Latest news with #parasite
Yahoo
21 hours ago
- Health
- Yahoo
Officials step up plans to combat flesh-eating screwworm
Texas officials are stepping up their plans to stop the spread of a flesh-eating parasite, [Reuters reports]( The parasite, known as the New World screwworm (Cochliomyia hominivorax), has triggered a public health emergency in Costa Rica, prompting experts to warn Canadian travellers to take precautions. State-side, Texas officials said Wednesday they are building a sterile fly dispersal facility. The Department of Agriculture also announced plans for a sterile fly production facility at Moore Air Base, which could take two to three years to construct. New World screwworm (NWS) was eradicated from the U.S. in 1966, but the current health emergencies in central America and Mexico have seen the parasite moving northward. On its website, the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) says it has been partnering with other USDA agencies, including the U.S. Department of State, the Food and Agriculture Organization of the United Nations, and affected countries to combat the outbreak. "APHIS is investing $109.8 million to combat new NWS detections in Central America and Mexico to keep the pest from spreading into North America," the agency's website reads. "With this funding, APHIS aims to eradicate NWS in Central America and Mexico and re-establish the biological barrier." On Wednesday, U.S. Agriculture Secretary Brooke Rollins said the USDA is also working with state animal health officials to draft an emergency response and stockpile medications in case NWS breaches the border, according to Reuters. In March, infectious disease specialist Dr. Issac Bogoch took to X to spread awareness and warn Canadians, especially those travelling to destinations like the Dominican Republic, Costa Rica, and Mexico. "The "barrier" preventing New world screwworm flies (Cochliomyia hominivorax) from spreading north of Panama has been breached," The Toronto-based doctor said on social media. "We recently cared for a patient who contracted this infestation on a trip to Costa Rica." Despite what its name suggests, the New World screwworm is not a worm at all—it is a species of parasitic fly. Female screwworm flies lay their eggs in open wounds, scrapes, or insect bites on people and animals. When the eggs hatch, the larvae burrow into the flesh, feeding on living tissue and potentially causing serious wounds, infections, and even death if left untreated. Infections occur primarily in livestock but people can and do get infected, including an 80-year-old Canadian male traveller who went to a Toronto hospital with an NWS infection (also called myiasis) after visiting Costa Rica. Speaking with CP24, Dr. Bogoch said NWS is a public health issue that can also impact food security. 'This infection can decimate wildlife and livestock,' he told the news outlet. NWS is commonly found in Cuba, Haiti, the Dominican Republic, and South American countries but (APHIS) says cases are spreading to Costa Rica, Nicaragua, Honduras, Guatemala, Belize, El Salvador and Mexico, beyond a biological border that had previously contained the spread. The agency says there has been an "explosion" in NWS detections in Panama. In 2023 cases went up from an average of 25 cases annually to more than 6,500 cases in one year. (APHIS/ APHIS and Panama co-managed the biological border that "successfully" contained the pest in South America for "decades," APHIS says on its website. The now-breached barrier resides in the eastern portion of Panama. The outbreak declarations in Costa Rica and Mexico have triggered emergency responses in the United States, Mexico, and Costa Rica, which first declared an NWS emergency in February. According to the U.S. Centers for Disease Control and Prevention, you can become infected if: You travel to affected areas (like Costa Rica, Nicaragua, or Mexico); You have open cuts, sores, or scratches; You come into contact with livestock or wildlife carrying the parasite. Canadian travellers can protect themselves by: Covering any cuts or scratches with clean, dry bandages; Using insect repellent, especially on exposed skin; Wearing long sleeves and pants in rural areas or places with plants and trees; Avoiding close contact with stray animals or livestock; Consulting a travel health clinic and a medical professional before travelling. There are no vaccines or medications that prevent infection. If you suspect infection: Seek medical attention immediately. Do not attempt to remove larvae yourself. Treatment usually involves the extraction of the larvae and prescription antibiotics. The parasite typically needs warm conditions to survive and Canada's cooler climate acts as a natural barrier. This parasite is not currently found in Canada, but with travel-related cases increasing and the barrier that once stopped its spread now breached, Canadians heading south should be on alert. Always check travel health advisories and when in doubt, speak to a medical professional before travel. Header image: File photo of new age screwworm larvae (CDC].
