Mask-wearing cuts Covid incidence by 53%, says global study | Coronavirus | The Guardian This is all over my timeline today. I’m a fan of masks, and it is AMAZING progress to see a meta-analysis of public health interventions for covid. But….. theguardian.com/world/2021/nov…
..we need to look past headlines. This study looked at a range of measures, including masks, handwashing+disinfection. It’s well written and methodologically fine. But a meta-analysis can only analyse primary research and it’s conclusions are only as good as those studies….
…While people have been screaming at public health to “follow the science”, public health has been saying the science is blighted by confounders. So we need to be careful about interpreting the finding around masks, as the authors themselves point out. 6 studies. Big bias risk…
…Authors also concluded that handwashing is useful. But wide confidence intervals make it hard to determine effect size. Reassuring to see that handwashing *seems* to be beneficial. Important to note they’re doing a meta-analysis of mostly retrospective observational studies…
…They also looked at social distancing. 25% risk reduction looks about right, but is clearly dependent on the actual distance in the real world. Again, these studies weren’t particularly well designed for the outcome in question, so no surprise that the risk of bias was high…
..Disinfection of surfaces in households got a look-in too. Interesting to see very high reduction in odds of transmission, but mega wide confidence intervals and only one study made the grade. So, again, this shows the uncertainty we work with every day in managing this virus…
…I think it’s important for people not to pull the pieces that they’re ideologically tethered to out of this study to increase the “follow the science” noise in the pandemic space. Let’s just acknowledge uncertainty. The accompanying editorial to this paper says it best…
…Here’s what the editorial says about the section on masks, as this is pretty measured and I suspect the headlines generated from this paper will mostly be about masks. Most likely a small but welcome reduction in risk…
..A bit more context on this from someone who knows what he’s talking about.
It’s been a real Rabies/Lyssavirus week for me. And whenever that happens, I’m always amazed how much of an absolute operator the virus is. Some of it’s basic abilities include - Fooling your body into reducing its immune response (considering these viruses are 100% fatal….
…that’s quite the evolutionary achievement). One of the ways it does this is by inhibiting your body’s ability to produce B-interferon, which is a vital part of our immune machinery. In fact the #rabies virus has a whole chunk of its genome dedicated to doing just that….
…Rabies/lyssavirus also heads straight for your brain, where it increases the concentration of nitric oxide by about 25 times. That leads to a LOT of CNS overexcitement and it decreases your ability to fight off cell death; bad news when that’s happening in your 🧠……
As an end-user of the frankly awful data in the covid public health space, the best contributions that the various scientific advocacy groups and individuals around the globe could make, in my opinion, would be proper rigorous *systematic* reviews, especially around efficacy….
…of various mitigation strategies (many of which seem to be over-sold to the public) and the actual prevalence of the now well-defined long covid in different age groups. Without certainty around these questions, it’s really difficult to conduct rigorous risk assessments….
…,which are really the key to proper health protection. Instead we just get noise, with the public believing the 99% of stuff on twitter that is pure fiction, even from people who seem very credible and post links to convincing-looking papers. Most of what I see here is wrong.
People keep saying that when this pandemic is over, we have to make sure our contact tracing capacity is strengthened to cope with future threats. This reflects a misunderstanding of what contact tracing is. Contact tracing involves talking to a case and finding out who…..
…they’ve been in touch with. This is really important stuff, but that data is then used by specialists in outbreak control to assess and manage those contacts. Ultimately, public health teams need to use data from many sources to make a plan to control the disease. This is….
…complex work and requires years of training. Our contact tracers are superb, but people can be trained to contact trace in a short space of time. That function can be ramped up pretty quickly when required. What we need before the next pandemic are enough outbreak control…
When reporting on Covid in Australia, the world’s media is keen to report on a perceived inability to control the virus as time goes on. But context is important. This is a country that’s the size of a continent….
A lot of people were chuffed to report that Brisbane went into lockdown last week. That ended today, with all cases in South East Queensland in recent days linked to other known cases. That’s a great result in the public health world, though we’re DEFINITELY not out of the woods
I’ve been delighted to see the sudden surge in support for mandatory hotel quarantine (MHQ) in Ireland, with the aim of achieving zero covid. While it is, on balance, the best option, I fear that some commentators have underestimated the challenges. Here are some examples....
...1) MHQ is frequently framed as a temporising measure, with the aim of establishing quarantine-free travel bubbles with other zero covid regions. Not many countries have achieved zero community transmission. But in those that have, travel bubbles have been vanishingly rare...
...2) MHQ is super strict. The point of it is that it would allow Ireland to open up society again. If you miss cases in that context, you let infectious people into a country where socialising is the norm. The result is explosive outbreaks. In countries that have MHQ, you...