SAN FRANCISCO —  After surging during the COVID pandemic into a crushing public health emergency, drug overdose deaths in San Francisco plummeted in 2024, according to preliminary data compiled by city health officials.

The chief medical examiner’s office recorded 586 fatal overdoses in San Francisco in the first 11 months of 2024. That represents a nearly 23% decrease, or 174 fewer deaths, compared with the first 11 months of 2023. In total, 810 people died from drug overdoses in 2023, the highest number in city records.

The development mirrors both national and statewide data showing overdose deaths on the decline. Provisional data from the federal Centers for Disease Control and Prevention indicate a 14.3% decrease in fatal overdoses across California when comparing the 12 months that ended in July 2023 with the 12 months that ended in July 2024. Fatal overdoses fell 16.9% nationwide during that period, according to CDC figures.

Los Angeles County health officials have not yet released fatal overdose figures for 2024. But the most recent data also showed progress: Deaths from drug overdoses and poisoning plateaued between 2022 and 2023, after years of historic increases, according to the L.A. County Department of Public Health. In 2023, the county recorded 3,092 fatal overdoses, down slightly from 3,220 deaths the year before.

San Francisco public health experts attributed the decline in fatal drug use in the city to the widespread availability of naloxone, a medication commonly sold under the brand name Narcan that can rapidly reverse the effects of opioid overdoses, as well as buprenorphine and methadone, prescription medications that treat opioid addiction long-term.

“We are cautiously optimistic that our public health interventions are starting to see results in terms of saving lives,” said Dr. Grant Colfax, director of the San Francisco Department of Public Health.

Methadone prescriptions issued by the health department increased by more than 30% and buprenorphine prescriptions by nearly 50% in the last year, Colfax said. The department recently partnered with a “night navigator team” that works after dark to offer treatment, including a telehealth program that quickly connects people who abuse opioids with healthcare providers who can prescribe medications. The department has logged more than 2,300 calls since the program launched in March.

San Francisco has added about 400 residential treatment beds to 2,200 existing spots in recent years and tripled the number of street care workers in the last two years, according to the public health department and Mayor London Breed’s office.

Dr. Christopher Colwell, chief of emergency medicine at Zuckerberg San Francisco General Hospital and Trauma Center, said he has seen a notable increase in the number of people open to accepting treatment in the last year.

“I think a lot of patients are recognizing, more so in the last year than I’ve ever seen, how dangerous opioid use disorder is, watching their friends and colleagues die,” Colwell said. “I’ve seen a lot more willingness to at least have that discussion, and consider it, than I did even just a couple years ago.”

Keith Humphreys, a Stanford University psychiatry professor who studies addiction, called the 2024 numbers a “big deal.”

“Both because of the lives that are saved, but also just for the morale of every front-line worker, every harm-reduction worker, every treatment professional, every police officer who has been despairing that this is never going to get better,” Humphreys said. “This is a big boost.”

San Francisco, like many urban areas, recorded a sharp rise in fatal overdoses in the early years of the COVID pandemic, when government shutdowns made it more difficult to directly address the introduction of fentanyl into the street drug scene. For example, San Francisco counted 259 deadly overdoses in 2018, when fentanyl first hit the streets, and 441 fatalities in 2019. A year later, as the city effectively shut down to slow the spread of COVID-19 and it became more difficult to do community outreach, overdose deaths skyrocketed to more than 720.

Humphreys said the pandemic’s wane has also made it easier to address some of the social factors underlying addiction.

“Everything about COVID was terrible from a drug viewpoint. You had more reasons to use drugs: sadness, isolation, bereavement, loneliness,” Humphreys said. “The kind of structures that help people get and stay in recovery, like work, accountability, daily routines, social obligations, all went down.”

Breed lost her November reelection bid to nonprofit executive and Levi Strauss heir Daniel Lurie, a result widely attributed to voter frustration over homelessness and street drugs. Still, Breed said the recent decline in overdose deaths is a testament to her administration’s decision to take a “harder stance” against illicit drug use, arresting dealers and mandating treatment for some users.

Last March, for example, she sponsored a successful ballot measure to require drug screening and treatment for people receiving county welfare benefits who are suspected of illicit drug use.

Colwell said that although last year’s numbers are a positive sign, opioid use remains a serious problem. He stressed the importance of adding treatment options such as buprenorphine and methadone, which are more effective long-term than overdose reversal medications. And although he appreciates the city’s efforts to invest in treatment beds and housing, he said, “I don’t go a day where I don’t feel like we need more.”

He and other experts said it is crucial that the city and Lurie continue investing in solutions, even as San Francisco faces a projected $876-million budget shortfall. Lurie has pledged to declare a fentanyl emergency when he takes office Jan. 8 and to “get tough” on drug dealers.

“We’ve seen what can be helpful,” Colwell said, “and we need to keep doing this.”

With the winter cold and flu season upon us, Americans should be on the lookout for another ultra-contagious virus: our most common stomach bug.

The U.S. experienced the largest December norovirus surge since at least 2012, according to data from the Centers for Disease Control and Prevention.

During the week of Dec. 5, state health departments recorded 91 separate outbreaks nationwide, according to the CDC. The next highest figure for that week since 2012 was 65 outbreaks.

Through November, there have been 55 laboratory-confirmed cases of norovirus in California, according to the state department of public health. Data from December are not yet available.

Outbreaks are typically more widespread in January and February, the data show, raising concerns that the spike could continue.

Most norovirus cases are transmitted directly from one person to another, the CDC said, from actions such as touching food or eating utensils. Restaurants, cruise ships, healthcare facilities and schools are common transmission sites.

Additionally, contaminated food, water and surfaces can spread the virus.

