Pages

Sunday 29 March 2020

Malaysian part of Oxford team developing fast Covid-19 test kit

A Malaysian PhD student is part of a team of scientists from the University of Oxford’s Engineering Science Department and the Oxford Suzhou Centre for Advanced Research (OSCAR) that has developed a rapid testing technology for Covid-19.

By Zaharah Othman

March 23, 2020 @ 12:01pm

Lim Boon Chuan is studying synthetic biology at University of Oxford. -Pic courtesy of Lim Boon Chuan


LONDON: A Malaysian PhD student is part of a team of scientists from the University of Oxford’s Engineering Science Department and the Oxford Suzhou Centre for Advanced Research (OSCAR) that has developed a rapid testing technology for Covid-19.
Lim Boon Chuan, 26, a Public Service Department (PSD) scholarship student studying synthetic biology at the university, said the new technology produced results faster and could potentially be used by anyone at home.
“We can use a single temperature, which is 65°C for half an hour to see the results,” said Lim, who had won several awards, including the third prize at the 2018 Chief Data International Big Data Forum & Competition for Innovation and Entrepreneurship.
The diagnostic kit does not need a complicated instrument.
Lim said previous viral RNA tests needed up to two hours to produce a result. The new technology, however, can give results in just half an hour, over three times faster than the current method.
“We don’t need the extraction step done — this is the step that requires another set of kits, equipment and chemicals to do the test.



PSD scholar Lim Boon Chuan.
PSD scholar Lim Boon Chuan.

“Our goal is to design and produce something that can be sent to households, so people should be able to do the testing at home easy and fast without going to a diagnostic centre or to the hospital.
“In the United Kingdom, if you go for tests, it takes three days to come back (to retrieve the results).
“But if we are able to produce or design something that people can use to test at home, they can get the result within half an hour without a cycle of temperatures.
“Initially, the kits were sent to China to test cases there to see if the kits work on real clinical samples, and they worked. And since the cases are on the increase in the UK, we are going to do more collaboration with universities and hospitals here.”
Lim, from Kuala Lumpur, became involved with the project, which started last month, when the Covid-19 virus was raging in China with very few cases in Europe and the UK. His role was to design and run all the experiments.



Prof Zhanfeng Cui
Prof Zhanfeng Cui

“(Actually) this (the research) has nothing to do with my PhD work. My supervisor, Prof Wei Huang, who is from China, is one of two scientists leading the team,” he said during a Skype interview.
The other leading scientist for the team is Prof Zhanfeng Cui, who is also the OSCAR director. The team of 13 had been working to improve test capabilities as the virus spreads internationally.
According to the press release, the technology is very sensitive.
“This means that patients in early stages of infection may be identified sooner, potentially helping to reduce the spread of the coronavirus SARS-CoV-2 (Covid-19).
“The technology requires only a simple heat-block which maintains a constant temperature for RNA reverse transcription and DNA amplification, and the results can be read by the naked eye.
“This makes it potentially useful in rural area or community healthcare centres,” the statement read.
The technology had been validated with real clinical samples at Shenzhen Luohou People’s Hospital in China. The hospital applied the rapid detection kits on 16 clinic samples, including eight positives and eight negatives, which have been confirmed by conventional RT-PCR methods and other clinical evidence.
The test results using the rapid detection kits were all successful.
Prof Zhanfeng Cui said: ‘I am proud of our team that has developed a useful technology and can make a contribution in combating Covid-19. We are very grateful to the hospital’s medical team led by Dr Xizhou Sun, Dr Xiuming Zhang and Dr Dan Xiong for their part in testing this new technology.’
The Oxford scientists are now working to develop an integrated device so that the test can be used at clinics, airports or even at home. They are planning to run clinical validations within the UK and exploring options for production of the test kits.
https://www.nst.com.my/news/nation/2020/03/577222/malaysian-part-oxford-team-developing-fast-covid-19-test-kit

Unexpected Loss Of Smell And Taste In Coronavirus Patients

One of the most unusual symptoms of coronavirus (COVID19) infection is the loss of a sense of smell and taste. I learned about this yesterday from a friend in Italy who I’ve been so worried about. 

