Several states, primarily in the Midwest and on the East Coast, have reported thousands of cases of cyclosporiasis, a parasitic disease that can cause an extended bout of debilitating diarrhea.

There have been cases of cyclosporiasis infection in California this year, but none has been linked to the current outbreak. Public health officials, however, have advice for residents to stave off illness.

Cyclosporiasis is an intestinal illness caused by several species of the microscopic parasite Cyclospora cayetanensis and is spread through the feces from an infected person that has contaminated food or water, according to the federal Centers for Disease Control and Prevention.

People become infected with the illness by consuming food or water that has been contaminated with the parasite — the infection is not transmitted from person to person.

The epicenter of the current outbreak is in Michigan, which has reported more than 1,000 cases since June, including 44 people who were hospitalized. The state typically reports about 50 cases of cyclosporiasis annually. Now there may be hundreds more infected as 17 states have reported numerous cases.

Officials say the true number of infected people is likely higher because some people recover without medical care and are not tested for the parasite.

In the United States, food-borne outbreaks of cyclosporiasis have been linked to various types of fresh produce imported from Latin America, including raspberries, cilantro, basil, snow peas and mixed salad, according to the California Department of Public Health.

Officials say those who have fallen ill became sick after eating food in the United States and did not report travel during the 14 days before they got sick.

Those who have contracted cyclosporiasis have ranged in age from 5 to 86.

There is currently no evidence of a single, multi-state cyclospora outbreak, meaning there isn’t a common source linking all cases, according to the CDC and the U.S. Food and Drug Administration, which are working with local public health authorities to investigate the cases in each state.

At this time, there aren’t any local outbreaks in California, and current cases of cyclosporiasis infection are not linked to the multi-state outbreak, according to the California Department of Public Health.

“From January to June 2026, California has reported 41 provisional cases of cyclosporiasis, compared to 80 cases during the same period in 2025,” said Beth Deines, information officer for the state agency.

Most of these cases are associated with recent international travel, she said.

“With the significant increase in cases in the Eastern and Midwestern states, we will monitor for cases that may be associated with travel to areas of the country that are experiencing these increases,” Deines said.

Similarly, officials with the public health department will look for clusters of cases that may indicate transmission occurring in California.

There have been four domestic cases reported since May 1.

Two of those who were infected reported that they had traveled to the Midwest. Investigation of these cases is ongoing. To protect patient privacy, the state public health department does not disclose where in the state the patients reside.

Symptoms of cyclosporiasis

Cyclosporiasis cases are reported year-round; however, infections are most common when temperatures are warmer, in the summer and early fall.

Infected people experience symptoms from two days to two weeks after consuming food or drinking water containing the parasite.

Some people who are infected, particularly those from areas where cyclosporiasis is endemic, may not have any symptoms.

Those who do develop symptoms could experience:

• Watery diarrhea
• Loss of appetite
• Weight loss
• Cramping
• Bloating
• Increased gas
• Nausea
• Fatigue

Less common symptoms may include:

• Vomiting
• Body aches
• Headache
• Low-grade fever
• Other flu-like symptoms

Cyclospriasis can be treated with a combination of antibiotics. Without treatment, symptoms can last from a few days to a month or longer.

Some symptoms, such as diarrhea, may go away and then return.

How to protect yourself

When traveling to areas where cyclospriasis is endemic — including tropical or subtropical regions — avoid drinking tap water. Also make sure hot food is served piping hot, health officials say, and cold food should be kept thoroughly chilled. Germs that cause food poisoning can grow quickly in lukewarm food.

A complete list of food and drink considerations provided by the CDC can be found here.

Most food-borne outbreaks of cyclosporiasis in the U.S. have been linked to various types of imported fresh produce, so public health officials in California and in states reporting infection cases recommend:

• Wash your hands with soap and water before and after handling or preparing raw fruits and vegetables. Note that hand sanitizer does not kill the parasite that causes cyclosporiasis.
• Wash all fruits and vegetables thoroughly under running water before eating, cutting or cooking.
• Scrub firm fruits and vegetables, such as melons and cucumbers, with a clean produce brush.
• Cut away any damaged or bruised areas on fruits and vegetables before preparing and eating.
• Refrigerate cut, peeled or cooked fruits and vegetables as soon as possible.

SOUTH LAKE TAHOE, Calif. — For years, Reid Reichardt walked the forest trails behind his Tahoe Basin cabin nearly every day with his dog Jasmine. Then in 2021, the Caldor fire swept through, incinerating it all.

