COVID-19 saliva diagnosis cheaper, faster alternative to swab testing, say scientists - The New Indian Express | Canada News Media
Connect with us

Science

COVID-19 saliva diagnosis cheaper, faster alternative to swab testing, say scientists – The New Indian Express

Published

 on


By PTI

NEW DELHI: A low-cost saliva test that will enable people to collect their own samples with minimal discomfort, without invasive nasal or throat swabs, could well be the way forward to detect the novel coronavirus, say scientists.

Giving a thumbs up to the alternative testing technology that is yet to be introduced in India, scientists said it would deliver results faster and more accurately and also minimise the risk for healthcare workers collecting samples.

The saliva-based COVID-19 diagnosis offers an improvement over standard nasopharyngeal swab methods because people can collect their own samples with ease — simply spit into a sterile tube and mail it to a lab for processing.

“It is also unique because it does not require a separate nucleic acid (RNA) extraction step. This is significant because the extraction kits used for this step in other tests have been prone to shortages in the past,” A R Anand, senior associate professor at Chennai’s L&T Microbiology Research Centre, told PTI.

Noting that the ‘saliva direct’ test is easier to carry out, he said it needs only a few reagents and a real-time polymerase chain reaction (RT-PCR) machine.

Discussion on the technology intensified after the US Food and Drug Administration (FDA) this week gave the Yale School of Public Health emergency use authorisation for its ‘Salivadirect’ COVID-19 diagnostic test.

The FDA said in a statement that SalivaDirect does not require any special type of swab or collection device.

A saliva sample, it said, can be collected in any sterile container.

Though saliva tests are yet to be approved in India for mass use, scientists such as Anand suggest the matter be explored further.

“A fast-tracked study should be conducted in an Indian setting comparing the saliva RT-PCR tests with the nasopharyngeal RT-PCR tests before large-scale implementation in our country,” Anand said.

An Indian Council of Medical Research (ICMR) scientist added that India is exploring the availability of kits and other aspects.

“At present, no kit is approved in India,” he said on the condition of anonymity.

According to a recent study published in ICMR’s Indian Journal of Medical Research, gargled water samples may be another viable alternative to swabs for detecting COVID-19, enabling easy self-collection and removing the need for trained healthcare workers for sample collection.

Asked about the saliva test cleared by the FDA, ICMR Director General Balram Bhargava on Wednesday told a parliamentary panel that taking samples from gargled water is already under consideration and further details will be available soon.

There are two types of diagnostic tests for COVID-19 testing, both using swabs from the nose and the throat.

The RT-PCR test, which can take hours or even days before a result, detects genetic material of the virus using a lab technique called polymerase chain reaction.

The second diagnostic test, the antigen COVID-19 test, detects certain proteins in the virus.

An antigen test can also produce results in minutes.

Saliva tests would be an improvement on both.

“The collection does not involve material such as swabs — which can be in short supply — and the person doing the collection does not need as much training,” Satyajit Rath, from New Delhi’s National Institute of Immunology, told PTI.

“Such systems also reduce the cost since we don’t have to depend on one company. Saliva is a much easier sample to collect from patients, compared to nasopharyngeal swabs, which are a little invasive and cause some discomfort to patients,” Anand added.

Vineeta Bal, an immunologist from Pune’s Indian Institute of Science, Education and Research, said saliva tests might become easily accessible like rapid paper strip tests available for testing blood or urine glucose.

“Hence, life can come closer to the ‘normal’ that we knew of before the pandemic. In India, some researchers are developing the tests for detection from saliva. But as far as I know they are far from reaching the market,” Bal added.

Noting the pluses of the Yale saliva test, virologist Shahid Jameel pointed to the ease of sample collection and the reduced cost for extracting RNA, the genetic material of a virus.

It would also lead to fewer false negative results.

“Most false negative results in the RT-PCR test today are due to improper sampling from the nasopharyngeal area, which is also uncomfortable for the person being tested,” Jameel, CEO of the Wellcome Trust/DBT India Alliance, a public charity that invests in building biomedical sciences, told PTI.

In addition to the Yale saliva test, Israel’s Center for Geographic Medicine and Tropical Diseases has developed a  test that aims to determine in less than a second whether a person is infected with the novel coronavirus.

Noting that the Israel test is yet to be approved, Jameel said it uses the scattering of light by virus particles in mouth washings to estimate both presence or absence, and quantity of virus particles in the sample.

“This is based on obtaining data from a large number of positive and negative people and training an algorithm to pick the right scattering patterns. Besides the light source, this test uses artificial intelligence (AI) and machine learning, hoping to get better with time as more samples are analysed,” Jameel explained.

Machine learning is  an application of AI that provides systems the ability to automatically learn and improve from experience.

“Both  the tests will reduce time. The Yale test will only cut RNA extraction time as the rest of the process is the same. The Israel test is very quick,” Jameel added.

Virologist T Jacob John agreed that the saliva test is a low-cost alternative.

Explaining one of the ways in which saliva test can work, he said, “There is a process of viral genetic material (RNA) converted to DNA, which is then detected by a method different from PCR. It is called ‘loop-mediated isothermal amplification’, or LAMP, an original Japanese invention,” John, former head of clinical virology at Christian Medical College, Vellore, told PTI.

LAMP is a cheaper PCR alternative previously used to detect outbreaks of zika and ebola in resource-poor countries.

“The final reading is taken by colour reaction — pink turning to yellow. The equipment is cheaper than PCR equipment, If spit is collected, it avoids the use of special swabs which are in short supply,” said John.

Israel and India are conducting trials here on a large sample of patients for four different kinds of technologies, including two COVID-19 tests that could give results in minutes from a saliva sample, according to a statement by the Israeli Embassy in Delhi.

Let’s block ads! (Why?)



Source link

Continue Reading

News

Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

Published

 on

 

More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

___

Follow AP’s climate coverage at https://apnews.com/hub/climate

___

Follow Seth Borenstein on Twitter at @borenbears

___

Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

Source link

Continue Reading

Science

‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

Published

 on

 

It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

Source link

Continue Reading

News

The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

Published

 on

 

TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

Source link

Continue Reading

Trending

Exit mobile version