What you need to know about cyclosporiasis: How it spreads, how it’s treated
Cyclospora cayetanensis is a unicellular parasite that causes an intestinal infection called cyclosporiasis. (CDC)
(NEW YORK) — Multiple states are reporting an increase in cyclosporiasis cases, an intestinal infection caused by a parasite.
Health officials in Michigan have reported more than 1,200 cases and, in neighboring Ohio, cases have topped 170.
Here’s what you need to know about the infection, including how it spreads, how it’s diagnosed and how to treat it.
What is Cyclosporiasis?
Cyclosporiasis is an intestinal infection caused by the microscopic parasite Cyclospora cayetanensis, also known as Cyclospora, according to the Centers for Disease Control and Prevention (CDC).
The infection affects the small intestine and can cause watery diarrhea with sometimes “explosive” bowel movements, according to the federal health agency.
Other symptoms can include cramping, bloating, low-grade fever, nausea and vomiting.
The agency further said it takes about one week from the time of infection to become symptomatic, but that time can range from two days to two weeks.
How it spreads
The parasite usually spreads through food or water contaminated with feces, according to the CDC.
Foodborne outbreaks of cyclosporiasis have been linked to various types of imported fresh produce, such as raspberries, basil, snow peas, mesclun lettuce and cilantro, according to the CDC.
How the infection is diagnosed
A healthcare provider will diagnose cyclosporiasis by testing stool samples, according to the CDC.
Patients may have to submit several stool samples on different days to detect the parasite because laboratory tests may have a hard time detecting Cyclospora.
The CDC says a patient’s healthcare provider will need to specifically request testing for the parasite.
How cyclosporiasis is treated
Cyclosporiasis is treated with the oral antibiotic trimethoprim-sulfamethoxazole (TMP-SMX), commonly sold as Bactrim, Septra and Cotrim, and taken for 10 days, according to the CDC.
The CDC says most people with healthy immune systems will eventually recover without treatment, but if left untreated, patients may be sick for a few days to a month or longer.
How to prevent infection
It’s unclear exactly how Cyclospora contaminates food and water, according to the CDC.
The agency says people can prevent infection by thoroughly washing produce, cutting away bruised or damaged parts of fruits and vegetables, and refrigerating pre-prepared or pre-cut produce.
Additionally, the CDC recommends washing hands thoroughly with soap and water before handling or preparing raw fruits and vegetables.
Medical staff direct some of the last passengers to be evacuated from the MV Hondius on May 11, 2026, in Tenerife, part of the Canary Islands, Spain. (Chris Mcgrath/Getty Images)
(NEW YORK) — Health experts tell ABC News that the current science behind the hantavirus that circulated throughout the MV Hondius does not show the same levels of transmission as with COVID-19, while acknowledging that the scenario may seem similar to the beginning of the 2020 pandemic.
“Our current understanding is that person-to-person transmission of Andes virus is relatively rare and generally associated with prolonged close contact,” the current Centers for Disease Control and Prevention public health assessment said. “There is also no documented evidence of presymptomatic transmission.”
Officials around the globe have taken major steps to prevent the spread of the hantavirus, and an American doctor who was onboard noted how conditions on the cruise ship may have helped the virus propagate.
In the U.S., the boat’s 18 American passengers have been put in quarantine in Nebraska, while more than 40 people with exposure to the sick are being monitored to see if they develop the illness.
“In the vast majority of cases it happens when people breathe in mouse secretions,” Dr. Emily Abdoler, a clinical associate professor of medicine at the University of Michigan, who specializes in infectious diseases, told ABC News.
“The Andes strain found in Chile and Argentina has the possibility of human-to-human transmission, but that’s really more really close contact. It’s not sharing the same household,” she added. “It’s more like sharing the same bed.”
Dr. Stephen Kornfeld, an American oncologist who became the ship’s de facto doctor after the Hondius’ physician contracted the virus, initially received inconclusive results with samples taken from the ship but later tested negative.
