An antibody test for the virus that causes COVID-19, developed by researchers at The University of Texas at Austin in collaboration with Houston Methodist and other institutions, is more accurate and can handle a much larger number of donor samples at lower overall cost than standard antibody tests currently in use. In the near term, the test can be used to accurately identify the best donors for convalescent plasma therapy and measure how well candidate vaccines and other therapies elicit an immune response.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)spreads via respiratory droplets and can survive on many surfaces for long periods. This is a known risk factor for nosocomial spread since various surfaces in hospitals can be contaminated with the virus.

A new study published in the journal Science of The Total Environment in September 2020 reports that the virus can be detected rapidly using already available technology, which will help to monitor viral spread within healthcare facilities more closely and enable better control of the pandemic.

LAMP: Alternative to PCR

Earlier studies on hospital ward surface contamination relied on real-time reverse transcriptase-polymerase chain reaction (RT PCR). In the typical PCR set-up, the virus is first deactivated, the nucleic acid is extracted, and finally, the RNA present is amplified. However, the extraction step can cause a marked reduction of the nucleic acid, as well as demanding a very low limit of detection for the successful application of the technology. This is a time-consuming step, contributing to the total span of 2.5 to 4 hours required per batch.

The current method is more rapid to enable on-site detection. It is called loop-mediated isothermal amplification (LAMP) and has brought the detection time down to 45 minutes, and preventing damage to the RNA by avoiding extraction.

Rapid Detection of Virus

The researchers collected 31 surface contamination samples from different wards before the daily cleaning and disinfection routines. The center of research was the Chengdu Center of Disease Control (Chengdu CDC). Seven surfaces were designated, from bedrails to fingertip of ECG monitors and bathroom door handles. The sample collection took place on five days over March and April.

The LAMP kit used the N gene for detection. Instead of RNA extraction, the researchers added the sample elution into a simple reaction MIX preparation. The detection kit integrates the RNA releasing agents, thus speeding up the process. Either a standard isothermal amplification instrument with a FAM channel can be used, or a standard real-time PCR instrument. The detection limit was at 20 copies/reaction, which is adequate for detecting surface contamination.

The researchers obtained 49 positive results from 14 cases, with 2-6 sites of contamination per case. With 9 cases, no surface tested positive. Overall, more than 70% of surfaces were contaminated by the virus from confirmed COVID-19 cases, which indicates a strong chance of cross-infection by surfaces in isolation wards.  

High-Risk Surfaces

Over 70% of positive cases showed contamination of the ECG fingertip, which showed a higher viral RNA as well. This may indicate that these are high-risk surfaces for viral spread, requiring extra cleaning. The second highest risk was with the bedrail, with 10 samples being positive, probably from contact with the patients themselves as they lie down or get up.

The researchers, therefore, defined these as ultrahigh-contamination risk surfaces, which should be cleaned more often. Other less common sources of contamination were the beeper and the room cupboard.

The researchers then analyzed the correlations between the sampling sites, finding the highest value to be between the cupboard and the bedrail. In other words, if the bedrail was positive, the cupboard was likely to be positive as well. Bedrails were also correlated with several other surfaces. In fact, bedrails were correlated with more surfaces than any other. This would indicate the necessity of positioning bedrails as the most frequent site for sampling in future studies of this kind. Moreover, the bedrail may be a mirror of the degree of contamination of room surfaces.

There were five positive tests from bathroom door handles, which were all from cases where the ECG fingertips were positive as well. Four of the positive handle results also had positive bedrail samples, and three had, in addition, positive cupboard and light switch handles. This prompted the investigators to suggest a daily analysis of samples from these handles, since “A surface contamination sample from the door handle can be interpreted as an ultra-high risk label,” and should prompt increased attention to the cleaning of that ward.

Implications

The results showed which areas of a ward or room housing a COVID-19 patient should be monitored regularly to pick up contamination. The study also shows that monitoring for the presence of the virus is essential for ward management. The sample from the bathroom door handle is an indicator for more rigorous cleaning. ECG monitor fingertips are also prime spots for contamination.

Three of the samples came from six surfaces each, from outside mainland China, and from patients with moderate symptomatic disease. Thus, the presence of symptoms might affect the extent of contamination and risk of infection, but further work is needed.

Isothermal amplification fluorescent instruments can be used for on-site analysis as they are more cost-effective and portable than the standard PCR instruments. This study, which is the “first on-site analysis of COVID-19 surface contamination in wards,” may act as a guideline for disease control and ward hygiene protocols.

An experimental treatment for eczema that aims to modify the skin microbiome safely reduced disease severity and increased quality of life for children as young as 3 years of age, a National Institutes of Health study has found. These improvements persisted for up to eight months after treatment stopped, researchers report Sept. 9 in Science Translational Medicine.

