Here’s how public health fared in 2024

Extreme heat and viral outbreaks are among the year’s big public health headlines

A worker unloads cardboard boxes containing medical supplies from a delivery truck in the Democratic Republic of Congo while another worker walks in the foreground.

The World Health Organization delivered to the Democratic Republic of Congo medical supplies in September to help stem the country’s mpox outbreak. The supplies included personal protective equipment and treatments.

© Junior Diatezua/WHO

The world faced many public health challenges this year, including dangerous heat waves and outbreaks of the infectious diseases dengue and mpox. In the United States, after years of increases, there are early but promising signs of a downward trend in drug overdose deaths.

Dengue, mpox and bird flu raised alarms

Dengue exploded in the Americas, where countries have reported more than 12.6 million cases as of early December, according to the Pan American Health Organization. In 2023, there were about 4.6 million cases. Mpox became a public health emergency again, with close to 60,000 confirmed and suspected cases in Africa by early December, according to the World Health Organization. And bird flu spread at U.S. diary farms (SN: 12/12/24). There have been 60 confirmed cases of bird flu in people in the United States as of December 13, mostly in workers exposed at dairy and poultry farms.

Extreme heat put health at risk

Heat endangered health around the world in 2024, from India to Europe to Northern Africa. A heat dome brought sweltering temperatures to the United States earlier than usual this summer (SN: 6/21/24). People in Australia and Brazil experienced scorching heat during their winter (SN: 9/2/24). The extreme heat is due in part to climate change (SN: 12/5/24).

In the United States, a new online resource called HeatRisk, which uses data from the National Oceanic and Atmospheric Administration and the U.S. Centers for Disease Control and Prevention, made its debut this spring. People can enter a zip code to learn about the current risk that heat in their area poses to health and what the air quality is (SN: 6/1/24, p. 4).

A map of the midwestern and eastern United States shows the risks of extreme heat on June 22. Magenta, or extreme risk, in Ohio, Indiana and Illinois is surrounded by red, or major risk. Orange, or moderate risk, encompasses the red and magenta, stretching from Texas to Wisconsin and New York. The rest of the states in the photo are yellow, or minor risk.
A heat dome brought record-breaking temperatures to parts of the United States in late June, boosting the risk of heat-related illnesses and death. This HeatRisk map shows the forecast for June 22, 2024. Magenta denotes extreme risk, red is major risk, orange is moderate risk and yellow is minor risk.NOAA

Clean water is inaccessible to billions of people

More than half the world’s population lack access to safe drinking water (SN: 9/7/24 & 9/21/24, p. 7). Clean drinking water is a human right, but a new estimate, based on surveys and computer simulations, projected that more than 4.4 billion people don’t have access. That’s more than twice the official tally provided by the World Health Organization and based on country reports.

A stock image of a person holding a glass under a running faucet. The cup is filling with drinking water.
The World Health Organization estimates around 2 billion people don’t have access to clean water. The number may be twice as high, a new study suggests.d3sign/Getty Images

U.S. drug overdose deaths trended lower

The CDC estimates that drug overdose deaths have dropped from around 113,000 in the year ending in July 2023 to about 94,000 in the year ending in July 2024, a decrease of nearly 17 percent. It is the largest drop recorded for U.S. overdose deaths, according to a statement from the White House Office of National Drug Control Policy. The CDC had announced a downward trend in May, when the agency reported that the estimated total for 2023 — close to 108,000 overdose deaths — was the first annual decrease since 2018. Experts are still assessing what is contributing to the drop.

COVID-19 is still with us

March marked four years since the COVID-19 outbreak was declared a pandemic (SN: 4/6/24, p. 14). The CDC loosened COVID-19 isolation guidelines in 2024. The SARS-CoV-2 virus continues to spread, making people sick. There were high levels of SARS-CoV-2 in wastewater this summer and a spike in infections (SN: 7/19/24). The U.S. Food and Drug Administration approved updated vaccines in August to better match variants that are circulating (SN: 8/22/24). And the Biden Administration restarted a program that mails free COVID-19 rapid tests to homes ahead of an expected winter spike in cases.

A box of Moderna's COVID-19 mRNA vaccine, 2024-2025 formula.
The FDA has now approved updated COVID-19 vaccines that are formulated to more closely target the omicron variants currently circulating. Moderna

Long COVID got an official definition

With the input of patients, the U.S. National Academies of Sciences, Engineering and Medicine announced a definition for long COVID (SN: 7/13/24 & 7/27/24, p. 13). The medical condition persists for at least three months after infection with the coronavirus, affects any organ or system in the body and can include more than 200 symptoms. An official definition may help with diagnosis and treatment.

In this illustration, a woman stands slightly knockkneed, holding her hands by either side of her face, while a giant red coronavirus with yellow bulbous projections hovers right over her head.
Long COVID affects millions of Americans of almost all ages, but there has been no standard definition for the condition until now.pilli/Getty Images Plus

Nasal spray for severe allergic reactions gained approval

The first epinephrine nasal spray for adults and kids who weigh 30 kilograms or more got the nod from the FDA (SN: 8/27/24). The medicine treats severe allergic reactions, including anaphylaxis. The new formulation, available by prescription, provides a non-shot option for the first time and may encourage wider use of the medication for severe reactions.

A picture of an epinephrine nasal spray for the treatment of severe allergic reactions.
Neffy, a new epinephrine nasal spray, offers a needle-free option for the treatment of severe allergic reactions.ARS Pharmaceuticals, Inc.

Sensitive exams require written informed consent

Hospitals must obtain informed consent in writing to conduct breast, pelvic, prostate and rectal exams that aren’t medically necessary (SN: 4/24/24). The U.S. Health and Human Services guidance came in response to ethical concerns over unauthorized exams for medical training done on patients under anesthesia.

An empty operating room.
According to new federal guidance, U.S. hospitals need to get informed consent from patients in writing before subjecting them to intimate exams performed under anesthesia for training purposes.ER Productions Limited/DigitalVision/Getty Images Plus

A new rule for mammograms

Mammography reports in the United States must now include whether the examined person has dense breast tissue, according to an FDA rule that went into effect September 10. Having dense breasts modestly increases the risk of a breast cancer diagnosis but is just one component of a person’s overall risk (SN: 3/10/23).

Two x-ray images of breasts. The image on the left shows the breast's fatty tissue as more transparent while the image on the right shows more dense breast tissue which appears white.
Fatty tissue is more transparent on a mammogram, as shown on the left. Dense breast tissue, shown on the right, looks white, which might hide tumors or other areas of concern.CDC