Telegraph
2 days ago
- Health
- Telegraph
Could the answer to the male fertility crisis be lurking in your cat's litter tray?
It may come as a surprise but there's about a one-in-three chance that a parasite for which there is no cure has invaded your body and is lying dormant inside you. Your chances of having picked it up are higher if you have a cat, as the parasite only reproduces inside the feline intestinal tract and its eggs end up in the litter tray, or wherever else your pet does its business. From there, it spreads through the environment to other animals, including ones we eat, so those partial to a steak tartare ought to be careful too. Yet there is no reason to panic. The vast majority of people infected with Toxoplasma gondii, the single-celled organism that causes toxoplasmosis, will never know they've had it. It can be dangerous to pregnant women and the people with compromised immune systems. But for the rest of us, any symptoms that do emerge tend to be mild and flu-like – unless you're a sperm. A growing body of evidence suggests toxoplasma gondii may be contributing to a dramatic global decline in male fertility counts. The discovery came by accident. Dr Zahady Velásquez, a researcher from the Institute for Parasitology at the University of Giessen in western Germany, was investigating how toxoplasma takes control of cells when she peered into her microscope and saw what looked like the aftermath of an execution. Dozens of sperm lay dismembered in the petri dish. They had clearly been decapitated after coming into contact with toxoplasma. 'The first thing that I saw was a lot of heads and tails,' she said of the scene. Dr Velásquez's initial reaction was that something had gone awry with the experiment. 'I thought: 'Oh my god, I did something wrong!',' she told The Telegraph. When it happened again, she decided to consult with a colleague who persuaded her that something interesting was going on. Then the work began. Sperm samples were exposed to the single-celled parasite for differing lengths of time, and the damage done was measured. After just five minutes in a test tube with the parasite, almost a quarter (22.4 per cent) of the sperm had been decapitated, and the number of beheadings rose the longer the sperm were exposed. Some of the sperm that survived were left misshapen and scarred by the encounter, their tails curled up or bent at right angles. Others bore characteristic puncture wounds to their heads suggesting the toxoplasma had tried to invade them in the same way they do other cells. The researchers also carried out experiments on mice and found that the toxoplasma were able to reach the testes and epididymis – the coiled tube at the back of the testicle where the sperm are stored – within two days of infection. It is the Toxoplasma gondii's mostly benign relationship with its hosts and ability to infect almost every warm-blooded animal on Earth that explains why toxoplasma has been so successful. However, the new research suggests that the parasite may just be acting slowly. The findings, coupled with the high prevalence of the parasite in the global population, suggest toxoplasma could be having 'an underappreciated impact on male fertility,' the researchers conclude in their report, which was published in the Federation of European Biochemical Societies journal in April. For years scientists have been grappling with an apparent crisis in male fertility, particularly after a 2017 meta-analysis (a statistical technique for combining the results of multiple studies) estimated that global sperm counts had fallen by 59 per cent since 1973. To be clear, this is a separate issue from declining birth rates. While the belief that civilisation faces oblivion because people are no longer interested in having children is currently in vogue, in fact, a range of factors including the high cost of parenthood and housing, as well as fears for the future, are to blame for declining birth rates, a recent major UN study found. The issue of sperm counts is similarly controversial. The reason behind the decline has so far eluded scientists. Numerous culprits have been put forward, from pollution, microplastics, food additives, obesity and even radiation emitted by mobile phones and microwaves. The discovery by Dr Velásquez and her colleagues has helped to open up a new line of enquiry, building on a handful of previous studies that suggested a correlation between toxoplasma infection and male infertility. A 2002 study in China, for instance, found that infertile couples were almost three times more likely to have a toxoplasma infection than fertile couples, while a 2005 study, also in China, found that sterile men were more likely to be infected. 'There's enough evidence out there from different independent labs across the world to pique my interest,' said Dr Bill Sullivan, a professor of pharmacology and microbiology at the Indiana University School of Medicine. 