The war between people and disease-causing pathogens is old as humanity itself. This has helped shaped our so-called behavioral immunity, which can lead us, for example, to automatically avoid people who are visibly sick. But it can also misfire; previous studies have shown that people with compromised immune systems (due to a recent illness), and even people who describe themselves as afraid of germs or susceptible to disease, are more likely to avoid and feel prejudiced toward otherwise healthy people who merely look different than them, like foreigners or immigrants.
It appears this prejudice can be reduced or erased by public health measures like vaccination or the simple act of washing your hands, according to a recent study in Psychological Science. In the study’s first experiment, conducted at the height of the 2009 H1N1 swine flu, researchers gathered a group of participants, some of whom had already received a vaccine against H1N1. They were then randomly broken into two groups, which I’ll call group A and group B (each had roughly equal numbers of vaccinated and non-vaccinated people). Group A read news articles describing the flu’s health effects and the vaccine’s effectiveness, in order to remind or “prime” them to the threat posed by the virus. Group B read no such articles. All participants then took a test that measures prejudicial attitudes towards immigrants. In group A, unvaccinated people were more prejudiced against immigrants than those who had received the vaccine. In the “unprimed” group B, there was no measurable difference.
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Swine flu is not gone, and it is not stagnant. Though the public health scare about the 2009 swine flu pandemic subsided, the virus—like avian flu—remains in pockets of animals, shuffling its genes while hidden from the watchful eyes of virus experts. Virologists call this genetic switcheroo “reassortment,” and it’s how new and dangerous strains of flu snuck up on humankind in the past—and how they could do it again. This time, though, virologist Jinhua Liu and colleagues are trying to get a jump on the viruses.
For a new study in the Proceedings of the National Academy of Sciences today, this team of Chinese researchers simulated what could be a dire situation for humans: swine flu (H1N1) and avian flu (H9N2) together in one animal. When these flu strains are together they can exchange genetic material. So to test what that mixing might produce, Liu’s team swapped genes between the two and created 127 hybrid viruses, testing each on mice.
Eight of these hybrid strains turned out to be more virulent and dangerous in the mice than their parent strains of swine flu and bird flu. [National Geographic]
According to Dutch virologist Ab Osterhaus, we can’t be sure that these eight nasty strains are the ones that would hit humans hardest—animal studies aren’t perfect.
“Mice mirror, to a certain extent, what happens in humans,” he says, but they are not perfect model animals. Liu agrees. He plans to investigate how contagious his new viral blends are in guinea pigs and ferrets—animals whose respiratory system better reflects our own feverish battle with flu. [ScienceNOW]
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A new study is providing insights into the 2009 swine flu epidemic, and why more serious complications arose in healthy middle-aged people than expected. The researchers say the culprit may be antibodies to seasonal flu found in the seriously ill patients, which might have caused an immune system overreaction in the lungs.
“Nobody really had a good explanation for why middle-aged people seemed to have more severe disease than would have been expected,” says Richard Scheuermann, an immunologist at the University of Texas Southwestern Medical Center in Dallas. “This explanation is the first one that I’ve seen that actually makes sense.” [Nature News]
Normally, severe flu illness happens in the very young (who haven’t been previously exposed to the flu and don’t have protective immunity) and the elderly (who have weakened immune systems). Instead of affecting these groups, the 2009 pandemic H1N1 “swine flu” primarily caused severe reactions in middle-aged adults.
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It’s still out there, you know.
A study out today in the journal Science tracks the path of swine flu, which may have receded from the forefront of humanity’s attention but hasn’t quit mixing and moving and making ready. The scientists led by virologist Malik Peiris say the flu virus that the world feared last year has gone back into pigs in China, where it’s laying down and recombining its genetics with other flu strains. And, they say, we’re not sufficiently monitoring the danger of a new strain jumping back to people.
“Just because we’ve just had a pandemic does not mean we’ve decreased our chances of having another,” said Dr. Carolyn B. Bridges, an epidemiologist in the flu division of the Centers for Disease Control and Prevention. “We have to stay vigilant” [The New York Times].
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News that an Iowa cat has been diagnosed with swine flu has sparked a new round of concerns, as pet-owners worry both that their furry companions could get sick, and that their pets could pass the virus on to other humans. The 13-year-old, mixed-breed cat showed the symptoms of lethargy, sneezing and coughing typical to sick cats [ABC News]. The veterinarians who treated him say that several people in the cat’s home had been experiencing flu-like symptoms, and lab work confirmed that the feline had the H1N1 virus.
