Will norovirus surge early again this year? Here's what scientists say
Will the upcoming norovirus season be just as early and active as the past year?
While the answer may be anyone's guess right now, federal health officials recently warned that the dominant strain of the contagious virus — the leading cause of vomiting, diarrhea, and foodborne illness in the U.S. — has changed between the 2022-2023 and 2024-2025 seasons.
'GII.17 has caused 75 percent of all norovirus outbreaks during the 2024–25 season so far, thereby replacing GII.4 as the predominant norovirus outbreak strain in the United States,' Centers for Disease Control researchers wrote in an article published this month by the agency's Emerging Infectious Diseases journal.
This past season also started at the earlier date of October, as opposed to December. GII.17 also drove a record wave of outbreaks.
But, what all of this might mean going forward needs further research.
'Additional sequence analysis of complete GII.17 genomes and identification of cross-protective neutralizing antibodies of GII.17 compared with GII.4 viruses could help clarify whether GII.17 viruses will persist. Continued surveillance is needed to determine if this genotype remains the dominant genotype, as well as whether the norovirus season continues to start earlier than previous years,' they wrote.
A spokesperson for the agency told CBS News that there are 'currently insufficient historic data to predict whether norovirus GII.17 will remain the dominant genotype and lead to an earlier onset of the norovirus season later this year.'
They pointed to a surge of GII.17 strains in Asia and Europe in 2014 that was followed by no reports of a change to seasonality, and noted that there has been no clear evidence to prove that GII.17's emergence was the cause of a change to the norovirus season last year.
Still, this past season reached the worst levels in a decade. There were 91 suspected or confirmed outbreaks during the first week of December, which Yale Medicine said exceeded the number of outbreaks during the same week in any year since 2012. The majority were the GII.7 strain. In years when there is a new strain of the virus, there can be 50 percent more norovirus illness.
Cases continued to tick up months into this year. By May 7, there were 2,571 outbreaks. During the same time last year, there were only 1,358.
'The total number of outbreaks reported during the 2024 to 2025 seasonal year is above the range reported during the same period during the 2012 to 2020 and 2021 to 2024 seasonal years,' the CDC said.
But, cases in the previous season were lower than normal. Typically, there are about 2,500 reported norovirus outbreaks in the U.S. each year.
Cases have fallen markedly since January, and are now at low levels. While the outbreaks occur throughout the year, they are the most common from November to April as people head indoors and it's easier to spread norovirus through infected particles. Anyone who consumes raw shellfish is also at risk of contracting it.
Infection can be deadly largely among adults aged 65 and up, but anyone can get sick. Children younger than 5 years old and people with weakened immune systems are more likely to develop severe infections. There are 900 deaths on average each year and between 19 and 21 million illnesses. There's no specific treatment for norovirus, but most people recover with a period of up to three days.
'The norovirus can spread so quickly, but also, as we already talked about, norovirus can be very — it's usually very fast. So yeah, if people are taking care of themselves, we leave them alone,' explained Dr. Joanna Bisgrove, a family physician at Rush University Medical Center. 'But if it keeps going, we're like, maybe this isn't norovirus, and we need to do other things.'
