India's new paper Covid-19 test could be a ‘game changer’

‘A team of scientists in India has developed an inexpensive paper-based test for coronavirus that could give fast results similar to a pregnancy test. The test, named after a famous Indian fictional detective, is based on a gene-editing technology called Crispr. Scientists estimate that the kit - called Feluda - would return results in under an hour and cost 500 rupees (about $6.75; £5.25). Feluda will be made by a leading Indian conglomerate, Tata, and could be the world's first paper-based Covid-19 test available in the market.

‘Researchers at the Delhi-based Institute of Genomics and Integrative Biology (IGIB), where Feluda was developed, as well as private labs, tried out the test on samples from about 2,000 patients, including ones who had already tested positive for the coronavirus. They found that the new test had 96% sensitivity and 98% specificity...’

Read here (BBC, Oct 4, 2020)

Rapid, cheap home tests: Companies attempt to make coronavirus tests widely available

‘Nearly two months after federal regulators unveiled rules for at-home coronavirus tests, no company has federal approval to sell these fast and cheap tests even though the technology is ready.

‘Molecular PCR tests processed at medical labs remain the standard of accurate testing, but they are more expensive and results can take days to process. Antigen tests are less expensive, plentiful and deliver results in minutes. Three companies gained Food and Drug Administration authorization to sell antigen testing instruments to labs or clinics. A fourth company, Abbott Laboratories, won approval to market a $5 rapid, credit card-sized test administered by a health care professional.

‘But no company has been cleared to sell tests directly to consumers for widespread screening – a step some believe is necessary to slow the spread of COVID-19, as more than 200,000 Americans have died and people worry about safely returning to work, school, travel or sporting events. “The way to get this under control is if people find out as early as possible they are infected and then quarantine from others,” said Dr. Yukari Manabe, a Johns Hopkins University professor of medicine.’

Read here (USA Today, Sept 25, 2020)

Dogs used to detect coronavirus in pilot project at Helsinki airport

‘Dogs trained to detect the novel coronavirus began sniffing passenger samples at Finland’s Helsinki-Vantaa airport this week, authorities said, in a pilot project running alongside more usual testing at the airport. The dogs’ efficiency has not been proven in comparative scientific studies so passengers who volunteer to be tested and are suspected as carrying the virus are instructed to also take a swab to confirm the result.’

Read here (Reuters, Sept 24, 2020)

As more local lockdowns begin, the hard truth is there’s no return to ‘normal’ [comment on Britain]

‘As well as the risk Covid poses to individuals, our actions affect others including vulnerable and elderly people. Think of it as a chain of infections – if you are a part of this and it gets passed on, others may become ill and die because of your role in that chain. A wedding in Maine resulted in more than 170 people contracting the virus, and seven people dying. None of those who died attended the wedding...

‘Nine months after South Korea and Senegal started building diagnostic capacity, it is comically depressing that the UK government, one of the richest in the world, does not have a functional testing system that returns results within 24 hours. In addition, given that we know the virus spreads easily through households, those who test positive should have the offer to isolate in external facilities (such as hotels). The “14-day isolation” measures for people entering the UK are also a box-ticking exercise where given the lack of screening or monitoring, a constant stream of infections keep coming into the country. It’s like trying to empty a bucket under a tap.’

Read here (The Guardian, Sept 21, 2020) 

Fast coronavirus tests: What they can and can't do

‘Rapid antigen tests are designed to tell in a few minutes whether someone is infectious. Will they be game changers? At present, antigen tests are administered by trained professionals, but some companies are developing versions that are simple enough to be used at home — similar to pregnancy tests.

“Making the tests faster, cheaper, easier is definitely the goal — and I think the antigen test is the way to get there,” says Martin Burke, a chemist at the University of Illinois at Urbana-Champaign, who is co-developing rapid tests, including antigen-based assays. “This is by no means the perfect solution, it’s just the fastest thing we could get going now,” he says.

Read here (Nature, Sept 16, 2020) 

US health agency says testing not needed for some exposed to Covid-19, sparking outcry

‘The US Centers for Disease Control and Prevention (CDC) said this week that people who were exposed to COVID-19 but are not symptomatic may not need to be tested, sparking outcry among officials and experts who fear the changed guidance was politically motivated. The advice marks a reversal of the agency's previous position recommending testing for all close contacts of people diagnosed with COVID-19, narrowing the scope of instances where the CDC recommends testing. CNN and The New York Times reported on Wednesday that US public health officials were ordered by high-level members of the Trump administration to push forward with the changes.’

