Adrian Esterman
@profesterman.bsky.social
Professor of Biostatistics & Epidemiology, Adelaide University.
Evidence-based updates on public health & outbreaks.
Also on X/Twitter: @profesterman
Evidence-based updates on public health & outbreaks.
Also on X/Twitter: @profesterman
Pinned
Case numbers reflect testing, not true spread.
Hospitalisations, aged-care outbreaks and wastewater matter more — but in Australia they’re reported inconsistently.
The new CDC has a real opportunity to fix this.
Hospitalisations, aged-care outbreaks and wastewater matter more — but in Australia they’re reported inconsistently.
The new CDC has a real opportunity to fix this.
Case numbers reflect testing, not true spread.
Hospitalisations, aged-care outbreaks and wastewater matter more — but in Australia they’re reported inconsistently.
The new CDC has a real opportunity to fix this.
Hospitalisations, aged-care outbreaks and wastewater matter more — but in Australia they’re reported inconsistently.
The new CDC has a real opportunity to fix this.
February 7, 2026 at 2:13 AM
Case numbers reflect testing, not true spread.
Hospitalisations, aged-care outbreaks and wastewater matter more — but in Australia they’re reported inconsistently.
The new CDC has a real opportunity to fix this.
Hospitalisations, aged-care outbreaks and wastewater matter more — but in Australia they’re reported inconsistently.
The new CDC has a real opportunity to fix this.
COVID, flu and RSV haven’t suddenly changed.
They now circulate year-round, but testing and reporting don’t.
When surveillance weakens, outbreaks aren’t prevented — they’re detected later.
Hospitalisations/aged-care homes/wastewater now matter more than raw case counts. Hopefully, CDC will help.
They now circulate year-round, but testing and reporting don’t.
When surveillance weakens, outbreaks aren’t prevented — they’re detected later.
Hospitalisations/aged-care homes/wastewater now matter more than raw case counts. Hopefully, CDC will help.
COVID notifications in South Australia are very low for summer. Why?
Short answer: this says more about surveillance than about the virus disappearing.
Short answer: this says more about surveillance than about the virus disappearing.
February 6, 2026 at 6:52 AM
COVID, flu and RSV haven’t suddenly changed.
They now circulate year-round, but testing and reporting don’t.
When surveillance weakens, outbreaks aren’t prevented — they’re detected later.
Hospitalisations/aged-care homes/wastewater now matter more than raw case counts. Hopefully, CDC will help.
They now circulate year-round, but testing and reporting don’t.
When surveillance weakens, outbreaks aren’t prevented — they’re detected later.
Hospitalisations/aged-care homes/wastewater now matter more than raw case counts. Hopefully, CDC will help.
This is why raw case numbers now mislead.
Surveillance should shift from population-wide testing to fragments: hospitals, aged care, wastewater - however, very sporadic reporting in Australia at the moment.
When signals weaken, outbreaks don’t vanish — they arrive late.
Surveillance should shift from population-wide testing to fragments: hospitals, aged care, wastewater - however, very sporadic reporting in Australia at the moment.
When signals weaken, outbreaks don’t vanish — they arrive late.
February 6, 2026 at 6:48 AM
This is why raw case numbers now mislead.
Surveillance should shift from population-wide testing to fragments: hospitals, aged care, wastewater - however, very sporadic reporting in Australia at the moment.
When signals weaken, outbreaks don’t vanish — they arrive late.
Surveillance should shift from population-wide testing to fragments: hospitals, aged care, wastewater - however, very sporadic reporting in Australia at the moment.
When signals weaken, outbreaks don’t vanish — they arrive late.
Bottom line:
Low notifications ≠ low circulation.
This is mostly a surveillance effect, helped by strong population immunity — reassuring, but COVID hasn’t gone away.
Low notifications ≠ low circulation.
This is mostly a surveillance effect, helped by strong population immunity — reassuring, but COVID hasn’t gone away.
February 6, 2026 at 5:38 AM
Bottom line:
Low notifications ≠ low circulation.
This is mostly a surveillance effect, helped by strong population immunity — reassuring, but COVID hasn’t gone away.
Low notifications ≠ low circulation.
This is mostly a surveillance effect, helped by strong population immunity — reassuring, but COVID hasn’t gone away.
