infectious disease
tsmith | May 4, 2006The latest edition of Animalcules, the microbial blog carnival, is up over at Discovering Biology in a Digital World. A nice little collection today; and for those of you who are interested in stuff for the kiddos, be sure to check out her links to the American Society for Microbiology's Microbe World activities.
Another programming note--I'll be back out playing with cows for much of the day today. Have a few posts scheduled, but I won't be around much if comments need approved, etc. Please be patient--thanks!
tsmith | May 3, 2006It's been awhile since I've discussed prions on here. (Indeed, so long that the last time was on my old blog, but I imported a few of them that can be found here, here, and some background on prions here). Allow me to copy a bit of that to re-introduce the topic:
Prions are, of course, the transmissible agents that cause diseases such as kuru and Creutzfeldt-Jakob in humans, and related disease such as "mad cow" disease, scrapie, and chronic wasting disease in animals. Though there was initially much controversy about these agents in the early years (most notably, because they did not…
tsmith | May 2, 2006I see that Hank's still touting his "Padian found ZERO seroconversions among 176 discordant heterosexual couples over 6 years" line, even after that study was extensively analyzed here (and his ideas about it were shown to be mistaken). At least he's dropped it from 10 years down to 6 years--progress, I suppose. He's now discussing a new MMR report that documents 88 HIV transmission events over a 17-year period in Georgia prisions. Despite the fact that Hank doesn't dispute that these sexual transmission events occurred (noting that the "infectivity is low, low, low"), Hank still ends his…
tsmith | May 1, 2006[From the archives; originally published Nov. 3, 2005]
Ebola is one of my favorite pathogens. With the reputation it has, many people assume it's killed many more worldwide than it actually has. People hear of Ebola and all kinds of grotesque images come to mind: organs "liquefying" (doesn't really happen quite like that); bleeding from every orifice (okay, that one can be on-target); the victims dying a horrible death from a virus with an incredibly high mortality rate. There are four known subtypes of Ebola, named for their place of isolation: Ebola Reston, Ivory Coast, Sudan, and Zaire.…
tsmith | April 29, 2006More topics I'd have covered this week, given endless time and energy:
An update on the Chikungunya outbreak I discussed here (and see this comment on the outbreak from a medical entomologist in the region dealing with it first-hand).
Orac on viruses as cancer treatment, inspired by a recent episode of House (more episode reviews by Scott at Polite Dissent can be found here).
An update on mumps activity from the Iowa Department of Health. I haven't written about this in a few days because there's not much more to tell. Cases are still increasing, and they're recommended that students…
tsmith | April 28, 2006Nanotechnology. What does it mean to you? How does it affect health? Does the phrase only conjure up images of Crichton-esque nanobots with a sinister motive?
Nanotechnology is a field defined solely by its size. By definition, it involves the manufacture and manipulation of materials at the atomic or molecular level--materials which are typically less than 100 nanometers in diameter. (For comparison, a human hair is roughly 50,000 nm thick, and a piece of paper 100,000 nm thick).
This technology has potential applications in a host of fields. For example, it's been used as a…
tsmith | April 26, 2006Novel Swine Influenza Virus Subtype H3N1, United States
In several of my influenza posts, I've discussed ways that the viruses can evolve. These are termed "antigenic drift," where the virus accumulates small mutations in the RNA genome; and antigenic shift, where large sections of the genome are swapped, generally in their entirety. While it was long thought that the latter was the most likely type of mutation to cause a pandemic, we now know that even the right kind of antigenic drift may be enough to allow a novel influenza virus to enter the human population, which seems to have…
tsmith | April 25, 2006...whereby the Catholic church may be more accepting of condom use (and discussion thereof) than some American "sex education" classes.
tsmith | April 24, 2006So, I've had this research article on multiple drug-resistant Salmonella in the drafts section for about a week now, waiting for me to do a bit of background research before commenting on it. (Anything involving Salmonella always makes me a bit hesitant--one almost needs a PhD on the bacterium just to keep up with the nomenclature). This morning I'm doing my quick glance-through of my blogroll, and lo and behold, what do I find but these posts by Mike the Mad Biologist, who just happens to have been quoted in the New York Times write-up of the research.
Michael Feldgarden, who helps…
tsmith | April 22, 2006Again, I never get to discuss all the topics I find interesting. So to keep you busy over the weekend, check out a few that I didn't have time to emphasize this week:
Neurotopia on the zombies among us.
Orac's series on medicine and evolution:
Part 1
Part 2
Part 3
Part 4
Part 4a
New studies suggesting that mercury fillings aren't harmful.
Can you name that virus over at Buridan's ass?
Professional societies spurning women editors? (More here from Evolgen).
Ewen on the science behind the recent monoclonal antibody drug trial gone bad.
The National Science Foundation website is up for a…
tsmith | April 21, 2006Skeptics warn bird flu fears are overblown
Doomsday predictions about bird flu seem to be spreading faster than the virus itself. But a small group of skeptics say the bird flu hype is overblown and ultimately harmful to the public's health.
