Siouxsie Wiles

Dr Siouxsie Wiles is a research scientist with a background in medical and environmental microbiology. She has made a career out of combining her twin passions of bioluminescence (the production of light by living organisms — think glow worms and fireflies) and nasty microbes. In a nutshell, Siouxsie and her team make nasty bacteria glow in the dark to better understand infectious diseases. Originally from the UK, Siouxsie now leads the Bioluminescent Superbugs Lab at the University of Auckland. She was the 2013 winner of the Prime Minister's Science Media Communicator's Prize. Siouxsie is on Twitter @SiouxsieW

Your questions on the latest NZ Covid cases, answered - Infectious Thoughts

Feb 16, 2021

Three new community cases of Covid-19 and an unknown source have plunged Auckland into lockdown and the rest of the country into alert level two. Microbiologist Siouxsie Wiles tackles some of the critical questions we now face. Could we be looking at a situation as worrying as last August in Auckland? Yes. Like in August, it isn’t clear yet how the family have come into contact with the virus. Also worrying is that the family have the B.1.1.7 variant which was first identified in the UK last year and is one of the more infectious variants of the SARS-CoV-2 virus. One of the infected family worked at a company that provided laundry services to airlines. How likely is it that this is the source? It’s a possibility, as part of their job has apparently been handling laundry items from international … Read More

What do we know about Covid transmission via pipes and ventilation? - Infectious Thoughts

Jan 29, 2021

Is it plausible that the new cases contracted in the Pullman hotel in Auckland were transmitted via pipes? Here’s what the science tells us. As the investigation to determine how three people became infected with Covid-19 during their stay in New Zealand’s managed isolation and quarantine system gets away, it is worth considering a few studies published recently that point to drainage and ventilation systems as a possible route of transmission. That isn’t to say this is the case for the MIQ hotels but is definitely warrants investigating and ruling out. China’s Block X – transmission through the drainage system? Min Kang and colleagues investigated how Covid-19 might have spread between three families living in a high-rise apartment building in Guangzhou, China, referred to as Block X. The first family had travelled to Wuhan. The other two families had not … Read More

How worried should we be about these new Covid-19 mutations? - Infectious Thoughts

Jan 26, 2021

The new Northland case has been linked to the South African strain of Covid-19, one of a number of new, more contagious Covid variants. Here’s how they emerge and why. Let’s start with the basics. The genetic material of the SARS-CoV-2 virus responsible for Covid-19 is a strand of RNA made up of almost 30,000 nucleotides. Those nucleotides – adenine, cytosine, guanine, and uracil – are more commonly known by their abbreviations: A, C, G, and U. Nucleotides code for amino acids which in turn give us the proteins that make up the virus, like the spike protein the virus uses to enter its hosts cells. Each time the virus enters a new host, it turns some of that host’s cells into virus-producing factories. Those cells copy the virus’s genetic material which then gets repackaged into new virus particles. These … Read More

The Plan B implosion – what Brazil teaches us about the herd immunity hogwash - Infectious Thoughts

Jan 18, 2021

As families around the world mourn more than two million people dead from Covid-19, the Plan B academics and their PR industry collaborator continue to argue that the New Zealand government should stop focusing on our managed isolation and quarantine system and instead protect the elderly so that they can reopen the border and allow everyone else to get on with their lives.  Like their friends over at the Great Barrington Declaration, the Plan B’ers are arguing that the pandemic is manageable by the herd-immunity-by-infection route. They are even hosting another online symposium in February where some of the architects of the Great Barrington Declaration will get the chance to impress their astonishing views of the pandemic on 500 people who are willing to donate to Plan B’s cause. Should you need any further convincing, Brazil’s experience with Covid-19 shows it … Read More

Just how worrying is the new Covid-19 strain for Britain – and the rest of us? - Infectious Thoughts

