysts on IF slides indicated a mean oocyst loss ranging from 51.2 to 99.6%, depending on the stool consistency as determined by the FEA concentration procedure. Our findings suggest that the most commonly used coprodiagnostic techniques may fail to detect cryptosporidiosis in many immunocompromised and immunocompetent individuals.

Mammographic densities and risk of breast cancer.

Abstract: To determine the relation of mammographic densities to subsequent breast cancer risk, a case-control study was undertaken using prediagnostic mammograms of screening program participants. Mammograms of cases (n = 266) and controls (n = 301) were blindly assessed for mammographic densities, which were measured by planimetry. The odds of breast cancer increased steadily with increasing breast density (test for trend, P less than 0.0001). Breast cancer odds was 1.7 for densities between 5% and 24.9%, 2.5 for 25% through 44.9%, 3.8 for 45% through 64%, and 4.3 for densities of 65% and greater (referent = less than 5% densities). Odds ratios also increased with increasing densities among women with the P2 and DY mammographic patterns. These findings suggest that the percentage of mammographic densities in the breast can predict breast cancer risk more accurately than a qualitative assessment of mammographic patterns.

Placebo-Controlled Clinical Trial of Sodium Stibogluconate (Pentostam) versus Ketoconazole for Treating Cutaneous Leishmaniasis in Guatemala

Abstract: : To determine the relative efficacy and toxicity of stibogluconate and ketoconazole for the treatment of cutaneous leishmaniasis, we conducted a comparative trial in which 120 Guatemalan men with parasitologically proven cutaneous leishmaniasis were randomly divided into three treatment groups: sodium stibogluconate (20 mg of antimony per kg per day intravenously for 20 days); ketoconazole (600 mg per day orally for 28 days); and placebo. Stibogluconate was associated with occasional moderate but manageable adverse effects, including abnormal electrocardiograms and elevated transaminase values. Treatment outcome was influenced by species. Among patients infected with Leishmania braziliensis, 24 (96%) of 25 in the stibogluconate group responded. Among L. mexicana-infected patients, only four (57%) of seven in the stibogluconate group but eight (89%) of nine in the ketoconazole group responded. These differences emphasize the importance of specification in the treatment of leishmaniasis.