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BBC News
an hour ago
- BBC News
The mystery rise of lung cancer in non-smokers
The number of lung cancer cases in people who have never smoked is increasing. The disease is different from lung cancer caused by smoking, so what causes it? Martha first realised that something was wrong when her cough changed and the mucus in her airways became increasingly viscous. Her doctors put it down to a rare disorder she had that caused her lungs to become chronically inflamed. "No worry, it must be that," she was told. When she finally had an X-ray, a shadow was detected on her lung. "That set the ball rolling," Martha recalls. "First, a CT scan was done, then a bronchoscopy [a procedure that involves using a long tube to inspect the airways in a person's lungs] to take tissue samples." After the tumour was removed, about four months after she'd first reported symptoms to her GP, she received the diagnosis: Stage IIIA lung cancer. The tumour had infiltrated the surrounding lymph nodes but had not yet spread to distant organs. Martha was 59 years old. "It was a total shock," says Martha. Although she would occasionally light up a cigarette at a party, she never considered herself a smoker. Lung cancer is the most common cancer worldwide and the leading cause of cancer death. In 2022, about 2.5 million people were diagnosed with the disease and more than 1.8 million died. Although tobacco-related lung cancers still account for the majority of diagnoses worldwide, smoking rates have been declining for several decades. As the number of smokers continues to fall in many countries around the world, the proportion of lung cancer occurring in people who have never smoked is on the rise. Between 10 and 20% of lung cancer diagnoses are now made in individuals who have never smoked. "Lung cancer in never-smokers is emerging as a separate disease entity with distinct molecular characteristics that directly impact treatment decisions and outcomes," says Andreas Wicki, an oncologist at the University Hospital Zurich, Switzerland. While the average age at diagnosis is similar to that of smoking-related lung cancers, younger patients with lung cancer are more likely to have never smoked. "When we see 30- or 35-year-olds with lung cancer, they are usually never-smokers," he says. Another difference is the type of cancer being diagnosed. Until the 1950s and 1960s, the most common form of lung cancer was squamous cell carcinoma – a type which begins with the cells that line the lungs. In contrast, lung cancer in never-smokers is almost exclusively adenocarcinoma – a type which starts in mucus-producing cells – which is now the most common form of lung cancer in both smokers and never-smokers. Like other forms of lung cancer, adenocarcinoma is usually diagnosed at an advanced stage. "If there's a 1cm (0.4in) tumour hidden somewhere in your lungs, you won't notice it," says Wicki. The early symptoms, which include persistent coughing, chest pain, shortness of breath or wheezing, often only appear when the tumour is larger or has spread. In addition, the historically strong link between smoking and lung cancer may inadvertently lead non-smokers to attribute symptoms to other causes, says Wicki. "Most cases in never-smokers are therefore only diagnosed at stage 3 or 4." Lung cancer in never-smokers is also more common in women. Women who have never smoked are more than twice as likely to develop lung cancer as male never-smokers. Aside from lung anatomy and environmental exposures, at least part of the answer may lie in genetic mutations that are more common in women, especially in Asian women. One of the most prevalent is a mutation known as EGFR. Lung cancer cells in people who have never smoked usually have a number of mutations that could be causing their cancer, explains Wicki – so-called driver mutations. These genetic changes drive tumour growth, such as the EGFR gene which codes for a protein on the surface of cells and is called epidermal growth factor receptor. The reasons why these driver mutations are more frequently found in female patients, particularly those of Asian descent, are not entirely understood. There is some evidence that female hormones may play a role, with certain genetic variants that affect oestrogen metabolism being more prevalent in East Asians. This could potentially explain the higher incidence of EGFR-mutant lung cancer in Asian women, although the data is very preliminary. Following the discovery of mutations which can lead to lung cancer in non-smokers, the pharmaceutical industry began to develop drugs that specifically block the activity of those proteins. For example, the first EGFR inhibitors became available around 20 years ago and most patients showed an impressive response. However, treatment often led to resistant cancer cells, resulting in tumour relapse. In recent years, much effort has been put into overcoming this problem, with newer types of drugs now entering the market. As a result, the prognosis for patients has steadily improved. "The median survival rate of patients who carry such driver mutations is now several years," Wicki explains. "We have patients who have been on targeted therapy for more than 10 years. This is a huge step forward when you consider that the median survival rate was less than 12 months about 20 years ago." As the proportion of lung cancer in never-smokers increases, experts say it is crucial to develop prevention strategies for this population. A number of risk factors have been implicated. For example, studies have revealed that radon and second-hand smoke can elevate the risk of lung cancer in non-smokers. Additionally, exposure to cooking fumes or to stoves burning wood or coal in poorly ventilated rooms may also increase this risk. Since women traditionally spend more time indoors, they are particularly vulnerable to this type of indoor air