Dec 21, 2020

Let’s start with the basics. The genetic material of the SARS-CoV-2 virus responsible for Covid-19 is a strand of RNA made up of almost 30,000 nucleotides. These are code for the amino acids that in turn give us the proteins that make up the virus. Each time the virus enters a new cell and replicates, its genetic material is copied, and nucleotides can get replaced by mistake. As Toby Morris and I have explained before, these mistakes mean that there are now different varieties, or lineages, of the Covid-19 virus circulating around the world. Researchers around the world have been uploading their SARS-CoV-2 genome sequences to the Nextstrain website. This allows them to see how the virus is changing. From this data it looks like we’re seeing roughly two nucleotide changes happening a month which means the … Read More

Aches on a plane – new findings on in-flight Covid transmission - Infectious Thoughts

Nov 24, 2020

One of the good things about New Zealand pursuing an elimination strategy for Covid-19 (aside from the obvious) is that we are able to help answer some of the questions there are about how the SARS-CoV-2 virus transmits between people. Take air travel. As many people in the US start to head off around the country to spend Thanksgiving with their friends and family, will some of them be spreading the virus on the journey? A new study suggests yes. Before I get to the study, one important thing to note is that many airlines around the world now won’t let people board a plane unless they have a negative test a few days before they are due to travel. I’ve said it before, and I’ll say it again: that doesn’t guarantee people won’t be infectious on the plane. People … Read More

Don’t fall for the Covid contrarians - Infectious Thoughts

Oct 20, 2020

As life in Aotearoa gets back to some kind of normal after our latest Covid-19 outbreak, cases in the northern hemisphere are on the rise again and that puts us all at risk. Because no one is safe until we are all safe. This is a tricky virus. We now know that it spreads well through droplets and aerosols and that people are infectious before they realise they have symptoms. And while most people will only infect one or two others, in the right conditions, one case can result in tens, hundreds or even thousands of infections. These super-spreader events have happened indoors and outdoors, though especially indoors at weddings, funerals, church services, choirs, bars, and workplaces. Super-spreader events have even happened at the White House. There’s now an abundance of evidence that this virus is more … Read More

How to strengthen the post-isolation Covid rules - Infectious Thoughts

Sep 21, 2020

Over the weekend, the Ministry of Health reported a case of Covid-19 in Auckland that is not related to the current Auckland cluster. Before we start to panic, here’s how I think the case happened and how we can strengthen our current border controls. The new Covid-19 case is someone who returned to New Zealand from India on August 27. They spent their two weeks in managed isolation in Christchurch and returned two negative tests before flying home to Auckland on September 11. Five days later, on September 16, they developed symptoms and got tested again. That test was positive. Two of their household contacts have also tested positive. They have all been moved to the Auckland quarantine facility and their close contacts are isolating. So how could someone who has been through managed isolation and returned two negative tests … Read More

How the PCR test works and why it’s such a critical weapon against Covid-19 - Infectious Thoughts

Sep 21, 2020

I’ve been asked by several people in recent days whether there is any truth to a video about the Covid-19 PCR test that is currently doing the rounds on social media. I’m not linking to it, because it is chock full of false information; the fewer people who see it the better. It is by a medical doctor who talks about the difference between diagnostic and screening tests. She sounds like she knows what she’s talking about so I can see why people are confused. Before I get into what the current Covid-19 tests can and can’t tell us, what I will say is that just because someone is medically qualified doesn’t necessarily mean they know anything about diagnostic testing and the intricacies of quantitative PCR (polymerase chain reaction). The same goes for epidemiologists, engineers, and low-carb diet advocates. It’s … Read More

Now let’s flatten the infodemic curve - Infectious Thoughts

Sep 08, 2020

It’s likely you’re being exposed to masses of Covid information on a daily basis, and not all of it will be reliable. Here are some tips for telling the difference, and stopping the spread. Thanks to Covid-19, most of us have a new word in our vocabulary. Epidemiology: the branch of medical science that deals with the who, what, when, where and how of a disease in a population. Now it’s time to learn about infodemiology. We humans are a curious and innovative species. We want to understand the world around us and help solve the challenges we face. One of the ways we do this is by seeking out and sharing information. Lots of information. This means that at the same time as experiencing a pandemic, the world is also experiencing an “infodemic” – the overabundance of information that … Read More