How to prepare your child for a COVID test

Posted on August 12, 2021 by particularkev

Therese O’Sullivan, Edith Cowan University and Mandy Richardson, Edith Cowan UniversityWe’ve been urged to get COVID tested even if we have mild symptoms. Or perhaps we don’t have symptoms but are a close or casual contact of a known case. This includes children.

So what can you do to make COVID testing as simple and stress-free as possible for your child?

With a bit of preparation, role play and modelling the type of behaviour you’d like to see, the process can be plain sailing.

Start the conversation now

Ideally, you want to start the conversation about COVID testing before your child actually needs a swab. Reflect together on the pandemic so far and envision what might happen in the future.

Child's drawing of how 'Covid-19 sucks' — Here’s what 10-year-old Roisin from Ireland thinks of lockdown.
Our COVID-19 Artwork/Children’s Artwork Project, CC BY-NC-ND

Let your child know COVID tests ensure sick people are cared for and stop them spreading the virus to others.

Point out COVID testing sites when you drive past.

Preparation is the key

Knowledge of what is going to happen is important for children to feel in control and empowered in situations like COVID testing.

Encourage them to watch videos showing kids having a COVID test, like this one.

Encourage questions and be open to answering them honestly. Acknowledge it feels uncomfortable to have something pushed up your nose. But the discomfort will be only temporary.

This Canadian video shows the swab going right up a child’s nose. The video says this feels a bit like what happens when you get water up your nose, or the tingly feeling you get in your nose after a fizzy drink.

The swab goes up your nose, but only for about five seconds. Count them.

Children report feeling deceived if they are told a procedure won’t hurt when it does. This can lead them to distrust future medical procedures.

Depending on the age of the child, you could also help prepare with some role play, known as therapeutic play. This type of preparation helps children feel more comfortable and less anxious before medical procedures.

For COVID testing, this can include asking your child to try wearing a mask. Then your child can use a couple of cotton buds taped together to make a long swab, to “test” their teddy or doll.

Before you go

To help your child feel in control of what is happening to them, think about how they can participate in the process. Give them choices where possible.

Which testing centre would they like to go to? What toy would they like to take with them to hold during the test? There may be a long wait for the test. What fun things could they take with them or do to help pass the time? What snack would they like to take?

During the test

Children are good at picking up on cues from their parents, so stay calm and confident when taking your child for testing. If you are also being tested, they may like to see you go first.

Ask the tester to talk through what they are doing. Avoid distractions and bribes. Offering a bribe can give the child the impression there is something to be worried about, and distractions can leave the child suspicious of why they were distracted.

As with vaccinations, some children may like to watch so they know what is happening, rather than shutting their eyes. Give your child the option.

Be fully present with your child during the procedure and put your phone away.

Humour can help keep things light hearted and it reduces stress levels. What do COVID-19 jokes have in common? They’re catchy!

After the test

You need to go home until you receive a result so brainstorm with your child about some fun things to do while you wait.

Explain their result will come back either positive or negative. Positive means you have COVID-19, negative means you don’t.

Consider how best to help your child deal with a positive result. Some children may have some anxiety around this, even if they have very mild symptoms.

In a nutshell

Overall, this respectful approach to child-centred health care focuses on developing a cooperative relationship with the child, rather than using authority or incentives.

We have used this approach successfully in our child research projects involving invasive assessments. It helps the child feel in control, helps reduce anxiety around medical procedures and helps them feel empowered by their experiences.

Look at COVID testing as an opportunity for your child to learn more about how health care works. An empowering COVID testing experience can help set up your child for future interactions with the health system.

Therese O’Sullivan, Associate Professor, Edith Cowan University and Mandy Richardson, PhD candidate, Edith Cowan University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Airline policies mandating vaccines will be a turbulent test of workplace rights

Posted on June 29, 2021 by particularkev

Giuseppe Carabetta, University of SydneyAirlines want you vaccinated. They want as many people as possible vaccinated. The sooner that happens, the sooner borders open and they can get back to profitability.

They also have reasons to want to protect both customers and staff from COVID-19. Qantas staff, for example, have been considering legal action over workplace transmissions.

Qantas has dangled the carrot of extra frequent flyer points for fully vaccinated passengers, plus ten “mega prizes” of a year’s free travel for familes. Virgin Australia has similar plans. It also has a scheme to encourage its workers to get vaccinated. This will reportedly include the chance to win extra annual leave.

Could they go further and mandate vaccines? This is something Cathay Pacific is doing, telling its Hong Kong-based flight crews they must be vaccinated by August or their employmnet will be reviewed.

Qantas chief Alan Joyce signalled in November that once vaccines are widely available it will require international travellers to be vaccinated. This implicitly suggests it will require the same from international flight staff.

But the legal ground in Australia for employers to insist that employees be vaccinated remains murky.

Whether Qantas or Virgin – or indeed any other company – do so may depend on the case of Queensland regional carrier Alliance Airlines, the first employer in Australia to insist all employees be immunised.

A question of common law

Alliance Airlines specialises in flights to and from mining sites. It is 19.9% owned by Qantas, and collaborates with both Qantas and Virgin Australia.

It announced its mandatory policy for both influenza and COVID-19 vaccinations in late May. Its stated reason is to fulfil its duty to employees and passengers. But unions have questioned the policy’s lawfulness, arguing it is beyond the airline’s powers.

In Australia, there has been no general government guidance on whether employers can insist on employees getting COVID-19 vaccinations.

This differs to the United States, where the federal Equal Employment Opportunity Commission ruled in December 2020 that employers could (with some exemptions for medical and religious reasons) require employees to be vaccinated.

