Influenza A subtype H3N2 is associated with an increased risk of hospital dissemination - an observational study over six influenza seasons.

BACKGROUND: Previous studies on hospital-acquired influenza (HAI) have not systematically evaluated the possible impact of different influenza subtypes. HAI has historically been associated with high mortality, but clinical consequences may be less severe in a modern hospital setting. AIMS: To identify and quantify HAI for each season, investigate possible associations with varying influenza subtypes, and to determine HAI-associated mortality. METHODS: All influenza-PCR-positive adult patients (>18 years old) hospitalized in Skåne County during 2013-2019, were prospectively included in the study. Positive influenza samples were subtyped. Medical records of patients with suspected HAI were examined to confirm a nosocomial origin and to determine 30-day mortality. RESULTS: Of 4110 hospitalized patients with a positive influenza PCR, 430 (10.5%) were HAI. Influenza A(H3N2) infections were more often HAI (15.1%) than influenza A(H1N1)pdm09, and influenza B (6.3% and 6.8% respectively, P<0.001). The majority of HAI caused by H3N2 were clustered (73.3 %) and were the cause of all 20 hospital outbreaks consisting of ≥4 affected patients. In contrast, the majority of HAI caused by influenza A(H1N1)pdm09 and influenza B were solitary cases (60% and 63.2%, respectively, P<0.001). Mortality associated with HAI was 9.3% and similar between subtypes. CONCLUSIONS: HAI caused by influenza A(H3N2) was associated with an increased risk of hospital dissemination. Our study is relevant for future seasonal influenza infection control preparedness and shows that subtyping of influenza may help to define relevant infection control measures. Mortality in HAI remains substantial in a modern hospital setting.

Contexts of condom use and non-condom use among young adolescent male perpetrators of dating violence.

The purpose of this study was to examine qualitatively the context of and reasons for condom use and non-use among adolescent male perpetrators of dating violence. Semi-structured anonymous interviews were conducted with 19 adolescent males recruited from intervention programs for adolescent perpetrators of dating violence. Interviews included questions about dating violence perpetration, sexual relationships and risk behaviors. Interviews were analyzed using a content analysis approach and coded to examine boys' condom use and non-use behaviors and contexts. Participants (n=19) were aged 17-21 years and were predominantly white (n=9; 47%) or black (n=4; 21%). Half (n=10; 53%) indicated four or more sex partners in the past three months; half (n=10; 53%) reported no or inconsistent condom use in the past three months. Qualitative findings from this study revealed condom use in high-risk casual sex encounters, including 'trains' (1-2 girls having sex with several boys sequentially). Non-use of condoms was more common in steady, often abusive, relationships, although boys reported sexual infidelity in these relationships. These results indicate that non-use of condoms is occurring among adolescent male perpetrators of dating violence, particularly in the context of their steady relationships and despite reports of very high risk sexual activity including sexual infidelity, involvement in 'trains' and multiple sex partners. Sexual health interventions integrated with dating violence and sexual assault prevention efforts and tailored to adolescents are needed.

Verve and Jolt: deadly new Internet drugs.

As regulatory agencies have increased restrictions on the sale and marketing of gamma-hydroxybutyrate (GHB), they have been frustrated by the appearance of precursor molecules such as gamma-butyrolactone (GBL) that have become widely available over the Internet. These dangerous precursors are vigorously marketed to adolescents and young adults as dietary supplements that increase muscle mass and enhance sexual performance with seductive names such as Verve and Jolt, both easily recognizable teen icons. We present the case of an adolescent who ingested both of these GBL products 2 weeks apart, resulting in life-threatening respiratory depression and emergent intubation on both occasions. The GBL toxidrome, necessary acute interventions, and public health implications are reviewed. We urge all health care providers to report similar cases immediately to the FDA MedWatch system. Gamma-butyrolactone, gamma-hydroxybutyrate, respiratory insufficiency, central nervous system depressants, substance abuse.

Confidentiality and adolescents' use of providers for health information and for pelvic examinations.

OBJECTIVE: To examine the relationship between adolescents' perception of the confidentiality of care provided by their regular health care provider and their reported use of this provider for private health information and for pelvic examinations. DESIGN: Anonymous, self-report survey. SETTING: Thirty-two randomly selected public high schools in Massachusetts. PARTICIPANTS: Of 2224 students in systematically selected 9th and 12th grade classrooms, 1715 (50% male) had a regular provider and a checkup within the last year. RESULTS: Of teens surveyed, 76% wanted the ability to obtain confidential health care, but only 45% perceived their regular provider to provide this, and only 28% had discussed it explicitly. Logistic regression analyses revealed strong relationships between confidentiality and all outcomes studied. Among adolescents, the likelihood of having discussed sexually transmitted diseases, pregnancy prevention, and/or facts about sex with their provider was greater among teens who received a confidentiality assurance than that for teens who did not (odds ratio [OR] = 2.7; 95% confidence interval [CI], 2.2-3.4). A similar relationship for teens' likelihood of having discussed substance use with the provider was found (OR = 1.8; 95% CI, 1.4-2.3). Among sexually active females, the likelihood of a recent pelvic examination for those who received a confidentiality assurance was greater than for those who did not (OR = 3.3; 95% CI, 2.1-5.5). CONCLUSIONS: This study furthers evidence of an important link between teens' perception of confidentiality and use of health care services and information. Because teens' health risks lie largely in potential risks from health-related behaviors, confidentiality in health care may be a critical factor in disclosure and discussion of risky behaviors, and ultimately in appropriate use of health care services. Efforts should be made to increase teens' access to confidential health care sources.

Echocardiographic markers for mitral valve surgery to preserve left ventricular performance in mitral regurgitation.

BACKGROUND: The timing of mitral valve (MV) surgery to preserve left ventricular (LV) contractility in patients with mitral regurgitation (MR) has been defined by complex cardiac catheterization techniques. Whether noninvasive methods can identify patients with MR, a normal LV ejection fraction, and early LV contractile impairment is unknown. We hypothesized that echocardiographic measures would separate patients with MR and a normal LV ejection fraction into those with and without contractile dysfunction and, thus, prospectively predict the response of LV size and performance to MV surgery. METHODS AND RESULTS: We studied 27 patients with micromanometer LV pressures and radionuclide angiography to obtain a determination of LV volumes and ejection fraction and calculate chamber elastance, a measure of LV contractility, before MV surgery. Echocardiographic studies were performed before MV surgery and repeated at 3 and 12 months after surgery. Age, New York Heart Association class, LV plus maximum pressure per unit change in time, LV systolic and end-diastolic pressures, and echocardiographic posterior wall thickness and radius to wall thickness ratio did not identify preoperative LV contractile dysfunction. However, other echocardiographic measures were related to LV contractility, including LV end-diastolic dimension (r = -0.50, P <.005), LV end-systolic dimension (r = -0.60, P <.0001), and LV fractional shortening (r = 0.50, P =.005). From analysis of receiver operator characteristic curves, an LV end-systolic dimension of >/=40 mm was identified as most predictive for separating patients with MR before surgery into those with and without LV contractile dysfunction (sensitivity of 82% and specificity of 100%). The patients with MR and impaired preoperative LV contractility showed a dramatic deterioration in LV fractional shortening at 3 months after MV surgery (P =.01), which recovered to within the normal range for fractional shortening at 12 months (P =.02) from a progressive reduction in LV end-systolic dimension. This response in LV size and performance temporally differed from that in the patients with MR and normal contractility (2-way analysis of variance P <.0001). However, at 12 months after MV surgery, LV end-diastolic dimension, end-systolic dimension, and fractional shortening were normal in both groups of patients with MR. CONCLUSION: We conclude that echocardiographic measures, particularly an end-systolic dimension of >/=40 mm, may be useful for identifying patients with MR before surgery with early, occult LV contractile dysfunction in whom MV surgery may be recommended to preserve LV systolic performance.

Congenital colocutaneous fistula as presenting sign of prenatally closed gastroschisis.

MATERIALS AND METHODS: An infant was born with a congenital colocutaneous fistula to the right of the base of the umbilicus, along with distal small bowel atresia. RESULTS: These findings produced a unique presentation of a prenatally closed gastroschisis with absorption of the extruded intestine. CONCLUSION: This child, like all five previously reported infants with prenatally closed gastroschisis, died from complications of short-gut syndrome.

Gastroesophageal reflux in infants with hydrocephalus before and after ventriculo-peritoneal shunt operation.

Gastroesophageal reflux (GER) is common in neurologically impaired children, especially those with central nervous system disorders. The cause of GER in these children has not yet been defined, but in animal studies, acute elevation of intracranial pressure (ICP) has been shown to result in a decrease in lower esophageal sphincter pressure. Ten infants with hydrocephalus underwent esophageal pH monitoring prior to and after a ventriculoperitoneal (V-P) shunt operation. A significant degree of reflux was present in 5 patients with hydrocephalus prior to shunt operation and reverted to normal in 2. In the other 3 infants, the degree of reflux decreased as evidenced by fewer abnormal parameters and lower scoring in each of the parameters measured. Our study supports the contention that increased ICP in infants is indeed associated with GER. As 4 of the 5 infants with significant reflux suffered from an Arnold-Chiari malformation, a causal relation between increased ICP due to defects involving the fourth ventricle floor and GER is suggested.

Nerve and tendon gliding exercises and the conservative management of carpal tunnel syndrome.

While developments continue in the surgical management of carpal tunnel syndrome, little emphasis has been placed on the evaluation of a comprehensive non-surgical treatment. In this study, 197 patients (240 hands) presenting for treatment of carpal tunnel syndrome were divided into two groups. Patients in both groups were treated by standard conservative methods, and those in one group were also treated with a program of nerve and tendon gliding exercises. Of those who did not perform the nerve and tendon gliding exercises, 71.2% underwent surgery compared with only 43.0% of patients who did perform them. Patients in the experimental group who did not undergo surgery were interviewed at an average follow-up time of 23 months (range, 14-38 months). Of these 53 patients, 47 (89%) responded to this detailed interview. Of the 47 who responded, 70.2% reported good or excellent results, 19.2% remained symptomatic, and 10.6% were non-compliant. Thus, a significant number of patients who would otherwise have undergone surgery for failure of traditional conservative treatment were spared the surgical morbidity of a carpal tunnel release (p = 0.0001).

Multimodality staging optimizes resectability in patients with pancreatic and ampullary cancer.

Few patients with pancreatic cancer have resectable disease at the time of diagnosis, and a variety of nonsurgical techniques are available to provide effective palliation of jaundice and pain. Accurate preoperative staging is essential to identify patients with unresectable disease, thereby minimizing unnecessary surgery. Currently used diagnostic tests include contrast-enhanced computerized tomography (CT), visceral angiography, endoscopic ultrasound, and laparoscopy, but their utility remains controversial. To evaluate the accuracy of these various diagnostic tests, 30 consecutive patients with histologically proven pancreatic or ampullary adenocarcinoma treated between 1992 and 1996 were evaluated. All 30 patients had contrast-enhanced CT and laparoscopy, 22 patients (73%) had visceral angiography, and 16 patients (53%) had endoscopic ultrasound. Individual and combined predictive values of resectability and unresectability as well as the sensitivities and specificities were determined for all diagnostic tests and compared with intraoperative findings. When CT, visceral angiography, and laparoscopy were combined, the predictive values of resectability and unresectability were 75 and 90 per cent, respectively, with a sensitivity of 75 per cent and a specificity of 90 per cent. Therefore, the combined use of selected diagnostic tests proved more effective than any single diagnostic test for accurately staging patients with pancreatic head and ampullary cancers and should be considered to minimize unnecessary surgery.

Responsiveness of leg alignment changes associated with articular pressure testing to spinal manipulation: the use of a randomized clinical trial design to evaluate a diagnostic test with a dichotomous outcome.

OBJECTIVE: A study was undertaken to assess the stability of leg alignment reaction to a pressure challenge and its responsiveness to an adjustive intervention. DESIGN: Prospective, double-blind clinical trial of a diagnostic test. SETTING: Laboratory: Center for Technique Research. PARTICIPANTS: Forty-two chiropractic college students, faculty and staff. INTERVENTIONS: A high-velocity, low-amplitude, short lever adjustment of a single vertebra from among C1 and T3-T7; or a sham adjustment similar to a manual diagnostic pressure test at C1, T3-T7 or T9-T10. MAIN OUTCOME MEASURES: Leg alignment reactivity: An increase in leg alignment discrepancy (yes or no) following a metered pressure challenge to a vertebra. RESULTS: On average, stability was poor at T3-T7 (Kappa = 0.04), moderate at C1 (K = 0.47), and fair for sham pressure tests (K = 0.30). Responsiveness: The proportion of positive baseline leg alignment reactions that responded (became negative) to sham adjustment was 95% at T3-T7 and 55% at C1. Further analysis was untenable since too few vertebrae were implicated for an adjustment. CONCLUSIONS: For the population investigated, the majority of the responsiveness of the leg alignment diagnostic test to a rotatory adjustment appears to be a diagnostic illusion (i.e., background noise unrelated to a treatment intervention). Further research with different subject populations, regions of investigation, leg alignment measurement techniques and vertebral challenge techniques are indicated.

Reactivity of leg alignment to articular pressure testing: evaluation of a diagnostic test using a randomized crossover clinical trial approach.

OBJECTIVE: A study was undertaken to assess the reliability of detecting leg alignment changes (reactivity) and to determine if the observed leg alignment reactivity can be attributed to a rotatory articular pressure challenge. DESIGN: Prospective double-blind crossover trial of a diagnostic test. SETTING: Laboratory: Center for Technique Research. PARTICIPANTS: Forty-two chiropractic college students, faculty and staff. INTERVENTIONS: A standardized force of 2 or 3 kg was applied with a 1 cm2 rubber-tipped pressure algometer on the lateral aspect of the T3-T7 spinous processes and the posterior aspect of the lateral masses of C1. MAIN OUTCOME MEASURES: Leg alignment reactivity: an increase in leg alignment discrepancy (yes or no) following a diagnostic intervention. RESULTS: The reliability for detecting leg alignment reactivity was poor: on average, Kappa = 0.05 in the thoracics and 0.06 at C1. On average, the attributable risk of leg alignment reactivity (pressure test risk--sham test risk) was less than 4%. In many cases, the sham rate was greater than the pressure test rate. CONCLUSIONS: For the population investigated, leg alignment reactivity to rotatory pressure testing can, in the majority of cases, be attributable to background noise. This procedure was not found to be viable for identifying vertebrae for adjustment. Further research with different subject populations, regions of investigation, leg alignment measurement techniques and vertebral challenge techniques are indicated.

Fiscal impacts of immigration to the United States.

"The purpose of this paper is to fill a gap in the demographic literature by reviewing previous fiscal studies of immigration in the United States. Each study is introduced by describing the data it uses, the methodologies employed in calculating costs and revenues, and the resulting estimates of fiscal consequences. Evaluative comments are also stressed. Seventeen studies are included in this review, divided into those that emphasize national fiscal impacts (these studies aggregate the effects of immigrants across all levels of government), state fiscal impacts, and fiscal effects on local governments."

Anterior shoulder stability: Contributions of rotator cuff forces and the capsular ligaments in a cadaver model.

The purpose of this study was to quantify in a biomechanical model the contributions to shoulder joint stability that are made by tensions in the four tendons of the rotator cuff and by static resistance of defined portions of the capsular ligaments. A materials testing machine was used to directly determine anterior joint laxity by measurement of the force required to produce a standard anterior subluxation. Shoulders were tested in external or neutral humeral rotation. Data were analyzed by multiway analysis of variance with regression analysis. This model simulated tensions in the rotator cuff musculature by applying static loads at the tendon insertion sites acting along the anatomic lines of action. A load in any of the cuff tendons resulted in a measurable and statistically significant contribution to anterior joint stability. The contributions between different tendons were not significantly different and did not depend on the humeral rotation (neutral or external). In neutral humeral rotation the superior and middle glenohumeral ligaments together function equally with the inferior glenohumeral ligament as primary stabilizers against anterior humeral translation. The posterior capsule is a secondary stabilizer. The external rotation of the abducted humerus increases anterior stability by more than doubling the stability contribution from the inferior glenohumeral ligament. The stability contribution from the posterior capsule is larger in external rotation than in neutral rotation but is still of secondary magnitude. In external rotation the stability contribution of the anterior capsule, including the superior glenohumeral ligament and the middle glenohumeral ligament, becomes insignificant. The model presented here simulates the combined effect of two major sources of shoulder stability. This versatile model permits the direct measurement of the contributions to anterior shoulder stability that are made by tensions in the rotator cuff tendons and by static resistance of defined capsular zones. The use of multiple regression analysis-a standard statistical technique but one relatively new to the orthopaedic literature-permits quantitative determination of the contribution of each independent variable to the dependent variable, shoulder stability.

Bacterial cholangitis after surgery for biliary atresia.

We retrospectively studied the incidence of bacterial cholangitis in 129 infants operated on because of biliary atresia over 5 years. Forty-six of the 101 children who underwent hepatic portoenterostomy had a total of 105 episodes of cholangitis (range one to eight episodes per child). Most episodes occurred within 3 months of the operation. Factors associated with cholangitis included good or partial restoration of bile flow, abnormal intrahepatic bile ducts or cavities at the porta hepatis, and routine postoperative use of antibiotics. External jejunostomy was not effective in preventing cholangitis. In addition to fever and decreased bile flow, increased erythrocyte sedimentation rate and signs of shock were frequently observed. The responsible organisms, most often gram-negative bacteria, were identified in 79 (75%) episodes by blood or liver cultures. Most were susceptible to trimethoprim-sulfamethoxazole and third-generation cephalosporins during the first episode, but only to cephalosporins during later episodes. The incidence of signs of portal hypertension in children with normal serum bilirubin values at age 5 years was not higher in those who had previously experienced one or more episodes of cholangitis.

A revised indirect estimate of mutation rates in Amerindians.

We have previously raised the possibility that the mutation rate resulting in rare electrophoretic variants is higher in tribal/tropical-dwelling/nonindustrialized societies than in civilized/temperate-dwelling/industrialized societies. Here, we report the results of examining 11 additional proteins for the occurrence of rare electrophoretic variants in 10 Amerindian tribes, for a total of 8,968 determinations and a total of 17,648 locus tests. When these data are combined with the results of all our previous similar studies of Amerindians, a total of 272,298 polypeptides, the products of 43 different loci, have been examined for the occurrence of rare electrophoretic variants. On the assumption that these variants are maintained by mutation pressure and are essentially neutral in their phenotypic effects, we have calculated by three different approaches that it requires an average mutation rate of 1.3 X 10(-5)/locus per generation to maintain the observed variant frequency. Concurrently, we are reporting elsewhere that a direct estimate of the mutation rate resulting in electromorphs in various studies of civilized industrialized populations is 0.3 X 10(-5)/locus per generation. Although this difference appears to have statistical significance, the nonquantifiable uncertainties to both approaches are such that our enthusiasm for a true difference in mutation rates between the two types of populations has diminished. However, even the lower of these estimates, when corrected for all the types of genetic variation that electrophoresis does not detect, implies total locus and gametic mutation rates well above those which in the past have dominated genetic thinking.

A model of weak selection in the infinite alleles framework.

Ewens (1972) proposed a model in the infinite allele framework for populations with neutrality of all alleles at a particular locus. This paper proposes a generalisation of Ewens' result for situations where there is a form of weak selection. The models considered here are continuous time, discrete state space Markov processes.

Time domain analysis of diaphragmatic electromyogram during fatigue in men.

Diaphragmatic fatigue has been correlated with a change in the electromyogram recorded from the diaphragm (EMGdi), which suggests that the electromyogram is a potential clinical tool to detect respiratory muscle fatigue. Changes in the EMGdi have previously been quantified by using the power spectral parameters high-low ratio or mean frequency. In this study, we developed an autoregressive model of the EMG in an attempt to improve the analysis of the EMGdi. This model was tested on recordings of the EMGdi that were obtained from an esophageal electrode in five normal subjects breathing to fatigue through an inspiratory resistor. The data obtained from the autoregressive model were directly compared with data from the high-low ratio and mean frequency techniques. The autoregressive model showed an excellent correlation with mean frequency. Both techniques were superior to the high-low ratio measurement. Because the autoregressive model requires much less computation than mean frequency and can be easily implemented in real time on a minicomputer, we propose this as a preferable approach.