pollution. However, outdoor air pollution is an even more significant factor in the development of lung cancer. In fact, outdoor air pollution is the second leading cause of all lung cancer cases after smoking. Studies have revealed that people who live in highly polluted areas are more likely to die of lung cancer than those who do not. Particulate matter less than 2.5 microns in diameter (about a 30th of the width of a human hair), typically found in vehicle exhaust and fossil fuel smoke, seems to play an important role. And intriguingly, research has shown a strong link between high levels of PM2.5 and lung cancer in individuals who have never smoked and who carry an EGFR mutation. How air pollution may trigger lung cancer in never-smokers carrying the EGFR mutation has been the focus of research at the Francis Crick Institute in London. "When we think about environmental carcinogens, we usually think about them as causing mutations in the DNA", says William Hill, a post-doctoral researcher in the cancer evolution and genome instability laboratory of the Francis Crick Institute. Cigarette smoke, for example, damages our DNA, thus leading to lung cancer. "However, our [2023] study proposes that PM2.5 doesn't directly mutate DNA, rather it wakes up dormant mutant cells sitting in our lungs and starts them on the early stages of lung cancer." In their experiments, the researchers showed that air pollutants are taken up by immune cells called macrophages. These cells normally protect the lung by ingesting infectious organisms. In response to PM2.5 exposure, macrophages release chemical messengers known as cytokines, which wake up cells carrying the EGFR mutation and causes them to proliferate. "Both air pollution and EGFR mutations are needed for tumours to grow," says Hill. Understanding how PM2.5 acts on the microenvironment of cells carrying EGFR mutations to promote tumour growth, he adds, could pave the way for new approaches to preventing lung cancer. The association between air pollution and lung cancer is not new. In a landmark paper establishing the link between smoking and lung cancer in 1950, the authors suggested outdoor pollutants from the burning of fossil fuels as a possible cause. But policies to date have focused almost exclusively on tobacco control. But 75 years later, air pollution is finally coming into focus. Air pollution levels in Europe and the US have fallen in recent decades. But the effect of changes on lung cancer rates has not yet become apparent. "It probably takes 15 to 20 years for changes in exposure to be reflected in lung cancer rates, but we don't know for sure," says Christine Berg, a retired oncologist from the National Cancer Institute in Maryland, US. Moreover, the picture is not static: climate change is likely to have an impact in the future. "With the increasing risk of wildfires, air pollution and PM2.5 levels are rising again in certain regions of the US," says Berg. "At least one study has shown an association between wildfire exposure and increased incidence of lung cancer. Transitioning away from coal, oil and gas is therefore crucial not only to slow global warming but also to improve air quality." In 2021, the WHO halved the annual mean air quality guideline for PM2.5, meaning it has adopted a more stringent approach to particulate matter. "But 99% of the world population lives in areas where air pollution levels exceed [these updated] WHO guideline limits," says Ganfeng Luo, a postdoctoral researcher at the International Agency for Research on Cancer (IARC) in Lyon, France. In a recent study, IARC researchers estimated that approximately 194,000 cases of lung adenocarcinoma worldwide were attributable to PM2.5 in 2022. "The highest burden is estimated in East Asia, especially in China," says Luo. In the future, the number of lung cancer deaths attributable to air pollution could increase in countries such as India, which currently has some of the highest levels of air pollution, according to the WHO. In Delhi, the average PM2.5 levels are above 100 micrograms per sq m, which is 20 times above the WHO air quality guidelines. In the UK, 1,100 people developed adenocarcinoma of the lung as a result of air pollution in 2022, the IARC study found. "But not all of these cases will be in never-smokers," says Harriet Rumgay, an epidemiologist and a co-author of the study. Adenocarcinoma also occurs in smokers, especially in those using filtered cigarettes. "There's still a lot we don't know," says Rumgay. "More research is needed to disentangle the different factors and also to understand, for example, how long you would need to be exposed to air pollution before developing lung cancer." As treatments continue to improve, lung cancer in never-smokers is becoming more survivable. It is conceivable that this type of lung cancer will one day become the most common form of a disease that has historically been associated with older male smokers, changing the way we think about the disease in popular culture; "…the idea that they [patients] are at least partly to blame for their disease is unfortunately still widespread," says Wicki. Martha was found to have an EGFR mutation and has been taking an inhibitor since her diagnosis almost three years ago. "It's definitely not a vitamin pill," she says. The drug has some nasty side effects: chronic fatigue, muscle pain, skin problems. Balancing the risks and benefits of drug treatment and maintaining a reasonable quality of life is not always easy, she says. But the drug is working. "And the fatalistic view of the disease is changing, and that is good." -- For trusted insights into better health and wellbeing rooted in science, sign up to the Health Fix newsletter, while The Essential List delivers a handpicked selection of features and insights. For more science, technology, environment and health stories from the BBC, follow us on Facebook, X and Instagram.