The Queensland and Western Australian governments have passed legislation mandating workers be vaccinated, but only in certain health and quarantine workplaces.

Whether Alliance Airlines’ policy is lawful therefore depends on a general common law “test” for determining the validity of workplace policies.

This test asks if a policy or direction is “lawful and reasonable” given the circumstances. These include:

the nature of the job, especially where it requires regular interactions with colleagues, clients and suppliers
if the work can be done remotely, or other reasonably practical precautions exist
the effectiveness or success rates of the vaccine
any guidance or directives from government and medical experts
the circumstances of individuals employee, such as whether they have reasonable grounds to refuse vaccination.

Unfair dismissal cases

Australia’s Fair Work Commission has demonstrated the balancing act needed to apply these factors in its most recent ruling in an unfair dismissal case involving a refusal to get an influenza vaccination.

The claim was brought by Maria Corazon Glover, a 64-year-old community care assistant, against Queensland aged and disability care provider Ozcare, her employer since 2009.

In May 2020, public health orders in Queensland required influenza vaccinations for entry into aged care facilities. Ozcare went “above and beyond” those requirements, mandating the flu vaccine for all its aged care workers, even those who did not work in facilities. Glover, a home-care provider, refused. She said she believed she would suffer an allergic reaction, based on what she understood had happened to her as a child. She was ultimately dismissed.

Commissioner Jennifer Hunt upheld her dismissal despite Ozcare’s policy exceeding the relevant public health orders and Glover’s concerns. Hunt ruled those factors were outweighed by the vulnerability of Ozcare’s clients, the frequency with which care workers visited clients’ homes (and their potential to become “super-spreaders”), and the employer’s “prerogative” to make a decision considered necessary to safeguard its clients and employees “so far is practicable to do so”.

Individual circumstances do count

Perhaps the most important takeaway from Glover v Ozcare is that it was decided on its particular facts. Employers must carefully assess employees’ situations to decide if a mandatory vaccination policy is justifiable.

An airline might reason that cabin crew interact with people in environments with a higher risk of COVID-19 transmission and where social distancing is impossible.

But an employee might counter that, unlike aged or disability care workers, they have much less close contact with high-risk, vulnerable individuals.

The case-by-case nature of the reasonableness test means any generalised “all in” vaccination policy is problematic. Even more so if there is employee resistance.

Discrimination may be valid

Employees who are dismissed for refusing to vaccinate might also argue it amounts to discrimination on prohibited grounds such as disability or pregnancy, where COVID-19 vaccination may be unsafe or pose medical risks.

Under the Fair Work Act, however, employers have a valid defence for discriminatory action if a policy or decision is based on the “inherent requirements” of the job.

In November 2020, Fair Work Deputy president Ingrid Asbury noted that vaccination against influenza was likely to be an inherent requirement for a position involving caring for young children, and so could be justified for child-care employees.

However, outside high-risk contexts such as child and health care, this defence may be limited and will turn on the employee’s role and the organisational context.

Looking for safe ground

The Fair Work Commission’s rulings on influenza vaccines give a fair indication of the principles it will apply to any case involving COVID-19 vaccines.

But given the different circumstances, whether it will give a green light to a general policy like that of Alliance Airlines remains up in the air.

Qantas and Virgin might be on safer ground because of their international operations, if proof of vaccination becomes mandatory for other destinations.
However, I think the issue of employee vaccinations for the airline industry will ultimately be resolved via government intervention.

In other sectors, owing to the complexities in determining whether mandatory policies are “legal”, many employers will likely stick with the safer route of voluntary “incentive schemes” to encourage vaccinations.

Giuseppe Carabetta, Senior Lecturer, Sydney University Business School, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Why are some COVID test results false positives, and how common are they?

Posted on June 21, 2021 by particularkev

Adrian Esterman, University of South AustraliaTwo COVID-19 cases previously linked to Melbourne’s current outbreak have now been reclassified as false positives.

They’re no longer included in Victoria’s official case counts, while a number of exposure sites linked to these cases have been removed.

The main and “gold standard” test for detecting SARS-CoV-2, the virus that causes COVID-19, is the reverse transcriptase polymerase chain reaction (RT-PCR) test.

The RT-PCR test is highly specific. That is, if someone truly doesn’t have the infection, there is a high probability the test will come out negative. The test is also highly sensitive. So, if someone truly is infected with the virus, there is a high probability the test will come back positive.

But even though the test is highly specific, that still leaves a small chance someone who does not have the infection returns a positive test result. This is what’s meant by a “false positive”.

First off, how does the RT-PCR test work?

Although in the age of COVID most people have heard of the PCR test, how it works is understandably a bit of a mystery.

In short, after a swab has been taken from the nose and throat, chemicals are used to extract the RNA (ribunocleic acid, a type of genetic material) from the sample. This comprises a person’s usual RNA and RNA from the SARS-CoV-2 virus, if present.

This RNA is then converted to deoxyribonucleic acid (DNA) — this is what the “reverse transcriptase” bit means. To detect the virus, the tiny segments of the DNA are amplified. With the help of some special fluorescent dye, a sample is identified to be positive or negative based on the brightness of the fluorescence after 35 or more cycles of amplification.

What causes false positive results?

The main reasons for false positive results are laboratory error and off-target reaction (that is, the test cross-reacting with something that’s not SARS-CoV-2).

Laboratory errors include clerical error, testing the wrong sample, cross-contamination from someone else’s positive sample, or problems with the reagents used (such as chemicals, enzymes and dyes). Someone who has had COVID-19 and recovered might also show a false positive result.

