Hospital-onset COVID-19 infection surveillance systems: a systematic review

Hospital-onset COVID-19 infections (HOCIs) are associated with excess morbidity and mortality in patients and healthcare workers. The aim of this review was to explore and describe the current literature in HOCI surveillance. Medline, EMBASE, the Cochrane Database of Systematic Reviews, the Cochrane Register of Controlled Trials, and MedRxiv were searched up to 30 November 2020 using broad search criteria. Articles of HOCI surveillance systems were included. Data describing HOCI definitions, HOCI incidence, types of HOCI identification surveillance systems, and level of system implementation were extracted. A total of 292 citations were identified. Nine studies on HOCI surveillance were included. Six studies reported on the proportion of HOCI among hospitalized COVID-19 patients, which ranged from 0 to 15.2%. Six studies provided HOCI case definitions. Standardized national definitions provided by the UK and US governments were identified. Four studies included healthcare workers in the surveillance. One study articulated a multimodal strategy of infection prevention and control practices including HOCI surveillance. All identified HOCI surveillance systems were implemented at institutional level, with eight studies focusing on all hospital inpatients and one study focusing on patients in the emergency department. Multiple types of surveillance were identified. Four studies reported automated surveillance, of which one included real-time analysis, and one included genomic data. Overall, the study quality was limited by the observational nature with short follow-up periods. In conclusion, HOCI case definitions and surveillance methods were developed pragmatically. Whilst standardized case definitions and surveillance systems are ideal for integration with existing routine surveillance activities and adoption in different settings, we acknowledged the difficulties in establishing such standards in the short-term.

[From the bench to the clinic: The challenge of translating platelet production in vitro]

Platelet transfusions, which are currently totally dependent on altruistic donations, are absolutely necessary to the treatment of patients with thrombocytopenia following trauma, surgery or other pathologies (especially malignancies). Producing platelets in vitro represent a major technological and scientific breathrough that would address logistical issues (supply chain, stock holding…) and medical concerns (compatibility and biosafety). The translation of this innovation will need to be accompanied by rigorous quality control, harmonised between laboratory when it comes to functionality and biosafety for use in the clinic.

In vitro-derived platelets: the challenges we will have to face to assess quality and safety

Platelet transfusions are given to patients in hospital who have a low blood platelet count (thrombocytopenia) either because of major bleeding (following trauma or surgery) or because the bone marrow production of platelets is impaired often due to chemotherapy, infiltration with malignant cells, fibrosis or genetic disorders. We are currently entirely reliant on blood donors as a source of platelets in transfusion medicine. However, the demand for platelets continues to rise, driven by an aging population, advances in medical procedures and ever more aggressive cancer therapies, while the supply of blood donors continues to remain static. In recent years, several groups have made major advances toward the generation of platelets in vitro for human transfusion. Recent successes include results in both generating mature human megakaryocytes as well as in developing bioreactors for extracting platelets from these megakaryocytes. Platelets made in vitro could address several issues inherent to platelets derived from blood donors - the ability to scale up/down more flexibly according to demand and therefore less precarious supply line, reduction of the risk of exposure to infectious agents and finally the possibility of engineering stem cells to reduce immunogenicity. Here we define the quality control tools and suggest measures for implementation across the field for in vitro platelet genesis, to aid collaboration between laboratories and to aid production of the burdens of proof that will eventually be required by regulators for efficacy and biosafety. We will do this firstly, by addressing the quality control of the nucleated cells used to make the platelets with a particular emphasis to safety issues and secondly, we will look at how platelet function measurement are addressed particularly in the context of platelets derived in vitro.

Planning to halve Gram-negative bloodstream infection: getting to grips with healthcare-associated Escherichia coli bloodstream infection sources

BACKGROUND

A thorough understanding of the local sources, risks, and antibiotic resistance for Escherichia coli bloodstream infection (BSI) is required to focus prevention initiatives and therapy.

AIM

To review the sources and antibiotic resistance of healthcare-associated E. coli BSI.

METHODS

Sources and antibiotic resistance profiles of all 250 healthcare-associated (post 48 h) E. coli BSIs that occurred within our secondary and tertiary care hospital group from April 2014 to March 2017 were reviewed. Epidemiological associations with urinary source, gastrointestinal source, and febrile neutropenia-related BSIs were analysed using univariable and multivariable binary logistic regression models.

FINDINGS

E. coli BSIs increased 9% from 4.0 to 4.4 per 10,000 admissions comparing the 2014/15 and 2016/17 financial years. Eighty-nine cases (36%) had a urinary source; 30 (34%) of these were classified as urinary catheter-associated urinary tract infections (UTIs). Forty-five (18%) were related to febrile neutropenia, and 38 (15%) had a gastrointestinal source. Cases were rarely associated with surgical procedures (11, 4%) or indwelling vascular devices (seven, 3%). Female gender (odds ratio: 2.3; 95% confidence interval: 1.2-4.6) and older age (1.02; 1.00-1.05) were significantly associated with a urinary source. No significant associations were identified for gastrointestinal source or febrile neutropenia-related BSIs. Forty-seven percent of the isolates were resistant to ciprofloxacin, 37% to third-generation cephalosporins, and 22% to gentamicin.

