Boar’s Head Provisions Co. recalled its liverwurst because it may be tainted with the listeria bacteria, the U.S. Agriculture Department said. The company is also recalling additional deli meats that were produced on the same line and on the same day as the liverwurst.

The USDA said a sample of Boar’s Head liverwurst from a Maryland store tested positive for listeria. The sample was from an unopened package, collected by the Maryland Department of Health as part of an investigation into the listeria outbreak.

Testing is underway to determine if the liverwurst sample is connected to the outbreak, health officials said.

The outbreak was first reported last week. As of Thursday, 34 people were sickened, with all but one hospitalized. Two people died.

People most commonly reported eating deli-sliced turkey, liverwurst and ham, officials said.

Listeria can contaminate food and sicken people who eat it. Symptoms include fever, muscle aches, nausea and diarrhea. It can be treated with antibiotics, but it is especially dangerous to pregnant women, newborns, the elderly and those with compromised immune systems.

An estimated 1,600 people get listeria food poisoning each year and about 260 die, according to the Centers for Disease Control and Prevention.

The Boar’s Head recall includes a number of products stamped with an August 10 sell-by date, including bologna, garlic bologna, beef bologna, beef salami, Italian Cappy-style ham and Extra Hot Italian Cappy-style ham. Also included is Steakhouse Roasted Bacon Heat and Eat, with a sell-by date of Aug. 15.

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.

NEW YORK (AP) — U.S. health officials on Tuesday warned doctors to be alert for dengue cases as the tropical disease breaks international records.

The virus, which is spread by mosquitoes, has been surging worldwide, helped by climate change. In barely six months, countries in the Americas have already broken calendar-year records for dengue cases.

The World Health Organization declared an emergency in December, and Puerto Rico declared a public health emergency in March.

Dengue remains less common in the continental United States, but in the 50 states so far this year there have been three times more cases than at the same point last year. Most were infections that travelers got abroad, and officials note there is no evidence of a current outbreak. But they also warn that local mosquitos pose a threat.

In its health alert Tuesday, the Centers for Disease Control and Prevention advised doctors to know the symptoms, ask questions about where patients recently traveled and consider ordering dengue tests when appropriate.

Dengue (pronounced DEHN’-gay) is caused by a virus spread by a type of warm weather mosquito that is expanding its geographic reach because of climate change, experts say.

Many infected people don’t get sick, but some experience headache, fever and flu-like symptoms. Severe cases can involve cause serious bleeding, shock and death.

Repeated infections can be especially dangerous.

There are four types of dengue virus, simply known as 1, 2, 3 and 4. When someone is first infected, their body builds antibodies against that type for life. If they get infected with another type of dengue, the antibodies from the first infection may fail to neutralize the second type — and actually can help the virus enter immune cells and replicate.

That’s a concern in Puerto Rico, which for the last two decades has been widely exposed to type 1. Last month, the island reported its first dengue death of the year.

“We’re currently seeing is increases in the cases due to dengue 2 and dengue 3, for which the population has very little immunity,” said Dr. Gabriela Paz-Bailey, the Puerto-Rico-based chief of the CDC’s dengue branch.

There is no widely available medicine for treating dengue infections.

Vaccines have been tricky. U.S. officials in 2021 recommended one vaccine, made by Sanofi. The three-dose vaccine is built to protect against all four dengue types and is recommended only for children ages 9 to 16 who have laboratory evidence of an earlier dengue infection and who live in an area — like Puerto Rico — where dengue is common.

Given those restrictions and other issues, it hasn’t been widely used. As of late last month, only about 140 children had been vaccinated in Puerto Rico since shots became available there in 2022, and Sanofi Pasteur has told the CDC it is going to stop making the vaccine.

A different vaccine made by the Tokyo-based pharmaceutical company Takeda is not currently licensed in the U.S. Others are in development.

Across the world, more than 6.6 million infections were reported by about 80 countries last year. In the first four months of this year, 7.9 million cases and 4,000 deaths have been reported, according to the World Health Organization. It’s been particularly intense in the Americas, including in Brazil and Peru.

In the United States, the numbers have been far more modest — about 3,000 cases last year in U.S. states and territories. But it was the worst in a decade, and included more infections that occurred locally, courtesy of native mosquitoes. Most were in Puerto Rico, but about 180 were in three U.S. states — Florida, Texas and California.

So far this year, there have been nearly 1,500 locally-acquired U.S. cases, nearly all of them in Puerto Rico.

