If left untreated, it kills about half of those it infects.

It can spread through pretty much every fluid your body makes,

including blood and sweat.

Even the dead can transmit the disease, often doing so at their own funerals.

On December 26th, 2013, a two-year-old boy in southern Guinea got sick.

Just two days later, he died.

It took local doctors working with the international community

four months to discover that Ebola was to blame,

largely because it had never before been detected outside of Central Africa.

In those four months, Ebola gained a head start that would prove devastating.

The outbreak lasted two years

and mushroomed into the largest Ebola epidemic in recorded history.

More than 28,000 people contracted the disease and over 11,000 died.

In 2013, Guinea had no formal emergency response system,

few trained contact tracers, and no rapid tests,

border screenings, or licensed vaccine for Ebola.

After that epidemic, Guinea,

with the support of the US and other international partners,

completely overhauled their epidemic response system.

And in January 2021, that system faced its first real test.

It started when a nurse in southern Guinea developed a headache, vomiting, and fever.

A few days later, she died.

As dictated by traditional burial practices,

her family prepared her body for the funeral.

Within a week, the nurse's husband and other family members

started experiencing symptoms.

Health officials suspected Ebola much quicker than in 2013 and ordered tests.

They came back positive,

and Guinea activated its epidemic alert system the next day.

Then, lots of things happened very quickly.

Guinea's National Agency for Health Security

activated 38 district-level emergency operations centers,

as well as a national one.

Teams of epidemiologists and contact tracers began the painstaking job

of figuring out exactly who was exposed and when,

generating a list of 23 initial contacts that quickly grew to over 1,100.

Advanced rapid testing capacity spun up in the city where the outbreak started.

At Guinea's borders with Liberia and Cote d'Ivoire,

public health workers screened more than 2 million travelers.

A large-scale vaccination campaign was started.

And, finally, more than 900 community mobilizers

alerted people of the outbreak

and suggested alternative burial practices that were acceptable to the community

and reduced the risk of spreading Ebola.

Thanks to all these measures,

the 2021 outbreak ended just four months after it began.

Only 23 people contracted Ebola; only 12 died.

That's less than 1% of the deaths in the prior outbreak.

The 2021 outbreak cost $100 million to control—

which sounds like a lot but pales in comparison

to the global economic cost of the previous outbreak:

$53 billion.

So should every country just copy Guinea's approach?

Not exactly.

It is always important to respond to an outbreak quickly,

so an early warning system is essential.

But beyond that, a successful response can look very different

for different diseases in different countries.

For example, Brazil quenched an outbreak of yellow fever,

which is spread by mosquitoes,

primarily by mounting a massive vaccination campaign.

That strategy worked well for Brazil

because it's one of the major global producers of the yellow fever vaccine,

and its population was accustomed to regular, routine vaccinations.

But for many diseases, you don't even need a mass vaccination program.

In August of 2021, a truck driver tested positive for cholera in Burkina Faso.

Health care workers alerted the government that same day

and contact tracing began immediately.

Cholera is caused by a bacterium,

so Burkina Faso gave antibiotics to those exposed or potentially exposed.

This extremely fast response stopped the outbreak

just a few weeks after it started.

Cholera often rears its head in West Africa—

in 2021, there were over 100,000 cases and more than 3,700 deaths.

Because Burkina Faso was so well prepared, they had zero deaths that year.

Zero.

In Chiang Mai, Thailand, health officials piloted

a community-owned, community-driven outbreak alert system

to monitor animal health—

that's important because some animal outbreaks have the potential

to spill over and become human outbreaks.

Villagers used an app to alert health authorities about outbreaks in animals.

Over the course of 16 months, 36 animal outbreaks were identified.

For any outbreak response system to be effective,

it needs to be trusted, valued, and ultimately used by communities.

That means reaching people where they are, in the language they speak,

and aware of the culture, beliefs, and practices with which they live.

Perhaps most importantly, we can't expect to do nothing for years

and then just swing into action when an outbreak occurs.

One of the best ways to save lives is to invest in lasting health infrastructure,

365 days a year, for everyone,

especially the most vulnerable among us.