Stories tagged influenza

May
24
2009

Antigenic shift in flu viruses: is when at least two different strains of a virus combine to form a new subtype having a mixture of the surface antigens of the two original strains.
Antigenic shift in flu viruses: is when at least two different strains of a virus combine to form a new subtype having a mixture of the surface antigens of the two original strains.Courtesy National Institute of Allergy and Infectious Diseases (NIAID)

Model of H1N1 flu virus takes shape

Genetic analysis of the new H1N1 virus shows that the hemagglutinin (the H in H1N1) and two other genes are from the 1918 Spanish flu virus and have been living in pigs ever since. Studies also show that the neuraminidase (the N in H1N1) segment is from the Eurasian swine flu virus that probably leaped from birds to pigs in about 1979.

The new virus differs in 21 of 387 amino acids from the H5N1 virus and the 1918 Spanish flu (also an H1N1 virus). - Singapore’s Agency for Science and Technology Research report in Biology Direct.

Shape shifting viral surface challenges vaccination success

"Viruses isolated from patients during the first two weeks of the current outbreak already have changes on the outer surface on the neuraminidase protein that could interfere with antibodies against the virus or alter the effectiveness of future vaccines. But none of the changes have altered the parts of the protein targeted by antiviral drugs, such as Tamiflu or Relenza." Science News

Learn more
If you click through to the source article in Science News, you will see a great three dimensional model of the influenza A/H1N1 virus with the origin of each of the virus's pieces explained.

A new study has found that many Americans over the age of 60 have some immunity to the H1N1 swine flu virus. Using stored blood samples scientists at CDC have discovered that 1/3 of those over age 60 have antibodies that may help protect them from a new infection. It's likely that this is because they were exposed to a similar strain decades ago. If a vaccine is developed and is in short supply, this information may help scientists decide how to distribute doses of the vaccine. Right now most serious cases seem to be occurring in younger populations, which also have been shown to have fewer antibodies. This Washington Post article explains more.

May
17
2009

Cold noses are good for preventing bird flu

Don't let your children do this
Don't let your children do thisCourtesy KnOizKi

A recent study may explain why the bird flu has not become a pandemic. The human nose is too cold. Avian flu viruses prefer 104 degree F. The temperature in our noses is usually less than 90 degrees F. Critics of the study point out that it was only done in petri dishes so may not be an accurate reflection of what happens in humans.

Since the bird flu virus re-emerged in 2003, there have been only 423 reported cases. If the viruses manage to get into the lower lung, however, they replicate so quickly that 6 out of 10 victims (258) died.

The normal seasonal flu kills only 1 out of 1000 victims (250,000 to 500,000 people per year world wide).

Figuring the odds of a deadly mutation

Please comment what you think about this logic.

"When more people get the flu, the chances of a deadly mutation increases. Say the chance of a deadly mutation is one in a million. If 10,000 people get sick, the odds are 10,000/1,000,000 or 1/100. If a million people get sick the chance of a deadly mutation is almost a sure thing."

The new H1N1 virus appears to be more contagious

The percentage of contacts who catch the regular variety of flu from an infected person is between 5 and 15 percent, but current estimates for H1N1 being spread range from 22 to 33 per cent (according to WHO). Reuters via Yahoo News

As of May 15, 2009, 34 countries have officially reported 7520 cases of influenza A(H1N1) infection. World Health Organization

An intriguing mutation has been detected

The virus isolated from the second swine flu patient in the Netherlands has an intriguing mutation in a gene called PB2 that could mean that the virus has become better at spreading from person to person, a team of Dutch researchers reported on Friday on ProMED, a monitoring system for disease outbreaks. But they're the first to acknowledge that it could also be a red herring. Science Insider

You can make a difference

If you can behave in ways that prevent you from catching or spreading this new type of H1N1 flu, you will minimize the odds its changing into a more deadly form.

How would you direct research in a flu epidemic?
How would you direct research in a flu epidemic?Courtesy CDC
Imagine you're the director of the
Center for Disease Control, the US government’s top job for handling public health concerns.

Suddenly you’re faced with a new strain of flu, and must make a series of decisions over the course of a year on how to handle the outbreak. What will you do? Head on over to the Science Buzz swine flu feature and play the, "Swine flu: what would you do?" simulation. Test your decision-making ability to handling a possible flu crisis. See how your decisions compare with others who’ve tried this activity.

May
05
2009

So this is how it gets snotty: I thought it would be more subtle.
So this is how it gets snotty: I thought it would be more subtle.Courtesy The Rapscallion
Buzzketeers—quick, for your own safety, de-cash yourself now! Come on!

There’s a flu pandemic brewing, and y’all are just sitting there, lining your pockets with little green rags that carry as much disease as monetary value. So, please, for health’s sake, empty your wallets of cash, stuff those plague bills into manila envelopes, and send them to JGordon, The Science Museum of Minnesota, The Western Hemisphere (I don’t remember the exact address here, but I’m sure the postal service can figure out the details). I’m willing to sacrifice my health—for you—and disinfect your cash money. None of that money will be returned (please, I’m not made of postage), but I’m sure that the knowledge that you have done your part to slow the pandemic is compensation enough.

(This message goes doubly for the younger, or “lil,” Buzzketeers out there. I understand that you have less money, but your immature immune systems are particularly vulnerable to viral infection. Trust me on this one, and send those piggybanks my way.)

