Adrian Esterman | Epidemiology

During COVID. many epidemiologists found themselves explaining complex, uncertain data in real time - often without any training in communication. I wrote about what it was actually like: @adrian.esterman/i-got-called-at-6am-and-sat-alone-in-the-dark-for-an-hour-4dece7bdf0a1" target="_blank" rel="nofollow noopener">medium.com/@adrian.esterm…

My latest article in The Conversation. Why diphtheria, whooping cough and measles have come back in Australia theconversation.com/why-diphtheria… via @ConversationEDU

See my comments in this CNN news article: edition.cnn.com/2026/05/18/afr…

New Ebola outbreak hits Democratic Republic of Congo cidrap.umn.edu/ebola/new-ebol… WHO taking the lead again

@deborahbrian @camybobany Because virtually everyone who has been infected gets symptoms withing the first three weeks. The passengers will be carefully monitored at home for at least another 4 weeks, checking for a fever or any other symptoms.

@profesterman @camybobany So why are they not being quarantined for the full incubation period — 42 days or 8 weeks, depending who you ask?

Friday epi explainer: why are cruise passengers being quarantined for 3 weeks, but monitored for 42 days? Because incubation periods matter. The Andes hantavirus linked to the Hondius outbreak can take up to 42 days after exposure before symptoms appear. Most infections show earlier, but public health planning has to cover the outer limit, not just the average. That’s why “I feel fine” at 3 weeks doesn’t necessarily mean someone is fully in the clear. It’s also why outbreak control often looks overly cautious to the public. Epidemiology plans for the tail of the distribution, not just the middle.

Australia has recorded >200 diphtheria cases so far this year, compared to only a handful of cases in previous years. Most of these have been in the NT, and sadly we have seen the first death from diphtheria in nearly a decade. Diphtheria is a toxin-producing bacterial infection spread via respiratory droplets or close contact. It can cause severe throat swelling, breathing difficulty, and heart or nerve complications. It’s preventable. Protection from childhood vaccines wanes, so adult boosters (every 10 yrs) matter. This outbreak reflects gaps in booster coverage, not vaccine failure.

The Hanta virus outbreak is an example of disastrous the American withdrawal from WHO is. @adrian.esterman/america-left-the-who-heres-what-that-actually-means-e3186263192c" target="_blank" rel="nofollow noopener">medium.com/@adrian.esterm…

@JohanVanbrabant @Globalbiosec Anything over 1 is exponential growth

@Globalbiosec R0 of 2 would support exponential growth, right?

Great to see these important guidelines and a systematic outbreak protocol. However, the old 2m rule is not based on data, assumes the droplet vs airborne dichotomy, based on old studies done 50-80 years ago with blunt instruments. And R0 of Andes was 2.21 in the last big outbreak. academic.oup.com/jid/article/22…

The elderly are the group who end up in hospital with COVID, yet few protect themselves. Read my latest Medium article: @adrian.esterman/the-world-has-stopped-watching-covid-the-risk-for-older-people-hasnt-48f9e6d029f8" target="_blank" rel="nofollow noopener">medium.com/@adrian.esterm…

Friday epi basics: epidemiologists worry most about viruses that combine: • efficient human-to-human spread • respiratory transmission • little existing immunity COVID and influenza fit that pattern. Andes hantavirus is dangerous, but transmission is usually linked to rodents, and person-to-person spread appears much less efficient.

@Globalbiosec An excellent discussion on the risk to the general population is on this video: yourlocalepidemiologist.substack.com/p/hantavirus-s…

Human to human transmission suspected. The ship took off from Southern Argentina on April 1, first death April 11. Incubation period is 2-4 wks, but can range from 1-8 wks. 1st case could be explained by infection on shore, as Argentina is known for hantavirus cases, more commonly in the north, but also in south, although not so much in Ushuaia island. 1/2 edition.cnn.com/2026/05/05/afr…

For most of the last century, public health focused on infectious disease, then on lifestyle risks like smoking and diet. Loneliness sits awkwardly between the two. We often hear it’s “as deadly as smoking”. That’s not quite right, but the real story is more interesting, and more concerning. My latest piece @adrian.esterman/loneliness-is-not-quite-as-deadly-as-smoking-it-still-deserves-the-same-attention-6222c5cf0cb4" target="_blank" rel="nofollow noopener">medium.com/@adrian.esterm…

Hantavirus is part of the Hantaviridae family, carried by rodents and usually spread to humans via inhaled particles from urine or droppings. There’s no widely available vaccine and no specific antiviral treatment. Management is supportive, often in ICU. For the virus either attacks the lungs (HPS) or kidneys (HFRS). Passengers on ship had HPS which has 40-50% fatality. Early care matters as severe cases can deteriorate rapidly, particularly with the HPS.

WHO confirming lab diagnosis shows that robust international surveillance is working. Key lesson: even "routine" travel can involve emerging infectious disease risks. Cruise ships = unique epidemiological challenges due to closed populations + international ports of call. My condolences to those who have lost love ones.

Tragic hantavirus outbreak on MV Hondius cruise ship (Argentina→Cape Verde) has killed 3, with 1 in ICU. This is significant for several reasons: Hantavirus is typically zoonotic (rodent→human via aerosolized excreta), but human-to-human transmission, while rare, can occur. Confined cruise ship environment likely facilitated spread among passengers in close quarters over 3+ weeks at sea.

Australia had a flatter COVID summer wave this year - likely because current variants (Nimbus & BA.3.2) are co-circulating rather than one dominating. BA.3.2 is particularly strong in WA. Shows how the virus continues evolving but in a more manageable pattern.

Wastewater is doing its job again. Vaccine-derived poliovirus has been detected in Perth - not unexpected, not a public health emergency, but a useful signal. Likely a returning traveller shedding virus, not local spread.

@ThailandMedicaX This is one of many small offshoots of Omicron we’re seeing globally. It shows the virus is still evolving, particularly to evade immunity, but there’s no evidence at this stage that it behaves differently in terms of severity or overall risk.

COVID-19 Cases Involving New SARS-CoV-2 PQ.2.1.11 Variant Growing in China. Airports Should Increase Screenings of Chinese Travelers

@newscientist Blood transfusions are one of the most regulated areas of medicine. There’s no evidence donor COVID vaccination status affects safety. Misinformation can delay life-saving transfusions.

Patients are requesting that blood transfusions come from people who they know have not been vaccinated against covid-19, which can cause dangerous delays #Echobox=1777293837" target="_blank" rel="nofollow noopener">newscientist.com/article/252315…

@Globalbiosec COVID contributed, but it’s not the main driver here. The UK’s decline in healthy life expectancy began pre-pandemic. This is about underlying population health, obesity, mental health, inequality, and prevention gaps.

It's a mystery. #COVID