Most cases in the continental U.S. continue to be people who were infected while traveling internationally.

It’s “a traveler’s nightmare” and a growing international concern, said Dr. Lulu Bravo, who studies pediatric tropical diseases at the University of the Philippines Manila and who has worked with Takeda on its vaccine.

“When you have an outbreak in a country, tourists might not want to come,” Bravo said.

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Agency officials noted the data is provisional and could change after more analysis, but that they still expect a drop when the final counts are in. It would be only the second annual decline since the current national drug death epidemic began more than three decades ago.

Experts reacted cautiously. One described the decline as relatively small, and said it should be thought more as part of a leveling off than a decrease. Another noted that the last time a decline occurred — in 2018 — drug deaths shot up in the years that followed.

“Any decline is encouraging,” said Brandon Marshall, a Brown University researcher who studies overdose trends. “But I think it’s certainly premature to celebrate or to draw any large-scale conclusions about where we may be headed long-term with this crisis.”

It’s also too soon to know what spurred the decline, Marshall and other experts said. Explanations could include shifts in the drug supply, expansion of overdose prevention and addiction treatment, and the grim possibility that the epidemic has killed so many that now there are basically fewer people to kill.

CDC Chief Medical Officer Dr. Deb Houry called the dip “heartening news” and praised efforts to reduce the tally, but she noted “there are still families and friends losing their loved ones to drug overdoses at staggering numbers.”

About 107,500 people died of overdoses in the U.S. last year, including both American citizens and non-citizens who were in the country at the time they died, the CDC estimated. That’s down 3% from 2022, when there were an estimated 111,000 such deaths, the agency said.

The drug overdose epidemic, which has killed more than 1 million people since 1999, has had many ripple effects. For example, a study published last week in JAMA Psychiatry estimated that more than 321,000 U.S. children lost a parent to a fatal drug overdose from 2011 to 2021.

“These children need support,” and are at a higher risk of mental health and drug use disorders themselves, said Dr. Nora Volkow, director of the National Institute on Drug Abuse, which helped lead the study. “It’s not just a loss of a person. It’s also the implications that loss has for the family left behind.”

Prescription painkillers once drove the nation’s overdose epidemic, but they were supplanted years ago by heroin and more recently by illegal fentanyl. The dangerously powerful opioid was developed to treat intense pain from ailments like cancer but has increasingly been mixed with other drugs in the illicit drug supply.

For years, fentanyl was frequently injected, but increasingly it’s being smoked or mixed into counterfeit pills.

A study published last week found that law enforcement seizures of pills containing fentanyl are rising dramatically, jumping from 44 million in 2022 to more than 115 million last year.

It’s possible that the seizures indicate that the overall supply of fentanyl-laced pills is growing fast, not necessarily that police are whittling down the illicit drug supply, said one of the paper’s authors, Dr. Daniel Ciccarone of the University of California, San Francisco.

He noted that the decline in overdoses was not uniform. All but two of the states in the eastern half of the U.S. saw declines, but most western states saw increases. Alaska, Washington, and Oregon each saw 27% increases.

The reason? Many eastern states have been dealing with fentanyl for about a decade, while it’s reached western states more recently, Ciccarone said.

Nevertheless, some researchers say there are reasons to be optimistic. It’s possible that smoking fentanyl is not as lethal as injecting it, but scientists are still exploring that question.

Meanwhile, more money is becoming available to treat addiction and prevent overdoses, through government funding and also through legal settlements with drugmakers, wholesalers and pharmacies, Ciccarone noted.

“My hope is 2023 is the beginning of a turning point,” he said.

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AP medical writer Carla K. Johnson contributed to this report.

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U.S. health and agriculture officials pledged nearly $200 million in new spending and other efforts Friday to help track and contain an outbreak of bird flu in the nation’s dairy cows that has spread to more than 40 herds in nine states.

The new funds include $101 million to continue work to prevent, test, track and treat animals and humans potentially affected by the virus known as Type A H5N1, the U.S. Department of Health and Human Services said. And they include about $98 million to provide up to $28,000 each to help individual farms test cattle and bolster biosecurity efforts to halt the spread of the virus, according to the Agriculture Department.

In addition, dairy farmers will be compensated for the loss of milk production from infected cattle, whose supply drops dramatically when they become sick, officials said. And dairy farmers and farm workers would be paid to participate in a workplace study conducted by the USDA and the Centers for Disease Control and Prevention.