'I think we need to be vigilant and look at every possibility – because it's probably not just one thing,' he told The Telegraph. 'I think it's worthy of further investigation.' Dr Velásquez agrees: 'I really love our results, but I believe that [toxoplasma] is not the only issue that is inducing infertility in men. 'You need to consider that the diet that we have now is deficient in a lot of different minerals and vitamins, also the stress that we live in every day [...] we are not sleeping enough. It's a really big package and I believe that Toxo is just one part of it.' The discovery by Dr Velásquez and her team is the latest in a series of surprising findings about Toxoplasma. Studies have shown that infected mice lose their fear of cats, making them more likely to become prey, as the parasite causes inflammation in parts of the brain that process anxiety. Dr Velásquez is currently applying for grants for further research into the effects toxoplasma have on sperm. Of particular interest is the extent to which the parasite can interfere with sperm production while it is in its dormant stage. After spreading around the body, the organism forms cysts that can survive for long periods within the tissue of the host, including in the testes but also muscle tissue, the heart and the brain. It's these cysts that are excreted by infected cats, and that then find their way into the bodies of other mammals, including grazing cattle, sheep and domestic cat owners. The 'spy in your body' In another sign of how widespread the parasite is, a recent study from the UK suggested that 80 per cent of all sheep in the country carried the infection. While most people can easily overcome the initial infection and force the parasite into dormancy, removing these cysts entirely and ridding the body of the infection has so far proved impossible, largely because the parasite is so similar to the cells it infects, said Dr Velásquez. 'The Toxo, in this case, is like a spy in your body. It's exactly like your cells – they have almost exactly the same proteins inside, they do division as our cells do. So if I try to cut the life of the parasite, I'm probably going to affect your body a lot, and I could kill you.' Blood tests can identify whether a person has a latent toxoplasma infection which, as it can be passed from mother to child, can pose a serious threat to pregnant women. The parasite, in its active phase, can cause miscarriages and birth defects. People with compromised immune systems are also at risk. When the immune system goes down, the dormant parasite can reawaken and attack the body, leading to serious complications – a particularly sinister feature of the parasite that came to the fore during the height of the Aids epidemic. 'There's no cure to get rid of the tissue cysts that could be in your brain and your heart, and those are like time bombs ready to go off if your immune system should falter,' said Dr Sullivan. For the time being our best course of action to mitigate against the spread of the infection is by fostering greater awareness. 'Educational measures have gone a long way to diminish seroprevalence in more developed countries that are aware of the problem,' said Dr Sullivan. 'In France, the seroprevalence in the past was upwards of 80 to 90 per cent – an outrageous number [which] was believed to be through the consumption of a lot of rare meat, steak tartare, for example,' he said. But thanks to educational campaigns and improvements to food hygiene, rates of infection have come down to about 50 per cent. 'Still a huge number, but almost cut in half.' And what about pet cats? Should we be more careful about sharing our homes with these carriers of the parasite? 'There's certainly an element of risk that people need to be aware of in taking care of cat waste properly. But you certainly don't need to throw the baby out with the bathwater, so to speak. You don't need to get rid of your cat.' In its advice for avoiding toxoplasmosis, the NHS recommends wearing gloves when emptying your cat's litter tray and washing your hands afterwards. You should also wear gloves while gardening, thoroughly cook meat 'especially lamb, pork and venison' and wash fruit and vegetables thoroughly. Dr Velásquez would like to see more attention given to the potential effects of toxoplasma infection on male fertility. We know that it can be dangerous for pregnant women, but no one is paying attention to how it could affect men, she said. In some countries, including Austria, France and Uruguay, pregnant women undergo mandatory screening to detect Toxoplasma. But most countries do not test for it in women and none test for it in men, meaning families around the world are having children without ever knowing whether they carry the parasite, potentially putting themselves and their offspring at risk. 'When I was pregnant in Chile, we didn't have any test for us to know – but probably I was infected,' she said. 'I'm a little bit scared now, because what happens if it's in my brain?'