A health-care worker performs a COVID swab test on a patient. — There are a few reasons an RT-PCR test can result in a false positive.
Shutterstock

How common are false positive results?

To understand how often false positives occur, we look at the false positive rate: the proportion of people tested who do not have the infection but return a positive test.

The authors of a recent preprint (a paper which hasn’t yet been peer-reviewed, or independently verified by other researchers) undertook a review of the evidence on false positive rates for the RT-PCR test used to detect SARS-CoV-2.

They combined the results of multiple studies (some looked at PCR testing for SARS-CoV-2 specifically, and some looked at PCR testing for other RNA viruses). They found false positive rates of 0-16.7%, with 50% of the studies at 0.8-4.0%.

The false positive rates in the systematic review were mainly based on quality assurance testing in laboratories. It’s likely that in real world situations, accuracy is poorer than in the laboratory studies.

A systematic review looking at false negative rates in RT-PCR testing for SARS-CoV-2 found false negative rates were 1.8-58%. However, they point out that many of the studies were poor quality, and these finding are based on low quality evidence.

No test is perfect

Let’s say for example, the real-world false positive rate is 4% for SARS-CoV-2 RT-PCR testing.

For every 100,000 people who test negative and truly don’t have the infection, we would expect to have 4,000 false positives. The problem is that for most of these we never know about them. The person who tested positive is asked to quarantine, and everyone assumes they had asymptomatic disease.

This is also confounded by the fact the false positive rate is dependent upon the underlying prevalence of the disease. With very low prevalence as we see in Australia, the number of false positives can end up being much higher than the actual true number of positives, something known as the false positive paradox.

Because of the nature of Victoria’s current outbreak, authorities are likely being extra vigilant with test results, potentially making it more likely for false positives to be picked up. The Victorian government said:

Following analysis by an expert review panel, and retesting through the Victorian Infectious Diseases Reference Laboratory, two cases linked to this outbreak have been declared false positives.

This doesn’t make clear whether the two people were retested, or just the samples were retested.

Either way, it is unlucky to have two false positives. But given the large numbers of people being tested every day in Victoria at present, and the fact we know false positives will occur, it is not unexpected.

An illustration of SARS-CoV-2. — The RT-PCR test for SARS-CoV-2 is highly accurate, but not perfect.
Shutterstock

The broader implications

For an individual who received a false positive test result, they would be forced to go into quarantine when there was no need. Being told you have a potentially lethal disease is very stressful, especially for elderly people or those at risk because of other health conditions. They would also likely be worried about infecting other members of their family, and could lose work while in quarantine.

Particularly given authorities initially pointed to these two cases as examples of transmission of the virus through “fleeting” contact, no doubt many people have wondered whether without these cases, Victoria might not be in lockdown. This is just conjecture and we can’t really know one way or the other.

False negative results are clearly very concerning, as we don’t want infectious people wandering around the community. But false positives can also be problematic.

Adrian Esterman, Professor of Biostatistics and Epidemiology, University of South Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Could a test really detect if someone is a COVID-19 ‘superspreader’?

Posted on October 29, 2020 by particularkev

Lara Herrero, Griffith University

Last week we heard Queensland-based biotech company Microbio had developed a test that could, according to media reports, tell whether someone is a COVID-19 superspreader.

While this may sound like an exciting prospect, there are a few questions to answer before we know what role this test might have in managing the spread of COVID-19.

First, what is a superspreader?

It’s important to understand there’s no scientific definition of a “superspreader”.

In the context of COVID-19, the term “superspreader” has been used to describe someone who can spread the virus and cause infection in many people with minimal contact.

There are many factors thought to contribute to what makes someone a superspreader. The most talked about is infectious viral load. Put simply, this is the amount of live infectious virus a person carries.

Current thinking is that people with a higher infectious viral load are more likely to infect others, but it may not be that simple.

An illustration of SARS-CoV-2, the coronavirus that causes COVID-19. — SARS-CoV-2 is the coronavirus that causes COVID-19.
Shutterstock

When a person has a COVID-19 test, the health-care worker uses a swab to collect samples from the back of the person’s nose and throat. These are the areas where the virus likes to live. The swab is then sent to a pathology lab which tests for the presence of viral genomic material.

The test returns as a positive (that is, the virus has been detected) or negative (virus not detected). There’s no indication of how much virus is present, or whether it’s replicating.

So, back to the new test

Microbio says the newly developed InfectID-COVID-19-R test can detect “replication-competent virus”. This essentially means the test would detect the amount of active live virus a person is carrying. Researchers believe the patient is most likely to be infectious when the virus is replicating.

Like current COVID-19 tests, the test requires a sample of viral genetic material from a patient swab. The genetic material is “extracted” from the swab (termed RNA extraction). The resulting sample is put through a machine to detect an important part of the virus genome which indicates whether the virus is alive and replicating.

InfectID-COVID-19-R claims to accurately detect a virus concentration as low as 1,500 TCID50 per millilitre with 99% specificity. (TCID50 stands for tissue culture infectious dose 50% — it’s currently the accepted standard to quantify the amount of infectious SARS-CoV-2.)

This equation may be tricky to grasp, but the important part to understand is that below this threshold, the person has a lower amount of replicating virus than the test can guarantee to detect. They can’t say for certain the person has no replicating virus.

If a person records a result above the threshold, that tells scientists the virus is alive and replicating.

The suggestion is the test will be able to quantify the amount of replicating virus present in the swab. But exactly what that means — and how the test will achieve this — is uncertain.