The Guardian
an hour ago
- The Guardian
‘Tastes like water': how a US facility is recycling sewage to drink
As the pumps whir around us, Denis Bilodeau motions to the liquid in the vats below. It looks like iced tea, but in fact it's secondary treated sewage, cleaned of any solids by the plant next door. In less than an hour, and after three steps of processing, we will be drinking it – as pure water. The Groundwater Replenishment System facility in Orange County, California, houses the pipes, filters and pumps to move up to 130m gallons each day – enough for 1 million people – processing it from dark to clear. The facility, which opened in 2008, is part of broader moves to help conserve water. Bilodeau, the president of the water district, says: 'This is going to be a blueprint for any community that's facing water scarcity, or wants to have more locally controlled water.' The idea is to take the water from the sanitation district next door and to push it through a three-step process – microfiltration, reverse osmosis and ultraviolet light purification – to make clean water. The facility provides 45% of central Orange County's water and helps manage stormwater inflows and reduce reliance on imported water. View image in fullscreen The Orange County project generates about 130m million gallons of clean drinking water each day –enough for 1 million people. Photograph: Mario Tama/Getty In general, once sewage has been treated, the water is returned to our rivers, but extreme droughts and climate change are pushing cities to consider using recycled sewage for drinking water. It is already done in Israel, Singapore and Kuwait, but Orange County has been a US pioneer in this area, hoping to reduce dependence on water piped from faraway rivers or pumped from shrinking aquifers under the ground. Orange County has a population of about 3 million and gets about 14 inches (35.5cm) of rain per year, some years far less, so recycling isn't just a way to reduce costs, it's a way to make sure everyone has what they need. 'Everything's going to have to be reclaimed and recycled,' says Bilodeau. When the liquid reaches the plant it has already been through some treatment and is clean enough to discharge into the oceans, but nowhere near clean enough to drink. The first step is to pump the water through bundles of hollow polypropylene fibres – which look like tiny plastic straws – to remove particulates as well as bacteria and other unwanted elements. Pipes then carry the filtered water to a building to undergo reverse osmosis, where it is pushed through membranes that squeeze out the salts, organic chemicals and any pharmaceutical leftovers. View image in fullscreen Pipes carry the filtered water to a building to undergo reverse osmosis, where it is pushed through membranes that squeeze out the salts, organic chemicals and any pharmaceutical leftovers. Photograph: Mario Tama/Getty Finally, the water is blasted with high-intensity ultraviolet light and hydrogen peroxide to disinfect anything that might remain. 'It's concentrated sunlight,' Bilodeau says, 'like what you would see in a tanning booth.' Except this would injure your eyes, because it's so strong. After walking around all three buildings, we reach a sink with running, clear water. I drink a cup of the stuff, expecting a whiff of what it used to be – but no, it's super clean, with almost a flat taste. That's because it no longer contains any salts or minerals – they have been blasted out by the cleaning process. On the cup is a motto, 'Tastes like water … because it is water', chosen because it is the number one comment, says Mehul Patel, the executive director of operations at the Orange County Water District, who oversees the facility. 