“It was really a sense of mourning and grief to lose this,” Reichardt said, eyes fixed on the towering blackened sticks around him.

Since then, Reichardt has watched birds, flowers, a sea of green shrubs and baby conifers fill in the moonscape. It’s been a ray of hope for him, as Jasmine aged and eventually passed.

But two months ago, Reichardt got a text from a friend: The Forest Service had approved a plan to kill off shrubs it says are blocking the conifers from growing. It plans to use glyphosate, an herbicide California has determined causes cancer.

“I think many people, including me, would say, I’d rather my house burn down than get cancer,” he said.

Increasingly severe wildfires — fueled by climate change and more than a century of forest mismanagement — have forced an environmental reckoning on mountain towns nestled in California’s Sierra Nevada. Their residents face difficult questions: Will some kind of forest grow back? And, if not, should humans intervene to make that happen? Two communities, 100 miles apart, may be choosing different answers.

Many foresters and fire ecologists argue the plentiful baby conifers behind Reichardt’s home will struggle to compete with the fast-growing shrubs for sunlight, water and soil nutrients. Should another fire roll through, the seedlings are not yet tall enough to hold their branches above the flames.

But many Tahoe Basin residents say they are willing to live with whatever grows back, if it keeps glyphosate away.

Reid Reichardt stands next to Saxon Creek in the Caldor fire burn scar, near the area the Forest Service wants to use herbicide to kill the shrubs it says are crowding out the baby conifers.

(Scott Sady / For The Times)

“I’ll never see it like it was in my entire lifetime, and we need to be OK with that,” said Madeline Moritsch, who spent summers at her parents’ Tahoe cabin growing up and now lives in town. “It’s really sad … to lose connection to the forest, but then also, it is part of the forest life cycle. I have great trust that the forest is going to do what it’s going to do.”

In the Tahoe basin, opposition to the herbicide reached a fever pitch after an article chronicling the Forest Service’s use of the chemical across California appeared in Mother Jones magazine.

The agency had posted newspaper notices and sent emails mentioning herbicide use and seeking public input last year, but Tahoe residents said they had missed them or didn’t make much of them.

“We continue to welcome feedback from community members and appreciate the ongoing interest and involvement from the public,” the Forest Service said in a statement.

The controversy over reviving the forest is a shame, some say, because, done right, these projects can help restore the identity of forest towns and a feeling few have felt in decades: safety.

The stewards of the forest

Material to be burned is piled in an area the Konkow Valley Band of Maidu manage in the Dogwood District of Plumas National Forest.

(Sara Nevis / For The Times)

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About 100 miles northwest of the Tahoe Basin, lower down in the foothills, survivors of the epic 2018 Camp fire that destroyed the town of Paradise have a very different relationship with forest stewards.

The Butte County Fire Safe Council — made up of three dozen foresters, former firefighters and local fire survivors — has countless stories of working with local landowners to heal forests and reduce wildfire risk.

In a ride with four of them in one of the council’s heavy-duty white pick-ups, conversation is constantly interrupted as they point out areas across the county’s rugged wild lands that they’ve worked on.

More than a third of Butte County’s 1 million acres have burned over the past decade. That has made taking action and having tough conversations — including about herbicide — unavoidable.

A flag marks a Konkow Valley Band of Maidu cultural site.

(Sara Nevis / For The Times)

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Connor Gilmartin, the Fire Safe Council’s director of development, sympathized with residents in the Tahoe Basin. “It’d be completely reasonable that people feel slighted if they were to have something happening in their proverbial backyard without knowing about it,” he said. “It’s a non-option for us.”

The Fire Safe Council and forestry herbicide experts stressed that when herbicide is used, crews take significant precautions to protect ecosystems and communities. They post signs along trails and mix in dye so residents can see where the chemical has been used. It can’t be applied near streams and lakes.

Experts also said it is extremely unlikely for people using trails to get accidentally exposed to glyphosate levels that scientists deem unsafe.

Why use glyphosate

For well over a century, the state and federal government aggressively suppressed all fire in California forests — many of which were adapted to low-severity flames that rolled through the understory every five to 20 years. These free-range “good” fires, set by lightning and Indigenous tribes, thinned out and rejuvenated forests for millennia.

Without them, parts of the Sierra Nevada have grown five to six times as dense as they were a few hundred years ago.

