Medical Science

Researchers develop smartphone-based COVID-19 test that delivers results in about 10 minutes

By University of Arizona

Researchers at the University of Arizona are developing a COVID-19 testing method that uses a smartphone microscope to analyze saliva samples and deliver results in about 10 minutes.

The UArizona research team, led by biomedical engineering professor Jeong-Yeol Yoon, aims to combine the speed of existing nasal swab antigen tests with the high accuracy of nasal swab PCR, or polymerase chain reaction, tests. The researchers are adapting an inexpensive method that they originally created to detect norovirus—the microbe famous for spreading on cruise ships—using a smartphone microscope.

They plan to use the method in conjunction with a saline swish-gargle test developed by Michael Worobey, head of the UArizona Department of Ecology and Evolutionary Biology and associate director of the University of Arizona BIO5 Institute.

The team’s latest research using water samples—done in collaboration with Kelly A. Reynolds, chair of the Department of Community, Environment and Policy in the UArizona Mel and Enid Zuckerman College of Public Health—is published today in Nature Protocols.

“We’ve outlined it so that other scientists can basically repeat what we did and create a norovirus-detecting device,” said Lane Breshears, a biomedical engineering doctoral student in Yoon’s lab. “Our goal is that if you want to adapt it for something else, like we’ve adapted it for COVID-19, that you have all the ingredients you need to basically make your own device.”

Yoon—a BIO5 Institute member who is also a professor of biosystems engineering, animal and comparative biomedical sciences, and chemistry and biochemistry—is working with a large group of undergraduate and graduate students to develop the smartphone-based COVID-19 detection method.

“I have a couple of friends who had COVID-19 that were super frustrated, because their PCR results were taking six or seven days or they were getting false negatives from rapid antigen tests. But when they got the final PCR tests, they found out they had been sick, like they’d suspected,” said Katie Sosnowski, a biomedical engineering doctoral student who works in Yoon’s lab. “It’s really cool to be working on a detection platform that can get fast results that are also accurate.”

Cheaper, Simpler Detection

Traditional methods for detection of norovirus or other pathogens are often expensive, involve a large suite of laboratory equipment or require scientific expertise.

The smartphone-based norovirus test developed at UArizona consists of a smartphone, a simple microscope and a piece of microfluidic paper—a wax-coated paper that guides the liquid sample to flow through specific channels. It is smaller and cheaper than other tests, with the components costing about $45.

The basis of the technology, described in a 2019 paper published in the journal ACS Omega, is relatively simple. Users introduce antibodies with fluorescent beads to a potentially contaminated water sample. If enough particles of the pathogen are present in the sample, several antibodies attach to each pathogen particle.

Under a microscope, the pathogen particles show up as little clumps of fluorescent beads, which the user can then count. The process—adding beads to the sample, soaking a piece of paper in the sample, then taking a smartphone photograph of it under a microscope and counting the beads—takes about 10 to 15 minutes. It’s so simple that Yoon says a nonscientist could learn how to do it by watching a brief video.

The version of the technology described in the Nature Protocols paper makes further improvements, such as creating a 3-D-printed housing for the microscope attachment and microfluidic paper chip. The paper also introduces a method called adaptive thresholding. Previously, researchers set a fixed value for what quantity of pathogen constituted a danger, which limited precision levels.

The new version uses artificial intelligence to set the danger threshold and account for environmental differences, such as the type of smartphone and the quality of the paper.

Medical Science

From headache to soar throat: New common symptoms of Delta variant of COVID-19

(Asian News Hub) – The Delta variant of the COVID-19 infection could be behind the change in symptoms as more people are reporting cold-like symptoms in the UK.

Headaches, a sore throat and a runny nose are the most common symptoms of this variant, according to the data collected as part of the app-based Zoe Covid symptom study.

The study is being led by Tim Spector, a professor of genetic epidemiology at King’s College London.

“Covid is … acting differently now, it’s more like a bad cold,” he said. “People might think they’ve just got some sort of seasonal cold, and they still go out to parties … we think this is fuelling a lot of the problem.

So, what’s really important to realise is that since the start of May, we’ve been looking at the top symptoms in all the app users, and they’re not the same as they were. So, the number one symptom is headache … followed by sore throat, runny nose and fever.”

The ZOE project which began at the start of the pandemic has been tracking people’s symptoms throughout and experts believe the virus is ‘acting differently now’.

The NHS still lists the three tell-tale signs of the virus as a fever, new continuous cough and loss of taste and smell.

With Delta, a cough appears to be the fifth most common symptom, and the loss of smell doesn’t make the top 10, according to Spector’s study.

The study also believes that now the majority of the UK’s older residents are vaccinated, and younger people are the ones infected that are more likely to only suffer a mild illness.

Spector said the Delta variant is now ‘more like a cold’ in younger people. “I think the message here is that if you’re young and getting milder symptoms any way, it might just feel like a bad cold or some funny feeling … do stay at home and do get a test,” Spector said.

AGENCY

Medical Science

COVID19: Single dose of vaccine sufficient for those already infected; Study

(Asian News Hub) – A study by Hyderabad’s AIG Hospitals has claimed that a single dose of COVID-19 vaccine is sufficient for those already infected by the disease before.

The hospital said it conducted a study on 260 healthcare workers who got vaccinated between January 16 and February 5 to assess the immunological memory response in all those patients. All patients were given the Oxford-Serum vaccine Covishield.

Two significant observations came out of the study, which has been published in the International Journal of Infectious Diseases, a peer-reviewed journal.

The previously infected group (people who got infected with COVID-19) showed a greater antibody response to a single dose of vaccine compared with those who had no prior infection.

It also revealed that Memory T-cell responses elicited by a single dose of vaccine were significantly higher in the previously infected group compared with those who had no prior infection.

It was concluded that higher memory T and B-cell responses in addition to higher antibody response with a single dose of vaccine given at 3-6 months after recovery from COVID-19 may be considered at par with two doses of vaccine for individuals already infected with COVID-19.

“The results show that people who got infected with COVID-19 need not take two doses of vaccine yet with a single dose can develop robust antibody and memory cell response at par with two-doses for those who didn’t get the infection.

This will significantly help at a time when there’s a shortage of vaccine in the country and more people can be covered using the saved doses,” said Dr. D Nageshwar Reddy, Chairman, AIG Hospitals, and one of the co-authors in the study.

“Once we attain the requisite number of people vaccinated for achieving herd immunity, these patients who got infected and received only one dose can take the second dose of the vaccine.

At this point, all our strategies should be directed at the widespread distribution of available vaccines and to include the maximum number of people at least with a single dose,” he added.

During the second Covid wave when cases were growing exponentially; the vaccination rate took a downturn. As of April 27, when the growth rate of active infection was 5%, the growth of vaccinated people was just 1.4 per cent.

“We need to modify vaccination strategy based on scientific evidence and with the objective that a larger set of the population can be covered in the shortest duration,” he said.

WITH IANS INPUTS

Medical Science

New Coronavirus found in bats in china, Scientists worried

(Asian News Hub) – In a shocking revelation, Chinese researchers claim to have found a batch of new coronaviruses in bats. They even say that the newly found viruses in the bats include one that may be the second-closest yet (genetically) to the COVID-19 virus, reports CNN.

According to the researchers, their discoveries in a single, small region of Yunnan province, southwestern China show just how many coronaviruses there are in bats and how many have the potential to spread to people.

In a report published in the journal Cell, the Chinese researchers from Shandong University said, “In total, we assembled 24 novel coronavirus genomes from different bat species, including four SARS-CoV-2 like coronaviruses.”

One was very similar, genetically to the SARS-CoV-2 virus that’s the cause of the current COVID-19 pandemic, they said.

It would be the closest strain to SARS-CoV-2 except for genetic differences on the spike protein, the knob-like structure that the virus uses when attaching to cells, they said.

Researchers are trying to find where SARS-CoV-2 came from. Although a bat is a likely source, it’s possible the virus infected an intermediary animal. The SARS virus that caused an outbreak in 2002-2004 was tracked to an animal called a civet cat.

Three of the samples described in Thursday’s report were also close to SARS genetically.

This discovery of new coronaviruses in bats comes at a time when scientists and countries across the world are calling for further investigations to figure out whether the virus originated naturally or leaked from the Wuhan Institute of Virology.