So far, farmers have been reluctant to allow health officials onto their farms to test cattle because of uncertainty about how it would affect their businesses, researchers have said. Also, farm workers, including many migrant workers, have been reluctant to be tested for fear of missing work or because they didn’t want to be tracked by the government.

The National Milk Producers Federation, a trade group representing dairy farmers, said they welcomed the new resources. “Care for farm workers and animals is critical for milk producers, as is protecting against potential human health risks and reassuring the public,” the group said in a statement.

The incentives should help increase farmers’ willingness to test their herds, said Keith Poulsen, director of the Wisconsin Veterinary Diagnostic Laboratory, who has been monitoring the outbreak.

“It provides the latitude and capacity to start going in the right direction,” he said.

The new spending comes more than six weeks after the first-ever detection of an avian bird flu virus in dairy cattle — and one confirmed infection in a Texas dairy worker exposed to infected cows who developed a mild eye infection and then recovered. About 33 people have been tested and another 260 are being monitored, according to the CDC.

As of Friday, 42 herds in nine states have confirmed infections in dairy cows. Agriculture Secretary Tom Vilsack said that the outbreak has not spread more widely.

“It’s still in the same nine states and that’s the most positive thing about where we are,” he told reporters.

Samples of grocery store milk tested by the U.S. Food and Drug Administration showed remnants of the virus in about 1 in 5 samples of retail milk nationwide, however, suggesting that the outbreak could be more widespread, scientists have said.

Under a federal order issued last month, farmers are required to test lactating dairy cattle for H5N1 before the animals are moved between states. The Agriculture Department said Friday that 112 out of 905 tests conducted between April 29 and May 5 by federal animal health laboratories appeared to be positive. Officials could not say how many cows tested positive because multiple samples may have been collected from a single cow. Labs are conducting about 80 more tests per day than before the order took effect, an Agriculture Department spokesman said.

About 50,000 dairy cattle typically cross state lines every week, Poulsen estimates.

The FDA found that pasteurization, or heat-treating, killed the virus in the grocery samples of milk, cottage cheese and sour cream. The agency reiterated warnings that people should not consume raw, or unpasteurized milk, because of possible risk from the virus. Officials on Friday also said they expect results soon from tests of pooled raw milk samples sent to commercial processors to “determine potential levels of virus that pasteurization must eliminate.” The USDA found no evidence of the virus in a small sample of retail ground beef.

“The risk to the public from this outbreak remains low,” Health and Human Services Secretary Xavier Becerra said.

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This story has been updated to clarify the count of H5N1 test results in U.S. cattle. The Agriculture Department initially told reporters 80 cows were tested between April 29 and May 5. The department later said it collected 905 samples, and that 112 appeared to be positive. It could not provide the number of cows tested because multiple samples may have been collected from a single cow.

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NEW YORK (AP) — All dogs coming into the U.S. from other countries must be at least 6 months old and microchipped to help prevent the spread of rabies, according to new government rules published Wednesday.

The new rules require vaccination for dogs that have been in countries where rabies is common. The update applies to dogs brought in by breeders or rescue groups as well as pets traveling with their U.S. owners.

“This new regulation is going to address the current challenges that we’re facing,” said Emily Pieracci, a rabies expert at the Centers for Disease Control and Prevention who was involved in drafting the updated regulations.

The CDC posted the new rules in the federal register on Wednesday. They take effect Aug. 1 when a temporary 2021 order expires. That order suspended bringing in dogs from more than 100 countries where rabies is still a problem.

The new rules require all dogs entering the U.S. to be at least 6 months, old enough to be vaccinated if required and for the shots to take effect; have a microchip placed under their skin with a code that can be used to verify rabies vaccination; and have completed a new CDC import form.

There may be additional restrictions and requirements based on where the dog was the previous six months, which may include blood testing from CDC-approved labs.

The CDC regulations were last updated in 1956, and a lot has changed, Pieracci said. More people travel internationally with their pets, and more rescue groups and breeders have set up overseas operations to meet the demand for pets, she said. Now, about 1 million dogs enter the U.S. each year.

Dogs were once common carriers of the rabies virus in the U.S. but the type that normally circulates in dogs was eliminated through vaccinations in the 1970s. The virus invades the central nervous system and is usually a fatal disease in animals and humans. It’s most commonly spread through a bite from an infected animal. There is no cure for it once symptoms begin.

