There may be 500,000 additional malaria deaths by 2050 according to peer-reviewed research published in 2026.

See what regions report new leprosy cases

This graphic shows the burden of leprosy by region for 2023, based on data provided from the World Health Organization, which collates this information. Southeast Asia leads in the number of cases by region. (Some readers may experience a paywall.)

Hear what it's like to have malaria from a patient who suffered from the mosquito-borne disease.

See the global blindness burden by cause and continent.

10 locally acquired malaria cases were reported in the US in 2023—a surprise

The cases, reported in Florida, Texas, Maryland, and Arkansas, broke a 20-year streak since there had been no reported locally acquired mosquito-transmitted malaria in the country since 2003, when there was a case in Florida.

See this graphic of the complex malaria transmission lifecycle.

Children under 5 account for 76% of all malaria deaths in Africa

The main hypothesis for why the disease hits this age group the hardest is that children this young have still-developing immune systems. Pregnant women and people with HIV/AIDS are also at higher risk of severe infection.

Florida reports 71 imported malaria cases annually—4% of all the US cases.

See the polio cases that occur worldwide each year by region

Worldwide, the number of cases of polio reported each year from 1980 to 2024 has declined. This graphic depicts regional trends and declines by year.

Vector-borne diseases kill more than 700,000 people globally each year—and are growing

The diseases with the greatest potential to spread widely aren't the ones that quickly kill human hosts. Instead, the best hosts or reservoirs for vector-borne diseases would be chronically ill over the long term, increasing the likelihood that the pathogen could be transmitted to others.

Molecular evidence suggests the deadliest malaria parasite may be 100,000 years old.

See how anxiety disorder rates vary across 200+ countries, with Portugal, Brazil, and Iran reporting the highest burdens.

West Nile was reported in 47 states in 2025, with more than 1,400 people severely affected

Tracking numbers from the CDC indicate that the virus spread widely that year, with more than 2,000 reported human cases and many states seeing more than 25 sickened people. More than 1,400 people had neuroinvasive cases of the disease—meaning the virus had entered the nervous system, which can cause severe, potentially life-threatening illness.

The most severe form of malaria is caused by the Plasmodium falciparum parasite.

Malaria comes from the Italian term 'mal'aria,' meaning 'bad air'

The term refers to marshy areas associated with the disease. An estimated 94% of malaria cases—215 million—occur in Africa.

See MS prevalence by region in the United States

This map underscores that people in the northeastern United States have more cases of the disease as compared to the south, west, and midwest. On an individual level, these numbers may still differ based on genetic makeup and other factors irrespective of where people live.

US West Nile case numbers were up 40% in 2025 across the United States though theories vary to explain this surge.

Antimalarials must be taken before traveling to a malaria-endemic area

Malaria prevention involves avoiding getting bitten by mosquitoes (with bug spray and clothing choices) and taking malaria preventative drugs before, during, and after spending time in an area with malaria risk. The drug must be in the blood before the traveler is exposed to malaria parasites.

A malaria case in Maryland stumped doctors in 2023—leading to the wrong treatment and underscoring the challenge of physicians being mindful of tropical diseases in our interconnected world.

More than 4,000 people died from cholera in 2023

This global health threat sickened more than half a million people in 2023 and killed 4,007 people. That's a 71% increase in deaths as compared to a year earlier. (Report only offered in PDF format.)

Climate change is influencing the spread of disease

Rising temperatures and water levels are forcing animals and pathogens beyond their typical boundaries. This article and its data visualizations explore the proliferation of climate-driven diseases.

Visualize population densities around the world represented as geographic terrain and how those densities changed from 1900 to 1975 to 2015.

Treating black fever can result in a complication that spreads the deadly disease

Black fever, a deadly parasitic disease second only to malaria, threatens more than 1 billion people across more than 83 countries. Also known as kala-azar or visceral leishmaniasis, the disease is caused by parasites that spread through sandfly...

See how cholera spreads in a community

This animated video offers a comprehensive look at how cholera spreads. It makes clear why it's so difficult to stamp out this disease in communities around the world. It also details what steps can help control cholera.

Explore this interactive visualization of illnesses known to jump from animals to people, and learn how these zoonotic diseases spread.

What if we killed every mosquito on Earth?

Mosquitoes aren't just annoying, they're deadly. they're also responsible for an estimated 725,000 deaths worldwide, every year. Would it be so bad if we found a way to wipe them out completely? Real scientists have gamed out this hypothetical scenario, concluding it actually wouldn't be that bad. This five-minute video breaks down one way this could happen.

See the incidence of Lyme disease across all 50 states in 2023

The US states with the highest rate of Lyme disease—meaning cases per 100,000 people—were Rhode Island, Vermont, and Maine, in 2023. Rhode Island had 260 cases per 100,000 people, based on cases reported to the US Centers for Disease Control and Prevention. (Some users may encounter a paywall.)

Researchers are breeding genetically modified mosquitoes to be malaria-resistant.

Malaria vaccines are not routine because they have limited effectiveness.

West Nile virus was detected in UK mosquitoes for the first time in 2023

Fragments of the virus were detected in mosquitoes that were being collected in Britain for the first time in 2023, but the UK government considers the overall risk to people to be low. As of spring 2026, there have never been detected locally-acquired cases of the disease.

Explore this database to discover Lyme disease incidence in your county.

Female Anopheles mosquito bites are the primary way malaria spreads.

World health experts expect more than 240 million global cases of AMD in 2030

The World Health Organization estimated in 2019 that by 2020 there would be roughly 195.6 million cases of age-related macular degeneration and projected that the number would continue to grow. (Some users may experience a paywall.)

There are two recommended malaria vaccines by world health experts, but both have limited effectiveness.

See the total number of Lyme cases per state in 2023

New York, Pennsylvania, and Massachusetts had the highest total number of Lyme disease cases in 2023. New York had more than 22,000 cases that year. Maine had one of the highest Lyme incidence rates of disease that year—213 per 100,000 people—but only 2,942 cases overall.

Influenza infects up to a billion people worldwide each year

The World Health Organization estimates that seasonal influenza causes about 1B cases annually, including 3 to 5M severe illnesses and between 290,000 to 650,000 deaths.

Mosquitoes top the ranking of the world's deadliest animals.

Visualizing the economic impacts of 5G

5G is set to revamp industries around the world, but the benefits may not be equally distributed. This nifty graphic illustrates what the global landscape may look like in 2035.

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.