CONCLUSION

The gastrointestinal tract and febrile neutropenia together accounted for one-third of E. coli BSI locally but were rare associations nationally. These sources need to be targeted locally to reduce an increasing trend of E. coli BSIs.

Gas exchange kinetics following concentric-eccentric isokinetic arm and leg exercise

PURPOSE

To evaluate the effects of exercise velocity (60, 150, 240deg∙s^-1) and muscle mass (arm vs leg) on changes in gas exchange and arterio-venous oxygen content difference (avDO₂) following high-intensity concentric-eccentric isokinetic exercise.

METHODS

Fourteen subjects (26.9±3.1years) performed a 3×20-repetition isokinetic exercise protocol. Recovery beat-to-beat cardiac output (CO) and breath-by-breath gas exchange were recorded to determine post-exercise half-time (t_1/2) for oxygen uptake (V˙O₂pulm), carbon dioxide output (V˙CO₂pulm), and ventilation (V˙_E).

RESULTS

Significant differences of the t_1/2 values were identified between 60 and 150deg∙s^-1. Significant differences in the t_1/2 values were observed between V˙O₂pulm and V˙CO₂pulm and between V˙CO₂pulm and V˙_E. The time to attain the first avDO₂-peak showed significant differences between arm and leg exercise.

CONCLUSIONS

The present study illustrates, that V˙O₂pulm kinetics are distorted due to non-linear CO dynamics. Therefore, it has to be taken into account, that V˙O₂pulm may not be a valuable surrogate for muscular oxygen uptake kinetics in the recovery phases.

A descriptive profile of elite U.S. women's collegiate field hockey players

BACKGROUND

The purposes of this study were to develop a descriptive profile and examine the relationships between grip strength, power and sport specific test performance in 37 elite, female collegiate field hockey players (N=8 backs, N=13 forwards, N=4 goalkeepers, N=8 midfield players, N=4 wings).

METHODS

The tests included circumference and limb lengths, %body fat, Margaria-Kalamen stair test, 50-yard dash test, Queen's College step test, grip strength, Illinois agility test, field hockey specific skills tests, and a coordination test.

RESULTS

Mean (+/-SD) height, weight, percent body fat, and predicted oxygen consumption were 164.26 (+/-5.17) cm, 63.06 (+/-8.60) kg, 17.29 (+/-3.79)% and 42.87 (+/-9.08) ml x kg(-1) x min(-1), respectively. Although the goalkeepers were significantly (p<0.05) heavier and had a higher %body fat, there were no significant differences (p>0.05) between any of the player positions in height, limb length, 50-yard dash time, predicted VO(2max), grip strength, agility, or in the field hockey specific tests. There were no significant (p>0.05) correlations (r=0.03 to -0.13) between right and left grip strength and sport-specific test scores but significant (p<0.05) relationships were found between power and pushing accuracy, as well as between the 50 yard dash and coordination test, pushing power and pushing accuracy.

CONCLUSIONS

In profiling a sample of elite collegiate field hockey players in the Unites States, the results of this study indicate that there are similarities amongst the defensive and offensive players with international level field hockey players, and that measures of power and sport specific tests are significantly correlated.

The effects of physical training of functional capacity in adults. Ages 46 to 90: a meta-analysis

BACKGROUND

There is a progressive decline in the functional capacity (FC) of the cardiovascular system with aging. This deterioration is reflected in a decrease in the maximal oxygen consumption (VO2max). The purpose of this quantitative review was to determine the effects of various components of the exercise prescription on FC in older individuals (ages 46-90 years).

METHODS

This study synthesized the results of 27 studies by meta-analysis, which generated a total of 34 effect sizes. Each effect size represented an independent measure of the impact of physical training on maximal oxygen consumption (VO2max). A total of 720 subjects were included in this review. The studies were coded according to intensity, session duration, length of training and mode of exercise.

RESULTS

A significant difference was found (p < 0.001) in FC between studies in which the intensity of exercise was > or = to 80% of VO2max compared to those with training intensities of 60-75% of VO2max. A significant difference was found (p < 0.002) for exercise duration; namely, a duration of > or = 30 minutes produced significantly greater improvements in VO2max when compared to an exercise duration less than 30 minutes. There was no significant difference reported in FC between studies that lasted 15 or more weeks in duration compared to those that lasted less than 15 weeks. Finally, there was no significant difference reported in FC in studies that utilized a walk/jog training mode compared to those which utilized cycle ergometry.

CONCLUSIONS

Despite the inevitable decline in VO2max with aging, exercise training imparts favorable adaptations in FC in individuals well into their seventh and eighth decades of life.