Do you not believe me? I think I’ve proven my scientific reliability time and time again… but here, a real link to a real story: cash is a pretty good way to transmit the influenza virus.

See, according to researchers at the Central Laboratory of Virology in Switzerland, a lonely lil’ flu virus on a fresh and clean piece of paper money can only live for about an hour. Unfortunately, viruses are rarely lonely, and our cash money is not very clean. So the researchers observed how long a virus could live on cash when it was mixed with a little nasal mucus (we’ll call it “snot”).

Under a cozy little film of mucus, the flu viruses were much hardier. Some strains of influenza lived as long as 17 days on the bill. And while the scientists didn’t test the exact strain of swine flu that we’re dealing with now, they did see how long other varieties of the H1N1 virus would last. H1N1 influenza remained viable (it could still infect someone) on the cash for up to 10 days.

It turns out that about 94 percent of dollar bills may carry pathogens (germs, viruses, etc). So let me shoulder this burden of worry, and let’s see that cash.

On to part 2 of this post…

Researchers at Northwestern University and Indiana University are also using money to study the spread of disease, but in a totally different way. It’s a little more complicated, and a little cooler.

Even if cash is totally clean, and doesn’t act as a vector for passing the flu, a cash transaction represents a face-to-face exchange between multiple people, the sort of encounter that could result in the flu virus being passed on.

And, hey, look: a project designed to follow the journey of individual dollar bills across the country.

The Northwestern and Indiana scientists took data from this bill-tracing project (called Where’s George?, and combined it with information on air traffic and commuter traffic patterns for the country to make a mathematical model of how people move and interact in the US. They then added information about the H1N1 swine flu into the system—the locations of confirmed cases, rates of infection, the time it takes to become contagious… that sort of thing. With all the variables taken into consideration, the model becomes incredibly complex—so complex that it takes a supercomputer about ten hours to make all the calculations, and come up with a forecast of where future infections will be, and how many of them we might expect.

But the model seems to work. Both universities, working independently, came up with strikingly similar models, and when predictions from the models were compared to real-life figures they matched up pretty well.

So far the models’ estimates have been slightly lower than actual infections, but they predict that there will be about 2,000 cases of the swine flu in the United States by the end of May, with most of those occurring in New York, Miami, Los Angeles and Houston. The researchers didn’t run any predictions beyond about a month, however. The flu, they say, as well as public response to it, are so unpredictable that using the models to look too far ahead doesn’t work. (The flu could mutate into something more virulent, or the government could do something drastic to control its spread, or, you know, we could get invaded by space aliens.)

(Liza, by the way, talked about these models a little last week.)

How about that? Money follows us around, viruses follow us around, viruses follow money around, and we trade all of it.

Here’s the link to Northwestern’s flu model

Here’s the link to Indiana’s model.

The Texas Department of State Health Services announced today that they're attributing a second US death to the A/H1N1 virus. The Cameron County woman, who had unspecified underlying health problems, died earlier this week. The CDC also reported that, so far, 35 people have been hospitalized in the US. However, the new flu virus doesn't seem as dangerous as public health officials feared last week. And because of that, and because the strategy no longer seems to be containing the spread of the disease, federal officials rescinded the recommendation that schools close when they discover suspected cases of the flu.

Official CDC case counts

May
04
2009

Not to freak y'all out, but did you know that germs are on everything you touch? Using a special powder called Glo Germ (get it here) you can actually see how germs spread from one thing to another. It will make you want to wash your hands more often. (And the CDC recommends washing your hands frequently. In fact, why don't you go wash up right now?)

Scrub 'em: Use soap and water, and wash for 20 seconds. That's about the time it takes to sing the "Happy Birthday" song twice.
Scrub 'em: Use soap and water, and wash for 20 seconds. That's about the time it takes to sing the "Happy Birthday" song twice.Courtesy mitikusa

TRY THIS:
Goal: to observe how germs are spread
Age level:: 3 and above
Activity time: 2 - 5 minutes
Prep time: 5 minutes

Materials needed:

  • Glo Germ powder
  • Toys or common household/school/office objects to "spike" with germs
  • UV lamp or detector box

Preparation:

  1. Sprinkle Glo Germ powder on your objects.
  2. Arrange them somewhere where others can handle them.
  3. Plug in UV lamp, but don't turn it on.

Directions:
Encourage others to pick up and play with the objects. Ask them what they know about germs.

  • Do you know where microbes are found?
  • Do you know what a microbe/germ is?
  • Do you know what illnesses are caused by germs?
  • Do you know the best way to avoid getting sick because of germs?

After the discussion, tell them that, as part of an experiment, you've put "pretend" germs on one or some of the objects they may have touched today. Switch on the UV lamp: what glows?

Reinforce the fat that the Glo Germ powder is just to simulate germs. It won't make you sick. You can get rid of the germs by washing your hands. In fact, encourage your audience to wash their hands and then hold them under the UV light again.

(On the other hand, remember that not all germs are bad. Exposure to some germs is thought to protect people against asthma and allergies or colitis, and overuse of antibacterial products leads to antibiotic resistance and superbugs as well as potential damage to the environment.)

Vincent Racaniello, a professor of microbiology at Columbia University Medical Center, is blogging about the 2009 H1N1 swine flu. He's answering questions and addressing comments, but he's also posting daily about new developments and basic influenza virology. Fascinating...