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

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

What is the Covid-19 ‘triangle’? - Infectious Thoughts

Aug 31, 2020

Since this pandemic started, I’ve been getting lots of messages from people and hearing an awful lot of pundits who sum up Covid-19 as a simple case of virus vs person, with a binary outcome: the infected person either lives or dies. If only it were that simple, but there’s more to it than just the microbe against its unfortunate host – there’s also what I’ll call the “environment”. Together, these factors make up the disease triangle. It’s the differences between these factors in any given place or situation that are giving us the dynamic pandemic the world is currently experiencing. Let me explain. The microbe While viruses and bacteria have their own names, like humans they can come in different varieties. And sometimes those varieties can differ in how infectious they are or how much damage they can do … Read More

Why Covid elimination remains the best game-plan for NZ - Infectious Thoughts

Aug 25, 2020

Here in Aotearoa, we’re playing Covid-19 in “elimination” mode. Some countries are trying “suppression” mode, while others are running with what seems like “survival-of-the-fittest/wealthiest” mode. Over the last few weeks, I’ve been getting messages from people who don’t think our elimination game-plan is going to work. Some of them point to the fact we are currently experiencing an outbreak. Others send links to interviews with experts from “survival-of-the-fittest/wealthiest” countries, like the UK and the US. And others mention “flu” and the “common cold”. Is any of this evidence our strategy is failing or the wrong one for us to be following? I’ve explained before why I support elimination, but let’s start by making sure we are all on the same page about what elimination actually means for Covid-19. Because unfortunately, elimination is one of those tricky words that means … Read More

What does a robust Covid response look like for New Zealand? - Infectious Thoughts

Aug 23, 2020

Because we don’t have widespread community transmission of Covid-19 in New Zealand, our response managing our border and responding to any outbreaks will also help the rest of the world understand more about Covid-19. Let me explain how, and what I think a robust Covid-19 response looks like at least in the short term. Controls at the border are all about minimising the risk of further spread of Covid-19 from someone coming into the country with the virus. The current model of using a network of hotels overseen by the state is a good one, as is having an entirely separate facility for people who test positive for the virus and are more of a risk for transmission and needing medical attention. The isolation hotel network It may be useful to have the managed isolation facilities operate on a similar … Read More

They say, ‘learn to live with Covid-19’. Here’s what I say back - Infectious Thoughts

Aug 18, 2020

Around the world, different countries are taking different approaches to dealing with the global pandemic. Here in Aotearoa, our government listened to the advice of the overwhelming majority of its medical experts and scientists and settled on an elimination strategy, which we’ll call Plan A. But a vocal minority has been calling for us to take a different path, which we’ll call Plan B, or “learning to live with the virus”. Before I compare the two plans and see how they stack up, let’s start with a summary of what happens to people who get Covid-19. Deaths from Covid-19 A lot of people focus on the fatality rate of this virus – in other words, how many infected people die of the disease. It’s a surprisingly hard thing to pin down, partly because the data coming from … Read More

Why we’re adding masks to our Covid-19 toolkit - Infectious Thoughts

Aug 17, 2020

Lots of people might be wondering why we’re now being asked to wear face masks when we didn’t use them the first time we were stamping out Covid-19 in Aotearoa New Zealand. Back in April I wrote about how even the experts couldn’t agree whether masks should be worn by everyone. Some of that disagreement was based on different studies saying different things, and the worry that if everyone rushed out to buy face masks there wouldn’t be enough for those who really needed them. Now it’s August, and things have moved on a lot in four months. We certainly understand much more about how the virus is transmitted from person to person. Early on it was thought that coughs and sneezes were one of the main routes of transmission. Instead, it turns out that people … Read More