There's no guarantee bird flu will become a pandemic, and if it does there's no guarantee it will kill millions of people. The real trouble, these skeptics say, is that bird flu hysteria is sapping money and attention away from more important health threats.
While I agree with some points the so-called "skeptics" make (we don't know if H5N1 will become…
tsmith | April 21, 2006California woman hospitalized with plague
Health officials in Los Angeles have confirmed the city's first human case of bubonic plague in more than two decades.
They say a woman, who was not identified, was admitted April 13 with a fever, swollen lymph nodes and other symptoms. A blood test confirmed she had contracted the bacterial disease. Officials said she was placed on antibiotics and is in stable condition.
Though this case is notable because it's the first one reported in Los Angeles in decades, plague is endemic in many areas of the United States, though it's infrequently transmitted…
tsmith | April 19, 2006According to msnbc:
Normally adventurous Chinese diners are eating fewer owls, civets and other wildlife due to fears of SARS and bird flu, according to a survey released Tuesday by U.S. and Chinese conservation groups.
The survey of 24,000 people in 16 cities found that nearly 72 percent had not eaten wild animals in the past year, up from 51 percent in a similar 1999 survey, said San Francisco-based WildAid and the official China Wildlife Conservation Association.
For those who may be unfamiliar with civets, they're almost like a cross between a cat and a weasel, and have been linked to…
tsmith | April 17, 2006Seems Janet has been a bit under the weather...and has taken to haiku to describe her ailments. I think this should be the new format for journal case reports.
In other news, I'm heading off to my son's preschool class later this morning to give a talk on germs and hand-washing (and a bit about being a scientist in general, since they're discussing careers and community helpers this month), so blogging will be light today. Tomorrow I'm giving a talk out of town in the evening that I still have to polish a bit, but I have a few things in the hopper to keep you busy until I'm back up to…
tsmith | April 15, 2006I don't know how other bloggers decide what to post. For me, everytime I run across a "oh, that would be so cool to discuss" topic/link/story etc., I copy the topic/link/story etc. into a new entry here, hoping to have time to elaborate on it at a later date. Some of them I get to--some of them just drift slowly to the bottom of the pile, untouched. But they're still interesting topics, so here are a few more that I didn't have time to write about, and as new topics come up, probably won't be able to get to in the immediate future:
A recent CNN story referring to the hygiene hypothesis.…
tsmith | April 14, 2006If you're in the food service industry, don't go back to work while you still have an intestinal bug. Or, fer crimeny's sake, at least wash your hands thoroughly.
The majority of cases of foodborne gastroenteritis in the United States are caused by noroviruses. This report summarizes an investigation by the Kent County Health Department (KCHD) in Michigan into three norovirus outbreaks and a cluster of community cases that were associated with a national submarine sandwich franchise restaurant during May 3--9, 2005. The investigation identified a potential source, a food handler who had…
tsmith | April 13, 2006Orac highlighted here a post over at Vox Populi which doubted the effectiveness of the mumps vaccine, in light of the recent epidemic in Iowa. I was prepared to write a whole post on the math of it, but Mark at Good Math, Bad Math saved me some work. Nevertheless, I have a few things to add after the jump.
As has been mentioned, the given efficacy rate for the mumps vaccine is 95%. This is actually likely a bit high; previous outbreaks have suggested it's more like 85-90% effective, so that as many as 15% of the vaccinated population won't actually be immune. The key to telling whether…
tsmith | April 13, 2006 Okay, so I lied. I was planning to wrap up the emerging diseases and zoonoses series with the post on monkeypox, but I think I'll just continue it as a sporadic event, since a new paper fits into the series perfectly.
I talk a lot here about streptococcus. As regular readers know, there's a good reason for that. Though my main research right now is on Streptococcus agalactiae (group B streptococcus, GBS), I also have a project working on a related organism, Streptococcus suis. As the "suis" name suggests, this is mainly a pathogen of swine. Indeed, it's kind of the pig equivalent of…
tsmith | April 12, 2006 A new study in the journal Pediatrics suggests this common procedure may improve the condition of kids diagnosed with attention defecit/hyperactivity disorder (ADHD). I think it's an excellent case of some true "alternative explanations" for the data.
Creationists often try to validate their position by saying that both they and mainstream scientists start from the same data, but that creationists use their "Bible glasses" to interpret it, while scientists view it through their "evolution glasses." In other words, they're not wrong--it's just a different interpretation of the same data,…
tsmith | April 11, 2006I attended a lecture yesterday given by Patty Quinlisk, Iowa's state epidemiologist. The bad news: there have been over 500 reported cases of mumps as of Monday, April 10, with more cases in neighboring states (30-50 in Nebraska, for example). She did, however, give a bit more history on the epidemic, described below.
The outbreak can be traced back to last December, when 2 cases were found to be IgM-positive for mumps. (IgM is the first type of antibody produced to a new infection; therefore, this is diagnostic of a current infection, whereas looking at a different type of antibody--…