Latest news with #BillSullivan
Scottish Sun
3 days ago
- Health
- Scottish Sun
New threat to plummeting male fertility rates identified as common but ‘silent' parasite that ‘DECAPITATES sperm'
Find out if you could have toxoplasmosis below OH BABY New threat to plummeting male fertility rates identified as common but 'silent' parasite that 'DECAPITATES sperm' Click to share on X/Twitter (Opens in new window) Click to share on Facebook (Opens in new window) FERTILITY rates appear to have been declining in both men and women globally - and now scientists have found a common single-celled parasite may be a contributor. Male fertility rates in particular have been plummeting over the past half-century, with an analysis from 1992 showing a steady decrease in sperm counts and quality since the 1940s. Sign up for Scottish Sun newsletter Sign up 3 Male fertility rates are shown to have plummeted over the past half-century Credit: Getty 3 Toxoplasma gondii could be a contributor, say scientists Credit: Getty And a more recent study found male infertility rates increased nearly 80 per cent from 1990 to 2019. Declining fertility rates have been attributed to a combination of factors, including rising costs associated with raising children. But now accumulating evidence suggests parasitic infections could also be a threat. A study published in April this year showed for the first time "human sperm lose their heads upon direct contact" with a parasite called Toxoplasma gondii. Toxoplasma gondii causes toxoplasmosis - an often harmless infection but can cause serious problems in individuals with weakened immune systems, pregnant women, and newborns. The parasite is found in the faeces of infected cats and in undercooked meat. Writing for The Conversation, Bill Sullivan, Professor of Microbiology and Immunology, Indiana University, said how the "new study bolsters emerging findings that underscore the importance of preventing this parasitic infection". Foodbourne transmission and animal to human transmission are the top ways people can get toxoplasmosis. Eating raw or undercooked meat, particularly lamb, pork, and venison, is a primary source of infection. And eating unwashed fruits and vegetables that have been contaminated with cat faeces or soil can also lead to infection. Major health advice for couples as HSE offers new resources for anyone struggling with fertility Ingesting the parasite through contact with cat faeces (poop) or soil contaminated with cat faeces is a common way to get toxoplasmosis. Cleaning cat litter boxes without proper hygiene can also expose people to the parasite. While toxoplasmosis is generally harmless for most people with healthy immune systems, often causing no symptoms or mild, flu-like symptoms that resolve on their own, Sullivan said toxoplasma remains in the body for life as dormant cysts in brain, heart and muscle tissue. And these cysts can reactive and cause additional episode of severe illness that damage critical organ system. He explains: "Between 30 per cent and 50 per cent of the world's population is permanently infected with toxoplasma due to the many ways the parasite can spread. "Upon infection, toxoplasma spreads to virtually every organ and skeletal muscle. Evidence that toxoplasma can also target human male reproductive organs first surfaced during the height of the AIDS pandemic in the 1980s, when some patients presented with the parasitic infection in their testes. 3 In a study published this year, sperm were found to be beheaded after coming into contact with the parasite Credit: Getty "While immunocompromised patients are most at risk for testicular toxoplasmosis, it can also occur in otherwise healthy individuals. "Imaging studies of infected mice confirm that toxoplasma parasites quickly travel to the testes in addition to the brain and eyes within days of infection." Evidence in past studies suggesting toxoplasma can reside in male reproductive organs has prompted analysis of fertility in infected men. In the April 2025 study, researchyers from Germany, Uraguay and Chile observed that toxoplasma can reach the testes and epididymis - the tube where sperm mature and are stored - two days after infection in mice. Looking at what happens when the parasite comes into direct contact with human sperm in a test tube, they observed that after only five minutes, 22.4 per cent of sperm cells were beheaded. The number of decapitated sperm also increased the longer they interacted with the parasites. Sperm cells that maintained their head were often twisted and misshapen, and sperm cells had hole sin their head, suggesting the parasites were trying to invade them as it would any other type of cell. Sullivan added: "The evidence that toxoplasma can infiltrate male reproductive organs in animals is compelling, but whether this produces health issues in people remains unclear. "Testicular toxoplasmosis shows that parasites can invade human testes, but symptomatic disease is very rare. "Studies to date that show defects in the sperm of infected men are too small to draw firm conclusions at this time. "Additionally, some reports suggest that rates of toxoplasmosis in high-income countries have not been increasing over the past few decades while male infertility was rising, so it's likely to only be one part of the puzzle."