Last week, the U.S. Food and Drug Administration issued advisories warning businesses and consumers against serving or eating oysters from Washington state, Canada and Korea which may be contaminated with norovirus.

Annually, the CDC reports some 2,500 outbreaks nationally. But real-time monitoring data only cover 14 states: Alabama, Colorado, Massachusetts, Michigan, Minnesota, Nebraska, New Mexico, North Carolina, Ohio, Oregon, South Carolina, Tennessee, Virginia and Wisconsin.

Around half of outbreaks of food-related illness are caused by norovirus, per the CDC.

The most common symptoms of norovirus are vomiting, diarrhea, nausea and stomach pain. Symptoms usually improve in one to three days, but those infected can still spread the virus for several days after symptoms ease.

The best ways to prevent the virus from spreading: washing hands, cooking shellfish thoroughly, washing fruits and vegetables, cleaning and disinfecting contaminated surfaces, washing laundry in hot water and staying home for two days after symptoms stop.

The main treatment for norovirus is hydration to replace fluids lost by the patient. Those with severe dehydration should seek medical attention, the CDC advises.

The ads on podcasts and social media were tantalizing: over-the-counter probiotic supplements that could ward off the worst effects of a hangover if taken before drinking.

As a bourbon reviewer who enjoys the flavor of spirits but has always been easily prone to hangovers, Eric Burke was intrigued. He ordered a few bottles of Pre-Alcohol, a probiotic drink from the company ZBiotics, to test it out.

He downed the mixture of water, salt, flavoring and genetically modified bacteria. He followed it with a cocktail, a meal and two bourbons, and woke the next morning feeling considerably more chipper than he’d have expected.

The next night, emboldened by success, he drank another half-ounce bottle of Pre-Alcohol. He drank a bit more than the previous night — a beer with dinner and then four tumblers of bourbon.

That amount that typically would leave him feeling achy and sluggish the day after.

Which was exactly how he felt when he opened his eyes hours later.

“That one was unpleasant,” said Burke, 48. “I woke up that morning being just like, ‘Well, I’m not 21 anymore.’ ”

A hangover is a collection of physical and mental symptoms resulting from the inflammation and oxidative stress that alcohol wreaks in the human body.

One of many factors contributing to day-after misery is the accumulation of acetaldehyde, a chemical byproduct of the beverages’ ethanol breaking down in the body. Acetaldehyde is a carcinogen that features prominently in the nausea, stomach upset, sweats and other physical symptoms associated with over-consumption.

ZBiotic’s Pre-Alcohol and the Swedish biotech company De Faire Medical AB’s competitor supplement Myrkl both rely on live bacteria to process excess acetaldehyde. Other researchers and recreational drinkers have also experimented with probiotics for similar ends.

Reducing the amount of acetaldehyde, the hypothesis goes, should also reduce the physical symptoms caused by its buildup.

“The more you drink, the more you’ll have to deal with the effects of other things besides acetaldehyde,” ZBiotics CEO Zack Abbott said via email when asked about Burke’s results. “That being said, for the vast majority of people, acetaldehyde is a major factor, and Pre-Alcohol therefore results in them feeling better (if not perfect) the next day.”

The U.S. Food and Drug Administration considers ZBiotics and Myrkl to be dietary supplements or functional foods, not drugs, and thus doesn’t evaluate their health claims. Microbiome experts caution that a probiotic supplement alone won’t spare you from the worst effects of overindulgence.

For starters, the bloodstream carries most of the ethanol in an alcoholic beverage straight to the liver, where an enzyme called alcohol dehydrogenase breaks it down into acetaldehyde. The brain, gastrointestinal tract and pancreas process some alcohol as well. Only a relatively small amount of ethanol is metabolized in the intestines, where probiotics do their work.

Adding probiotics to your pre-party regimen won’t cause you any harm, said Karsten Zengler, a microbiologist and professor of pediatrics and bioengineering at UC San Diego.

But it’s also unlikely to have a substantial effect on how you feel the next day, as your intestines come pre-equipped with an army of bacteria capable of breaking down alcohol’s byproducts, he said.

“There is not a lot of ethanol and acetaldehyde in your large intestine to start with,” Zengler said, and “the vast majority of the bacteria in your gut already metabolize acetaldehyde for you, so just adding something more might not do the trick.”

ZBiotics has funded studies demonstrating both the safety of their product and that their bacteria effectively broke down a significant amount of acetaldehyde in simulated gut conditions in a lab. As for the real-world effects of that breakdown, Abbott pointed to an outside 2006 paper that found that rats given ethanol had fewer hangover-like symptoms the next day when acetaldehyde was removed.

Myrkl funded a small study that showed its product lowered blood-alcohol levels in some participants. Subjects were instructed to take the supplement for a week prior to drinking, rather than the single pre-party dose instructed on the packet.

The hard truth, said Joris C. Verster, a pharmacology professor at Utrecht University in the Netherlands and founder of the Alcohol Hangover Research Group consortium, is that there is currently one scientifically validated way to prevent hangovers: drink less alcohol.

“Although there are many hangover products marketed, there is no convincing scientific evidence that these treatments are effective. Independent double-blind, placebo-controlled clinical trials in social drinkers are needed,” Verster said. “Currently, the only effective way to prevent a hangover is to consume alcohol in moderation.”

Unpleasant as they are, hangovers serve a valuable purpose, said Dr. Daryl Davies, a clinical pharmacy professor and director of the Alcohol and Brain Research Laboratory at USC Mann School of Pharmacy and Pharmaceutical Sciences.

“What I tend to tell people is if you are getting hangovers, you are drinking too much,” Davies said. “It is the body trying to tell you that something is wrong.”