Happily, the cat is expected to make a full recovery. But both vets and public health officials are rushing to reassure the public that one sick cat probably does not indicate a coming crisis. While it’s possible that more cats will be diagnosed with the swine flu, vets point out that the virus was circulating for more than six months before the first cat case was discovered, indicating that the virus probably doesn’t jump from species to species very easily. Doctors also note that there’s very little chance that a cat will spread the virus to humans: Even when inter-species transmissions do occur, the H1N1 virus seems more likely to move from humans to animals, rather than the other way around [HealthDay News].
There have been no reported cases of dogs catching the virus, but there is one type of pet that is known to be vulnerable. Ferrets are generally susceptible to the seasonal flu, and the AP reported Wednesday that H1N1 infection has been confirmed in two ferrets, one in Nebraska and the other in Oregon. “Not only can they be infected with the flu but they are clearly able to transmit the flu back to people,” Treanor said [HealthDay News]. But the bottom line appears to be: Unless you’re a ferret-owner, you probably have nothing to worry about.
Related Content:
80beats: This Week in Swine Flu: How It Kills, Lawsuits, and a Pregnant Woman’s Story
80beats: This Week in Swine Flu: Vaccines Arrive, and Doctors Combat Myths
80beats: This Week in Swine Flu: Pregnant Women’s Concerns & Hospital Woes
Image: flickr / theogeo
As swine flu is now prevalent in 41 states, doctors are getting plenty of chances to study the workings of the disease. They now know that in severely ill patients, intense inflammation in the lungs prevents oxygen from being tranfered to the blood stream. Says physician Robert Fowler: “Most patients are still able to take breaths, but these breaths are ineffective” [Science News]. That oxygen deprivation can cause widespread organ damage.
The speed with which swine flu patients can go downhill marks the H1N1 virus as strikingly different from the seasonal flu virus, doctors say. “In severe cases, patients generally begin to deteriorate around three to five days after symptom onset. Deterioration is rapid, with many patients progressing to respiratory failure within 24 hours, requiring immediate admission to an intensive care unit” [Reuters], says World Health Organization doctor Nikki Shindo.
Doctors say that severely ill patients should promptly be put on breathing machines and given antiviral drugs like Tamiflu. In cases where patients’ respiratory systems have already crashed, some doctors are trying a treatment called extracorporeal membrane oxygenation, in which blood is extracted from each patient and passed through a machine that adds oxygen [Science News].
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Swine flu vaccines have arrived! Or more accurately, limited amounts of the first available vaccine, a nasal spray, have been delivered to distribution points around the country, and several states began vaccinating health care workers and young children on Monday. It’s not a moment too soon: The Centers for Disease Control and Prevention have announced that flu is now widespread in most of the United States. The infections are “overwhelmingly” pandemic H1N1 influenza, commonly known as swine flu. The flu season generally lasts well into May, so many months of uncertainties lie ahead [Los Angeles Times].
CDC director Thomas Frieden says that so far, vaccine “demand is outstripping supply, but we expect that fairly soon supply will be outstripping demand.” … Over the next two to three weeks, tens of millions of additional doses will become available [Los Angeles Times]. The injectable form of the vaccine will be ready for distribution next week.
Now that the vaccines have been successfully hustled off the assembly lines, the next daunting challenge for public health officials is convincing people to go get vaccinated. Myths and worries about the vaccine have spread on talk radio and anti-vaccine Web sites [The New York Times], with even celebrities like Bill Maher unhelpfully chiming in via Twitter. At a Tuesday press conference, Frieden strongly refuted one of the most commonly voiced concerns: that in rushing the vaccine through production, it wasn’t properly tested for safety.
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As the nation prepares for a massive vaccination campaign to protect the most vulnerable people from the swine flu virus, scientists are preparing to combat public fears over the vaccine. Scientists worry that the public (or at least the activists who are convinced, against all scientific evidence, that vaccines cause autism and other diseases) will misinterpret coincidental deaths as side effects of the vaccine.
As soon as swine flu vaccinations start next month, some people getting them will drop dead of heart attacks or strokes, some children will have seizures and some pregnant women will miscarry…. “There are about 2,400 miscarriages a day in the U.S…. You’ll see things that would have happened anyway. But the vaccine doesn’t cause miscarriages. It also doesn’t cause auto accidents, but they happen” [The New York Times], says Jay Butler of the Centers for Disease Control and Prevention.