The Sun
3 days ago
- Health
- The Sun
New threat to plummeting male fertility rates identified as common but ‘silent' parasite that ‘DECAPITATES sperm'
FERTILITY rates appear to have been declining in both men and women globally - and now scientists have found a common single-celled parasite may be a contributor. Male fertility rates in particular have been plummeting over the past half-century, with an analysis from 1992 showing a steady decrease in sperm counts and quality since the 1940s. 3 3 And a more recent study found male infertility rates increased nearly 80 per cent from 1990 to 2019. Declining fertility rates have been attributed to a combination of factors, including rising costs associated with raising children. But now accumulating evidence suggests parasitic infections could also be a threat. A study published in April this year showed for the first time "human sperm lose their heads upon direct contact" with a parasite called Toxoplasma gondii. Toxoplasma gondii causes toxoplasmosis - an often harmless infection but can cause serious problems in individuals with weakened immune systems, pregnant women, and newborns. The parasite is found in the faeces of infected cats and in undercooked meat. Writing for The Conversation, Bill Sullivan, Professor of Microbiology and Immunology, Indiana University, said how the "new study bolsters emerging findings that underscore the importance of preventing this parasitic infection". Foodbourne transmission and animal to human transmission are the top ways people can get toxoplasmosis. Eating raw or undercooked meat, particularly lamb, pork, and venison, is a primary source of infection. And eating unwashed fruits and vegetables that have been contaminated with cat faeces or soil can also lead to infection. Major health advice for couples as HSE offers new resources for anyone struggling with fertility Ingesting the parasite through contact with cat faeces (poop) or soil contaminated with cat faeces is a common way to get toxoplasmosis. Cleaning cat litter boxes without proper hygiene can also expose people to the parasite. While toxoplasmosis is generally harmless for most people with healthy immune systems, often causing no symptoms or mild, flu-like symptoms that resolve on their own, Sullivan said toxoplasma remains in the body for life as dormant cysts in brain, heart and muscle tissue. And these cysts can reactive and cause additional episode of severe illness that damage critical organ system. He explains: "Between 30 per cent and 50 per cent of the world's population is permanently infected with toxoplasma due to the many ways the parasite can spread. "Upon infection, toxoplasma spreads to virtually every organ and skeletal muscle. Evidence that toxoplasma can also target human male reproductive organs first surfaced during the height of the AIDS pandemic in the 1980s, when some patients presented with the parasitic infection in their testes. 3 "While immunocompromised patients are most at risk for testicular toxoplasmosis, it can also occur in otherwise healthy individuals. "Imaging studies of infected mice confirm that toxoplasma parasites quickly travel to the testes in addition to the brain and eyes within days of infection." Evidence in past studies suggesting toxoplasma can reside in male reproductive organs has prompted analysis of fertility in infected men. In the April 2025 study, researchyers from Germany, Uraguay and Chile observed that toxoplasma can reach the testes and epididymis - the tube where sperm mature and are stored - two days after infection in mice. Looking at what happens when the parasite comes into direct contact with human sperm in a test tube, they observed that after only five minutes, 22.4 per cent of sperm cells were beheaded. The number of decapitated sperm also increased the longer they interacted with the parasites. Sperm cells that maintained their head were often twisted and misshapen, and sperm cells had hole sin their head, suggesting the parasites were trying to invade them as it would any other type of cell. Sullivan added: "The evidence that toxoplasma can infiltrate male reproductive organs in animals is compelling, but whether this produces health issues in people remains unclear. "Testicular toxoplasmosis shows that parasites can invade human testes, but symptomatic disease is very rare. "Studies to date that show defects in the sperm of infected men are too small to draw firm conclusions at this time. "Additionally, some reports suggest that rates of toxoplasmosis in high-income countries have not been increasing over the past few decades while male infertility was rising, so it's likely to only be one part of the puzzle." Could you have toxoplasmosis? Toxoplasmosis is a common infection that you can catch from the poo of infected cats, or infected meat. It's usually harmless but can cause serious problems in some people. Most people who become infected with the toxoplasma gondii parasite don't show any signs of infection. The parasite can reside in the body for life without causing issues. However, if you do have symptoms, they can be mild and flu-like, such as fever, swollen lymph nodes, and muscle aches. According to the NHS, some people may have more serious symptoms including: confusion blurred vision slurred speech unsteady walking Your GP may do blood tests to see if you've been infected with toxoplasmosis. They can also prescribe medicines to treat the infection if necessary. Most people who get toxoplasmosis get better without treatment. However, you'll usually be given medicines, including antibiotics, if you: are pregnant have a weakened immune system, for example, you're taking immunosuppressant medicines or you have HIV have symptoms affecting your eyes To avoid toxoplasmosis: wear gloves while gardening, and wash your hands thoroughly afterwards wash your hands before preparing food and eating wash hands, knives and chopping boards thoroughly after preparing raw meat wash fruit and vegetables thoroughly to get rid of any traces of soil thoroughly cook meat, especially lamb, pork and venison avoid cat poo in cat litter and soil if you can, wearing gloves if you need to empty cat litter trays and washing your hands afterwards Don't: eat raw or undercooked meat, or cured meats like salami or parma ham have unpasteurised goats' milk or any products made from it touch pregnant sheep or lambs do not feed cats raw or undercooked meat
