Saloni Profile picture
Thinking & writing about science. Researcher @OurWorldInData. Co-founder @WorksInProgMag. 🇭🇰🇮🇳🏳️‍🌈
江浩哲 Holger Jacobsen 🇹🇼 🇺🇦 Profile picture Olímpico de Jesus Moreira Chaves Profile picture 3 subscribed
Sep 3 5 tweets 2 min read
40 years ago HIV was invariably fatal: 100% of people with HIV died from the disease typically in a few years.

Today antiretrovirals lead to near-normal life expectancy & prevent the virus's spread.

It's estimated that antiretrovirals save over a million lives each year. Four decades ago, when HIV was first identified, it was an invariably fatal disease: 100% of those infected died, typically within a few years.  The virus spread rapidly around the world — especially in Africa, where almost two million were dying every year by the millennium.  Thankfully, medical advances and global public health efforts have entirely changed this course. Modern antiretroviral therapy is very effective in both treating HIV — returning people with HIV to near-normal life expectancy — and preventing the virus from spreading to others.  The chart above shows this impact based ... Recent medical advances could take this progress even further:

Aug 22 20 tweets 6 min read
I read this recent 'microplastics in the brain' article and I have a lot of questions. 🧵 First, the reporting of this study...

The Guardian article says it's "a pre-print paper still undergoing peer review that is posted online by the National Institutes of Health"

Note the NIH has many disclaimers on their site explaining they don't endorse the content of articles
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May 15 6 tweets 2 min read
@drStuartGilmour Hi! Thanks for the comments with this. I think there's a lot of confusion here, let me try to clarify each point further. @drStuartGilmour As I describe in the article, checkboxes don’t directly feed into vital stats in other countries. Italy has enhanced surveillance to investigate potential maternal deaths; it shows their vital stats also underreport maternal deaths

epicentro.iss.it/en/itoss/mater…
Mar 17 28 tweets 9 min read
What do people die from at different ages?

I hadn’t seen a satisfying chart that showed causes of death in different age groups all at once, so I just made it myself.

Turns out, in the US, “external causes” are a majority of deaths until ~age 40
scientificdiscovery.dev/p/20-so-many-g…
Image In childhood, the most common cause of death are ‘external causes’.

This is a broad category (in red) that includes accidents, falls, violence & overdoses.

Also a notable contribution from birth disorders (muted green), childhood cancers (blue) & respiratory diseases (cyan).
Feb 24 33 tweets 8 min read
Looking for a movie to watch this weekend?

I watched around 250 films from the “classic Hollywood era” of the 1930s-50s, while I was at university.

Screwball comedies, film noir, lots of great films still fun to watch today. Here are my favourites with one-line synopses. 🧵 First, the comedies:
Dec 15, 2023 6 tweets 3 min read
You probably knew that lung cancer death rates rose and fell greatly over the 20th century.

But did you know this also affected cardiovascular diseases?

Since the 1950s, crude cardiovascular death rates have declined by almost half, in the US
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If you look at age-standardized death rates, i.e. people of the same age, you'll see the decline is even larger:

a reduction of almost 75% since the 1950s: Image
Nov 29, 2023 13 tweets 5 min read
Women live longer than men.

On average, the gap in life expectancy is 5 years globally.

But this gap isn't a constant — it varies widely around the world and has changed over time. How and why?

New article by me!
ourworldindata.org/why-do-women-l…

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The sex gap in life expectancy begins at birth:

Newborn boys tend to have higher death rates than newborn girls, as they’re more vulnerable to diseases and genetic disorders.

In 2021, all countries were above the diagonal, showing that infant male death rates were higher. Image
Oct 27, 2023 7 tweets 3 min read
This is a great scientific achievement.

But I also see it as an economic & political blunder — the world could have had a malaria vaccine sooner. We should learn from this, not just celebrate & move on. That's what this 9000 word essay is about.
worksinprogress.co/issue/why-we-d…
Image The malaria vaccine was trialled for the first time in humans in 1997.

It was approved in 2021.

Each step of the journey faced struggles in funding and operations, to set up & run each next stage of trials.
May 19, 2023 6 tweets 2 min read
Some claim that flu cases were only very low during the pandemic because of a lack of testing for flu.

But this is not the case.

You can see here the *percentage of flu tests* that were positive.
ourworldindata.org/explorers/infl… Image So why did flu decline during the pandemic?

Social distancing had a much larger impact than one might expect, because of the mathematics of epidemics and the R number.
May 18, 2023 9 tweets 8 min read
Flu researchers 📢

We have a new global data explorer on @OurWorldInData that includes:

• Confirmed flu cases, by strain & surveillance
• Test positivity
• Flu-like illness metrics: ILIs, ARIs, SARIs

ourworldindata.org/explorers/infl… Image Here are some things you can do with the explorer.

1. See the share of flu tests that were positive, in different countries.

> by week or month
> by surveillance type: all, sentinel or non-sentinel
ourworldindata.org/explorers/infl… Image
May 18, 2023 21 tweets 11 min read
We have a new page on @OurWorldInData on Influenza!

• How many people die from flu each year?
• How has mortality changed over time?
• Which strains are currently circulating?
• What can flu-like illness trackers tell us?