Microbio’s media release is tight-lipped on a few key aspects of this test. We still don’t have answers to some questions, including:

what part of the virus genome it is detecting, and how is this different to our current diagnostic tests?
how does detecting this part of the virus ensure detection of replicating or “live” virus?
how will the test results be presented? For example, will the test provide a reference range and guide on how to interpret the result?
how can they prove that if a test comes back below the limit of detection for replicating virus that the person is not infectious?

In response to queries from The Conversation, Microbio’s chief scientific officer Flavia Huygens said the new test “targets the part of the virus’ genome that is present while it is replicating inside the human cell”, and that this target is different to existing COVID-19 tests. She added: “Our test detects the portion of the virus genome that is only present whilst the virus is replicating and hence is indicative that the virus is “live.”

Huygens also said the test has built-in references and guides for clinical laboratories to interpret the results.

It’s early days yet

Without more detail, it’s too early to tell just how useful this test will be.

Certainly, we need to know whether a low replicating viral load means a person is not infectious before using this test to make any decisions around quarantine. Research is still ongoing in this area.

A lecture theatre full of people. — It may be more accurate to describe ‘superspreading events’.
Shutterstock

The test hasn’t yet been approved for use. It has been independently validated by 360 biolabs, a clinical trial laboratory accredited by the Australian National Association of Testing Authorities. Huygens told The Conversation that Microbio is planning further validation of its test using patient samples.

Infecting volunteers with coronavirus may be one way to test potential vaccines. But there are risks

Posted on October 16, 2020 by particularkev

Euzebiusz Jamrozik, Monash University; Kanta Subbarao, The Peter Doherty Institute for Infection and Immunity, and Michael Selgelid, Monash University

Researchers are considering using “human challenge studies” to accelerate COVID-19 vaccine research and development. This would involve giving an experimental vaccine to healthy volunteers, then deliberately exposing them to the virus to see whether they’re protected from infection.

Challenge studies can also allow scientists to monitor the progress of infectious diseases from the moment they begin, and to study infection and immunity more closely than other types of research.

These studies can answer scientific questions in a short time. They recruit small numbers of participants — up to around 100 volunteers per study — usually young, healthy adults.

However, deliberate infection with SARS-CoV-2, the virus that causes COVID-19, involves risks to volunteers.

How do these studies differ from standard, larger studies?

Standard “field” trials for some COVID-19 vaccine candidates have already begun. Each aims to recruit at least 10,000 people. Usually, half or two-thirds receive the experimental vaccine and the rest might receive a placebo or a vaccine against another disease.

Participants then go about their daily lives. Scientists observe whether those who received the COVID-19 vaccine are less frequently infected with the virus than the other group, allowing them to determine how effective the vaccine is.

Two scientists in a lab look at a syringe. — Human challenge studies involve fewer participants than standard field trials.
Shutterstock

In large epidemics, field trials can quickly reveal whether a vaccine works. But proof may be delayed when there’s less community transmission, for example due to local public health measures.

If current field trials identify a highly effective vaccine, there might be less need for human challenge trials. However, if the first vaccines fail, or turn out to be only moderately effective, challenge studies could be used to select the next most promising candidates for future field trials.

Challenge studies need extra preparation

First, scientists need to prepare a strain of SARS-CoV-2 in the laboratory to administer to volunteers. The strain needs to be similar to the virus circulating in the community.

There’s also a need for special research facilities with health-care support and capacity to isolate participants.

Volunteers may have to remain in these facilities for 2–3 weeks to be closely monitored, and so they are not released into the community while they may be infectious.

Past experience and recent developments

While COVID-19 challenge trials are now making news, scientists have previously conducted these kinds of experiments with many different types of microorganisms.

Such studies have been used to develop vaccines against malaria, typhoid and cholera. They have also provided unique insights into immunity to influenza and “common cold” coronaviruses.

One research centre in London has announced a plan to conduct challenge studies with SARS-CoV-2. Another centre in the United States is also preparing a strain of the virus.

Ethical and scientific questions

The World Health Organisation (WHO) convened two advisory groups, in which we were involved, to consider COVID-19 human challenge studies. One focused on ethics, the other on scientific and technical aspects.

The ethics group identified eight criteria proposed challenge studies would need to meet before going ahead.

These included the need for researchers to consult and engage with the general public before, during, and after the trials. There would also need to be careful independent expert review, and demonstration that expected benefits are likely to outweigh risks.

Relevant risks might be especially hard to predict for SARS-CoV-2, partly because it’s a new pathogen.

While young, healthy people generally fare better with COVID-19 than older adults with pre-existing conditions, there are exceptions. For example, a multisystem inflammatory syndrome has been reported in rare cases among previously healthy adults after they contracted COVID-19.

Members of WHO’s science group agreed on a number of technical requirements for COVID-19 challenge studies to maximise volunteers’ safety and prevent wider spread of infection.

These included recruiting only healthy young adults, conducting the studies under strict biosafety procedures (for example, isolating participants), giving the virus via the nose to mimic natural infection, and carefully increasing the dose of the virus.

Group of young adult students outside looking at books and papers, studying — Only young adults without underlying health conditions could volunteer for these studies.
Shutterstock

However, the experts were split on other issues, such as whether:

challenge studies would actually accelerate vaccine approval
results in young healthy adults would demonstrate whether or not a vaccine works for older people
challenge trials should begin before a proven and highly effective treatment for COVID-19 becomes available.

What next?

To design an ethically acceptable challenge study, it’s important to minimise the risks to study volunteers, research staff, and the wider community.

In the future, there may be additional ways scientists can reduce the risks. They may be able to better identify those at lowest risk of severe infection, develop a weakened strain of the virus, or have a highly effective treatment on hand to use if needed.