Yahoo
3 days ago
- Health
- Yahoo
Brain worm spike detected in Australia following extreme weather event
A tiny parasite that can infect human brains has the potential to change our way of life in Australia, threatening not only our health but what we eat. Originally from Southeast Asia, rat lungworm is now established along our east coast, with infections found as far south as Jervis Bay. University of Sydney research has linked spikes in infections of the worm in animals to heavy rainfall, because the worm is commonly found in slugs and snails that proliferate during wet weather. A study of 93 dog infections in Sydney and Brisbane found 32 occurred directly after a single rain event, which were likely triggered after pets came into contact with common garden molluscs. The researchers found risk was elevated for between two and 10 months after heavy rain. The study's senior author, Jan Šlapeta from the Sydney School of Veterinary Science, told Yahoo News it's unclear how far south the parasite will spread. But with the world's weather becoming warmer and wetter, it's possible it could one day make its way down to Melbourne. "It has the potential to spread further. An indicator is that 20 or 30 years ago, we did not talk about it in America or Europe. Now it's in the southern states of the United States, it's creeping into Europe, it's in Spain," he said. "I think climate change is very much helping this parasite spread further." Interactions with slugs and snails are the most common way for people to become infected, either by accidentally or intentionally eating them, or by consuming unwashed salad they've had contact with. In 2010, a Sydney man died after he ate a slug following a dare. It's unusual for anyone in Australia to eat an infected snail because of their large size, but that could change if there's a similar biosecurity breach to what has occurred in Hawaii. It's on the Big Island that a tiny semi-slug,Parmarion martensi, has invaded the landscape. It's so small that it's easy to accidentally consume when eating salad greens and fresh fruit and vegetables. "You can't wash them off or see them. The number of human cases [of rat lungworm] have increased dramatically," Šlapeta said. "In Australia we do not have this semi-slug. Is there a potential? We can't yet tell. But we have areas up north that are similar to Hawaii. I don't want to be an alarmist, but this parasite could create more havoc. "If this semi-slug comes in, then it might end up on the veggies that people have got in their backyards. And that would change the landscape of this disease completely, like it changed in Hawaii." The semi-slug would complete a cocktail of invasive species that Šlapeta doesn't want to see become established in Australia. "The parasite is invasive, the rat is invasive, the European slugs that we see in the backyards of Sydney are invasive, but if we bring in the semi-slug... it could change the way we grow greens and behave in restaurants," he said. The first sign the worm has reached a city is usually that animals in its zoo have become sick, with curious primates often picking up slugs inside their cage and then becoming sick. Reports made by wildlife rescue volunteers are also useful in monitoring its spread, as tawny frogmouths and possums often get sick in large numbers. Since rat lungworm, also known as Angiostrongylus cantonensis, was first detected in Brisbane in the 1970s, at least six people have been infected, two of whom have died. When it comes to infections in people, most are asymptomatic, and many cases likely aren't diagnosed. Seven dire reasons it might be time to leave Australia – from floods to fungus Travellers could trigger mosquito disease outbreak in Australia as weather warms Details in satellite photos spark 'worrying' prediction about colony of thousands During its first phase of life, rat lungworm larvae hatch in the lungs of rats and is then passed through the animal as faeces. Slugs and snails consume that faeces and the worms grow inside of them. Rats then eat the slugs and snails and the process begins again. The process is relatively harmless to slugs, snails and rats, but in other hosts like humans, dogs or native birds and mammals, the body can overreact and try to kill the parasite. On rare occasions, it causes an infestation in the brain that triggers an immune response that causes inflammation. Symptoms normally set on between one and three weeks after a slug or snail is eaten, and include headaches, nausea, vomiting, a stiff neck, pain in the skin and fever. The University of Sydney study on rat lungworm infections in dogs advocates for a One Health approach to combating the parasite. This concept means recognising that animals and humans live in the same environment and are therefore interconnected. But how best to respond to the problems it's causing is something that's left Šlapeta stumped. "That's the million dollar question. The parasite is moving wherever it wants," he said. "We can't eliminate rats, we can't eliminate slugs, so we just have to be more vigilant around the clinical signs in our pets and ourselves. "But there's not much we can do about tawny frogmouths. They will keep looking for some sort of food, and if the slug or snail is infected then they will become infected too." The lead author of the study into rat lungworm in dogs was Sydney University's Phoebe Rivory. The research was published in the Journal of Infectious Diseases. Love Australia's weird and wonderful environment? 🐊🦘😳 Get our new newsletter showcasing the week's best stories.