Read here (Channel News Asia, August 27, 2020)

Being a coronavirus tester has been a life-changing experience

‘Back in the first week, the manual sample handling process allowed us to process several hundred samples. With more volunteers coming in, this increased to several thousand, and when we roped in robots to help, it quickly reached tens of thousands of processed tests per day. Just like the spread of the virus we were competing against, our capacity was growing exponentially. What would normally have taken months or years to establish, now took days or weeks.’

Read here (Channel News Asia, August 22, 2020)

What to know about Covid-19 tests, from PCR to antigen to antibody

‘People often talk about COVID-19 testing like it means only one thing. But in reality, the U.S. Food and Drug Administration (FDA) has so far granted emergency-use authorization to more than 200 different tests meant to detect a current or past infection from SARS-CoV-2, the virus that causes COVID-19. Most recently, the agency made headlines for approving the first such test that uses saliva samples, the aptly named SalivaDirect test out of the Yale School of Public Health.

‘These COVID-19 tests fall into three main categories: PCR, antigen and antibody. Dr. Aneesh Mehta, chief of infectious diseases services at Emory University Hospital in Atlanta, Ga., broke down the differences between them—and what to keep in mind if you decide to get tested.’

Read here (Time Magazine, August 20, 2020)

Quick and affordable saliva-based COVID-19 test developed by Yale scientists receives FDA Emergency Use Authorisation

‘A saliva-based laboratory diagnostic test developed by researchers at the Yale School of Public Health to determine whether someone is infected with the novel coronavirus has been granted an emergency use authorization by the U.S. Food and Drug Administration (FDA). With the FDA’s emergency use authorization, the testing method is immediately available to other diagnostic laboratories that want to start using the new test, which can be scaled up quickly for use across the nation — and, perhaps, beyond — in the coming weeks, the researchers said. A key component of SalivaDirect, they note, is that the method has been validated with reagents and instruments from multiple vendors. This flexibility enables continued testing if some vendors encounter supply chain issues, as experienced early in the pandemic.‘

Read here (Yale News, August 15, 2020)

Israeli hospital trials super-quick saliva test for Covid-19

‘A newly developed saliva test aims to determine in less than a second whether or not you are infected with the novel coronavirus, Israel’s largest medical center said on Thursday... The center said in an initial clinical trial involving hundreds of patients, the new artificial intelligence-based device identified evidence of the virus in the body at a 95% success rate... The company said they are in the process of getting regulatory approval. Each test costs less than 25 cents and it expects the device will eventually cost less than $200.’

Read here (Reuters, August 13, 2020)

Watch here (South China Morning Post video on Youtube)

Long and hard battle to clear worker dorms of Covid-19

On August 7, Singapore finished testing all 323,000 workers in dorms for Covid-19 -- a "massive undertaking" that has taken four months. This story with a video shows how the Sungei Tengah Lodge, a worker dormitory for 23,000, has been cleared of Covid-19. It provides some images of the living conditions there (after they have been cleaned up) and reveals how various agencies as well as the dorm operator have worked together to clear the virus.

Read here (Straits Times, August 8, 2020) 

Covid-19: Getting our SOPs right - Amar Singh HSS and Lim Swee Im

This article discusses a number of issues on SOPs pertaining to Malaysia today:

• How can we best monitor our pandemic when our numbers are low?
• How ready are our testing capabilities for a second and subsequent waves?
• How good are our safe physical distancing measures?
• Optimising masks in Covid-19 prevention
• There is no way for the poor (B40) to comply with this ruling without a government mandated free programme
• Mask etiquette and our leaders

Read here (The Malay Mail, July 27, 2020)

Viral loads: Review points to PCR-testing inadequacies and need to prioritise early case detection

A review of 79 studies on viral loads in people — specifically, SARS-CoV-2, SARS-CoV-1 and MERS-CoV — has shown that (1) ‘viral RNA can persist in and be shed from the body for long periods of time (more than 80 days in some cases)’ although ‘SARS-CoV-2 only remains viable and infectious for approximately one week after the onset of symptoms’ (2) ‘Viral load was at its highest approximately 3-5 days after the onset of symptoms, and there was a positive correlation between prolonged viral shedding and disease severity. Older patients also experienced prolonged viral shedding compared to younger patients, even when accounting for disease severity...