Better indicators than case counts now include:
• hospital admissions
• aged-care outbreaks
• wastewater
• syndromic surveillance (e.g. FluTracking)
• hospital admissions
• aged-care outbreaks
• wastewater
• syndromic surveillance (e.g. FluTracking)
February 6, 2026 at 5:38 AM
Better indicators than case counts now include:
• hospital admissions
• aged-care outbreaks
• wastewater
• syndromic surveillance (e.g. FluTracking)
• hospital admissions
• aged-care outbreaks
• wastewater
• syndromic surveillance (e.g. FluTracking)
Other respiratory viruses are circulating year-round.
They dominate symptoms and further reduce COVID testing, blunting seasonal peaks.
7/8
They dominate symptoms and further reduce COVID testing, blunting seasonal peaks.
7/8
February 6, 2026 at 5:38 AM
Other respiratory viruses are circulating year-round.
They dominate symptoms and further reduce COVID testing, blunting seasonal peaks.
7/8
They dominate symptoms and further reduce COVID testing, blunting seasonal peaks.
7/8
There’s no major “breakout” variant right now.
Current lineages spread steadily but don’t cause the sharp peaks we saw earlier in the pandemic.
Current lineages spread steadily but don’t cause the sharp peaks we saw earlier in the pandemic.
February 6, 2026 at 5:38 AM
There’s no major “breakout” variant right now.
Current lineages spread steadily but don’t cause the sharp peaks we saw earlier in the pandemic.
Current lineages spread steadily but don’t cause the sharp peaks we saw earlier in the pandemic.
Population immunity is high.
After the 2024 winter wave and decent booster uptake, many infections are mild or repeat — and never tested.
After the 2024 winter wave and decent booster uptake, many infections are mild or repeat — and never tested.
February 6, 2026 at 5:38 AM
Population immunity is high.
After the 2024 winter wave and decent booster uptake, many infections are mild or repeat — and never tested.
After the 2024 winter wave and decent booster uptake, many infections are mild or repeat — and never tested.
Mild illness, holidays, and fewer GP visits mean fewer PCRs ordered — so notifications fall even if transmission continues.
February 6, 2026 at 5:38 AM
Mild illness, holidays, and fewer GP visits mean fewer PCRs ordered — so notifications fall even if transmission continues.
Case numbers no longer track infections well.
Most notifications now come from PCR testing in hospitals and aged care, plus a small amount of voluntary RAT reporting. In summer, people test less.
Most notifications now come from PCR testing in hospitals and aged care, plus a small amount of voluntary RAT reporting. In summer, people test less.
February 6, 2026 at 5:38 AM
Case numbers no longer track infections well.
Most notifications now come from PCR testing in hospitals and aged care, plus a small amount of voluntary RAT reporting. In summer, people test less.
Most notifications now come from PCR testing in hospitals and aged care, plus a small amount of voluntary RAT reporting. In summer, people test less.
COVID notifications in South Australia are very low for summer. Why?
Short answer: this says more about surveillance than about the virus disappearing.
Short answer: this says more about surveillance than about the virus disappearing.
February 6, 2026 at 5:38 AM
COVID notifications in South Australia are very low for summer. Why?
Short answer: this says more about surveillance than about the virus disappearing.
Short answer: this says more about surveillance than about the virus disappearing.
Australia isn’t facing new viruses.
We’re facing weaker surveillance.
When testing and reporting drop, outbreaks don’t disappear — they’re just seen later, making events look sudden and alarming.
We’re facing weaker surveillance.
When testing and reporting drop, outbreaks don’t disappear — they’re just seen later, making events look sudden and alarming.
February 5, 2026 at 4:04 AM
Australia isn’t facing new viruses.
We’re facing weaker surveillance.
When testing and reporting drop, outbreaks don’t disappear — they’re just seen later, making events look sudden and alarming.
We’re facing weaker surveillance.
When testing and reporting drop, outbreaks don’t disappear — they’re just seen later, making events look sudden and alarming.
Herd immunity isn’t ideology — it’s arithmetic.
Dilute school-entry requirements and you shift risk onto infants, immunocompromised kids, and pregnant women.
Dilute school-entry requirements and you shift risk onto infants, immunocompromised kids, and pregnant women.
State vaccine requirements for school entry are absolutely essential if we have any hope of maintaining herd immunity.
It is madness for states to repeal these requirements. And vaccine exemptions should not be permitted unless for a documented medical contraindication.
It is madness for states to repeal these requirements. And vaccine exemptions should not be permitted unless for a documented medical contraindication.
February 5, 2026 at 12:33 AM
Herd immunity isn’t ideology — it’s arithmetic.