Time Magazine
23-05-2025
- Health
- Time Magazine
Be Careful Where You Swim This Summer
That glistening swimming hole might look—and feel—refreshing on a sweltering day. But writhing in pain from stomach cramps, nausea, and vomiting? Staring at the bathroom ceiling instead of the blue, sunny sky? Not so much. Jumping into even the prettiest and clearest rivers, lakes, creeks, and other natural bodies of water can expose you to a cesspool of unpleasant and invisible fellow swimmers—most commonly bacteria, viruses, and parasites. 'These germs are microscopic, so you're not going to be able to tell they're there,' says Bill Sullivan, a professor of microbiology and immunology at the Indiana University School of Medicine and author of Pleased to Meet Me: Genes, Germs, and the Curious Forces That Make Us Who We Are. 'Swimming is a great, fun activity—don't get me wrong. But you do need to be mindful that there are dangers that lurk out there.' That's especially true for certain people. If you're mostly healthy, you'll fare better than some; if you're exposed to bacteria or other nefarious germs, your body should recover fairly successfully. The people most susceptible to severe illness are 'the very young, the very old, and those with preexisting conditions that weaken their immune system,' Sullivan says. 'If you're in one of those vulnerable populations, you should definitely reconsider swimming in questionable water.' We asked experts what threats might be lurking in your favorite swimming hole, and how to stay safe. The problem with inland water Environmental scientists have a reliable way of monitoring the water quality at popular coastal beaches, often by taking samples on a daily or weekly basis. If bacteria levels surpass a certain threshold, they post an advisory online and put up signs that warn swimmers the water might be contaminated. 'The problem with inland locations is that it's hard to know where people are going to try to jump in,' says Rachel Noble, a professor in the Institute of Marine Science at the University of North Carolina who leads a laboratory that studies bacteria and viral pathogens in recreational and other types of water. Someone who's kayaking at a local lake, for example, might make their way to a small island away from the main swimming area and decide to dive in to cool off. Still, resources exist. There's data available for many inland bodies of water, though monitoring is less frequent than at coastal spots. Where Noble lives in North Carolina, for example, she can pull up a recreational water quality website and review data—and a helpful map—from the last week, six months, or year. Every state has a similar resource, she adds, and it's a good idea to check yours regularly. The most common health threats You might think of E. coli and Salmonella in relation to undercooked meat or tainted lettuce. But they're also the likeliest types of bacteria you'll encounter in a swimming hole, thanks to fecal contamination from humans or, more likely, animals, Sullivan says. Imagine livestock grazing in a tributary that feeds into the lake you're swimming in, for example. All it takes is one heavy rainstorm to push their manure and animal waste into the water. 'It washes downstream to where people might be swimming,' he says. If you end up with E. coli or Salmonella, you could experience potentially severe gastrointestinal symptoms—which sometimes get so bad, people land in the hospital with dehydration. A bacteria called Pseudomonas aeruginosa, meanwhile, causes swimmer's ear, which can lead to ear pain, swelling, and discharge. 'It's not an extremely dangerous infection, and sometimes it resolves on its own,' Sullivan says. 'Sometimes a shot of antibiotics will clear it right up, but it can still be a nuisance.' In addition to bacteria, rotavirus and norovirus could be lurking in the water. Both cause 'rapid-onset' diarrhea and vomiting, Sullivan says. Norovirus is particularly contagious, he adds, and can survive outside of the body for one to two weeks. If you get one of these viruses, your symptoms will likely last a few miserable days. Another threat, parasites, can cause longer-lasting distress. Cryptosporidium, which is excreted by cows, commonly contaminates natural bodies of water—and if you get sick, you'll experience watery diarrhea, stomach cramps, and vomiting. 'If you have any reason to believe that cattle are near the body of water you're swimming in, that would give me pause as to whether I want to dip my toe into those waters,' Sullivan says. Giardia, which is shed in the feces of animals like beavers and muskrats, is also common and leads to similar symptoms. Typically, people need pharmaceutical assistance to recover from parasites, Sullivan says, but there aren't as many treatments available for Giardia as there are Cryptosporidium. 'You've usually just gotta ride it out, and it's a really unpleasant experience that lasts about one to two weeks,' he says. Parasites tend to linger, especially if you're immunocompromised—and in addition to the physical symptoms, 'there's a psychological element, in that there are these creepy things living inside you,' he says. Rarer but more extreme risks You've probably seen headlines about the dramatic-sounding 'brain-eating amoeba,' or Naegleria fowleri —a parasite found in warm freshwater. It can enter swimmers' noses and then make its way to their brain, causing an infection called primary amebic meningoencephalitis that's almost always fatal. 