Stories tagged infectious disease

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...

May
01
2009

A research group led by Dirk Brockmann at Northwestern University has created a computer model that predicts the spread of the 2009 H1N1 influenza virus in the US. (It uses a complex set of mathematical equations to describe the movement of people and virus.)

How can you track and predict the movement of something so small?: Follow the money, of course! (This is a colorized negative stained transmission electron micrograph (TEM) showing some of the ultrastructural morphology of the A/CA/4/09 swine flu virus. Got that? Good.
How can you track and predict the movement of something so small?: Follow the money, of course! (This is a colorized negative stained transmission electron micrograph (TEM) showing some of the ultrastructural morphology of the A/CA/4/09 swine flu virus. Got that? Good.Courtesy CDC/C.S. Goldsmith and A. Balish

(Brockmann was a guest on Minnesota Public Radio's Midmorning show today, and you can listen to it online.)

The good news is that, based on what we know now, and assuming that no one takes any preventive measures, we could expect to see some 1,700 cases of swine flu in the next four weeks. Because of the preventive measures being taken wherever a suspected case of H1N1 flu has popped up, we should actually see fewer cases. (You can see Brockmann's models here.) That's lousy if you're one of the folks who picks up the virus, but not a devastating number of cases. Of course, this is a rapidly developing, fluid situation, and things may change. Still, tools like Brockmann's model help to ensure that emergency supplies and other resources get to the places likely to need them most before they're needed.

Professor's Computer Simulations Show Worst-Case Swine Flu Scenario from Northwestern News on Vimeo.

Don't have faith in computer models? Well, a second research group at Indiana University is using another model, with different equations, and getting very similar results. That's a pretty good indication that the predictions are reliable.

You might remember Brockmann from a 2006 study that used data from WheresGeorge.com, a site that allows users to enter the serial numbers from their dollar bills in order to see where they go, to predict the probability of a given bill remaining within a 10km radius over time. That gave him a very good picture of human mobility, reflecting daily commuting traffic, intermediate traffic, and long-distance air travel, all of which help to model how a disease could spread.

Apr
30
2009

Department of Health and Human Services
Department of Health and Human ServicesCourtesy Department of Health and Human Services

H1N1 Flu information

If you want valid information about Influenza A(H1N1), You should first check out the official disease control websites.

Here are some of the official web pages of our national and world leadership for information about fighting disease.

Also embeded is a webcast where public questions about the 2009 flu pandemic are answered by Acting Director of CDC, Dr. Besser.

Use the links below for official information about Influenza A(H1N1)

  1. Centers for Disease Control and Prevention
  2. PandemicFlu.gov
  3. CDC H1N1 flu information
  4. H1N1 Flu questions & answers
  5. World Health Organization info

President Obama's flu message

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Watch a webcast answering questions about the 2009 flu pandemic

Apr
30
2009

Is this the face of a pandemic threat?
Is this the face of a pandemic threat?Courtesy The Pug Father
No need to put down your pork chops, as health officials are quick to remind us: you can't get swine flu from eating products made from pigs. In fact, health officials have yet to find a pig with this particular strain of the virus. According to the CDC, the virus that's been making headlines this week contains not only pig, but also human and bird flu DNA. Viruses are complicated and mutate as they go from one host to the next, so it's difficult to tell just where novel strains originate. All of this has left many people to question whether it's appropriate to call the virus "swine flu" at all?

Pork producers say: leave pigs out of this!

They're afraid that the name "swine flu" will cause demand for their products to plummet, and have asked government officials and the news media to call the virus by it's scientific name, H1N1, which refers to the serotype of the virus - its particular chemical make-up. It's a rational fear on their part. Some countries have already banned meat and pork products from Mexico and parts of the US due to fear over the spread of the disease.

What do you think? Would a flu by any other name...smell like meat? When it comes to novel viruses like this one, what's in a name?

Apr
26
2009

Pandemic prevention in Mexico City
Pandemic prevention in Mexico CityCourtesy Chupacabras

No mass at Cathedral of Mexico City Sunday

In addition to churches, Mexico closed schools, museums, libraries and theaters, hoping to contain the outbreak of a swine flu variety that is killing people. Officials say as many as 81 people have died and more than 1,300 others are sickened from a new type of flu.

The virus contains genetic pieces from four different flu viruses; North American swine influenza, North American avian influenza, human influenza A N1H1, and swine influenza viruses found in Asia and Europe.

Swine flu symptoms

Symptoms of the flu-like illness include a fever of more than 100 degrees Fahrenheit (37.8 degrees Celsius), body aches, coughing, a sore throat, respiratory congestion and, in some cases, vomiting and diarrhea. Click this link for more key facts about swine influenza (swine flu).

Global swine flu alert

China, Russia and Taiwan plan to put anyone with symptoms of the deadly virus under quarantine. Ten students from New Zealand who took a school trip to Mexico "likely" caught this swine flu. Four possible cases of swine flu are currently under investigation in France. More than 100 students at the St. Francis Preparatory School, in Queens, New York recently began suffering a fever, sore throat and aches and pains. Some of them had recently been in Mexico.

"The United States government is working with the World Health Organization and other international partners to assure early detection and warning and to respond as rapidly as possible to this threat," Dr. Richard Besser, acting director of the CDC, said during a Friday afternoon press briefing.

How to track illnesses globally

There are several useful online resources that track health information and disease outbreaks.

  1. The World Health Organization (WHO) has an Epidemic and Pandemic Alert and Response (EPR) webpage.

    As of 26 April 2009, the United States Government has reported 20 laboratory confirmed human cases of swine influenza A/H1N1 (8 in New York, 7 in California, 2 in Texas, 2 in Kansas and 1 in Ohio).

  2. HealthMap is a website that aggregates news feeds from the WHO, Google News, ProMED, and elsewhere to map out all of the disease outbreaks. (Click the box in front of influenza under "Diseases, last 30 days" to see just flu cases.)

What is a pandemic?

The WHO's pandemic alert level is currently up to phase 3. The organization said the level could be raised to phase 4 if the virus shows sustained ability to pass from human to human. Phase 5 would be reached if the virus is found in at least two countries in the same region.

"The declaration of phase 5 is a strong signal that a pandemic is imminent and that the time to finalize the organization, communication, and implementation of the planned mitigation measures is short," WHO said. Associated Press

Phase 6 would indicate a full-scale global pandemic.

Sources:

I thought we were done with the flu season this year - but the CDC reports seven cases of a new strain of swine influenza A (H1N1). Check out the CDC alert and this Reuters article.

Most insecticides work by killing bugs before they get the chance to grow and reproduce, but a new research study suggests that when it comes to mosquitos and malaria, this strategy might be part of the problem. Killing young mosquitoes increases the selective pressure on the population to develop resistance to pesticides. This means that any given pesticide will stop working shortly after it is introduced, making it harder to fight the disease, which is caused by parasites and spread by mosquitoes. By killing the mosquitoes when they are older, but before they are old enough to spread Malaria, scientists believe they can prolong the effectiveness of pesticides and save lives. This article explains more about their ideas. Learn more about malaria and share your thoughts on Science Buzz.