The CDC is particularly focused on convincing pregnant women of the vaccine’s safety. A recent study in The Lancet reported strikingly high rates of death and of complications like pneumonia in pregnant women with H1N1 influenza. Pregnancy meant a fourfold risk of hospitalization, sometimes with a tragic outcome [The New York Times]. Experts note that pregnant women often avoid medications out of fear of harming the fetus, but say that these women should be among the first to get vaccinated for swine flu, and should swiftly start antiviral medications if they come down with the virus. To date, the virus has killed 28 pregnant women in the United States.
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Now that the first vaccines against swine flu are about to become available, scientists are busy working out the details of how the vaccines can best be administered. Researchers already knew that a single dose was sufficient to protect adults, and they’ve now found that one shot works for teenagers and children over the age of 10. But young children who have never had the flu or a flu shot, however, need two doses, they said…. Children 6 months to 9 years old received some protection from one shot, but not enough, so health officials will recommend that they get two shots 21 days apart [The New York Times].
At least 6 million doses of vaccine will be available the first week of October, federal health officials announced today, and this first batch is in the form of a nasal spray called FluMist. The intranasal vaccine has not been approved for children younger than 2, adults older than 49 or pregnant women, so it may go primarily to healthcare providers [Los Angeles Times]. Injectable vaccines should make it to doctors’ offices a week or two later.
New York State has taken the drastic step of requiring that all hospital, home health and hospice workers get the swine flu vaccine. Experts say the mandatory vaccination will protect not just the workers, but also their patients. But some workers are upset by the edict. Health workers’ union official Joel Shufro says the unions do not oppose vaccination “but we oppose a mandatory program,” he said. “This is: ‘You don’t get the shot, you’re fired’” [The New York Times].
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The big news in swine flu this week: Vaccines from four drugmakers have been approved for use in the United States, and with the companies’ production lines cranking there will be plenty to go around. Clinical trials have also shown that a single shot is enough to create a strong immune response, which means stockpiles will go twice as far as they would have if two shots were necessary. Said U.S. Health Secretary Kathleen Sebelius: “There will be vaccines for everyone.” … The first doses should be available within the next four weeks, according to the FDA [Reuters].
But as flu season is already ramping up, some people are wondering what they can do to protect themselves until the vaccine is available. One enterprising reporter decided to find out what her daily routine would be like if she wore a paper jumpsuit, mask, goggles, and gloves provided by a company called Flu Armor. But experts are reminding the public that face masks, which became a symbol of the initial outbreak in Mexico last spring, are really designed to stop the spread of droplets from the person wearing the mask, not to protect the wearer from viruses [Los Angeles Times].
The most effective preventive measure is also a simple one: wash your hands with soap often, or use an alcohol-based hand sanitizer. Experts note that hand-to-face contact has a surprising impact on health. Germs can enter the body through breaks in the skin or through the membranes of the eyes, mouth and nose [The New York Times].
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Let’s start with the good news: Clinical trials of the swine flu vaccines currently under production are showing that a single shot may be enough to protect a person against the H1N1 virus, rather than the series of two shots that was thought to be necessary. That means the vaccine supplies rolling off the pharmaceutical companies’ assembly lines will cover twice as many people. Experts say it should be possible to vaccinate — well before the flu’s expected midwinter peak — all the 159 million people that the Centers for Disease Control and Prevention estimate are in the high-risk groups: pregnant women, people under 24 years old or caring for infants, people with high-risk medical conditions and health-care workers [The New York Times].
In China, vaccinations are already underway, still Chinese health official Liang Wannian says the virus may well sicken tens of millions in the coming months. “The situation we face is not optimistic,” Liang said, noting that the virus had been found in all of China’s 31 provinces and regions [AFP]. While most cases won’t be severe, Liang says the sick could overwhelm the country’s hospitals and clinics.
While Chinese officials have said that vaccinations would start with high-risk groups, they also disclosed that people participating in the festivities of National Day on October 1st, which marks the 60th anniversary of the founding of communist China, will be at the front of the line. There are at least 200,000 official participants, plus thousands of security police. According to the BBC’s China analyst, Shirong Chen, they have been pushed to the front of the queue not just because it is a huge public event that carries national pride, but because all the top leaders and dignitaries will be in Beijing. The authorities cannot afford the political risk of any infection there [BBC News]. However, this prioritizing may leave less vaccine available for children, pregnant women, and health care workers.