Epidemiology and predictors of post-concussive syndrome after minor head injury in an emergency population

OBJECTIVE

To determine if clinical variables or neurobehavioural test (NBT) scores obtained in the ED within 24 hours of minor head injury (MHI) predict the development of postconcussive syndrome (PCS).

METHODS

Prospective, observational study of 71 MHI patients and 60 orthopaedic controls. MHI defined as loss of consciousness < 10 minutes or amnesia, GCS 15, no skull fracture or new neurologic focality on PE, and no brain injury on CT (if done). All patients received a seven part NBT battery in the ED. Telephone follow-up was done at 1, 3 and 6 months to determine if patients met the DSM IV definition of PCS.

ANALYSIS

Stepwise, multivariate, logistic regression.

RESULTS

Predictors of PCS at 1 month were female gender (OR = 7.8; 95% CI = 41.6, 1.98), presence of both retrograde and anterograde amnesia (OR = 0.055; CI = 0.002, 0.47), Digit Span Forward Scores (OR = 0.748; CI = 0.52, 1.03) and Hopkins Verbal Learning A scores (OR = 0.786; CI = 0.65, 0.91); at 3 months, presence of both retrograde and anterograde amnesia (OR = 0.13; CI = 0.0, 0.93), Digit Span Forward Scores (OR = 0.744; CI = 0.58, 0.94). No variables fit the model at 6 months. 92% of males scoring > 25 on Hopkins Verbal Learning A did not have PCS at 1 month, and 89% of females scoring < 9 on Digit Span Forward did have PCS at 1 month.

CONCLUSIONS

Gender and two NBTs can help predict PCS after MHI.

Perturbations in morphogen gradients induce budding in hydra

Lateral grafting of small pieces of midregion tissue into different levels of the hydra body column was done to assess the influence of the host hypostome and basal disc (or, of the underlying morphogenetic gradients) in inducing secondary structures in the transplanted tissue; and also to identify the role, if any, of the induced secondary structures (or, perturbed morphogen gradients) on the pattern of the host. The same midpiece tissue differentiated to a basal disc when grafted near the host hypostome, and to a small hypostome with tentacles when grafted near the host basal disc. Chimeras with induced secondary basal discs showed a phenomenal increase in budding compared to the controls and to the chimeras having induced hypostomes. These results indicate a positive cross-reaction between both organizing regions during patterning in hydra.

Nerve commitment during head regeneration in hydra

Most important event in head regeneration in hydra is a wave of conversion of many interstitial cells into nerve cells. Experimental evidence lends support to the idea that the commitment of interstitial cells into nerve cells is the first morphogenetic prerequisite for emergence of head structures, when the number of nerve cells increases. This increase in nerve cells is delayed when regeneration occurs at a site lower in the body column.

Thermoregulatory responses to skin wetting during prolonged treadmill running

We examined the physiological responses to skin wetting during a 120-min level treadmill run to assess whether skin wetting would reduce the dehydration and the increase in core temperature associated with prolonged exercise. Testing was conducted in an environmental chamber (T = 29.5 degrees C, wind velocity = 3 m X sec-1) under two different humidity conditions (33 or 66% relative humidity). Ten male subjects performed two runs in each humidity condition; one served as a control run. The other included spraying the body with 50 ml of water (T = 29.5 degrees C) every 10 min. Spraying had no effect on rectal temperature (Tre), heart rate, oxygen consumption, perceived exertion, sweat loss, or percent change in plasma volume in both the humid and the dry conditions. Spraying produced a significant reduction in mean skin temperature (Tsk), which increased the (Tre - Tsk) gradient. At the same time, overall skin conductance (K) was decreased, presumably as a result of cutaneous vasoconstriction due to the low Tsk. Since heat transfer from the body's core to the skin is expressed by the equation: heat transfer = K X (Tre - Tsk) the spraying had no effect on heat transfer away from the core, and Tre remained unchanged.

A four-variable model for the pattern-forming mechanism in Hydra

A generalized Gierer-Meinhardt model has been used to account for the transplantation experiments in Hydra. In this model, a cross inhibition between the two organizing centres (namely, head and foot) are assumed to be the only mode of interaction in setting up a stable morphogen distribution for the pattern formation in Hydra.

The Morphogenesis of the Notochord in Amphibia

In spite of the great progress of experimental embryology in recent years, we still know rather little about the physical processes by which the various parts of the egg become moulded into definitely shaped organs. It is obvious, however, that this phenomenon of morphogenesis is one of the most important and characteristic aspects of development, and further knowledge about it is much to be desired. The investigations to be reported here represent an attempt to obtain further understanding of such processes as they affect the Amphibian notochord. This organ was chosen because the final shape which is attained is of great simplicity, being no more than an unbranched cylindrical rod. Moreover, casual inspection shows that rather considerable changes in cell shape occur during the formation of this rod, and it appeared possible that these changes in the constituent cells would be found to be directly related to the morphogenesis of the organ as a whole.