The 1957 and 1968 influenza pandemics caused millions of deaths worldwide

A novel H1N1 influenza strain sparked a 2009 global pandemic

First detected in Mexico, the 2009 “swine flu” pandemic infected up to 1.4B people worldwide. While mortality rates were lower than earlier pandemics, the outbreak still caused more than 150,000 deaths.

Why the 1918 flu killed between 50 and 100 million people

The 1918–1920 flu pandemic (once called, incorrectly, the Spanish flu) killed quickly and in huge numbers, with estimates of the global death toll ranging from 50 to 100 million people. Several factors contributed to the high mortality rate: lack of antibiotics, the global disruption of World War I, and more.

Human records of influenza stretch back more than two millennia

Accounts of flu-like illness appear as early as 412 BCE, when Hippocrates described a sudden wave of cough and fever. Centuries of recurring outbreaks culminated in the first clearly documented pandemic in 1580, spreading from Asia into Europe and Africa.

A timeline of major pandemics from 1899–2025

Modern pandemics have been defined by the race between globalization (which increases risk) and the development of new medicines. The Great Influenza epidemic claimed some 50 million lives, and the COVID-19 pandemic killed more than 7 million. In between, diseases like Ebola, cholera, AIDS, and more have devastated communities.

Major genetic shifts in flu viruses can spark global pandemics

Antigenic shift happens when two different influenza viruses infect the same host and swap genetic material. The result is a brand-new subtype of influenza which, if easily spread among people, can trigger a worldwide pandemic.

How the 1918 pandemic spurred developments in virology and vaccines

This article provides an in-depth historical account of the 1918 Spanish Flu pandemic, including its impact on the global population and how its occurrence spurred significant advancements in the study of viruses—laying the groundwork for the...

Bird Flu is spreading—what does that mean for us and other species?

The rapid global spread of H5N1 bird flu—from remote Antarctic islands to US farms—shows how animal spillover, driven by human activity and ecological disruption, is accelerating pandemic risk across species long before sustained human transmission begins.

The flu is a contagious respiratory illness caused by influenza viruses

Unlike the common cold, influenza attacks suddenly with fever, body aches, and fatigue. Seasonal strains circulate worldwide, infecting up to a billion people each year and causing hundreds of thousands of deaths despite vaccines and treatments.

In 2012, a virus that causes HFMD may have killed dozens of kids in Asia

More than 50 young children in Cambodia died in spring 2012 for unknown reasons, but laboratory testing of samples available from a limited number of those children came back positive for Enterovirus 71. That virus, which can cause HFMD, is known to cause severe complications among some people who contract the disease. But health officials concluded that poor baseline health and then incorrect treatment using steroids helped exacerbate their condition, helping lead to the deaths.

The COVID-19 pandemic led to a decrease in immunizations in the US and worldwide

Public health funds and resources that were diverted to COVID-19 response reduced efforts to combat polio and vaccinations for polio and other diseases declined during the pandemic, putting more people at risk for polio.

Flu viruses use special proteins to invade and spread in the body

Influenza viruses carry two key surface proteins: hemagglutinin (H), which lets them enter cells, and neuraminidase (N), which helps them escape and spread. These proteins are the basis for the names of flu subtypes like H1N1 and H3N2

Learn the history and science of influenza in 'This Podcast Will Kill You'

In their flu episode, cohosts Erin Welsh and Erin Allmann Updyke unpack influenza’s biology, history, and impact—explaining everything from past pandemics to modern vaccines, all with their trademark mix of science and storytelling.

The Spanish flu had a major impact on the 1919 NHL season

Just two years after the National Hockey League was officially formed, its champion was playing the PCHA champion for the Stanley Cup. The series was tied, going into the deciding Game 5, when all but three NHL players fell ill with the Spanish flu. No champion was crowned that year.

The bubonic plague spread in three waves over 600 years

The Black Death refers to the first wave of the plague, which swept through Europe in the 14th century and killed 25 to 50 million people. Caused by the bacterium Yersinia pestis carried by fleas (often on rats), the human toll was roughly one-third of Europe's population at the time.

Nearly 5,500 crows died during four months in 1999 from West Nile in NYC

Subsequent testing made clear the disease at that point was 100% fatal to crows. From 1999 to 2004, millions of birds died as West Nile spread across North America, but the virus fortunately became less virulent as it moved westward.

Human-to-human transmission of hantavirus remains extremely rare, so the 2026 hantavirus cruise ship outbreak doesn't mean we're facing a COVID-style pandemic risk.

From 1970 to 2017, invasive species have caused $1.28T in damage globally

The costliest species were the Asian tiger and yellow fever mosquitoes ($149B), which arrived in the US from Asia and sub-Saharan Africa, respectively. The bulk of their damage came from their transmission of diseases such as Zika, chikungunya, and dengue. (Some readers may experience a paywall.)

Pneumonia was once a leading killer before penicillin treatments

In the early 20th century, pneumonia was a top cause of death worldwide, often fatal without effective treatment. Penicillin turned a once deadly infection into one of the most treatable bacterial diseases.