Speaking to ABC News from his quarantine on Thursday, Kornfeld noted that conditions on the ship — including ventilation and the size of rooms — could have created a “complicated” situation for transmission while observing some social casual contact.
“If you do have casual contact, you’re doing it repetitively,” he said. “There were three rooms that we would gather in many times a day, often for an hour or an hour and a half, for lectures and discussions and meals. And I can just envision lots of frequent casual contacts, and perhaps over time that adds up to something more than just a single casual contact.”
Abdoler, who helped diagnose a case of hantavirus in Michigan in 2021 — the type we have in the U.S. that does not spread between people –said the benefit that medical professionals and agencies, such as the World Health Organization, have now is that the hantavirus has been researched for over 30 years. It is not a new virus.
While the data around the Andes strain believed to have been on the boat is still limited given the rare number of cases outside of South America, Abdoler said there does not appear to be any indication that the transmission methods have changed for the Andes strain.
ABC News medical contributor and epidemiologist Dr. John Brownstein concurred, saying that previous research suggests the hantavirus is a respiratory illness. That means germs can be coughed up, he noted, but it is not an aerosol-based virus.
“It’s not like COVID or measles where it could linger in the air for some time,” he said.
Brownstein added that the incubation period for the virus is long, and despite the lower risk for person-to-person transmission, it is critical that health officials stick to their policies to isolate and monitor anyone connected to the Hondius. Isolation can then be initiated if they become a positive case.
“Incubation can be anywhere from one to eight weeks,” he noted.
During a news briefing Friday, WHO officials stressed that said there is no evidence so far that the virus has changed to become more transmissible or more severe.
Officials said transmission is believed to be based on several factors, including how infectious the patient is, the environment and whether protection and PPE was used.
On Friday, acting Centers for Disease Control and Prevention director Jay Bhattacharya told reporters no cases of hantavirus have been reported in the U.S.
There are now at least 10 cases that have been linked to the ship’s outbreak. Two passengers died from the virus and a third death has been deemed probable by WHO.
Sixteen Hondius passengers, including Kornfeld, initially were flown to the quarantine center at the University of Nebraska Medical Center and had not shown any symptoms as of early Friday. Kornfeld had been placed in a biocontainment unit at the facility.
Two other American passengers were flown to Atlanta for “assessment and care,” according to officials. They were later transferred to the quarantine unit in Nebraska on Friday.
The remainder of the passengers are in quarantine at home and are being monitored.
WHO warned more positive cases could still appear during quarantine because the virus’ incubation period is long, but said that would not necessarily mean the outbreak is growing.
Abdoler noted that the fact that there have not been as many positive cases from the ship and their contacts shows that the data about the Andes transmission is holding up and there are no signs that the virus can spread as easily as other pathogens.
She noted that he is glad that the risk is being taken seriously and that those that have been exposed are being monitored.
“My sense is that there is no really need to panic, but [WHO] is taking a very conservative approach to the outbreak and asking everyone to isolate during the intubation period,” she said.
“I think it is good they are taking a conservative approach because there are unknowns, but I am not personally altering my personal practices of travel or how I go out,” she added.
– ABC News’ Dragana Jovanovic contributed to this report.
A sign outside a mobile clinic offering measles and flu vaccinations on February 6, 2026 in Spartanburg, South Carolina. (Sean Rayford/Getty Images)
(NEW YORK) — A few months ago, a measles outbreak seemed poised to overwhelm the northern region of South Carolina.
More than 100 infections were being reported every week, with the total eventually surpassing that of last year’s record-setting outbreak in Texas.
However, after six months and nearly 1,000 cases, the outbreak took a dramatic turn in the right direction.
Over the weekend, the South Carolina Department of Public Health said no new cases had been confirmed for 42 days, leading to an announcement on Monday that the outbreak is officially over.
Public health experts told ABC News that the combination of a strong vaccination push, people following isolation and quarantine orders and an awareness campaign helped beat back the disease.