Four rabid dogs have been identified entering the U.S. since 2015, and officials worried more might get through. CDC officials also were seeing an increase of incomplete or fraudulent rabies vaccination certificates and more puppies denied entry because they weren’t old enough to be fully vaccinated.

A draft version of the updated regulations last year drew a range of public comments.

Angela Passman, owner of a Dallas company that helps people move their pets internationally, supports the new rules. It can especially tricky for families that buy or adopt a dog while overseas and then try to bring it to the U.S., she said. The update means little change from how things have been handled in recent years, she said.

“It’s more work for the pet owner, but the end result is a good thing,” said Passman, who is a board member for the International Pet and Animal Transportation Association.

But Jennifer Skiff said some of the changes are unwarranted and too costly. She works for Animal Wellness Action, a Washington group focused on preventing animal cruelty that helps organizations import animals. She said those groups work with diplomats and military personnel who have had trouble meeting requirements, and was a reason some owners were forced to leave their dogs behind.

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NEW YORK (AP) — U.S. deaths of moms around the time of childbirth have fallen back to pre-pandemic levels, new government data suggests.

About 680 women died last year during pregnancy or shortly after childbirth, according to provisional CDC data. That’s down from 817 deaths in 2022 and 1,205 in 2021, when it was the highest level in more than 50 years.

COVID-19 seems to be the main explanation for the improvement, said Donna Hoyert, a Centers for Disease Control and Prevention maternal mortality researcher.

The coronavirus can be particularly dangerous to pregnant women. And, in the worst days of the pandemic, burned out physicians may have added to the risk by ignoring pregnant women’s worries, experts say.

Fewer death certificates are mentioning COVID-19 as a contributor to maternal deaths. The count was over 400 in 2021 but fewer than 10 last year, Hoyert said.

The agency on Thursday released a report detailing the final maternal mortality data for 2022. It also recently released provisional data for 2023. Those numbers are expected to change after further analysis — the final 2022 number was 11% higher than the provisional one. Still, 2023 is expected to end up down from 2022, Hoyert said.

The CDC counts women who die while pregnant, during childbirth and up to 42 days after birth from conditions considered related to pregnancy. Excessive bleeding, blood vessel blockages and infections are leading causes.

There were about 19 maternal deaths for every 100,000 live births in 2023, according to the provisional data. That’s in line with rates seen in 2018 and 2019.

But racial disparities remain: The death rate in Black moms is more than two-and-a-half times higher than that of white and Hispanic mothers.

“In the last five years we’ve really not improved on lowering the maternal death rate in our country, so there’s still a lot of work to do,” said Ashley Stoneburner, the March of Dimes’ director of applied research and analytics.

The advocacy organization this week kicked off an education campaign to get more pregnant women to consider taking low-dose aspirin if they are at risk of preeclempsia — a high blood pressure disorder that can harm both the mother and baby.

There are other efforts that may be helping to lower deaths and lingering health problems related to pregnancy, including stepped-up efforts to fight infections and address blood loss, said Dr. Laura Riley, a New York City-based obstetrician who handles high-risk pregnancies.

But there’s a risk that those kinds of improvements are being offset by a number of factors that may reduce the ability of women to get medical care before, during and after a birth, she said. Experts say the list includes the closure of rural hospitals and a 2022 U.S. Supreme Court decision that did away with the federally established right to abortion — and contributed to physician burnout by causing doctors to feel constrained about providing care during pregnancy-related medical emergencies.

“I think there’s good news. We’re making strides in certain areas,” said Riley, head OB-GYN at Weill Cornell Medicine. “But the bad news and scary news is … there are these other political and social forces that make this (reducing maternal deaths) difficult.”

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.

Measles outbreaks in the U.S. and abroad are raising health experts’ concern about the preventable, once-common childhood virus.

One of the world’s most contagious diseases, measles can lead to potentially serious complications. The best defense, according to experts? Get vaccinated.

Here’s what to know about the year — so far — in measles.

How many measles cases has the U.S. seen this year?

Nationwide, measles cases already are nearly double the total for all of last year.

The U.S. Centers of Disease Control and Prevention documented 113 cases as of April 5. There have been seven outbreaks and most of U.S. cases — 73% — are linked to those flare-ups.

Still, the count is lower than some recent years: 2014 saw 667 cases and 2019 had 1,274.

Why is this a big deal?

The 2019 measles epidemic was the worst in almost three decades, and threatened the United States’ status as a country that has eliminated measles by stopping the continual spread of the measles virus.

