Tag Archives: microbes

Keeping up with all the flu news

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A lot of people are wondering, Just how dangerous is the swine flu virus? (More formally known as, 2009 H1N1.)

The word from epidemiologists is: Not very dangerous, for most of us.

However ….  It’s quite dangerous to people falling in certain categories.  Watch out if you are: a pregnant women, a baby, elderly, immune-compromised, morbidly obese.  Or, if you have: any lung disease or disorder, an underlying chronic health problem.  (More details on this at the federal flu website.)

H1N1 virus particles invading body tissue. (CDC)

H1N1 virus particles invading body tissue. (CDC)

The easiest way to think about swine flu is that it’s remarkably similar to regular flu, except it spreads more rapidly.  Most people get only mildly sick and are better in three days or so.  I was surprised to hear epidemiologist Jeff Duchin of Public Health Seattle & King County go so far even as to urge most of us not to call the doctor.  There’s too much over-crowding as it is.

But there is some research that indicates this virus might be a little more dangerous than seasonal flu—especially for those in the “vulnerable” list I mentioned above.  For example, one team of researchers (at Imperial College in London) found the novel H1N1 flu virus lodges deeper in the lungs than regular flu virus.  That enables it to cause more severe lung infections and may account for some of the fatalities.  But it also is less aggressive in the nose and throat – making most infections less severe.

The message from this is, if you notice complications, such as breathing problems, don’t delay seeking medical help.  The best way I’ve found to sort all the usual questions is via Children’s Hospital of Atlanta, on their website.

Other tidbits:

  • The vaccine tests are full of good news. It appears to be highly effective and can be given in a single dose.
  • The first vaccine shipments may arrive on time, or even in early October.

Other recent posts and stories:

Malaria and the Holy Grail

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Ah, the dilemma of Hope vs. Hype. I reported earlier this week that medical researchers and global health activists (including many at PATH in Seattle) are feeling a bit of success in the latest test of a malaria vaccine. It appears, so far, to be the best hope for protecting people living in malaria-infested areas. Malaria kills about a million people every year, mostly children in sub-Saharan Africa.

What I only mentioned, but didn’t have time in my radio report to explore, was the fact that the vaccine is still barely more than 50% effective. There’s no telling whether it will be better or worse than 50% once it gets into a less controlled context, in a final field trial that starts next year.  It likely will leave roughly half the population unprotected.

There are other potential malaria vaccines in the pipeline.  If any of them proves practical and at least partially effective, then you might combine two vaccines, and maybe make a big difference.  This would be like creating the “cocktail” of drugs that are helping AIDS patients survive.

Other researchers say we need a vaccine that’s at least 90% effective, ore else we’re going to allow malaria to remain the scourge of Africa.  But, there are vast challenges (scientific, technical) in creating a vaccine that good.  One candidate comes from Stefan Kappe’s lab at Seattle Biomedical Research Institute.  You can listen to my profile of him from last year, or read a recent profile by Luke Timmerman at Xconomy.com.

And, there are entire websites devoted to debunking all this as hype.

I think it’s great for science and possibly for human welfare that the Gates Foundation and others are funding this research into malaria.  But, for the next decade at least, it looks like old-fashioned remedies will have to do.

Microbes on the beach

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More on microbes. This time, it’s the effort to understand the vast number of species that live all over our environment. Most of these (like 95%) can’t be grown in the laboratory, so they haven’t been studied much. For the past decade there’s been a rush to use new DNA sequencing technologies to identify and learn about these bacteria. That’s how we became aware of how little we know.

One effort along these lines is happening in my backyard, or not far from it. A group at the University of Washington is sampling mud from Lake Washington. They’re developing ways to pinpoint species that live there, focusing on bacteria that subsist on methane and related compounds. If you’re interested, you can read a summary from the press release, or visit the lab’s website.

Spicy microbes

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Ecology is full of surprises. And often those surprises have to do with microbes. I’ll write more about microbes in the coming months. I was lucky this week to be able to write about chili peppers and the strange ecology that allowed them to evolve spiciness.

Short version: Josh Tewksbury at the University of Washington, and a team of researchers, found that the spicy substance inside peppers acts as a defense against a fungus. That fungus destroys the seeds inside the peppers. (It turns them black and generally very gross looking.) In climate zones where the fungus grows more readily, the peppers evolved to be spicier. Specifically, they produce more capsaicin. The same chili species in drier zones is not spicy at all.

But what makes it not just interesting, but fascinating, is the three-way relationship between the chili plant, the fungus and a tiny insect. Without all three, the world would be full of bland food.

The insects, as Tewksbury describes them, have mouths shaped like drill bits. They drill into the chili fruit and into the seeds, and eat the nutritious inside of the seeds. They can do a lot of damage, but they don’t destroy all the seeds. However, the holes they drill allow the fungus to get inside the waxy fruit surface and seed surface. By secreting a spicy substance around the seeds, the plant keeps the fungus at bay, just enough to keep the fruit and seeds looking healthy.

As long as the chili peppers look tasty, birds will eat them, as birds are not sensitive to spiciness. And birds are the main distributors of chili pepper seeds.

If you take any of the creatures out of the system, you don’t get spicy habaneros or jalapenos or any of the other peppers we know and love. In fact, all spicy peppers, along with sweet peppers, evolved in the dry forests of Bolivia, Argentina and Paraguay. People bred many varieties from just a few core species. They spread around the world, including to India and Thailand, only post-Columbus.

Wow.