Dilute school-entry requirements and you shift risk onto infants, immunocompromised kids, and pregnant women.
Dilute school-entry requirements and you shift risk onto infants, immunocompromised kids, and pregnant women.
The South Australian Dept of Health has just announced a local measles case for someone with no travel history. This is a concern. measles is lurking out there.
February 4, 2026 at 10:29 PM
The South Australian Dept of Health has just announced a local measles case for someone with no travel history. This is a concern. measles is lurking out there.
35 degrees at 8am in the morning - ridiculous. Even my dog didn't want to go out for a walk!
January 26, 2026 at 9:43 PM
35 degrees at 8am in the morning - ridiculous. Even my dog didn't want to go out for a walk!
What does this mean?
• Elimination ≠ eradication
• It means no sustained local transmission for ≥12 months
• Falling vaccination coverage allowed measles to return
This is preventable.
• Elimination ≠ eradication
• It means no sustained local transmission for ≥12 months
• Falling vaccination coverage allowed measles to return
This is preventable.
January 26, 2026 at 9:37 PM
What does this mean?
• Elimination ≠ eradication
• It means no sustained local transmission for ≥12 months
• Falling vaccination coverage allowed measles to return
This is preventable.
• Elimination ≠ eradication
• It means no sustained local transmission for ≥12 months
• Falling vaccination coverage allowed measles to return
This is preventable.
BREAKING: WHO announces the UK has lost its measles elimination status. Australia is close to the same threshold.
#Measles #VaccinesWork
#Measles #VaccinesWork
January 26, 2026 at 9:37 PM
BREAKING: WHO announces the UK has lost its measles elimination status. Australia is close to the same threshold.
#Measles #VaccinesWork
#Measles #VaccinesWork
Lowest COVID weekly case numbers for at least 2 years.
January 23, 2026 at 6:29 AM
Lowest COVID weekly case numbers for at least 2 years.
A lot of worry about myocarditis after COVID vaccines in kids.
Large England study shows it’s rare, usually short-lived, and less common than after COVID infection itself.
In short: infection carries the bigger risk.
www.thelancet.com/journals/lan...
Large England study shows it’s rare, usually short-lived, and less common than after COVID infection itself.
In short: infection carries the bigger risk.
www.thelancet.com/journals/lan...
Vascular and inflammatory diseases after COVID-19 infection and vaccination in children and young people in England: a retrospective, population-based cohort study using linked electronic health recor...
Children and young people have higher risks of rare vascular and inflammatory diseases
up to 12 months after a first COVID-19 diagnosis and higher risk of rare myocarditis
or pericarditis up to 4 week...
www.thelancet.com
January 19, 2026 at 11:31 PM
A lot of worry about myocarditis after COVID vaccines in kids.
Large England study shows it’s rare, usually short-lived, and less common than after COVID infection itself.
In short: infection carries the bigger risk.
www.thelancet.com/journals/lan...
Large England study shows it’s rare, usually short-lived, and less common than after COVID infection itself.
In short: infection carries the bigger risk.
www.thelancet.com/journals/lan...
New variant of the flu virus is driving surge of cases across the US and Canada
theconversation.com/new-variant-...
Another good article from The Conversation. Unusually for The Conversation, I did notice a typo "subclave" instead of "subclade".
theconversation.com/new-variant-...
Another good article from The Conversation. Unusually for The Conversation, I did notice a typo "subclave" instead of "subclade".
New variant of the flu virus is driving surge of cases across the US and Canada
A particularly infectious subvariant of influenza is keeping emergency room numbers high and causing especially severe illness in children.
theconversation.com
January 18, 2026 at 11:03 PM
New variant of the flu virus is driving surge of cases across the US and Canada
theconversation.com/new-variant-...
Another good article from The Conversation. Unusually for The Conversation, I did notice a typo "subclave" instead of "subclade".
theconversation.com/new-variant-...
Another good article from The Conversation. Unusually for The Conversation, I did notice a typo "subclave" instead of "subclade".
South Carolina reports hundreds of measles cases, with rapid growth in recent days — the U.S. is seeing one of the largest outbreaks in years amid low vaccination coverage.
January 18, 2026 at 4:27 AM
South Carolina reports hundreds of measles cases, with rapid growth in recent days — the U.S. is seeing one of the largest outbreaks in years amid low vaccination coverage.
www.sciencedirect.com/science/arti...