“Measles vaccinations [were] the most effective single containment tool,” Dr. James Harber, an internal medicine physician with Spartanburg Regional Medical Center, told ABC News. “And then to identify the index cases and their exposures and enforcing quarantine, and there’s that integrated public health and private sector collaboration. Those are the keys.”
Vaccination push
The Centers for Disease Control and Prevention (CDC) currently recommends people receive two doses of the measles, mumps, rubella (MMR) vaccine — the first at ages 12 to 15 months and the second between 4 and 6 years old.
One dose is 93% effective, and two doses are 97% effective against measles, according to the CDC.
In Spartanburg County — the epicenter of the outbreak in northwestern South Carolina — 88.9% of students had the required immunizations needed to attend school, among the lowest in the state, according to state health department data.
This is lower than the 95% threshold needed to achieve herd immunity.
In the wider Upstate region of South Carolina, some pockets have much lower vaccination rates. State data shows that, for the 2025-2026 school year, one elementary and middle school only had 17% of students with the required immunizations.
Of the 997 cases during the outbreak, 932 were among unvaccinated individuals who were mostly under the age of 17, state data shows. Experts told ABC News that a vaccination campaign helped play a big role in reigning in cases.
“We believe vaccination is one of the primary reasons this outbreak came to an end,” Dr. Brannon Traxler, deputy director of health promotion and services and chief medical officer at the state health department, told ABC News. “Thousands of people got vaccinated. An additional 3,788 doses of MMR were administered in Spartanburg County during the six months of the outbreak compared to the previous year.”
Traxler said that 15,000 additional doses were administered in the Upstate counties over this period competed to the year prior.
She added that January and February were record months for MMR vaccination in the state.
The health department does not track vaccine exemptions at the individual level, but Spartanburg Regional Medical Center’s Harber believes some vaccine-hesitant parents were encouraged to vaccinate their children — even those with previous exemptions on file — as the outbreak grew and their kids were exposed to the virus.
“I think the numbers … speak to the idea that that definitely happened,” he said. “Parents and/or young people who have historically requested and been granted exemptions and not been vaccinated saw what was happening within the community and then changed their minds.”
People following isolation, quarantine orders
South Carolina health authorities first confirmed the outbreak on Oct. 2, 2025, after eight cases were recorded in the Upstate region.
Most cases were recorded in Spartanburg County, with some confirmed in neighboring Anderson, Cherokee, Greenville and Pickens counties.
Only two other counties that didn’t border the epicenter saw measles cases: Lancaster County in the north central area and Sumter County in the central area.
Harber said that people generally followed health officials’ orders about quarantine and isolation, which helped keep the outbreak under control
“I think that’s probably the second most important part, the very aggressive quarantine and exposure control when index cases were identified,” he said. “They were very quickly provided with information around isolation and what they needed to do — staying away from others and to help prevent that spread.”
Harber said more than 2,000 quarantine orders were issued and almost 900 students stayed home when they tested positive across 33 schools in the Upstate region.
“That rapid identification and isolation of the suspected cases .. once they were confirmed really helped to prevent that secondary spread that is such a big problem because of how contagious [measles] really is,” he said. “So, we really had great compliance especially within families and that really helped shorten transmission window based on all the data we have.”
Awareness campaigns
Traxler said the state health department conducted wide-range outreach in Spartanburg County and surrounding areas to “educate the public about the facts regarding measles and the outbreak as well as to encourage people to consider being vaccinated to get long-term protection against the virus.”
She noted that the department communicated with schools, churches, community-based organizations, community leaders, local health care professionals and other organizations.
Traxler added that the health department offered vaccinations at mobile health units at libraries, churches and other locations, where workers also distributed educational materials.
Ukrainian and Russian-speaking communities in South Carolina were hard hit by measles during the outbreak, and so the health department translated measles fact sheets and vaccine information into Ukrainian and Russian, as well as Spanish, Traxler said.