EDITORS' PICK|230,540 views|


One of the most unusual symptoms of coronavirus (COVID19) infection is the loss of a sense of smell and taste. I learned about this yesterday from a friend in Italy who I’ve been so worried about. She finally confessed that she likely had it two-three weeks ago and is normalizing. Symptoms included profound fatigue, fevers, and cough. Her most peculiar symptoms, however, were a profound loss of smell and taste. She sanitized her flat, but did not smell the bleach. She watched garlic browning on the stove, but could not smell it. Nor could she taste these strongly scented vegetables like garlic or fennel. Fortunately, all of her symptoms are resolving. She is one of the lucky ones.
My friend also noted that, anecdotally, physicians have commented that a significant proportion of patients are presenting similarly. No studies have been done because these physicians are overwhelmed. According to the Lancet, 9% of all infections in Italy are among medical personnel; in the hardest hit region of Lombardy, 20% of providers were infected. They are struggling to stay alive, with a shortage of staff, ventilators, and personal protective equipment (masks, gloves, gowns). The European Union has failed to provide support. China has stepped up, sending tons of medical equipment, masks, and even physicians to help. While this is critically important now, it is likely not entirely altruistic. Some say Europe is being wooed by Chinese President Xi Jinping, who reportedly said he hoped to establish a “health silk road” as part of China’s global One belt, One Road initiative.
While the Italians have not been able to systematically study the loss or alteration of smell (anosmia) or taste (dysgeusia), German virologist Hendrik Streek has been busily at work. During an early cluster of cases in Germany, linked to auto supplier Webasto, Streek’s team had the opportunity to take daily samples from the infected workers isolated in a hospital, as well as interview them to learn about the progression of symptoms.
Today In: Healthcare
In an excellent interview, Streek described how his team went from house to house and to every infected person in the district of Heinsberg. They took many samples from the environment and interviewed a number of families.”Two thirds, described a loss of smell and taste lasting several days.” As with my friend, it is difficult for sick people to remember the exact time course of their illness. Streek’s sense was that the smell abnormality occurred a bit later in infection.
These same findings were also seen by Massimo Galli, Professor of Infectious Diseases at the University of Milan, though he has been too busy to  quantify the finding. He also noted that these peculiar symptoms were also noted later in the course of infection so won’t be of value as a clue to early diagnosis.
Having practiced infectious disease for forty years now, the only other infection I’ve seen with a loss of smell was Herpes simplex encephalitis, so I was intrigued by this unusual symptom.
It’s not entirely clear what is causing these symptoms. Some viruses destroy the cells or cell receptors in your noseOthers infect the brain via the olfactory sensory nerves. Most disturbingly, this ability to infect the brain is thought to explain some of the cases of respiratory failure in COVID19 infections.
It’s easy to test for loss of smell with a variety of household items—citrus, soap, or cleaning supplies. You can test taste with sweet, salty, sour, or bitter items.
There was also a report from Iran of patients with loss of smell and also of vision, per Dr. Ebrahim Razmpa, Deputy Chairman of Iran’s Rhinology Association.
Two prominent people also reported the odd symptom this week. Arielle Charnas, who has the blog Something Navy, noted loss of smell and taste. On Day 4 of her illness, Frozen 2 star Rachel Matthews, who provided the voice for Honeymaren reported, “Randomly lost my sense of smell and taste.”
Addendum: UK ENT (The British Association of Otorhinolaryngology) and BRS (British Rhinological Society) are “requesting that individuals with new onset of anosmia self-isolate. A lost sense of smell as marker of COVID-19 infection.”
Loss of smell and taste is a relatively newly reported symptom of coronavirus infection. We still don’t know how often it occurs nor why this has been reported more in some areas than others. Infectious diseases has never been a boring specialty. I wish it were now.
Follow me on Twitter or LinkedInCheck out my website or some of my other work here

I am an Infectious Disease specialist and author of Resilience: One Family's Story of Hope and Triumph over Evil and of Conducting Clinical Research, the essential guide to the topic. 
I survived 25 years in solo practice in rural Cumberland, Maryland, and now work part time. I especially love writing about ethical issues, and tilting at windmills as I advocate for social justice. When not slaving over hot patients, I can be found playing with photography, friends’ dogs, or in my garden. Follow on Twitter @drjudystone


https://www.forbes.com/sites/judystone/2020/03/20/theres-an-unexpected-loss-of-smell-and-taste-in-coronavirus-patients/

Loss of smell tracked as early clue in coronavirus cases

Studies underway in Japan and US to find link, with WHO monitoring reports
Loss of smell, and an ensuing loss of taste, have been reported in coronavirus patients who show few other symptoms.   © Reuters
TOKYO -- Loss of the ability to smell and taste can be an early sign of coronavirus infection, according to a growing number of reports from around the world.


Saturday 28 March 2020

How does coronavirus testing work and will we have a home test soon?

Because the symptoms of covid-19 are similar to those of other diseases, testing is the only way to know for sure if someone is infected with the coronavirus





HEALTH 25 March 2020

Swab test



A swab test is the best way to identify coronavirus infections

Roberto Pfeil/dpa

Because the symptoms of covid-19 are similar to those of other diseases, testing is the only way to know for sure if someone is infected with the coronavirus. Mass testing is therefore crucial to halting its spread. In the UK, a home test will apparently go on sale very soon.


How do you test for coronavirus infections?
At present, most tests are based on looking for genetic sequences specific to the covid-19 coronavirus. If these sequences are found in a sample, it must contain the virus.
What does testing involve?
Getting a sample to test involves pushing a swab – which resembles an extra-long cotton bud – deep inside the nose or to the back of the throat. The swab is then sent off to a lab.
What about testing blood or urine?
The virus is only detected in the blood, urine or faeces of roughly half of those who test positive based on nose or throat swabs, so blood, urine and stool tests aren’t reliable. If you are coughing up sputum, testing that can provide more accurate results than a nose or throat swab, according to a handbook summarising findings in China.
How long does it take to get a result?
How accurate are the tests?
In theory, genetic tests should be extremely accurate if done properly. However, there have been reports from China of many false negatives and false positives. This may be because the swabbing wasn’t done correctly, or because overworked lab technicians were making mistakes. In addition, if people are tested very soon after becoming infected, they may not be shedding the virus yet.
Why is it so hard to get tested in most countries?
There are obvious practical issues with scaling up testing, from lack of trained personnel to equipment. But South Korea, which is now testing more than 20,000 people per day, has shown how fast it can be done. Many other countries didn’t start ramping up testing capacity until local case numbers began to soar and – unlike South Korea – haven’t made testing central to their strategy as advised by the World Health Organization.
I have heard some tests can be done in 10 or 15 minutes. How do they work?
Rapid tests, such as the one that may roll out in the UK soon, are usually based on detecting proteins rather than genetic sequences. These proteins can either be viral ones, called antigens, or the antibodies our bodies make to kill the virus. Antigen tests can directly detect the presence of the virus, but are less accurate than genetic tests.
What about antibody tests?
The downside of antibody tests is that they cannot detect infections in the first two weeks or so, when people are most contagious. However, our bodies keep making antibodies even after we have recovered from an infection, so testing people’s blood for antibodies against the coronavirus will reveal how many of us have been infected so far. This will help us calculate the infection fatality rate.
Can antibody tests distinguish between people who have recovered and those who are still infected?
Sometimes. People start producing so-called IgM antibodies against the coronavirus around 10 days after showing symptoms (perhaps 15 days after infection). After another two days, their bodies start making IgG antibodies, and gradually stop making IgM. Most people will recover fully as soon as IgG levels ramp up. Many rapid tests can detect both types of antibodies. If IgM antibodies are present in someone’s blood, they are likely to be still infected. If only IgG is present, they are recovering or fully recovered.
How accurate are these rapid tests?
We don’t know. Numerous companies are producing different tests that haven’t been independently checked yet. In general, testing for antigens or antibodies is less accurate than genetic testing, but the tests are easier and cheaper to manufacture. Rapid tests could play a valuable role, especially in poorer countries with little testing capacity. If they can reliably tell us when people have already been infected, it would allow key workers – especially in healthcare – to continue working without worrying about becoming infected or infecting their families.

Read more: https://www.newscientist.com/article/2238477-how-does-coronavirus-testing-work-and-will-we-have-a-home-test-soon/

Genetic Sequence vs Antibody tests - Will a home antibody test for covid-19 really be a game changer?

The UK has ordered 3.5 million antibody tests designed to reveal whether people have been infected with the new coronavirus



HEALTH ANALYSIS 27 March 2020



Covid-19 test


We might soon have a home test for covid-19

ED JONES/AFP via Getty Images
The UK has ordered 3.5 million antibody tests designed to reveal whether people have been infected with the new coronavirus. The UK’s prime minister, Boris Johnson, who today announced he himself has tested positive for the virus, has said these tests will be a “game changer”, but the reality is they might not have that much of an impact in the short term.