The Independent
3 days ago
- Science
- The Independent
What is the New World screwworm? The flesh-eating fly making a comeback
A flesh-eating parasitic fly is invading North and Central America. The consequences could be severe for the cattle industry, but this parasite is not picky – it will infest a wide range of hosts, including humans and their pets. The 'New World screwworm' (Cochliomyia hominivorax) was previously eradicated from these regions. Why is it returning and what can be done about it? Flies fulfil important ecological functions, like pollination and the decomposition of non-living organic matter. Some, however, have evolved to feed on the living. The female New World screwworm fly is attracted to the odour of any wound to lay her eggs. The larvae (maggots) then feed aggressively on living tissue causing immeasurable suffering to their unlucky host, including death if left untreated. Cattle farmers in Texas estimated in the 1960s that they were treating around 1 million cases per year. Between the 1960s and 1990s, scientists and governments worked together to use the fly's biology against it, eradicating the New World screwworm from the US and Mexico using the sterile insect technique (SIT). A female screwworm mates only once before laying her eggs, whereas the males are promiscuous. During the eradication process, billions of sterile males were released from planes, preventing any female that mated with them from producing viable eggs. In combination with chemical treatment of cattle and cool weather, populations of the screwworm were extinct in the US by 1982. The eradication campaign reportedly came at cost of US$750 million (£555 million), allowing cattle production to increase significantly. For decades, a facility in Panama has regularly released millions of sterile flies to act as a barrier to the New World screwworm spreading north from further south. However, since 2022 – and after decades of eradication – the New World screwworm has once again spread northwards through several countries in Central America. Cases exploded in Panama in 2023 and the fly had reached Mexico by November 2024. Scientists have suggested several hypotheses for this spread, including flies hitchhiking with cattle movements, higher temperatures enhancing fly development and survival, and the possibility that females are adapting their sexual behaviour to avoid sterile males. Around 17 million cattle are now at risk in Central America, but worse may be to come. Mexico has twice as many cattle, and the spread towards the US continues, where around 14 million cattle would be at risk in Texas and Florida alone. Humans are not spared, with at least eight cases of the flies infesting people in Mexico since April. Live animal ban The US has responded by temporarily restricting live animal imports from Mexico. The governments of the US, Central American countries and Mexico are also working together to heighten surveillance and work towards the eradication of the New World screwworm by stepping up sterile insect releases. Sterile male screwworm pupae (juveniles) are currently produced and safely sterilised by irradiation at a rate of over 100 million per week at a facility in Panama. This is jointly funded by the US Department of Agriculture (USDA) and Panama's Ministry of Agriculture Development. However, a successful eradication campaign may need several times this number of sterile flies. For example, sterile fly production for releases in Mexico in the 1980s were reportedly in excess of 500 million flies per week. To combat this shortfall, the USDA is focusing releases in critical areas of Mexico and is already investing US$21 million to equip a fruit fly production facility in Metapa, Mexico, to also produce 60 million to 100 million sterile screwworm per week. Fly production, sterilisation and release is a long process, and a reduction in wild screwworm populations would not be immediate. History has shown us that integrated control with anti-parasitic veterinary medicines are essential to repel flies and treat infestations as they arise. Surveillance with trained personnel is also essential but is a great challenge due to an entire generation of veterinarians, technicians and farmers who have no living memory of screwworm infestations. Finally, climate warming means that we may not be blessed with the cool weather that facilitated previous eradication, and further work is needed to determine how this will impact current eradication plans.