In the meantime, scientists could obtain results relevant to COVID-19 by conducting less risky challenge studies with other viruses.

For example, challenge studies with “common cold” coronaviruses, which are being considered in Australia, could teach us about the types of immune responses that protect us against coronavirus diseases.

Research eventuating in safe and effective vaccines for COVID-19 could save many lives. However, whether the benefits of challenge studies in the current pandemic outweigh the risks depends on many factors.

We must carefully consider proposals for these studies in light of the current state of science and vaccine development, and update our evaluations as new data emerge.

Euzebiusz Jamrozik, Infectious Disease Ethics Fellow, Ethox & Wellcome Centre for Ethics and Humanities, Univeristy of Oxford. Adjunct, Monash University; Kanta Subbarao, Professor, The Peter Doherty Institute for Infection and Immunity, and Michael Selgelid, Professor of Bioethics, Monash Bioethics Centre, Monash University, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Why do some COVID-19 tests come back with a ‘weak positive’, and why does it matter?

Posted on October 11, 2020 by particularkev

Sheena G. Sullivan, WHO Collaborating Centre for Reference and Research on Influenza and Jennifer MacLachlan, The Peter Doherty Institute for Infection and Immunity

When we get a test result for a disease like COVID-19, we naturally expect it to be either positive or negative. But the results of these tests are not so black and white.

Polymerase chain reaction, or “PCR”, is the most common test to detect the presence or absence of SARS-CoV-2, the virus that causes COVID-19.

Recently, a “weak positive” case of COVID-19 was reported in the Northern Territory.

Let’s take a look at why someone might get a weak positive result.

Shouldn’t you just be ‘positive’ or ‘negative’?

PCR tests are used to detect a range of viruses and pathogens. They look for viral genetic material in a respiratory sample, such as a nose or throat swab or a saliva sample.

We identify a sample to be positive or negative based on the number of times we need to amplify the small segments of genetic material to detect the virus — and whether this number falls below or above a certain threshold.

When there’s a lot of virus present, we only need a few cycles of amplification to detect it. When there isn’t much virus, or there’s none, we need to amplify the sample several more times until finally we cross the threshold and deem the sample negative.

So in this process we can see the potential for a weak positive result. It would generally be a reading at or just above the threshold. And that threshold varies depending on the test used.

Importantly, thresholds are just the point at which we believe we’ve detected something. They’re not 100% precise. Sometimes results just above or below the threshold might be false negatives or false positives.

When might you have a weak positive result?

In most cases, the genetic material of a virus is only detectable when we’re infected and the virus is still replicating and shedding into our respiratory passages.

But sometimes, even when the virus is no longer alive and replicating, it can hang around and be detectable by PCR. In these cases, it’s unclear whether the virus is infectious.

A health worker dressed in PPE prepares to take a swab from a man in his car. — PCR tests for COVID-19 look for the genetic material of SARS-CoV-2.
Shutterstock

In the case of the NT man, he had earlier tested positive for COVID-19 in Victoria and recovered. Although he recorded a negative test before travelling to the NT, it’s likely he was still just shedding small amounts of the virus.

This may be more common among people with weaker immune systems, as it takes them longer to clear the virus from their system.

How do we handle weak positives?

A weak positive is treated as a “presumptive positive” result — we presume it to be positive, and generally classify it as such, until we have information to suggest otherwise.

National testing guidelines for COVID-19 recommend weak positive results be checked by testing the same sample again. They also recommend collecting another sample.

In some cases, retesting the original sample may give more confidence of an infection with SARS-CoV-2. But collecting and testing another sample can offer further confirmation.

The subsequent test might target a different region of the virus’ genetic material, or use a different type of test. Alternatively, the sample could be referred to a reference laboratory to verify the result using specialised tests.

We don’t know of any publicly available data which indicate how common weak positive results are. But we don’t think they’re unusual.

It’s one of the reasons the publicly reported case numbers for COVID-19 are sometimes revised downwards, as weak positives are later confirmed to be negative after retesting.

It’s also not unique to COVID-19 or PCR — many different tests, for a variety of diseases, can produce weak positives.

But the phenomenon has a unique impact when the infection is part of a pandemic.

The danger of assumption

During a pandemic, there are implications not just for the person being tested, but for their contacts, their workplace, and the whole population.

Incorrectly assuming a weak positive result isn’t COVID-19 could lead to a person continuing to transmit the disease to others. It could also prevent them receiving the proper monitoring and, if necessary, treatment.

Conversely, assuming a weak positive result is COVID-19 when it’s actually negative could lead to the person being unnecessarily quarantined, which has potential personal, psychological and financial effects.

A man wearing a mask looks out the open window of his home. — A weak positive result which turns out to be negative could see a person isolated unnecessarily.
Shutterstock

In the case in the NT, classifying this indeterminate result as a positive case would have meant the first COVID-19 infection in two months in that state.

While the man was isolated, NT authorities didn’t count him as a case based on advice from the health department that the result was likely due to residual virus from his previous infection. They said he didn’t have any symptoms and it was highly unlikely he was infectious.

When the elimination of community transmission is being used as a criteria for border closures, individual cases can have significant flow-on effects to the whole population.

For these reasons, it’s important to appreciate the complexities of COVID-19 testing. It’s not always as simple as “positive” or “negative”.

