General Epidemiology
tsmith | July 17, 2006Listeria monocytogenes is a gram-positive, rod-shaped bacterium. It can be found in the environment as a soil inhabitant. However, it also can be a frequent contaminant of our food supply. As the latter, the bacterium is a significant public health concern, as it is capable of causing serious infections. Listeriosis (infection with Listeria) causes ~2500 serious illnesses and 500 deaths each year in the United States, and the hardest-hit are those with poor immune systems due to age (the very young and old), other immunocompromsing conditions (such as chemotherapy, organ transplant, or…
tsmith | July 13, 2006I mentioned in this post on Ebola that I thought the authors were doing a bit too much extrapolation regarding their statement that the evolution of sociality in hominids has been constrained by pathogens such as Ebola. I didn't elaborate on that topic because it's a bit too far afield from my areas of expertise, but John Hawks has much more on the topic of pathogens and fitness in primate groups.
tsmith | July 12, 2006 The good Dr. Flea has taken some flack previously for comments he's made regarding the treatment of ear infections (or rather, the non-treatment of such). As he notes, most ear infections resolve without antibiotics. Despite this, ear infections are the most common illness for which children visit a pediatrician, receive antibiotics, and undergo surgery in the U.S., at a huge economic cost. A new paper in the Journal of the American Medical Association suggests at least some of that cost is wasted, because the bacteria are present in the form of antibiotic-resistant biofilms.
A biofilm…
tsmith | July 11, 2006 Longtime readers know of my fascination with Ebola. Much of it is fueled not by the fact that it's a major killer of humanity, because it's not: in 30 years, it's been responsible for a bit less than 2,000 human infections, and ~1,200 deaths. Bats have long been suspected to be a reservoir of the virus, and recent studies have confirmed that they can carry the virus.
With at least one strain of Ebola (Ebola Reston), we know that our primate cousins are more severely affected than we are. This strain has been found to infect captured primates brought into the United States from the…
tsmith | July 11, 2006If you're a parent, I'm sure you've had all kinds of people give you advice in myriad different areas. Many of them may be in-laws or friends or relatives with children themselves; or they might be strangers in the street with brilliant (or, not-so-intelligent) ideas on how to get your kid to stop throwing a temper tantrum (phrased a bit less politely, "shut that freakin' kid up!"). Or, they may be Evil Monkeys trying to get you to dose your kids with Benadryl to get them to sleep. However, Evil Monkey owns up to his wrong-headed acceptance of folk medicine, linking an article showing that…
tsmith | July 10, 2006Ames, Iowa may not exactly be thought of as a major tourist destination, or sporting venue. Last week, however, it was both, as the host of the first ever Special Olympics USA National Games, with Ames serving as an "olympic village." Most of it went off rather smoothly, but it also became newsworthy for another reason:
Illness identified at Special Olympics
Several people affiliated with Special Olympics teams who fell ill this week have tested positive for norovirus, a common cause of what is known as the stomach flu, state health officials announced Saturday.
Overall, 52 people…
tsmith | July 8, 2006Holy cow, it's Saturday again already. Since this was a short week, I didn't have as much time for posts or for story-gathering, but there are still a few goodies I missed:
I was planning on highlighting this new research that showed, once again, no link between vaccination and development of autism. But then I decided not to re-invent the wheel, as Orac already covered it extensively.
Similarly, Mike highlights a story drawing attention to the under-diagnosis of influenza in children, and its ramifications on the health of the rest of the population.
Malaria continues to be a scourge…
tsmith | July 7, 2006Those of you who have followed creationism/intelligent design literature over the years have probably felt as if you're living in an alternate universe sometimes. In that literature, many times it seems as if "up" means "down" and "highly supported by the evidence" means "a theory in crisis."
You may not have been following the comments to this thread on AIDS (and lord, I can't blame you), but if you have been, you've seen a similar phenomenon, where it's suggested that mutations found in RNA viruses are just due to sloppy lab work, essentially blowing off an entire field of research.…
tsmith | July 6, 2006 Some towns have all the luck. Brainerd, Minnesota, population ~13,000, was previously famous as the home of Paul Bunyan, and the setting of the Coen brothers' film, Fargo. Little did I know it had another claim to fame: its very own brand of mysterious diarrhea. All about it after the jump.
Brainerd was the site of the first outbreak of this eponymous diarrhea back in 1983. It is described as an idiopathic syndrome--meaning that we don't have a clue what causes it. The diarrhea is acute in onset, explosive and watery, can last for months, and doesn't respond to antibiotic treatment…
tsmith | June 30, 2006 One of the things I love about science--but that can also be frustrating--is that every new piece of information leads to a new unanswered question. We've learned so much about microbiology and human disease since the time of Koch and Pasteur, but in many other ways, we're still at square one. One reason is because research over the last century has largely focused on disease-causing organisms--and within those, many studies have focused on identifying factors that allow these organisms to cause disease. This concentration has led to many breakthroughs (such as vaccine targets), but it…
tsmith | June 29, 2006 People make terrible jokes about "mad cow" disease. ("Why is PMS called PMS? Because mad cow was already taken.") Pundits use it as an example of an over-hyped disease (and to be fair, estimates of total cases due to the consumption of contaminated beef in the UK have varied widely, ranging from a few thousand up to well over 100,000). Vegetarians note it as one benefit that comes from their soyburgers. Everyone, it seems, has an opinion.