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The week began with the news that Colombian president Alvaro Uribe had come down with swine flu while meeting with other South American leaders in Argentina. But Uribe is making a full recovery, and experts note that cases of the H1N1 flu are starting to taper off along with the influenza season in the Southern Hemisphere…. “All countries report that after mid-July, disease activity in most parts of the country decreased,” [Reuters], according to a U.S. government report.
Meanwhile, schoolchildren and college students across the Northern Hemisphere are heading back to school, and health officials are bracing for swine flu, round two. It’s already cropping up where conditions are right. Just as the football season is getting under way, Duke, Texas Christian and Alabama have reported cases of swine flu or of players experiencing flulike symptoms…. The strain tends to spread most quickly among young adults, who have not built an immunity to flu strains. Because the athletes share dorm rooms, cafeterias and sometimes unsanitary locker rooms, “it’s kind of an ideal situation for the flu,” said Artealia Gilliard, a spokeswoman for the Centers for Disease Control and Prevention [The New York Times]. Outbreaks were also reported at some colleges where women are attending sorority rush events before the start of classes.
Colleges have put a number of contingency plans in place to deal with outbreaks, including swine flu buses to spirit away the sick to infirmaries and drive-up vaccination clinics that will open as soon as vaccines are available, probably in early October. City education departments are also kicking their preventive machinery into high gear. On Tuesday, New York Mayor Michael Bloomberg announced that all primary school-age children in New York City will be offered free vaccines for seasonal and H1N1 flu this year [Reuters]. School officials in New York and elsewhere have said that they’re reluctant to close schools, as they did in the spring during the pandemic’s onset, because it disrupts parents’ work schedules and does little to halt the spread of the virus.
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Another day, another swine flu story: Amidst all the chatter, it can be hard to find the most reliable sources and relevant info. To keep you informed of the latest intelligence, 80beats will round up the news each week.
On Monday, the President’s Council of Advisors on Science and Technology issued an alarming report spelling out a “plausible scenario” for how the swine flu pandemic will play out during the coming flu season. The report estimated that the H1N1 virus could hospitalize 1.8 million Americans, potentially clogging emergency rooms and intensive care wards, and could kill up to 90,000 people in the United States. In a typical year, the seasonal flu virus kills about 35,000 Americans.
But on Tuesday, some public health officials walked back the report’s conclusions. One expert who helped prepare the report said that the numbers were probably on the high side, given that some weeks had passed since the calculations were finished in early August. “As more data has come out of the Southern Hemisphere, where it seems to be fading, it looks as if it’s going to be somewhat milder,” said the expert, Marc Lipsitch…. “If we were betting on the most likely number, I’d say it’s not 90,000 deaths; it’s lower” [The New York Times].
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Up to half of the U.S. population could contract swine flu this upcoming flu season, killing up to 90,000 people and hospitalizing 1.8 million, according to a report released by the President’s Council of Advisors on Science and Technology.
Americans lack immunity to the swine flu, which gives the virus the potential to infect more people than the seasonal flu generally does. And although many people who contract the disease might not show symptoms, and most would not be hospitalized, the pandemic would put a strain on the U.S. health-care system … because those patients could occupy between 50% and 100% of available intensive-care beds at the peak of the epidemic in affected regions, while ICU units normally operate close to capacity. Seasonal flu normally causes about 200,000 hospitalizations a year [The Wall Street Journal].
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Antiviral treatments such as Tamiflu should not be administered to children under the age of 12 because the risks of the drugs outweigh the possible benefits in lessening symptoms of swine flu, according to a study published in the British Medical Journal.
Although antiviral drugs can shorten the duration of the flu in children by an average of 1.5 days, they fail to fight certain effects of the infection, having little effect on the risk of asthma flare-ups, for instance. In fact, the drugs can bring dangerous side effects like vomiting, which can be dangerous because it puts children at risk of dehydration. In the research review, scientists looked at four trials of 1,766 children treated with antivirals, including 1,243 with confirmed flu, and three trials of 863 who were exposed to flu but didn’t exhibit symptoms and were treated with antivirals preventively. Only one trial looked at children with asthma [CBC]. Overuse of antivirals can also increase the risk of viral strains that become resistant to such treatments.
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