Combine that with increasingly hotter and drier weather due to climate change, and forests in the Sierra Nevada are left with a ton of stuff that’s ready to burst into flames.

Now when a fire ignites, it’s often high-intensity, devouring virtually everything in its path — including hundred-foot-tall trees.

After such a fire, shrubs that usually fight for scarce sunlight on the forest floor suddenly have it all day and take over.

One of many conifers seedlings among the shrubs the Forest Service would like to eradicate using herbicide.

(Scott Sady / For The Times)

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It’s for this reason many experts say intervention is necessary if the forests are to grow back within the next several decades.

Without intervening, “the Forest Service is not getting a forest back. That’s pure and simple,” said Scott Stephens, UC Berkeley professor of fire science. Hoping fire stays out of the forest during its slow recovery process, “I would call that risky business,” he said.

To cut back on the shrubs and give the conifers a chance, Stephens said land managers have a few options: Goats, hand crews and herbicides.

Goats are great at munching up unwanted vegetation; however, if they aren’t introduced immediately, the goats are no match.

Land managers can also send in hand crews to take down shrubs with loppers, hoes and chainsaws. But that is labor intensive, and when a fire burns thousands of acres, the time and cost involved can be too high.

That leaves herbicides.

Of those, glyphosate is one of the few reasonably priced, effective and, many argue, comparatively safe herbicides that land managers can rely on for restoration work.

Reid Reichardt hikes a well-known mountain bike trail, Toad’s Wild Ride, behind his home near South Lake Tahoe. Reichardt and others worry that hikers and bikers will be exposed to herbicide applied under a Forest Service plan.

(Scott Sady / For The Times)

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In the Tahoe Basin, the Caldor fire restoration plan outlines roughly 3,600 acres where the Forest Service could use ground crews to apply herbicide directly to shrubs — no aerial spraying.

“Even though it’s gotten a bad name because so much attention has been focused on it, it’s actually effective and comparatively benign,” Jon Souder, retired Oregon State University forestry professor, said of glyphosate.

Whether glyphosate causes cancer is still debated.

The U.S. Environmental Protection Agency determined it is not likely a human carcinogen. The cancer research arm of the World Health Organization says it probably is.

For many residents near Lake Tahoe, it’s not a risk worth taking.

Teaching the land to trust

Matthew Williford Sr., tribal chairperson of the Konkow Valley Band of Maidu, shook his head as he stood on a dirt road overlooking the fire-ravaged Concow Basin, separated from Paradise by just one canyon.

“Nature needs help too, just like we need help from nature,” he said. “We don’t understand that because we went another way. We lost connection with the land. That’s why.”

“This is 3A,” he said, referring to the Forest Service’s name for this plot. “We have a tribal name for it — it’s called the Place of the Grasshoppers.”

Growing up, Williford heard stories of ancestors catching giant grasshoppers, wrapping them in a maple leaf, adding a berry, then roasting them in fire and eating them like popcorn.

But those grasshoppers were long gone.

Matthew Williford Sr., tribal chairperson of the Konkow Valley Band of Maidu, stands in front of a hand-made burn pile in the Dogwood District of Plumas National Forest.

(Sara Nevis / For The Times)

California outlawed cultural fire in 1850, the year it became a state. The forests grew dense. Conifers took over the oaks. The plants and animals Williford’s ancestors held relationships with became strangers.

Then everything burned.

The Forest Service began increasingly approaching the tribe for help.

With the blessing and support of the Forest Service, the tribe began working to restore parts of its homeland — not as a shrubland, or thick conifer forest, but an open and free tapestry anchored by oaks.

For the work, the tribe has sometimes leaned on herbicide — particularly to kill ornamental French and Spanish broom, which are invasive. The alternative, digging it up, risks damaging cultural sites.

Matthew Williford Sr. points out a native plant in the Concow Basin.

(Sara Nevis / For The Times)

On plot 3A, the tribe worked with the Forest Service to grow oaks and bring back good fire.

One day, Williford stopped by 3A.

As he hopped back into his truck, a loud buzzing startled him. His truck was covered in giant grasshoppers.

“It’s just getting the land to trust us and to see that we’re here to help it — like we used to,” he said. “The land will respond. There’s no doubt about it.”

The lithium-ion batteries that supply much of today’s clean energy come with some infamous drawbacks, from fire risk to reliance on foreign mining.

Alternatives have been slow to get off the ground.