So-called "mad cow" disease, in humans, is a progressive neurological disorder more correctly called variant Creuzfield-Jacob disease (vCJD).…
tsmith | June 28, 2006 Especially in religious circles, much has been made about the "uselessness" of condoms for the prevention of infection with the human papilloma virus (HPV). This is the virus that is responsible for almost all cases of cervical cancer, against which a new vaccine was recently approved (for more background, see this post). Approximately 20 million Americans are currently infected with HPV, and over their lifetime, about half of sexually active adults will be infected at one point. Though most strains of the virus are harmless, a small portion of them cause cervical cancer in women, a…
tsmith | June 28, 2006One of the things that faculty get to do is go to lots and lots and lots of meetings. Today I'm at a 6-hour retreat focused on distance learning, PubMed, and data repositories. (I know, you're all seething with jealousy). I hope to have another post up later this afternoon if I can get to it; in the meanwhile, here are a few notable posts from elsewhere:
Revere at Effect Measure has an overview of H5N1 over the last 6 months, and discusses why SARS and West Nile aren't "false alarms."
Coturnix brings you a potpourri of science news. He also has a DonorsChoose update--check out how…
tsmith | June 27, 2006 I blogged a few months ago about a case of plague (due to the bacterium, Yersinia pestis) in a woman in California. I'm still doing some reading for the promised post on Black Death, CCR5, and other topics discussed in the comments section, but in the meantime, I wanted to alert y'all to an ongoing outbreak of the disease (in the pneumonic form, meaning the bacteria is present in the lungs and therefore is person-to-person transmissible) in the Democratic Republic of Congo:
The sole aid agency fighting an outbreak of pneumonic plague in the remote lawless corner of the Democratic Republic…
tsmith | June 19, 2006[From the archives; originally posted November 28, 2005]
Have you ever wondered how Kevin Bacon and the lights of fireflies related to malaria and power grids? I know it's something that's kept me up many a sleepless night. One word: interconnections.
Many of you have probably heard of the "Six degrees of Kevin Bacon"game. This is based on the work of Stanley Milgram beginning in the 1960s, and brought up again more recently in a 1998 Nature paper, "Collective Dynamics of 'Small-World' Networks," by mathematicians Watts and Strogatz. Milgram conducted a number of studies using his "lost…
tsmith | June 16, 2006[From the archives; originally posted October 20, 2005]
Measles is one of those diseases that we don't give much thought to in the United States anymore. Following an incubation period of about 10 days, flu-like symptoms appear: fever, malaise, cough, congestion, conjunctivitis. Soon, the rash appears, first near the ears, then the forehead, the face, and over the rest of the body. Complications were common. These could include a seconary bacterial pneumonia, encephalitis, myocarditis, miscarriage, and a condition called subacute sclerosing panencephalitis (SSPE).
(Continued below...)
SSPE…
tsmith | June 16, 2006Welcome to the June edition of Animalcules! Apologies for the lateness; I only had a few minutes to get online yesterday, and that was mainly devoted to checking email and making sure there were no crises that needed my attention. So, without further ado...
From the Scientific Creative Quarterly comes a humorous entry: Prokaryotes of America Unite. Almost makes me feel bad. (You also may want to check out Scientific Creative Quarterly editor David Ng's new blog here at Scienceblogs: The World's Fair.
Jennifer over at Science Matters has a nice post discussing background information on…
tsmith | June 15, 2006[From the archives; originally posted November 16, 2005]
I know, everyone's so sick of all the new "omics"es. But "metagenomics" is one that I don't see going away anytime soon. At its core, metagenomics is a way of looking at organisms in concert as a complex ecology, rather than as an individual, as genomic analysis has traditionally been done. Rather than isolating 10 different species of bacteria from, say, a gram of soil and analyzing them all separately, a metagenomics strategy would investigate all the organisms in the soil (or in sea water, dental plaque, or even human feces). A huge…
tsmith | June 14, 2006[From the archives; originally published November 18, 2005]
Malaria is one of the world's leading infectious killers. World-wide, almost 40% of the world's population is at risk of acquiring this disease--many of them in poor countries with limited resources to control the disease. Each year, malaria causes 300-500 million infections, and up to 3 million deaths--about 5000 Africans die of the disease every day; one child succumbs every 30 seconds. Mosquito-borne, simple devices (such as mosquito nets over beds) have been shown to drastically decrease the incidence of disease. Though these…
tsmith | June 13, 2006Sunday's New York Times has an article discussing the worldwide increase in diabetes:
The number of people around the world suffering from diabetes has skyrocketed in the last two decades, from 30 million to 230 million, claiming millions of lives and severely taxing the ability of health care systemsto deal with the epidemic, according to data released Saturday by the International Diabetes Federation.
While the growing problem of diabetes in the affluent United States has been well documented, the federation's data shows that 7 of the 10 countries with the highest number of diabetics are in…