Atopic dermatitis, commonly called eczema, is a chronic inflammatory skin disease characterized by dry, itchy skin and rashes. The disease is most common in children and is linked to an increased risk of developing asthma, hay fever, and food allergy. While available treatments can help manage eczema symptoms, current options can be costly, and many require multiple daily applications.

The experimental therapy contains strains of live Roseomonas mucosa—a bacterium naturally present on the skin—originally isolated from healthy volunteers and grown under carefully controlled laboratory conditions. For four months, clinical trial participants or their caregivers periodically applied this probiotic therapy to areas of skin affected by eczema.

"A child suffering from eczema, which can be itchy, painful and distracting for the child, also is very difficult for the entire family," said Anthony S. Fauci, M.D., director of NIH's National Institute of Allergy and Infectious Diseases (NIAID), which led the study. "These early-stage findings suggest that R. mucosa therapy may help relieve some children of both the burden of eczema symptoms and the need for daily treatment."

Numerous genetic and environmental factors contribute to eczema, and scientists are learning more about the role that the skin's microbiome plays in this condition. In 2016, NIAID researchers reported that R. mucosa strains isolated from healthy human skin improved outcomes in cell culture and mouse models of eczema.

To build on these preclinical findings, NIAID launched a Phase 1/2 clinical trial at the NIH Clinical Center in Bethesda, Maryland, to assess the safety and potential benefit of R. mucosa therapy in people with eczema. Interim results reported in 2018 for 10 adults and five children aged 9 to 14 years indicated that the treatment was safe and associated with reduced eczema severity. Since then, the trial has enrolled an additional 15 children, for a total of 20 children with mild to severe eczema ranging in age from 3 to 16 years.

Topical application of Roseomonas mucosa was associated with clinical improvement of atopic dermatitis in 15 children. The improvement may be related to lipid production by the bacteria which influence TNFR2-mediated epithelial repair through influences on nicotinic acetylcholine signaling and flagellar recognition. Credit: Art by Ian Myles

Twice weekly for three months and every other day for an additional month, children or their caregivers sprayed a solution of sugar water containing live R. mucosa onto areas of skin with eczema. For the first 15 children enrolled in the study, the dose of live R. mucosa was gradually increased each month. The last five children to enroll received the same dose throughout the four-month treatment period. Regardless of dosing strategy, no serious adverse events were attributed to the therapy.

"Most children in the study experienced substantial improvements in their skin and overall wellbeing following R. mucosa therapy. Encouragingly, the therapeutic bacteria stayed on the skin and continued to provide benefit after therapy stopped," said NIAID's Ian Myles, M.D., principal investigator of the trial. "These results support a larger study to further assess the safety and effectiveness of this experimental treatment by comparing it with a placebo."

Seventeen of the 20 children experienced a greater than 50% improvement in eczema severity following treatment. Improvement occurred on all treated skin sites, including the inner elbows, inner knees, hands, trunk, and neck. The scientists also observed increases in the skin's barrier function—its ability to seal in moisture and keep out allergens. Additionally, most children needed fewer corticosteroids to manage their eczema, experienced less itching, and reported a better quality of life following the therapy. These benefits persisted after treatment ended, and the therapeutic R. mucosa strains remained on the skin for up to eight months.

The NIAID researchers next set out to better understand how R. mucosa therapy improves eczema symptoms. They found that treated skin had increased microbial diversity and reduced levels of Staphylococcus aureus—a bacterium known to exacerbate eczema.

In addition to imbalances in the microbiome, the skin of people with eczema is deficient in certain lipids, or oils. By conducting experiments in cell and animal models of eczema, the NIAID scientists found that a specific set of lipids produced by R. mucosa strains isolated from healthy skin can induce skin repair processes and promote turnover of skin tissue. Study participants had increased levels of these lipids on their skin after treatment with R. mucosa.

The researchers emphasize that additional studies are needed to further elucidate the mechanism of R. mucosa therapy and to explore whether genetic or other factors may explain why some participants did not benefit from the experimental treatment. (by NIH/National Institute of Allergy and Infectious Diseases)

Source: https://medicalxpress.com/news/2020-09-probiotic-skin-therapy-eczema-children.html 

Robust and widespread antibody testing has emerged as a key strategy in the fight against SARS-CoV-2, the virus responsible for the COVID-19 pandemic. However current testing methods are too inaccurate or too expensive to be feasible on a global scale. But now, scientists at the Okinawa Institute of Science and Technology Graduate University (OIST) have developed a rapid, reliable, and low-cost antibody test.