Almost all testing for the virus around the world is based on looking for its genetic sequence. But such tests require nose or throat swabs to be taken by trained personnel and sent to a specialised lab for analysis, and there is a global shortage of equipment. Genetic tests also detect only active infections.
Antibody tests, by contrast, detect the antibodies our bodies produce to kill the virus, which we keep producing even after the virus is eliminated. These tests can reveal who has been infected even after they have recovered. Handheld tests that require only a drop of blood can give results in 10 minutes, and can be mass produced quickly and cheaply.
If we know someone has had the virus, they can potentially leave their home without risk of being re-infected, which would help countries get moving again. However, the accuracy of the tests has yet to be established. “The one thing that’s worse than no test is an inaccurate test,” Chris Whitty, the UK’s chief medical adviser, said on 25 March. Someone wrongly told they have already had covid-19 could go out and get infected.
How accurate do the tests need to be? “It’s very difficult to say,” says Emily Adams at the Liverpool School of Tropical Medicine in the UK, who is helping assess the tests developed by Mologic, one of the companies supplying the UK. Part of that process will be working out what accuracy is required for different uses, says Adams.
Ideally, we want to find out whether the thousands of health workers who are currently self-isolating because they or someone else in their home have symptoms that might be covid-19 can get back to work. Unfortunately, the antibody test may not help with this.
The antibody response to the coronavirus may be delayed compared with other infections. The tests can be used only 14 days or more after people develop symptoms, says Adams.
This also means antibody testing will be of limited use for tracing the contacts of infected people – which many think is crucial for controlling the outbreak – because health authorities will be weeks behind.
Widespread antibody testing will also reveal whether large numbers of mild infections have gone unnoticed. It would be great news if this is the case, allowing many to return to work and meaning that the infection fatality rate is lower than thought. Unfortunately, places like South Korea that have been doing lots of genetic testing haven’t found vast numbers of mild cases.
On the plus side, many groups are working on faster genetic tests and on antigen tests that can detect the virus in, say, saliva. Testing widely for both active infections and past infections should be a highly effective combination.

Read more: https://www.newscientist.com/article/2238834-will-a-home-antibody-test-for-covid-19-really-be-a-game-changer/

Does a high viral load or infectious dose make covid-19 worse?

Does being exposed to more coronavirus particles mean you will develop a more severe illness? 


HEALTH 27 March 2020

An illustration of coronavirus particles


An illustration of coronavirus particles

MAURIZIO DE ANGELIS/SCIENCE PHOTO LIBRARY
Does being exposed to more coronavirus particles mean you will develop a more severe illness? Rumours circulating on social media suggest that hospital workers or their household members exposed to a higher “viral load” become sicker than the general population. But emerging research indicates the relationship between infection and covid-19 severity may be more complex – and differ from that of other respiratory illnesses.
The average number of viral particles needed to establish an infection is known as the infectious dose. We don’t know what this is for covid-19 yet, but given how rapidly the disease is spreading, it is likely to be relatively low – in the region of a few hundred or thousand particles, says Willem van Schaik at the University of Birmingham, UK.
Viral load, on the other hand, relates to the number of viral particles being carried by an infected individual and shed into their environment. “The viral load is a measure of how bright the fire is burning in an individual, whereas the infectious dose is the spark that gets that fire going,” says Edward Parker at the London School of Hygiene and Tropical Medicine.
If you have a high viral load, you are more likely to infect other people, because you may be shedding more virus particles. However, in the case of covid-19, it doesn’t necessarily follow that a higher viral load will lead to more severe symptoms.
For instance, health workers investigating the covid-19 outbreak in the Lombardy region of Italy looked at more than 5,000 infected people and found no difference in viral load between those with symptoms and those without. They reached this conclusion after tracing people who had been in contact with someone known to be infected with the coronavirus and testing them to see if they were also infected.
Similarly, when doctors at the Guangzhou Eighth People’s Hospital in China took repeated throat swabs from 94 covid-19 patients, starting on the day they became ill and finishing when they cleared the virus, they found no obvious difference in viral load between milder cases and those who developed more severe symptoms.
Although it is difficult to draw firm conclusions at this stage, such studies “may impact our assumptions about whether a high number of viral particles predisposes to a more serious disease”, says van Schaik.
However, a study of patients hospitalised with covid-19 in Nanchang, China, found a strong association between disease severity and the amount of virus present in the nose. “Those with more severe disease had a higher level of virus replication, although we have no evidence to relay the initial exposure dose to disease outcome,” says Leo Poon at Hong Kong University, who was involved in the study. “That rumour is still an open question to me.”
For influenza, a higher infectious dose has been associated with worse symptoms. It has been tested by exposing volunteers to escalating doses of influenza virus in a controlled setting and carefully monitoring them over several weeks. This hasn’t been done with covid-19, and is unlikely to happen, given its severity.
Animals infected with higher doses of the SARS and MERS coronaviruses also experienced worse outcomes, says van Schaik. “I think we just have to conclude that while this virus is related to SARS, there are also important differences that are currently poorly understood,” he says.
Even if the infectious dose isn’t related to disease severity, it still pays to try and minimise our exposure to the virus because this will reduce our chances of falling ill in the first place. “We want to be taking every precaution we can to prevent ourselves getting infected, which will also reduce our ability to pass the virus on to others,” says Parker. “Any measures we can take to avoid infection are worth taking.”

Read more: https://www.newscientist.com/article/2238819-does-a-high-viral-load-or-infectious-dose-make-covid-19-worse/