The CDC on Thursday released a report on recent measles case trends, noting that cases in the first three months of this year were 17 times higher than the average number seen in the first three months of the previous three years.

While health officials seem to be doing a good job detecting and responding to outbreaks, “the rapid increase in the number of reported measles cases during the first quarter of 2024 represents a renewed threat to elimination,” the report’s authors said.

Where is measles coming from?

The disease is still common in many parts of the world, and measles reaches the U.S. through unvaccinated travelers.

According to Thursday’s report, most of the recent importations involved unvaccinated Americans who got infected in the Middle East and Africa and brought measles back to the U.S.

Where were this year’s U.S. measles outbreaks?

Health officials confirmed measles cases in 17 states so far this year, including cases in New York City, Philadelphia and Chicago.

More than half of this year’s cases come from the Chicago outbreak, where 61 people have contracted the virus as of Thursday, largely among people who lived in a migrant shelter.

The city health department said Thursday that cases are on the decline after health officials administered 14,000 vaccines in just over a month.

How does measles spread?

Measles is highly contagious. It spreads when people who have it breathe, cough or sneeze and through contaminated surfaces. It also can linger in the air for two hours.

Up to 9 out of 10 people who are susceptible will get the virus if exposed, according to the CDC.

Measles used to be common among kids. How bad was it?

Before a vaccine became available in 1963, there were some 3 million to 4 million cases per year, which meant nearly all American kids had it sometime during childhood, according to the CDC. Most recovered.

But measles can be much more than an uncomfortable rash, said Susan Hassig, an infectious disease researcher at Tulane University.

“I think that people need to remember that this is a preventable disease,” Hassig said. “It is a potentially dangerous disease for their children.”

In the decade before the vaccine was available, 48,000 people were hospitalized per year. About 1,000 people developed dangerous brain inflammation from measles each year, and 400 to 500 died, according to the CDC.

Is the measles vaccine safe? Where do vaccination rates stand?

The measles, mumps and rubella (MMR) vaccine is safe and effective. It is a routine and recommended childhood vaccine that is split into two doses.

Research shows it takes a very high vaccination rate to prevent measles from spreading: 95% of the population should have immunity against the virus.

During the COVID-19 pandemic, national vaccination rates for kindergartners fell to 93% and remain there. Many pockets of the country have far lower rates than that. The drop is driven in part by record numbers of kids getting waivers.

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ATLANTA (AP) — A person in Texas has been diagnosed with bird flu, an infection tied to the recent discovery of the virus in dairy cows, health officials said Monday.

The patient was being treated with an antiviral drug and their only reported symptom was eye redness, Texas health officials said. Health officials say the person had been in contact with cows presumed to be infected, and the risk to the public remains low.

It marks the first known instance globally of a person catching this version of bird flu from a mammal, federal health officials said.

However, there’s no evidence of person-to-person spread or that anyone has become infected from milk or meat from livestock, said Dr. Nirav Shah, principal deputy director of the Centers for Disease Control and Prevention. Genetic tests don’t suggest that the virus suddenly is spreading more easily or that it is causing more severe illness, Shah said. And current antiviral medications still seem to work, he added.

Last week, dairy cows in Texas and Kansas were reported to be infected with bird flu — and federal agriculture officials later confirmed infections in a Michigan dairy herd that had recently received cows from Texas. None of the hundreds of affected cows have died, Shah said.

Since 2020, a bird flu virus has been spreading among more animal species – including dogs, cats, skunks, bears and even seals and porpoises – in scores of countries. However, the detection in U.S. livestock is an “unexpected and problematic twist,” said Dr. Ali Khan, a former CDC outbreak investigator who is now dean of the University of Nebraska’s public health college.

This bird flu was first identified as a threat to people during a 1997 outbreak in Hong Kong. More than 460 people have died in the past two decades from bird flu infections, according to the World Health Organization.

The vast majority of infected people got it directly from birds, but scientists have been on guard for any sign of spread among people.

Texas officials didn’t identify the newly infected person, nor release any details about what brought them in contact with the cows.

The CDC does not recommend testing for people who have no symptoms. Roughly a dozen people in Texas who did have symptoms were tested in connection with the dairy cow infections, but only the one person came back positive, Shah said.

It’s only the second time a person in the United States has been diagnosed with what’s known as Type A H5N1 virus. In 2022, a prison inmate in a work program picked it up while killing infected birds at a poultry farm in Montrose County, Colorado. His only symptom was fatigue, and he recovered.