'There was a misperception that it tastes different or tastes like something,' he says. 'We're trying to show people scientifically, water is just water.' 'We wanted full transparency,' adds Bilodeau, 'because we're talking about serving recycled wastewater to people.' Even though we are drinking the super-clean water out of the facility, the liquid will actually head back underground. Some of it will travel in pipes to the coastline of the Pacific Ocean where it will serve as a buffer to keep the salty water out of the coastal aquifer. Most of it will zoom 15 miles in pipelines to the city of Anaheim, where it will create lakes to percolate down into the aquifer and replenish the water that people drink in the county. 'It's the one that's consistent, because we can control it,' says Bilodeau. 'And that's a big reason why we invested in recycled water so heavily.' skip past newsletter promotion Sign up to Down to Earth Free weekly newsletter The planet's most important stories. Get all the week's environment news - the good, the bad and the essential Enter your email address Sign up Privacy Notice: Newsletters may contain info about charities, online ads, and content funded by outside parties. For more information see our Newsletters may contain info about charities, online ads, and content funded by outside parties. For more information see our Privacy Policy . We use Google reCaptcha to protect our website and the Google Privacy Policy and Terms of Service apply. after newsletter promotion The big drawback to this system is that making water – instead of sucking it from the ground – takes a huge amount of energy and manpower. The system consumes 17 megawatts of electricity and has a monthly electricity bill of $2.5m (£1.85m), while to run the place takes 26 operators. But the technology also offers some control over an increasingly climate-changed future: Bilodeau says the team estimates several years ahead in terms of what they think their water needs will be and what the water sources will be. 'That's one of the main reasons why we developed this,' he adds. 'Because we wanted to sort of diversify our supply portfolio.' View image in fullscreen A sample of purified water, left, flows next to wastewater following the microfiltration treatment process. Photograph: Mario Tama/Getty Some places are looking to the oceans for drinking water, but wastewater is more cost-effective as a source of water, Bilodeau says, because there are fewer salts in wastewater than sea water. That makes the energy costs of cleaning the water about half of what it would be to desalinate. The model is increasingly being used in other water-scarce regions in the US. Los Angeles County is building a water recycling project in the San Fernando Valley to produce 20m gallons a day. Instead of sending treated wastewater out to sea, it will be cleaned for drinking water, just like in Orange County. There are also projects starting in Utah, Texas and Colorado. California's State Water Resources Control Board approved regulations for direct potable reuse in October 2024, which allow purified water to go directly into drinking water systems instead of being mixed in with other water sources. The technology in the treatment process allows for the water to be even cleaner than most drinking water. The Orange County model has won awards, including a Guinness World Records title for the most wastewater recycled to drinking water in 24 hours on 16 February 2018. But the best praise is the public support for the water, says Bilodeau – and the economic argument behind it. 'It's now cheaper to make our own water than to buy imported water, or to clean sea water,' he says.