The Independent
4 days ago
- Science
- The Independent
A flesh-eating fly is spreading. It can infest humans and their pets
A flesh-eating parasitic fly is invading North and Central America. The consequences could be severe for the cattle industry, but this parasite is not picky – it will infest a wide range of hosts, including humans and their pets. The 'New World screwworm' (Cochliomyia hominivorax) was previously eradicated from these regions. Why is it returning and what can be done about it? Flies fulfil important ecological functions, like pollination and the decomposition of non-living organic matter. Some, however, have evolved to feed on the living. The female New World screwworm fly is attracted to the odour of any wound to lay her eggs. The larvae (maggots) then feed aggressively on living tissue causing immeasurable suffering to their unlucky host, including death if left untreated. Cattle farmers in Texas estimated in the 1960s that they were treating around 1 million cases per year. Between the 1960s and 1990s, scientists and governments worked together to use the fly's biology against it, eradicating the New World screwworm from the US and Mexico using the sterile insect technique (SIT). A female screwworm mates only once before laying her eggs, whereas the males are promiscuous. During the eradication process, billions of sterile males were released from planes, preventing any female that mated with them from producing viable eggs. In combination with chemical treatment of cattle and cool weather, populations of the screwworm were extinct in the US by 1982. The eradication campaign reportedly came at cost of US$750 million (£555 million), allowing cattle production to increase significantly. For decades, a facility in Panama has regularly released millions of sterile flies to act as a barrier to the New World screwworm spreading north from further south. However, since 2022 – and after decades of eradication – the New World screwworm has once again spread northwards through several countries in Central America. Cases exploded in Panama in 2023 and the fly had reached Mexico by November 2024. Scientists have suggested several hypotheses for this spread, including flies hitchhiking with cattle movements, higher temperatures enhancing fly development and survival, and the possibility that females are adapting their sexual behaviour to avoid sterile males. Around 17 million cattle are now at risk in Central America, but worse may be to come. Mexico has twice as many cattle, and the spread towards the US continues, where around 14 million cattle would be at risk in Texas and Florida alone. Humans are not spared, with at least eight cases of the flies infesting people in Mexico since April. Live animal ban The US has responded by temporarily restricting live animal imports from Mexico. The governments of the US, Central American countries and Mexico are also working together to heighten surveillance and work towards the eradication of the New World screwworm by stepping up sterile insect releases. Sterile male screwworm pupae (juveniles) are currently produced and safely sterilised by irradiation at a rate of over 100 million per week at a facility in Panama. This is jointly funded by the US Department of Agriculture (USDA) and Panama's Ministry of Agriculture Development. However, a successful eradication campaign may need several times this number of sterile flies. For example, sterile fly production for releases in Mexico in the 1980s were reportedly in excess of 500 million flies per week. To combat this shortfall, the USDA is focusing releases in critical areas of Mexico and is already investing US$21 million to equip a fruit fly production facility in Metapa, Mexico, to also produce 60 million to 100 million sterile screwworm per week. Fly production, sterilisation and release is a long process, and a reduction in wild screwworm populations would not be immediate. History has shown us that integrated control with anti-parasitic veterinary medicines are essential to repel flies and treat infestations as they arise. Surveillance with trained personnel is also essential but is a great challenge due to an entire generation of veterinarians, technicians and farmers who have no living memory of screwworm infestations. Finally, climate warming means that we may not be blessed with the cool weather that facilitated previous eradication, and further work is needed to determine how this will impact current eradication plans.