Study of essential workers finds neurological Long COVID linked to rises in plasma pTau-181 after infection, especially with long-lasting central symptoms (brain fog etc). pTau-181 increases assoc. with amyloid changes. Early biomarker signal, not diagnosis.
Study of essential workers finds neurological Long COVID linked to rises in plasma pTau-181 after infection, especially with long-lasting central symptoms (brain fog etc). pTau-181 increases assoc. with amyloid changes. Early biomarker signal, not diagnosis.
Increased phosphorylated tau (pTau-181) is associated with neurological post-acute sequelae of coronavirus disease in essential workers: a prospective cohort study before and after COVID-19 onset
The COVID-19 pandemic led to a spectrum of post-acute sequelae including several neurological complications including cognitive dysfunction labelled N…
www.sciencedirect.com
January 17, 2026 at 11:06 AM
www.sciencedirect.com/science/arti...
Study of essential workers finds neurological Long COVID linked to rises in plasma pTau-181 after infection, especially with long-lasting central symptoms (brain fog etc). pTau-181 increases assoc. with amyloid changes. Early biomarker signal, not diagnosis.
Study of essential workers finds neurological Long COVID linked to rises in plasma pTau-181 after infection, especially with long-lasting central symptoms (brain fog etc). pTau-181 increases assoc. with amyloid changes. Early biomarker signal, not diagnosis.
pubmed.ncbi.nlm.nih.gov/41452424/
Large meta-analysis (250M+ person-years) - COVID-19 linked to ~50% higher relative risk of some autoimmune diseases. Risk higher after severe infection, lower in vaccinated people. Evidence moderate–low → signal, not certainty. Supports vaccination & follow-up.
Large meta-analysis (250M+ person-years) - COVID-19 linked to ~50% higher relative risk of some autoimmune diseases. Risk higher after severe infection, lower in vaccinated people. Evidence moderate–low → signal, not certainty. Supports vaccination & follow-up.
Association between COVID-19 and New-Onset Autoimmune Diseases: Updated Systematic Review and Meta-Analysis of 97 Million Individuals - PubMed
SARS-CoV-2 infection may induce long-term immune dysregulation; however, its contribution to the development of autoimmune disease remains disputed. We aim to quantify the relative risk of new-onset autoimmune diseases following COVID-19 and its modifiers through a systematic review and meta-analysi …
pubmed.ncbi.nlm.nih.gov
January 17, 2026 at 11:00 AM
pubmed.ncbi.nlm.nih.gov/41452424/
Large meta-analysis (250M+ person-years) - COVID-19 linked to ~50% higher relative risk of some autoimmune diseases. Risk higher after severe infection, lower in vaccinated people. Evidence moderate–low → signal, not certainty. Supports vaccination & follow-up.
Large meta-analysis (250M+ person-years) - COVID-19 linked to ~50% higher relative risk of some autoimmune diseases. Risk higher after severe infection, lower in vaccinated people. Evidence moderate–low → signal, not certainty. Supports vaccination & follow-up.
www.audacy.com/wwjnewsradio...
Reports that SARS-CoV-2 was found in wastewater from ~96% of flights sound alarming, but when global prevalence is high (2022), almost every large flight will include at least one infected passenger. This is non-infectious RNA. Useful for surveillance, not panic.
Reports that SARS-CoV-2 was found in wastewater from ~96% of flights sound alarming, but when global prevalence is high (2022), almost every large flight will include at least one infected passenger. This is non-infectious RNA. Useful for surveillance, not panic.
Coronavirus found in samples from 96% of flights
If you believe it’s now safe to fly without a protective mask, you might want to think again. New research shows the COVID-19 virus has been found on nearly every flight.
www.audacy.com
January 17, 2026 at 10:52 AM
www.audacy.com/wwjnewsradio...
Reports that SARS-CoV-2 was found in wastewater from ~96% of flights sound alarming, but when global prevalence is high (2022), almost every large flight will include at least one infected passenger. This is non-infectious RNA. Useful for surveillance, not panic.
Reports that SARS-CoV-2 was found in wastewater from ~96% of flights sound alarming, but when global prevalence is high (2022), almost every large flight will include at least one infected passenger. This is non-infectious RNA. Useful for surveillance, not panic.
Sorry - I should have mentioned that. It is mainly a site for doctors - hence the name.
January 16, 2026 at 11:34 AM
Sorry - I should have mentioned that. It is mainly a site for doctors - hence the name.