‘While there are fewer studies on the kinetics of viral load for asymptomatic infections, viral shedding appeared to be of a shorter duration, and overall viral load appeared to be lower compared to symptomatic cases.’ 

The authors conclude that (1) ‘PCR testing is likely not a good tool for evaluating patient recovery, because viral RNA is detectable long after the end of the infectious period’. (2) ‘Early case detection and isolation should be prioritised in order to maximise control efforts during the time when patients are the most infectious.’ -- Center for Health Security, John Hopkins University

https://www.medrxiv.org/content/10.1101/2020.07.25.20162107v2.full.pdf

Read here (Medrxiv, July 25, 2020)

German sniffer dogs show promise at detecting coronavirus

‘Scientists at the University of Veterinary Medicine Hanover have found that trained sniffer dogs could be used to detect COVID-19 in human samples with a relatively high rate of accuracy, a study published on Thursday revealed... The animals were able to positively detect SARS-CoV-2 infected secretions with an 83% success rate, and control secretions at a rate of 96%. The overall detection rate, combining both, was 94%.’

Read here (DW, July 23, 2020)

New rules: Malaysians to pay RM30-RM150 for Covid-19 test upon return abroad; foreigners pay RM60-RM250

‘Malaysians returning from overseas will have to pay a range of RM30 to RM150 to be tested for Covid-19 upon entering the country from today onwards, while non-citizens will pay higher fees depending on the type of tests conducted, new rules issued by the government said.

‘In the regulations made on June 26 by Health Minister Datuk Seri Dr Adham Baba, any Malaysian or foreigner entering Malaysia will be required to pay the specified fee depending on the type of Covid-19 detection tests taken "before proceeding for immigration clearance at any point of entry", with the type of tests used to be decided by the health director-general.’

Read here (The Malay Mail, June 29, 2020)

CDC head estimates US coronavirus cases might be 10 times higher than data show

‘In a press briefing on June 25, Dr. Robert Redfield, director of the U.S. Centers for Disease Control and Prevention (CDC), said that the current official count of COVID-19 cases in the U.S. may actually be a drastic underestimate.

‘Redfield said the new, much-higher estimate, is based on growing data from antibody testing, which picks up the presence of immune cells that react to SARS-CoV-2, the virus that causes COVID-19. People will test positive for antibodies to the virus if they have been infected—whether or not they ever got sick or even developed symptoms.’

Read here (Time Magazine, June 25, 2020)

Coronavirus antibody tests have a mathematical pitfall

‘...such [antibody] tests have been proposed as a way for individuals to find out if they have already been infected with the novel coronavirus. But a mathematical wrinkle makes these tests—and in fact, all screening tests—hard to interpret: even with a very accurate test, the fewer people in a population who have a condition, the more likely it is that an individual's positive result is wrong. If it is, people might think they have the antibodies (and thus may have immunity), when in fact they do not.

‘A positive screening test result for other diseases usually prompts follow-up testing to confirm a diagnosis. But for COVID-19 screening, such follow-up has been rare because testing resources are scarce or because other testing methods are prioritized for the sickest patients. Here's a look at the massive impact infection rates can have on the predictive value of these tests for individuals.’

Read here (Scientific American, July 2020, pre-published in June 19, 2020)

In this coronavirus wave, China tries something new: Restraint

‘The city of Beijing has tested 1.1 million people in less than a week and has halted many flights, but has not imposed the citywide lockdowns used in provincial outbreaks...

‘The brunt of the government’s measures has been borne by food traders at markets that were sealed off after cases were found, and by the residents of more than four dozen apartment complexes placed under lockdown. But in many other Beijing neighborhoods, the shops, restaurants and even hair salons are still operating. Traffic is a little lighter than usual, but plenty of cars are still on the road. City sidewalks remain busy.’

Read here (New York Times, June 19, 2020)

‘Epidemic stopped’: Results in from second Chinese city to do mass coronavirus tests

‘In all, 19 asymptomatic cases found among the 650,000 people tested in Mudanjiang, authorities say. Viral cultures reveal low level of infectiousness among those carriers.’

Read here (South China Morning Post, June 10, 2020)

Race, ethnicity data to be required with coronavirus tests starting August 1

‘Data on who is being tested “are rarely being reported to CDC in usable format,” Giroir said during a conference call with journalists. “It is critical for us to ensure that there is equitable access to testing, especially for underserved minorities. And without the data we are now requiring, there is simply no way to determine that.”

Read here (Washington Post, June 5, 2020)