Preventing community-wide transmission of Cryptosporidium: a proactive public health response to a swimming pool-associated outbreak--Auglaize County, Ohio, USA.

The incidence of recreational water-associated outbreaks in the United States has significantly increased, driven, at least in part, by outbreaks both caused by Cryptosporidium and associated with treated recreational water venues. Because of the parasite's extreme chlorine tolerance, transmission can occur even in well-maintained treated recreational water venues (e.g. pools) and a focal cryptosporidiosis outbreak can evolve into a community-wide outbreak associated with multiple recreational water venues and settings (e.g. childcare facilities). In August 2004 in Auglaize County, Ohio, multiple cryptosporidiosis cases were identified and anecdotally linked to pool A. Within 5 days of the first case being reported, pool A was hyperchlorinated to achieve 99·9% Cryptosporidium inactivition. A case-control study was launched to epidemiologically ascertain the outbreak source 11 days later. A total of 150 confirmed and probable cases were identified; the temporal distribution of illness onset was peaked, indicating a point-source exposure. Cryptosporidiosis was significantly associated with swimming in pool A (matched odds ratio 121·7, 95% confidence interval 27·4-∞) but not with another venue or setting. The findings of this investigation suggest that proactive implementation of control measures, when increased Cryptosporidium transmission is detected but before an outbreak source is epidemiologically ascertained, might prevent a focal cryptosporidiosis outbreak from evolving into a community-wide outbreak.

Cell surface energy, contact angles and phase partition. III. Adhesion of bacterial cells to hydrophobic surfaces.

The densities of adhesion of Staphylococcus epidermidis, Staphylococcus aureus and Serratia marcescens to five types of plastics were studied in relation to interfacial free energies at the aqueous interfaces of both the bacteria and the plastics. The free energy of adhesion of bacteria to plastic in an aqueous medium is a linear function of partititon of the bacteria between the solid surface and the liquid phase. These results show that the thermodynamics of the partitioning of a suspended particle between two immiscible liquid phases also apply to partitioning between a liquid and a solid phase.

Use of mental health services among victims of crime: frequency, correlates, and subsequent recovery.

The use of mental health services was examined within a sample of 392 victims of crime who were generally representative of that population in Kentucky. Respondents were interviewed twice at a 6-month interval. Of these victims, 12% had contact with mental health professionals within the first few months postcrime. Hierarchical discriminant analyses revealed that use of mental health services was most prevalent when depressive symptoms were present and the crime involved violence. Among victims of violence, urban residence, high social support, internal locus of control, and prior crime experience were also associated with use. The victims who recovered from the event most rapidly were those who reported receiving mental health services at both Waves 1 and 2. Implications of the study for policies and programs are discussed.

Foot-ground pressure pattern of standing hemiplegic patients. Major characteristics and patterns of improvement.

The study was designed to examine major weight-bearing characteristics of hemiplegic patients receiving physical therapy and to assess the usefulness of the Foot Print apparatus as an objective, clinical measurement tool of these characteristics. Measurements of the foot-ground pressure pattern of 23 patients were taken two times, three weeks apart. The results confirmed the clinical impression of lesser weight bearing by the patient on the affected leg, especially on the heel of that leg, compared with weight bearing on the contralateral leg. Consequently, stance stability was impaired. The difference between the foot-ground pressure of the two measurements indicated improvement in the stance characteristics of these patients after treatment. The Foot Print apparatus seems to be an objective measurement tool of assistance both to the patient and the physical therapist in execution of a treatment.

Employment-based health benefits: analysis of the April 1993 Current Population Survey.

The April 1993 CPS differs from the March 1993 CPS in a number of respects. The April 1993 CPS supplement surveys only workers, whereas the March CPS examines the noncash benefits received by all Americans. The April CPS asks workers about health coverage in the week in which the questions were fielded, whereas the March CPS asks about coverage in the preceding year. In April 1993, there were 112.5 million civilian American workers between the ages of 18 and 64 with jobs. Eighty-two million (73 percent) of them worked for an employer that sponsored a health insurance plan, and 65 million (58 percent of all workers) participated in their employer's health plan. About one-third of workers at firms with fewer than 10 employees had employers who offer health benefits; about one-quarter of all of the workers in these firms participated in their employer's plan. Conversely, 94 percent of workers at firms with more than 1,000 employees had an employer who sponsored health benefits, and over 77 percent of these workers participated in their employer's plan. There are 16.5 million American workers whose employers sponsored health benefits but who did not participate in these benefits. Over one-half of these workers (8.5 million) chose not to be covered. Another 36 percent of these workers (5.9 million) did not participate because they were ineligible or denied coverage. Over 66 percent of the ineligible workers did not participate because they were part-time, contract, or temporary workers. Another 26 percent had not yet completed a probationary period. Among the reasons that those who chose not to participate in their employer's coverage, the vast majority (75 percent) stated they were covered by another health care plan. Twenty-nine percent stated that they chose not to purchase coverage because it was too costly or that they did not need or want the coverage. In 1993, there were 16.7 million workers with no health insurance coverage. The vast majority of these workers (95 percent) were employed by private employers. Sixty-six percent of the workers with no health insurance coverage were self-employed or worked for firms with fewer than 100 employees.