Sheena G. Sullivan, Epidemiologist, WHO Collaborating Centre for Reference and Research on Influenza and Jennifer MacLachlan, Epidemiologist, WHO Collaborating Centre for Viral Hepatitis, The Peter Doherty Institute for Infection and Immunity

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Vital Signs: batch testing and contact tracing are the two keys to stop the lockdown yo-yo

Posted on September 13, 2020 by particularkev

Richard Holden, UNSW

Back in March and April I (and many other economists) argued for lockdowns to get COVID-19 infections under control and to give health systems time to put in place testing and tracing regimes to contain the virus in the longer term.

This was done pretty effectively everywhere in Australia except for Victoria. But if things go to plan, all states will be back on the same page by the end of October.

Or will they?

Concerns about Victoria’s contact-tracing regime remain, and although there is a lot of testing, how it is being done might not be as effective as possible.

More still needs to be done to avoid the “yo-yoing” Victorian premier Dan Andrews has warned about – in which relaxation of distancing rules leads to yet another outbreak big enough to require reimposing restrictions.

There is room for not just incremental improvement but dramatic improvement of testing and tracing.

Keeping the reproduction rate below 1

The key to avoiding the need for lockdown (unless and until a vaccine is widely deployed) is to keep what epidemiologist call the “effective” reproduction rate (R) below 1.

That is, on average each person infected with the virus must give it to less than one other person (R<1).

If R>1 infections will grow exponentially, overwhelming human contact-tracing systems and eventually the hospital system.

To keep the reproduction rate below 1 requires testing and contact tracing to be incredibly fast and effective.

Effective contact tracing

Victoria’s contact-tracing system is generally regarded as having performed poorly compared with systems such as in New South Wales.

The clunky system includes notifications of new infections still being sent by fax.

Only now is the state moving to adopt a more automated approach, using a data management system developed by IT giant Salesforce. The Victorian government rejected the system earlier in the year, on the grounds the state was too swamped by the first wave to implement and bed down a new system.

My University of NSW colleague, epidemiologist Raina MacIntyre, has observed that Victoria’s health system was less prepared than NSW because of 20 years of governments “stripping the health system bare”, and that:

No health workforce in the world, no matter how organised, well-resourced and efficient, can do manual contact tracing successfully when an epidemic becomes too large.

We could go down the more aggressive digital contact-tracing path akin to South Korea. But as the Financial Times has noted, the Korean systems:

include an extensive trawl of data from other sources, such as security cameras and credit card transactions, as well as smartphone apps that use wireless signals to detect who might have encountered an infected individual.

Given the relatively low voluntary uptake of the Australian government’s COVIDSafe smartphone tracing app, getting enough people to use it to make it effective will also require strong incentives – or compulsion.

Now, I’m strongly for such incentives (as well as smarter testing). But given the amount of bedwetting about the existing COVIDSafe app from the libertarian right and some elements of the soft left (who are paranoid about every smart light bulb spying on us), this is unlikely to happen.

Batch testing

The other crucial tool to keep R below 1 is efficient and large-scale testing.

Australia did well early in the pandemic ramping up testing capacity. Test results have been typically returned within a few days, though there have also been reports of results taking more than five days.

What we have not done is embrace the benefits of targeted batch testing.

Batch testing is a way to cost-effectively test large numbers of people by pooling together samples – say by postcode.

If the pooled sample comes back negative, then everyone who contributed to the batch is cleared. If it is positive, more targeted testing is done, using smaller batches (by suburb, then residential block, then by household).

As I’ve noted before, the optimal batch size depends on the base rate of the virus in the community. But this general idea has been around since World War II and is well understood. It is a way to stretch resources to test more of the population more often.

For Australia at this point of the pandemic, this kind of testing would enable rapid detection and isolation of any new infections, allowing social and economic activity to get back to a new normal.

The strategy going forward

Once the Victorian outbreak is under control, we need to reopen Australia’s internal borders. Then we can start thinking about easing external border restrictions with places such as New Zealand.

All of this will require keeping the reproduction rate below 1, which means catching any new infections fast. Really fast.

Yo-yoing lockdowns are costly and to be avoided if at all possible.

Automated contact tracing could help a lot, as could smart and aggressive batch testing. We should be doing both until a vaccine is deployed.

Some commentators talk about “living with this virus” which is basically code for letting it rip. Instead, what we need to do is engage in “relentless suppression” to keep the reproduction rate low and our economy open.

Richard Holden, Professor of Economics, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Worried you might test positive and put a spanner in Victoria’s COVID roadmap? Here’s why you should get tested anyway

Posted on September 13, 2020 by particularkev

Breanna Wright, Monash University

Victoria’s much-anticipated roadmap out of lockdown was released on Sunday, bringing with it a clear outline of how (and provisionally when) Victoria will see an easing of restrictions.

The plan is transparent about the case numbers, or lack of them, required for the state to move to each progressive stage. For example, moving to the second step, provisionally scheduled for September 28, will require an average of 30-50 new cases per day over a 14-day period.

Victorians are suffering from lockdown fatigue. They’re exhausted and drained. The reopening of playgrounds, the singles bubble, shortening the curfew, and an extra hour of daily exercise are all gestures to keep them going during this difficult time. But many people are still desperate for the lockdown to end.

Lockdown won’t be over until the number of positive cases falls. And there’s a risk that a desire to end restrictions might discourage Victorians from getting tested, for fear of adding to the numbers and prolonging the lockdown.

Not getting tested?

The way society views an illness affects how people who have it or might have it feel and behave. Since the beginning of the pandemic, terms such as “COVID suspect” or “superspreader” have risked creating a sense of shame for those who contract the virus.

Those feeling unwell may not want to be seen as “part of the problem”. We know from other diseases, when there is stigma attached to being sick, people with symptoms are less likely to seek care. No Victorian will want to be blamed for restrictions lasting any longer than they have to.