However, just because the outbreak is over doesn’t mean the work is done, she added.
Other states are continuing to see measles cases and the U.S. is currently at risk of losing its elimination status, which it earned in 2000. Measles would once again be considered endemic or constantly circulating.
“The outbreak is over, but our work to understand and prevent measles is not. Large outbreaks of measles, and other infectious diseases, can be prevented entirely when vaccine coverage in the population is very high,” Traxler said.
The Food and Drug Administration headquarters is shown in White Oak, Md. (Al Drago/CQ Roll Call via Getty Images, FILE)
(NEW YORK) — The Food and Drug Administration (FDA) approved the drug Auvelity this week for the treatment of agitation in adults with Alzheimer’s dementia.
The extended-release tablet is the first FDA-approved medication for this condition that is not an anti-psychotic.
Anti-psychotics carry serious risks including stroke, sedation and increased death in older adults, according to the FDA. Having a non-antipsychotic option may be safer for patients, experts say.
“We’ve needed a drug like this for decades, because agitation related to Alzheimer’s disease is one of the most challenging, disheartening symptoms that we manage,” Dr. Richard Issacson, director of research at the Institute of Neurodegenerative Diseases in Florida, told ABC News. “This new drug would be used because their tolerability profile is better.”
Auvelity was initially approved by the FDA in 2022 to treat major depressive disorder in adults. It carries a boxed warning for a higher risk of suicidal thoughts in teens and young adults taking antidepressants.
However, two recent randomized clinical trials found that the drug improved agitation symptoms in patients with dementia and Alzheimer’s disease based on caregiver reports and survey data, and helped delay relapse compared to a placebo.
Studies show the drug works by affecting brain chemicals such as glutamate and dopamine to help calm the overactive signals in the brain linked to agitation. Reported side effects include dizziness, nausea, headache, dry mouth, sweating and diarrhea.
The FDA cautions that Auvelity can worsen or reveal suicidal thoughts and behaviors, especially when starting the medication. It may also worsen irritability or mania in some patients. It’s additionally been linked to an increased risk for seizures, especially at higher doses, and may increase blood pressure.
Clinicians should closely monitor patients when initiating this treatment and throughout the treatment course, experts advise.
As of 2026, about 7.4 million Americans aged 65 and older are living with Alzheimer’s dementia, according to the Alzheimer’s Association. This number is expected to grow to 13.8 million by 2060.
Studies show the drug works by affecting brain chemicals such as glutamate and dopamine to help calm the overactive signals in the brain linked to agitation. Reported side effects include dizziness, nausea, headache, dry mouth, sweating and diarrhea.
The FDA cautions that Auvelity can worsen or reveal suicidal thoughts and behaviors, especially when starting the medication. It may also worsen irritability or mania in some patients. It’s additionally been linked to an increased risk for seizures, especially at higher doses, and may increase blood pressure.
Clinicians should closely monitor patients when initiating this treatment and throughout the treatment course, experts advise.
As of 2026, about 7.4 million Americans aged 65 and older are living with Alzheimer’s dementia, according to the Alzheimer’s Association. This number is expected to grow to 13.8 million by 2060.
Agitation is one of the most common and burdensome symptoms for those with Alzheimer’s dementia. A JAMA Neurology study found that 50 to 60% of people with Alzheimer’s experience agitation symptoms at some point.
Issacson said there needs to be more hope for Alzheimer’s patients and their loved ones.
“We also know that it’s not just about drugs. People can exercise, live a healthy lifestyle, eat a Mediterranean style diet, and manage risk factors like blood pressure, cholesterol, and diabetes,” Issacson said. “People can really take control of their brain health, reduce their risk of Alzheimer’s and have better treatment outcomes. There’s hope and there’s so much education and information now online. I think we’re making a lot of progress.”
Dr. Crystal Joseph, MD, MS is an anesthesiology resident at Beth Israel Deaconess Medical Center/Harvard Medical School and a member of the ABC News Medical Unit.