The Apo(a) gene is the major determinant of variation in plasma Lp(a) levels in African Americans.

The distributions of plasma lipoprotein(a), or Lp(a), levels differ significantly among ethnic groups. Individuals of African descent have a two- to threefold higher mean plasma level of Lp(a) than either Caucasians or Orientals. In Caucasians, variation in the plasma Lp(a) levels has been shown to be largely determined by sequence differences at the apo(a) locus, but little is known about either the genetic architecture of plasma Lp(a) levels in Africans or why they have higher levels of plasma Lp(a). In this paper we analyze the plasma Lp(a) levels of 257 sibling pairs from 49 independent African American families. The plasma Lp(a) levels were much more similar in the sibling pairs who inherited both apo(a) alleles identical by descent (IBD) (r = .85) than in those that shared one (r = .48) or no (r = .22) parental apo(a) alleles in common. On the basis of these findings, it was estimated that 78% of the variation in plasma Lp(a) levels in African Americans is attributable to polymorphism at either the apo(a) locus or sequences closely linked to it. Thus, the apo(a) locus is the major determinant of variation in plasma Lp(a) levels in African Americans, as well as in Caucasians. No molecular evidence was found for a common "high-expressing" apo(a) allele in the African Americans. We propose that the higher plasma levels of Lp(a) in Africans are likely due to a yet-to-be-identified trans-acting factor(s) that causes an increase in the rate of secretion of apo(a) or a decrease in its catabolism.

Characteristics of the structural components of the mouse mammary tumor virus. II. Viral proteins and antigens.

Mild Tween 80-ether treatment of mouse mammary tumor virus (MTV) results in disruption of the viral membrane and release of subviral components. Prolonged lipid extraction, however, results in virtually complete solubilization of the virion. Soluble proteins have been separated by Sephadex G-200 chromatography and used for immunization of rats These antisera identify five viral antigens (designated MTV-s1, s2, s3, s4, and s5). The s1 and s2 antigens are group-specific, and are the antigens of the viral nucleoid. MTV-s3 antigen is a structural protein of the viral membrane. Poly-acrylamide gel electrophoresis of MTV shows five major polypeptides in the virion; the molecular weights of these are p1 (90,000), p2 (70,000), p3 (52,000), p4 (33,000), and p5 (23,000). The major protein of the virus is p3; it is found in the nucleoid and carries the s1 antigen. Protein p5 is the structural protein of the membrane, and it carries the s3 antigen. Antisera prepared against isolated MTV proteins were used also in immunofluorescence tests to determine the intracellular deposition of MTV antigens. These studies show that all MTV structural proteins are synthesized cytoplasmically. Screening of a variety of neoplasms by immunofluorescence and immunodiffusion tests demonstrates MTV infection in only three types of neoplastic diseases, mammary tumors, ML+ leukemias, and Leydig cell tumors of MTV-infected mice. Mammary tumors synthesize all viral structural proteins, while the synthesis of MTV proteins in the ML+ leukemias and Leydig cell tumor is limited to the s1 and s2 antigens. Electron microscopic examination of these tissues confirms the synthesis and accumulation of viral nucleocapsids (A particles) without the production of budding virions.

A rabbit model for human cytomegalovirus-induced chorioretinal disease.

AD169, a well-characterized laboratory strain of human cytomegalovirus (HCMV), was used to establish an animal model of progressive HCMV chorioretinal disease by injection of 10(5) pfu into the rabbit vitreous. Chorioretinal, vitreous, and pulmonary disease were monitored by HCMV recovery, clinical observation, antigen localization, and histopathology. Vitritis and focal areas of immune cellular infiltrates were seen in inner retinal layers on days 2-4 after inoculation. Disease progressed with more severe vitritis and to involve the outer retinal layers in areas of mixed monocytic cellular infiltrates, retinal destruction, choroidal edema, and congestion. HCMV was recovered from chorioretinal cell sonicate cultures in titers ranging from 10(4) to 10(5) pfu during peak disease, and HCMV antigens were detected focally by immunofluorescence in retinal layers on days 2 and 4 after inoculation. A rabbit model of HCMV chorioretinitis similar to human CMV disease allows investigation of HCMV pathogenesis and new antiviral therapies and evaluation of immune system modulation of the HCMV ocular infection.