Testing is still vital

Nevertheless, it is crucial people continue to get tested. Without this information, it will be impossible for the government to negotiate a safe path out of restrictions. Gaps in our knowledge could mean the decision-makers don’t have enough confidence to progress to the next step.

Analysts already know when there are gaps in our understanding. Earlier this week, evidence of the coronavirus was found in sewage from Apollo Bay, about 200 kilometres southwest of Melbourne, despite no one in the area having tested positive.

Test results are just one piece of data — albeit a crucial one — that informs our understanding of the situation. Testing actually helps us move forward faster, not slower.

How to encourage testing

There are several ways to ensure the number of COVID-19 tests remains high. More than 2,403,388 tests have now been done in Victoria, 12,938 on Sunday.

1. Create a sense of pride in getting tested

Obviously, low numbers of positive tests are good. But high numbers of negative tests are much more informative than no test results at all. Telling your friends you’ve been tested, or posting it on social media, should be a source of pride that you’re doing your bit for Team Victoria.

2. Remove the stigma and shame

We should also work to remove the stigma of contracting COVID-19 — no one is catching it on purpose, after all. Campaigns such as Melbourne Strong aim to help people who are struggling in lockdown, and we should extend this kind of support to those going through COVID-19 itself.

3. Promote positive messaging

It’s important to remember how far we’ve come since the peak of Victoria’s second wave. On July 30 there were 723 new cases; on Monday we had 41. We also now know the targets we need to hit to end the restrictions, and Premier Daniel Andrews has raised the possibility they could even be lifted early. Influential community messengers can help reinforce this message of hope.

4. Make testing easier

The Victorian government has tried to make testing as easy as possible, through measures such as mobile testing, incentive payments and research into faster tests. They should also consider keeping information on wait times for different testing sites up to date, as for many places it is not currently available.

There’s no easy road out of this pandemic, but now we have the roadmap and we know where we need to get to. So if you have COVID-19 symptoms, don’t hesitate to get tested. You’ll be doing yourself and the whole state a favour.

Breanna Wright, Research fellow, BehaviourWorks Australia, Monash Sustainable Development Institute, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Do I need a referral for a COVID-19 test? What happens if you test positive? Your coronavirus questions answered

Posted on July 21, 2020 by particularkev

Trent Yarwood, The University of Queensland

As COVID-19 cases surge in Victoria and NSW, authorities have again urged anyone with symptoms, including cough, fever, or sore throat, to get tested. Most results should be available within a few days and people should self-isolate while they’re awaiting results.

Victorian Premier Daniel Andrews said today Victoria recorded 275 new COVID-19 cases. Mask-wearing whenever outside the home will be mandatory for residents of metropolitan Melbourne and Mitchell Shire from Wednesday at 11:59pm.

NSW Premier Gladys Berejiklian said there were 20 new cases in NSW today, and urged residents to avoid crowded places, consider wearing a mask when physical distancing wasn’t possible, and minimise any non-essential travel.

Here are the most important things to know about testing.

Do I need a referral to get a COVID-19 test?

For the vast majority of people, no — you don’t need a referral to get tested at dedicated public COVID-19 testing clinic.

However, you will need a pathology request form if you plan to get tested at a private pathology clinic.

COVID-19-testing clinics in NSW are listed here, and Victorian testing sites (including pop-up clinics) are listed here. The Victorian Department of Health and Human Services says on it website:

Please call ahead before visiting a testing site, unless you choose to be tested at a pop-up testing site.

Testing locations are listed on each state or territory’s health departments, including for Queensland, Western Australia, South Australia, Northern Territory and the Australian Capital Territory.

Start by seeing if there is a pop-up drive-through or walk-through clinic near you. Some public sector fever clinics have a booking system to reduce wait times but many of the pop-up testing drive-through sites will allow you just to show up in your car.

Do not walk unannounced into a private pathology clinic, hospital emergency department or into your GP’s surgery.

If you can’t get to a dedicated public COVID-19 testing clinic, call your GP and ask for a telehealth consult. The GP can organise a pathology request form to be sent electronically to a private pathology clinic and will advise you on how to get tested there.

While you’re waiting for your test results, it’s important to stay at home in case you are infectious.

What happens if I test positive?

You will be notified if you’ve tested positive to COVID-19. If you were tested at a private clinic, you may receive a call from your GP who ordered the test, or from the public health team.

If you were tested at a public testing site like a drive-through clinic, a state government public health official will contact you. They will usually do the contact tracing at the same time.

Their job is to find out about anyone else you may have given the virus to while you’ve been infectious. They will usually ask where you’ve been and who you’ve seen in the last few days before you became ill.

There are national guidelines for management of coronavirus, but how they are implement is usually a state decision. Generally, the facility where you got the test will tell you how long you need to isolate for.

It’s important to ask as many questions as possible when you’re informed of your result.

How can I get tested? Is there a blood test?

Most tests will usually be done by a swab around the back of the throat and the nose. Some sites will either just swab your throat, or just your nose, but the gold standard at the moment is to swab both.

There’s also a new saliva test, which tests a sample you spit into a small container. It’s used in limited circumstances where it’s not possible to take a nasal swab, such as with young children resisting a swab.

The problem is saliva seems to have less of the virus in it than sputum (which is collected from the back of the nose and throat), so a saliva test result may not be as reliable.

There are currently two types of blood tests. One is an antibody test, which can measure whether you’ve already had the virus and recovered. But it’s not very useful because health authorities are more concerned about finding out who has the virus now, so they can do contact tracing.