Watch an expert's take on the rare disease hantavirus—and why it's not of great concern to the general population

This rare zoonotic disease, transmitted to humans primarily through infected rodent droppings, urine, or saliva, is rarely spread between people. The disease was of particular concern in spring 2026, when an outbreak occurred on a 150-person cruise ship, prompting a flurry of action, including contact tracing for passengers in their home countries. The disease can be fatal. But early care—primarily oxygen support—can help patients survive.

The atomic bombs dropped on Japan had massive human costs

The US atomic bombings of Hiroshima and Nagasaki in August 1945 killed around 210,000 people—more than 38,000 of them estimated to be children—with tens of thousands more later dying from radiation-linked illnesses, leaving lifelong trauma and increased cancer risks.

Watch how viruses like Ebola can spill over from animals to humans—and vice-versa.

Hurricanes may kill 300 times more people than officially reported

A recent study suggests that, since 1930, more than 3.5 million people have died due to hurricanes. This incorporates the long-term effects of storms on people's health and economic well-being, contributing to thousands of premature deaths each year.

Three Ebola species are responsible for most large outbreaks of the disease

The Ebola Zaire, Sudan, and Bundibugyo species are the three ebolaviruses responsible for most large outbreaks in Africa. Among these, Ebola Zaire is the deadliest, with as many as 90% of cases resulting in death. Ebola Sudan has about a 50% fatality rate and has caused several outbreaks in Uganda. More recently discovered in 2007, Bundibugyo causes death in about 30% of people and has caused two large outbreaks in Uganda and the Democratic Republic of the Congo (DRC) before the spring 2026 DRC outbreak. Taï Forest virus is the rarest and is known to have infected a single person in the Côte d'Ivoire in 1994.

See how Ebola tore through Guinea, Sierra Leone, and Liberia in 2014-2016.

The first major norovirus outbreak sickened half an elementary school

In 1968, 50% of an Ohio school got ill from this foodborne pathogen. The disease name is a nod to that original strain discovered in Norwalk, Ohio, when half the elementary school students became ill. Almost all kids reported nausea and vomiting. Everyone recovered.

Roughly 1 in 5 cancers are caused by viruses

About 20% of cancers are caused by viruses, with seven specific oncoviruses causing between 10% and 15% of cancers worldwide. These include human papillomavirus and hepatitis B and C viruses, which can lead to diseases such as cervical and liver cancer. Understanding the mechanisms of these viruses is crucial for prevention and treatment strategies.

The coronavirus likely came from China’s wet markets

A wet market is a type of marketplace primarily selling fresh, perishable goods such as meat, fish, and produce, often in a non-supermarket environment. The term originated in Singapore during the 1970s, and the "wet" aspect refers to the wet floors resulting from the washing of stalls and the use of ice to keep food fresh. Such markets have been identified as a major source of zoonotic outbreaks, including the COVID-19 pandemic.

The global impacts of the 1877 'super' El Niño and what could result from similar future events

The 1877 El Niño event lasted approximately 18 months, raised temperatures in the Niño 3.4 region of the equatorial Pacific Ocean by 2.7 degrees Celsius (4.86 degrees Fahrenheit) above average, and contributed to a global famine that killed more than 50 million people. Such events are expected to exacerbate drought-related risks to global food security, driving up food prices worldwide. (Some readers may experience a paywall.)

Marburg virus, related to Ebola, is also extremely deadly, and has no available vaccine.

Volcanic activity may have triggered the Black Death by spewing gases that led to crop failures in Europe, thus forcing the import of grain ships with plague-infested fleas.

11 people died from firework injuries in the US in 2024.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

Before humans, the Soviet Union and the United States sent animals—including apes, dogs, and cats—to space during the Space Race.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

Some researchers have labeled nomophobia, the fear of being without your phone, as 'the phobia of the 21st century.'

'Shogun,' a 1980s TV series, helped popularize sushi in the US by stimulating an American interest in Japanese culture.

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

US housing costs have risen by roughly 175% between 1991 and 2026—but a growing number of Gen Zers are becoming homeowners anyway. In 2025, 4% of homebuyers were Gen Z, up from 3% the year before.

Between 10 million and 50 million people in the US develop rashes from poison ivy, poison sumac, and poison oak each year.

The US first hosted the World Cup in 1994, a tournament that lives in soccer infamy for its poor planning and the murder of Colombian player Andres Escobar, who'd accidentally scored on his own net.

The tragic Pulitzer Prize-winning image 'The Vulture and the Little Girl' (1993) generated controversy, raised concerns about ethics in photography, and eventually led to the photographer's death.

The US dollar is the most widely circulated currency in the world, and is involved in nearly 90% of global transactions

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

Exploring the Larry Bird punch that almost changed March Madness

When a Paris department store hesitated to sell Estée Lauder's perfume, she 'accidentally' broke a bottle, causing the smell to spread throughout the store and shoppers to start asking to buy the scent.

Coral polyps reproduce via broadcast spawning, where entire reefs simultaneously release reproductive cells for about one hour, once a year.

See the 25 of the best photos of auroras from around the world.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year