All here + thread below!
ourworldindata.org/influenza Image Here are 7 things you may not know about flu, from our new page.

1. Globally, flu kills around 400,000 people from respiratory disease on average each year.

This is shown as a rate per 100,000 people aged over 65.
ourworldindata.org/influenza?insi… Image
May 15, 2023 8 tweets 3 min read
You often hear that full siblings "share 50% of their DNA."

But did you know this is actually the median and the range is pretty wide, roughly between 40–60%? journals.plos.org/plosgenetics/a…
isogg.org/wiki/Autosomal… Image Why?

Children inherit chromosomes from each parent, but those had gone through recombination and have a mix of segments from their parents (the child's grandparent).

Siblings inherit some of the same segments and some different. Image
May 5, 2023 18 tweets 9 min read
This is not a complex question. Yes, let's talk about HPV vaccines.

HPV vaccines are vaccines against cancers: cervical, penile, oral, throat, head & neck cancers.

It's estimated that 4% of all new cancer cases worldwide are caused by HPV. Almost all cervical cancers are. Why does HPV cause so many cancers?

One reason is it degrades one of the most important proteins in our cells: p53.

This protein, also known as the guardian of the genome, is a major layer of protection against us developing cancer. ncbi.nlm.nih.gov/pmc/articles/P…
Mar 9, 2023 4 tweets 2 min read
My favourite type of paper is one that covers 'knowledge gaps' in a field:

• What isn't well understood / the unanswered questions
• How they might be answered: what kind of data is needed or the breakdown of the problem

…written by experts. Have you read an example of this? These aren't always theoretical or abstract problems that people don't know how to answer yet.

In many cases, the relevant data simply hasn't been collected from different places, contexts, specimens, or been made available.
Feb 19, 2023 4 tweets 2 min read
Many know that the Carter Center, founded by Jimmy Carter, has been working towards eradicating neglected diseases like Guinea worm.

But fewer know how successful this has been.

In 1989, there were >890,000 cases worldwide.

In 2021, there were 15.
ourworldindata.org/guinea-worm-pa… Chart showing the decline in reported cases of guinea worm d Since then, the preliminary count for 2022, which will be confirmed in March, is a total of 13 cases worldwide. cartercenter.org/news/pr/2023/2…
Oct 23, 2022 9 tweets 4 min read
There are many examples of medical knowledge that I think everyone should know. This is one of them. Usually, this is screened non-invasively (with breath, stool or antigen tests) and then confirmed (with endoscopies, for example).

In countries where H pylori is more prevalent, experts recommend mass screening and eradication of the pathogen: gut.bmj.com/content/69/12/…
Oct 20, 2022 16 tweets 8 min read
Influenza isn't inherently “mild.” It was made milder by vaccines, sanitation & healthcare.

It still kills an estimated 300,000–500,000 people globally, each year.

The burden remains high due to an ageing population.

NEW post by me & @f_spooner! 1/
ourworldindata.org/influenza-deat… People tend to leave the caveats until the end. But they're important so I'll start with them.

It's difficult to count the number of deaths from flu:

Flu symptoms are not specific; they resemble other diseases like RSV.
Many countries have limited testing to confirm the virus.
Oct 15, 2022 4 tweets 2 min read
It's been a great year for vaccine discovery:

- new malaria vaccine
- new dengue vaccine
- new RSV vaccines (the first)
- new pentavalent meningococcal vaccine
- new HPV vaccine

And I'm likely missing some. Links:

Malaria vaccine:
bbc.co.uk/news/health-62…

Dengue vaccine:
reuters.com/business/healt…

RSV vaccines:
pfizer.com/news/press-rel…
wsj.com/articles/gsk-p…

MenABCWY vaccine:
pfizer.com/news/press-rel…

HPV vaccine:
reuters.com/business/healt…
Oct 15, 2022 7 tweets 2 min read
When are people first diagnosed with depression?

The answer might surprise you.

On average, people are diagnosed at the age of 31. They tend to meet the criteria several years earlier: at the age of 26, on average. That is a long delay. Chart showing the age of onset of depression. The median age This has been changing.

Depression is being diagnosed earlier than in the past. So are other conditions like bipolar disorder and anxiety.

You can see this in Denmark, for example. In the 90s, people were often diagnosed for the first time in middle age. Now it's caught early.
Oct 13, 2022 8 tweets 3 min read
There's no reason for women to get cervical cancer – it's preventable with HPV vaccines.

Because of them, the UK and Australia are on track to eliminate cervical cancer.

But many countries, shown here in red, don't routinely administer these vaccines. Image In fact, HPV vaccines reduce the risk of many other cancers as well – specifically head, mouth, neck, throat, anal, penile, vulval and vaginal cancers.
Oct 13, 2022 5 tweets 2 min read
Did you know that there are vaccines against several cancers?

The HPV vaccine reduces the risk of cervical cancer, anal cancer, vaginal cancer, vulvar cancer & oropharyngeal cancers.

It was developed in 2006 – how long did it take for countries to routinely administer it? This is partly due to cost.

Over time more countries have begun to routinely administer HPV vaccines.

And earlier this year a new HPV vaccine was developed. reuters.com/business/healt…