But California startup Peak Energy announced Wednesday it’s building a factory in Sacramento that will be the first in the U.S. to make sodium-ion battery packs at commercial scale.

Sodium-ion batteries have long held promise. They are made from cheap and abundant sodium ash deposits. The materials are less prone to overheating, so they don’t have the fire risk of lithium.

But they also store less energy per cubic inch. That means they have to be bigger and heavier, which makes them harder to fit into electric vehicles. So far, they’ve struggled to compete.

Peak Energy thinks it has an edge. The company focuses on storage systems big enough to power large data centers, factories and whole segments of the grid, where battery size matters less.

The company already delivers battery packs out of a small pilot project in San Francisco, but it has gotten $1.1 billion in preorders and now needs more space.

CEO and co-founder Landon Mossburg said its first products, each about the size of a shipping container, will begin rolling out in early 2027.

“We’re a 3-year-old company with over a billion in deposit-backed customer contracts, we’ve got grid deployment already, and all those products are exceeding expectations on the grid,” Mossburg said. “Those are really great signals.”

He founded Peak after working at Tesla and the now-folded Swedish battery company Northvolt. The battery cells, which make up the systems, will come from China.

Customers for Peak who have put down a deposit include independent power providers Jupiter Power, Energy Vault and RWE Americas, who are connecting utilities, and increasingly data centers, with batteries. Peak also works with utilities directly including one unnamed customer in California, and is “in fairly advanced discussions with two of the major hyperscalers,” Mossburg said.

Not everyone is so optimistic about the technology. Lithium-ion batteries are still cheaper, at least up front.

“Sodium-ion batteries attracted considerable interest when lithium-ion battery prices surged in 2022,” said Isshu Kikuma, an energy storage analyst at BloombergNEF. Since then, he noted, those prices have come down.

And as with lithium-ion battery chemistry, Asian manufacturers already have an edge.

“Sodium-ion cells are currently exclusively manufactured on a commercial scale within China,” said Evan Hartley, a research manager at the Benchmark Minerals consulting firm. Large producers such as BYD and CATL are spending enormous amounts to research and develop new products, he said.

Other U.S.-based sodium-ion startups have floundered of late. Natron Energy canceled plans to produce sodium-ion battery cells in North Carolina last year after funding difficulties. Bedrock Materials, which was making sodium-ion batteries for EVs, also closed up shop, citing a bet on a lithium supply shortage that hadn’t panned out.

But Peak Energy’s model is different, Mossburg said. Unlike Natron, it won’t be trying to make the batteries that go into their systems at first. They’ll import them, initially from China and later from other countries in Asia.

“While working at Tesla, I saw the advantage of focusing on a great end product that customers want before you try to bite off more of the scope,” Mossburg said.

Last month, Peak announced a partnership with General Motors to develop their own cells.

Once up and running, Peak Energy’s Sacramento factory will make three to four battery systems per day, each filled with almost 8,000 battery cells. One system can power hundreds of homes for four hours, Mossburg said. Customers will deploy tens or hundreds in a single project, “basically creating a power-plant sized battery” that can store power and supply the grid when energy is expensive, or directly serve facilities like data centers.

Although sodium-ion batteries cost more than lithium ones, Mossburg said Peak Energy’s battery systems still save customers money: The technology does not heat up like lithium, so it eliminates the need for expensive cooling technology.

“Because lithium-ion needs to actively cool, you’re basically paying to refrigerate your batteries or using energy to refrigerate your batteries, and we don’t need any of that stuff,” said Mossburg.

The upshot is a battery that’s cheaper, quieter, and safer.

“Safety is a major advantage for sodium-ion batteries,” Kikuma said.

That could matter in California, where battery opposition has surged after a fire at a Moss Landing energy storage facility drove the evacuation of 1,200 residents and contaminated nearby wetlands.

California has typically been a hub of battery research and development, not manufacturing. Mossburg said Peak Energy, which also has offices in Colorado, chose Sacramento for its proximity to a talented workforce, a growing energy storage market and the company’s engineering teams in Burlingame. He said the factory would create 239 new jobs.

The company hasn’t received any federal clean energy tax credits, but it got a $10.5-million tax credit from the state of California.

While sodium-ion is likely to remain a small fraction of the global battery market, Kikuma said stationary energy storage is one of the fastest growing applications for sodium-ion batteries.

Mossburg sees Peak as being ahead in this corner of the market.

“Everybody from CATL to GM have sort of validated now what we’re doing,” he said. “The market is trying to catch up.”