'It can feel scary because it's probably essentially everywhere, but it doesn't cause disease very often,' says Dr. Daniel D. Rhoads, chair of the College of American Pathologists' microbiology committee, and section head of microbiology at the Cleveland Clinic. 'I'm sure pretty much all of us have been exposed to it, but it doesn't usually cause a problem because it's physically challenging to get all the way into the brain just from swimming in water.' When people do get infected, they almost always die within a week. Meanwhile, global warming has caused a spike in 'flesh-eating disease,' more formally known as necrotizing fasciitis. It's caused by bacteria in saltwater or brackish water and eats away at soft tissue and muscles. 'What happens is the bacteria get inside the body through a break in the skin—some kind of wound,' Sullivan says. 'Once it starts taking root, it happens pretty quickly. It causes extreme pain, and it looks like it's eating away at the flesh, but what's really happening is the bacteria is destroying muscle and nerves underneath the wound.' That prevents your immune cells from reaching the site where they would need to be to fight the bacteria—and keeps medicine from getting there, too. That's why the most common treatment is 'either carving away the infected tissue or even amputating the limb,' Sullivan says. The path to infection The most common way people swimming inland get sick is by swallowing the water. How much you consume matters: 'If you swallow just a teeny-tiny bit, you might be able to get away with it,' Sullivan says. 'But if you swallow a good mouthful, there's a reasonable chance that's enough to make you sick.' Keeping your head above water can help reduce the likelihood of gulping down germs. But it's not foolproof. When people emerge from the water, their skin might be covered with bacteria or viruses. The next thing you know, they're chowing down on a ham sandwich or passing around bottles of water, and those germs are hopping from person to person. That's why you should always sanitize or wash your hands with soap and water after swimming, Sullivan says; if possible, rinsing off in an outdoor shower is a good idea, too. When should you see a doctor? If you sense your gastrointestinal distress isn't typical, if you have a high fever, if your symptoms last beyond a few days, or if you see blood in your diarrhea, schedule an appointment, Rhoads says. How to stay safe If you're determined to swim in a river or lake, there are some ways to make the experience safer. Here's what experts recommend. Heed posted warnings Take signs about swimming risks and possible contamination seriously. 'If somebody's taking the time to provide health guidance, it's worth listening to it,' Rhoads says. In addition to checking local water-quality reports, click over to your destination's social-media account. Some parks, for example, post warnings about the water, especially after severe storms or if there's been a sewage leak. Use all of your senses Most of the time, the water you're swimming in won't have any noticeable signs of what's lurking beneath the surface. But if you do happen to detect a foul odor or notice a strange color in the water, stay out. Discoloration could indicate 'there's discharge from a pipe or a nearby golf course,' Noble says. 'If you see a lot of cloudiness, or if a lake is otherwise clear blue and it looks brown and covered with algae, then the likelihood is that there's some sort of runoff that's getting to that location,' she says. 'The runoff can contain things that make you sick, so use your senses.' Pay attention to the weather The risk of infection spikes in the aftermath of a storm. Heavy rain can wash all kinds of contaminants into the water: dog waste from nearby paths, debris, chemicals, human sewage, and more. It's impossible to say exactly how long the risk remains elevated, Noble says, because many factors influence it. But if you notice active runoff—or rainwater flowing across the land into the water—it's best to stay on dry land. Opt for well-maintained areas Always do a sweep of the area where you're swimming to get a pulse on its cleanliness, Noble advises. Is there visible dog waste? Overflowing garbage cans? 'If the trash cans aren't regularly emptied, you can get a lot of birds in them, and those birds will defecate,' she says. 'Then that feces will make its way into the water.' While birds will naturally inhabit areas with swimming holes, poorly maintained garbage disposal makes it more likely they'll congregate in high numbers, and that can affect water quality. Never drink the water Whether you get thirsty kayaking down the river—or while you're biking and happen to pass a nice stream—do not drink the water, however tempting it may look. One of the classic case reports Rhoads hears about is people who spotted nice-looking water in a mountain stream and filled up their water bottles—not realizing there were beavers upstream going to the bathroom. Then, he says, they end up with a parasite. Use ear plugs and nose plugs Wearing ear plugs when you swim can help protect you from the bacteria that causes swimmer's ear. And nose plugs (sometimes called clips) act like 'a clamp for the outside of the nose,' Sullivan says, which can block water from entering your nostrils. The U.S. Centers for Disease Control and Prevention recommends employing them to help ward off serious infection. Don't swim if you have open wounds This can help protect you from flesh-eating bacteria, Sullivan says. You should also cover any cuts, scrapes, or fresh tattoos or piercings with a waterproof bandage, he advises. Stay away from sharp objects while you're swimming, too: 'If there's a lot of rocks or shells, and they cut you while you're swimming, the flesh-eating bacteria can get into your body that way.'