Researchers from Monash University announced recently they’ve able to detect positive COVID-19 cases using blood samples in about 20 minutes, and identify whether someone has contracted the virus.

However, it’s very new research and likely won’t be rolled out on a large scale very soon. The researchers said last week they’re seeking commercial and government support to upscale production.

Despite problems with new types of tests, in a pandemic it’s important to research and trial novel testing methods that can help us fight the virus.

The most important thing you can do to help stop the spread is to try to maintain physical distancing as much as you can. Wash your hands frequently, and if you develop any symptoms — even very minor ones — err on the side of getting tested.

Trent Yarwood, Infectious Diseases Physician, Senior Lecturer, James Cook University and, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Got a COVID-19 test in Victoria and still haven’t got your results? Here’s what may be happening — and what to do

Posted on July 18, 2020 by particularkev

Hassan Vally, La Trobe University

Stories are emerging of Victorians who have followed advice and sought a COVID-19 test, only to find they’re still waiting to hear results more than five days later.

The scale of testing underway in Victoria — and Australia’s testing rates are among the highest in the world — means it’s likely this will happen from time to time. It’s unclear if this is happening to many people or to just a handful.

Nevertheless, it’s evidently happening to some people and we can piece together some information about what may be contributing to this problem, and what you can do if it happens to you.

What to do if it happens to you in Victoria

Firstly, if you are showing symptoms and still waiting on results of a test, it’s important you do not go out. Of course, that will grow increasingly difficult the longer you wait for a test result but self-isolating while awaiting test results is a crucial part of the pandemic management strategy.

Victorian health minister Jenny Mikakos said on Twitter results are usually available within 1-3 days or “sometimes longer” and referred people to a health department fact sheet.

The factsheet says:

Victorian and interstate labs are working around the clock to process all the tests, but with so many coming in every day, sometimes it takes a little longer to confirm the results.

It lists phone numbers to try if you haven’t got your result within the expected time frame.

Information from a Victorian health department factsheet.
DHHS

The factsheet doesn’t say what to do if you did the test using a home testing kit but the Victorian Department of Health and Human Services later tweeted to say:

Of course, if all else fails it might be simplest just to go and get another test.

Why might this be happening?

Again, we must acknowledge the enormous scale of the testing program underway in Victoria.

On Wednesday alone, 28,607 tests were undertaken in Victoria, and the total number of tests undertaken since January 1 is now at 1,225,999, Victorian Premier Daniel Andrews said in his Thursday press briefing.

Widespread testing is one of the best things we can do to control the spread of coronavirus, and these numbers are very impressive.

Many of these tests will be processed at laboratories in other states, as it is not possible for Victorian labs to test so many samples on their own.

A health department factsheet dated June 25, 2020 said:

Laboratories in Victoria, with surge staff capacity, can process 18,000 tests a day, noting that turn-around times are adversely affected when there is sustained testing above 14,000 tests per day.

New South Wales, South Australia, Queensland and Tasmania have agreed to provide surge lab capacity of over 4,000 tests a day. Private laboratories can also provide surge capacity of around 13,500 tests a day through their interstate operations. This will allow for at least 25,000 Victorian tests to be processed a day. There are currently sufficient test kits to meet this level of demand.

In addition, private pathology providers can draw on interstate supply chains. Safeguards, including repeat testing, will manage the risk of false positive tests.

So if you’ve got a test but haven’t heard back, it’s possible the delay is caused by test samples needing to be taken to interstate labs (which adds time) and the huge scale of testing underway.

It’s also possible there may have been some other problem with the test, so make sure you double check at the testing centre.

Who should get tested and why testing is important?

The Victorian health department says on its website:

Testing is currently available for people with the following symptoms, however mild: fever, chills or sweats, cough, sore throat, shortness of breath, runny nose, and loss of sense of smell or taste. The test takes around a minute and involves a swab from the back of your throat and nose.

The less invasive saliva test may also be available for some people in certain places and circumstances, the department has said.

Despite any difficulties you may be experiencing in getting tested or in getting your results, it’s vital to understand how critical getting tested is to protecting the community from this coronavirus. By being tested you are helping limit the spread of COVID-19. You are potentially helping save lives.

Hassan Vally, Associate Professor, La Trobe University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Sharing my thoughts with the world from a Particular Baptist perspective

Start the conversation now

Preparation is the key

Before you go

During the test

After the test

In a nutshell

Share this:

Like this:

A question of common law

Unfair dismissal cases

Individual circumstances do count

Discrimination may be valid

Looking for safe ground

Share this:

Like this:

First off, how does the RT-PCR test work?

What causes false positive results?

How common are false positive results?

No test is perfect

The broader implications

Share this:

Like this:

First, what is a superspreader?

So, back to the new test

It’s early days yet

More than a question of viral load

Share this:

Like this:

How do these studies differ from standard, larger studies?

Challenge studies need extra preparation

Past experience and recent developments

Ethical and scientific questions

What next?

Share this:

Like this:

Shouldn’t you just be ‘positive’ or ‘negative’?

When might you have a weak positive result?

How do we handle weak positives?

The danger of assumption

Share this:

Like this:

Keeping the reproduction rate below 1

Effective contact tracing

Batch testing

The strategy going forward

Share this:

Like this:

Not getting tested?

Testing is still vital

How to encourage testing

Share this:

Like this:

Do I need a referral to get a COVID-19 test?

What happens if I test positive?

How can I get tested? Is there a blood test?

Share this:

Like this:

What to do if it happens to you in Victoria

Why might this be happening?

Who should get tested and why testing is important?

Share this:

Like this: