Reinfection risk of novel coronavirus (COVID-19): A systematic ‎review of current evidence

BACKGROUNDThere is recently a concern regarding the reinfection and reactivation of previously reCoVered coronavirus disease 2019 (CoVID-19) patients.AIMTo summarize the recent findings and reports of CoVID-19 reinfection in patients previously reCoVered from the disease.METHODSThis study was a systematic review of current evidence conducted in August 2020. The authors studied the probable reinfection risk of novel coronavirus (CoVID-19). We performed a systematic search using the keywords in online databases. The investigation adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist to ensure the reliability and validity of this study and results.RESULTSWe reviewed 31 studies. Eight studies described reCoVered patients with reinfection. Only one study reported reinfected patients who died. In 26 studies, there was no information about the status of the patients. Several studies indicated that reinfection is not probable and that post-infection immunity is at least temporary and short.CONCLUSIONBased on our review, we concluded that a positive polymerase chain reaction retest could be due to several reasons and should not always be considered as reinfection or reactivation of the disease. Most relevant studies in positive retest patients have shown relative and probably temporary immunity after the reCoVery of the disease.     

Hospital Evaluations by Social Media: A Comparative Analysis of Facebook Ratings among Performance Outliers

BACKGROUND

An increasing number of hospitals and health systems utilize social media to allow users to provide feedback and ratings. The correlation between ratings on social media and more conventional hospital quality metrics remains largely unclear, raising concern that healthcare consumers may make decisions on inaccurate or inappropriate information regarding quality.

OBJECTIVES

The purpose of this study was to examine the extent to which hospitals utilize social media and whether user-generated metrics on Facebook^® correlate with a Hospital Compare^® metric, specifically 30-day all cause unplanned hospital readmission rates.

DESIGN AND PARTICIPANTS

This was a retrospective cross-sectional study conducted among all U.S. hospitals performing outside the confidence interval for the national average on 30-day hospital readmission rates as reported on Hospital Compare. Participants were 315 hospitals performing better than U.S. national rate on 30-day readmissions and 364 hospitals performing worse than the U.S. national rate.

MAIN MEASURES

The study analyzed ratings of hospitals on Facebook’s five-star rating scale, 30-day readmission rates, and hospital characteristics including beds, teaching status, urban vs. rural location, and ownership type.

KEY RESULTS

Hospitals performing better than the national average on 30-day readmissions were more likely to use Facebook than lower-performing hospitals (93.3 % vs. 83.5 %; p < 0.01). The average rating for hospitals with low readmission rates (4.15 ± 0.31) was higher than that for hospitals with higher readmission rates (4.05 ± 0.41, p < 0.01). Major teaching hospitals were 14.3 times more likely to be in the high readmission rate group. A one-star increase in Facebook rating was associated with increased odds of the hospital belonging to the low readmission rate group by a factor of 5.0 (CI: 2.6–10.3, p <  0.01), when controlling for hospital characteristics and Facebook-related variables.

CONCLUSIONS

Hospitals with lower rates of 30-day hospital-wide unplanned readmissions have higher ratings on Facebook than hospitals with higher readmission rates. These findings add strength to the concept that aggregate measures of patient satisfaction on social media correlate with more traditionally accepted measures of hospital quality.KEY WORDS: Performance measurement, Patient satisfaction, Consumer health informatics     

Helicobacter pylori Protection Against Reflux Esophagitis

Background and Aim

Negative association has been reported between presence of Helicobacter pylori and developing gastroesophageal reflux disease (GERD) and its complications. The aim of this study was to determine whether H. pylori (HP) can be protective against GERD in an African American (AA) population.

Methods

From 2004 to 2007, we studied 2,020 cases; esophagitis (58), gastritis (1,558), both esophagitis and gastritis (363) and a normal control group (41). We collected their pathology and endoscopy unit reports. HP status was determined based on staining of gastric biopsy.

Results

HP data was available for 79 % (1,611) of the cases. The frequency of HP positivity in gastritis patients was 40 % (506), in esophagitis patients 4 % and in normal controls 34 % (11), while HP was positive in 34 % of the patients with both esophagitis and gastritis. After adjusting for effects of age and sex, odds ratio of HP was 0.06 (95 % CI 0.01–0.59; P value = 0.01) for the esophagitis group versus the normal group.

Conclusions

Our results show H. pylori has a significant negative association with esophagitis in AAs which may point to a protective role of H. pylori in the pathogenesis of esophagitis. In addition, H. pylori may be the reason for the low GERD complications in AAs.     

Influence of asymmetry on the flexion relaxation response of the low back musculature

Background

The flexion relaxation phenomenon has been extensively studied in sagittally symmetric postures. Knowledge about this phenomenon in asymmetric trunk postures is less well understood, and may help to reveal the underlying physiology of the passive tissue/active tissue load-sharing mechanism in the lumbar region.

Methods

Twelve participants performed fifteen controlled, full range trunk flexion–extension motions toward three asymmetric lifting postures (0° (sagittally symmetric), 15°, and 30° from the mid-sagittal plane). The electromyographic activity data from the paraspinals at the L3 and L4 levels and trunk kinematics data from motion sensors over the C7, T12 and S1 vertebrae were recorded. The lumbar flexion angles at which these muscles' activities were reduced to resting levels during forward flexion provided quantitative data describing the effects of asymmetry on the passive tissue/active tissue interaction.

Findings

Flexion relaxation was observed in the muscles contralateral to the direction of the asymmetric trunk flexion motion. The response of the ipsilateral extensor musculature was much less consistent, with many trials indicating that flexion relaxation was never achieved. Increasing asymmetry from 0° to 30° led to a 10% reduction in the maximum lumbar flexion. Lumbar flexion angles necessary to achieve flexion relaxation in the contralateral muscles also decreased (L4 paraspinal-related angle decreasing by 15% and the L3 paraspinal-related angle decreasing by 21%).

Interpretation

Under asymmetric conditions the lumbar flexion angle at which the transition from active muscle to passive ligamentous extension moment is altered from that seen in symmetric motions and this transition can have implications for the loading of the spine in full flexion (or near full flexion) postures.     

Antioxidant effects of oleuropein versus oxidative stress induced by ethanol in the rat intestine

Purified oleuropein from olive leaf extract indicated antioxidant properties in our previous reports. The recent study demonstrated that the lesions of absolute ethanol could be attributed to the increasing reactive oxygen species, subsequently lipid peroxidation and gastric ulcers. Therefore, the antioxidant effects of oleuropein as a natural antioxidant agent on intestine mucosal damages induced by absolute ethanol were investigated in the present study. The 42 adult male rats were divided into four (control, oleuropein, ethanol, and oleuropein plus ethanol) groups. Oleuropein at a dosage of 12 mg/kg was used for 10 consecutive days in oleuropein and oleuropein plus ethanol groups, thereafter absolute ethanol (once, 1 ml/rat) was administrated orally in ethanol and oleuropein plus ethanol groups at fasting state by gavage. The duodena of rats were removed for histopathology and antioxidant assay. Histological evidence of severe mucosal damages were confirmed by histopathology findings in ethanol group and prevented in oleuropein plus ethanol group. In this setting, glutathione peroxidase and catalase activities were significantly higher in oleuropein and oleuropein plus ethanol groups than the ethanol-treated rats. In contrast, thiobarbituric acid reactive substances concentration (as a lipid peroxidation marker) significantly increased in ethanol-treated rats when compared to the other groups. Our results suggest that olive leaf extract (containing oleuropein) exerts a potent antioxidant agent against oxidative stress. These findings allow us to exploit the advantages of oleuropein treatment in various diseases induced by oxidative stress in humans.     

The Levels of Brachyspira hyodysenteriae Binding to Porcine Colonic Mucins Differ between Individuals,and Binding Is Increased to Mucins from Infected Pigs with De Novo MUC5AC Synthesis

Brachyspira hyodysenteriae colonizes the pig colon, resulting in mucohemorrhagic diarrhea and growth retardation. Fecal mucus is a characteristic feature of swine dysentery; therefore, we investigated how the mucin environment changes in the colon during infection with B. hyodysenteriae and how these changes affect this bacterium''s interaction with mucins. We isolated and characterized mucins, the main component of mucus, from the colon of experimentally inoculated and control pigs and investigated B. hyodysenteriae binding to these mucins. Fluorescence microscopy revealed a massive mucus induction and disorganized mucus structure in the colon of pigs with swine dysentery. Quantitative PCR (qPCR) and antibody detection demonstrated that the mucus composition of pigs with swine dysentery was characterized by de novo expression of MUC5AC and increased expression of MUC2 in the colon. Mucins from the colon of inoculated and control pigs were isolated by two steps of isopycnic density gradient centrifugation. The mucin densities of control and inoculated pigs were similar, whereas the mucin quantity was 5-fold higher during infection. The level of B. hyodysenteriae binding to mucins differed between pigs, and there was increased binding to soluble mucins isolated from pigs with swine dysentery. The ability of B. hyodysenteriae to bind, measured in relation to the total mucin contents of mucus in sick versus healthy pigs, increased 7-fold during infection. Together, the results indicate that B. hyodysenteriae binds to carbohydrate structures on the mucins as these differ between individuals. Furthermore, B. hyodysenteriae infection induces changes to the mucus niche which substantially increase the amount of B. hyodysenteriae binding sites in the mucus.     

Temporal bone borehole accuracy for cochlear implantation influenced by drilling strategy: an in vitro study

Purpose

Minimally invasive cochlear implantation is a surgical technique which requires drilling a canal from the mastoid surface toward the basal turn of the cochlea. The choice of an appropriate drilling strategy is hypothesized to have significant influence on the achievable targeting accuracy. Therefore, a method is presented to analyze the contribution of the drilling process and drilling tool to the targeting error isolated from other error sources.

Methods

The experimental setup to evaluate the borehole accuracy comprises a drill handpiece attached to a linear slide as well as a highly accurate coordinate measuring machine (CMM). Based on the specific requirements of the minimally invasive cochlear access, three drilling strategies, mainly characterized by different drill tools, are derived. The strategies are evaluated by drilling into synthetic temporal bone substitutes containing air-filled cavities to simulate mastoid cells. Deviations from the desired drill trajectories are determined based on measurements using the CMM.

Results

Using the experimental setup, a total of 144 holes were drilled for accuracy evaluation. Errors resulting from the drilling process depend on the specific geometry of the tool as well as the angle at which the drill contacts the bone surface. Furthermore, there is a risk of the drill bit deflecting due to synthetic mastoid cells.

Conclusions

A single-flute gun drill combined with a pilot drill of the same diameter provided the best results for simulated minimally invasive cochlear implantation, based on an experimental method that may be used for testing further drilling process improvements.