The Independent
an hour ago
- The Independent
Mobility expert says you should swap stretching for this exercise to ease tight hips
As a coach and fitness writer, having tight hips is one of the most common complaints I hear about. People usually default to stretching to sort this out, but a specialist says there are more effective ways to address the problem. Movement mechanics expert and Training Stimulus founder Ash Grossmann says regular movement and developing stability around the joint are likely to yield better long-term results for those seeking to banish tightness. 'In terms of broad, generalised advice, we want to establish what is causing the tightness,' Grossmann says. 'There are indirect reasons why a muscle could be becoming tight – the clue is if you stretch it and the tightness keeps coming back, stretching isn't solving the tightness. 'In a lot of situations, stretching can actually make it feel worse because you get into a wrestling match with your nervous system. Your nervous system generally has your best interests at heart with the tools it has available, so it thinks it's doing you a favour by tightening the muscle. Yanking on that tight muscle [via stretching] can be hurting your bigger picture goal rather than the small muscle tightness you're dealing with.' Below, Grossmann explains the possible causes of muscle tightness, and an accessible protocol for combatting this around the hips. Possible causes of muscle tightness Protection 'The first role of the nervous system, when it comes to movement, is survival and protection,' Grossman says. Muscle tightness might be your nervous system's way of preventing you from accessing a position it perceives as dangerous. For example, you might not be able to complete a full squat because your body 'doesn't feel strong, stable or in control' in the bottom position. Habit If we do anything consistently, the body will adapt to get better at it. Sitting at a desk all day with a flexed hip sends a strong message that this is a position to prioritise. As a result, the nervous system might tighten the hip flexor muscles (which raise the knee towards the chest) to do you a favour and save some energy. Regular, varied movement is the obvious remedy to this – think desk breaks, walking, side bends and rotations (like you'll find in this three-move ab workout). Instability Alternatively, Grossmann says the nervous system can use tightness in the hip flexors as a way of compensating for other muscle's shortcomings and creating stability in an otherwise unstable joint. 'If the body perceives a joint as loose or unstable, it will tighten the muscles it has to hand or that it's familiar with to try and create stability, even if they are not the ideal muscles to get the job done,' he explains. If this is the case, your first course of action should be to recruit and strengthen other key players such as the glutes, adductors and glute medius. You might do this through traditional strength training, or any number of other methods. As Grossmann says: 'Anything that gets length and load through the tissues [around the hip] will help.' The exercise below allows you to do just that, as well as work the hip through a wide range of motion, making it a top option for most people suffering from hip stiffness. The best exercise for fixing stiff hips: The Stimulus Six Lunges The body operates on a use it or lose it basis, as far as movement is concerned. To persuade it to regain range of motion around the hips and banish tightness, we need to build a solid business case for doing so, says Grossmann. 'The body is pretty rational, so unless you give it a compelling case to say, 'Actually, we need length through our hip flexors quite often and for reasonable amounts of time', it won't buy into it.' Doing the Stimulus Six Lunges daily is a good way to go about this. It involves lunging in six different directions, recruiting all the main musculature of the hip and moving in all three planes of motion; sagittal, meaning up, down, forward and backward; frontal, meaning side-to-side; and transverse, meaning rotational. Doing this acts like a mini movement assessment in itself, as you can work out your weaknesses by observing which lunges you struggle with. 'If you don't like doing a side lunge, maybe the adductors are super tight,' he explains. 'If you don't like doing a crossover lunge, maybe the lateral hip or the glute medius is really tight,' Grossmann says. 'By regularly training those movements, we're telling the body, 'We're going to be doing these movements, so you'd better get used to getting length in these muscles'.' Done daily, this will help the hips of your average desk job worker feel 'way, way better', he says. 'There's obviously a lot more nuance you could dig into on an individual basis, but their hips are going to be exposed to more positions and ranges of motion than even a lot of people who go to the gym all the time,' Grossmann explains. 'A lot of gym rats will just do squats and deadlifts, only moving up and down, but not moving sideways or rotating. If you do the Stimulus Six Lunges, you are maintaining your body's ability to access all the joint motions of the hip.' If you simply want to maintain your mobility, doing the sequence daily will help. If you're looking to improve your body's strength and performance in these positions for sport, you can progressively overload them by adding weight, upping the number of reps or increasing the range of motion accessed in each direction. 'If you can only do a side lunge to 90cm at first, gradually working towards a wider side lunge is another way to track and improve, beyond adding weight,' says Grossmann. 'Whether you need to do this all comes back to what your goals are. Do you need more mobility, or are you just trying to keep those hips feeling good and not lose access to those joint positions?' Ultimately the best thing you can do is listen to your body but if you're struggling with tightness, it could be worth asking yourself why the feeling keeps returning and look to Grossmann's advice for help. By taking a slightly different approach you might start to see changes and hopefully, improvements too.