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That’s a 4% increase from the year before. The Centers for Disease Control and Prevention released the data Friday, but has not released marriage data for last year.

In 2020, the first year of the COVID-19 pandemic, there were 1.7 million U.S. weddings — the lowest number recorded since 1963. The pandemic threw many marriage plans into disarray, with communities ordering people to stay at home and banning large gatherings to limit the spread of COVID-19.

Marriages then rose in 2021, but not to pre-pandemic levels. They ticked up again in 2022 and surpassed 2019 marriage statistics by a small margin.

New York, the District of Columbia and Hawaii saw the largest increases in marriages from 2021 to 2022. Nevada — home to Las Vegas’ famous wedding chapels — continued to have the highest marriage rate in the nation, though it slightly decreased from 2021.

The number and rate of U.S. divorces in 2022 fell slightly, continuing a downward trend, the CDC said.

Overall, marriages remain far less common than they once were in the U.S.

According to data that goes back to 1900, weddings hit their height in 1946, when the marriage rate was 16.4 per 1,000 people. The rate was above 10 in the early 1980s before beginning a decades-long decline. In 2022, the marriage rate was 6.2 per 1,000 population.

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The Centers for Disease Control and Prevention published a report that for the first time connects Acanthamoeba infections to neti pots and other nasal rinsing devices.

Officials also renewed their warning that extremely rare, but potentially deadly, consequences can come from flushing nasal passages with common tap water.

“We published this study because we want people to be aware of this risk,” said the CDC’s Dr. Julia Haston.

Neti pots are one of the better known tools of nasal rinsing. They look like small teapots with long spouts, and usually are made of ceramic or plastic.

Users fill them with a saline solution, then pour the liquid in one nostril. It comes out the other, draining the nasal passage of allergens and other bothersome contaminants.

Neti pot use in the U.S. has boomed in the last couple of decades, driven in part by the increasing prevalence of allergies and other respiratory diseases, market researchers say.

There also are other methods of rinsing nasal passages, including specially shaped cups and squeezable plastic bottles.

Tap water in the U.S. is treated to meet safe drinking standards, but low levels of microscopic organisms can still be found in it. It’s usually not a problem when people drink or cook with the water, but it can pose more of a danger when tap water is used for other purposes — like in humidifiers or for nasal irrigation.

CDC officials, citing a 2021 survey, say about one-third of U.S. adults incorrectly think tap water was free of bacteria and other microorganisms. Nearly two-thirds say tap water could be safely used for rinsing their sinuses.

The CDC recommends using boiled, sterile or distilled water.

If tap water is used, it must be boiled for a minimum of one minute — or three minutes at higher elevations — before it is cooled and used, officials say.

More than a decade ago, health officials linked U.S. deaths from a brain-eating amoeba — named Naegleria fowleri — to nasal rinsing. More recently, they started to note nasal rinsing as a common theme in illnesses caused by another microscopic parasite, Acanthamoeba.

Acanthamoeba causes different kinds of illness but is still dangerous, with a 85% fatality rate in reported cases.

“These infections are very serious and even life threatening,” said Haston who was lead author of the report published in the journal Emerging Infectious Diseases.

The new study focused on 10 patients who fell ill between 1994 and 2022, three of whom died. Researchers say they can’t be sure how the patients were infected, but they noted several commonalities: All had weakened immune systems and practiced nasal rinsing.

Seven patients reported nasal rinsing for relief of chronic sinus infections, and at least two of them used neti pots. Two other patients did nasal rinsing as part of a cleansing ritual that is part of Indian tradition.

This amoeba can be found naturally all over the environment — in lakes, rivers, seawater and soil.

It can cause diseases of the skin and sinuses, and can infect the brain, where it can cause a deadly form of inflammation. The microorganism also has been connected to non-fatal, but sight-threatening, eye infections, sometimes through contaminated contact lens solution.

U.S. health officials have identified about 180 infections from the single-cell organism since the first one was diagnosed in 1956.

In the vast majority of cases, researcher don’t know exactly how people became infected. But in reviewing cases in recent decades, CDC researchers increasingly received information that a number of the cases had done nasal rinsing, Haston said.

Research also has indicated it’s common in tap water. A study done in Ohio in the 1990s found more than half of tap water samples studied contained the amoeba and similar microorganisms.

“It’s very likely that we’re all exposed to Acanthamoeba all the time,” she said.

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.