General Epidemiology
tsmith | October 13, 2006Flu shots are rolling out, and there should be no shortage this year. A few new articles remind the public of the importance of these vaccinations, especially in high-risk groups (something that I touched on here regarding data showing that vaccination during pregnancy can help protect the newborn).
You can find the guidelines for target vaccination groups here. Essentially, it includes anyone immunocompromised or with conditions that make them increasingly susceptible to serious complications of influenza; those 50 years of age and older; and children from 6 months to five years old.…
tsmith | October 6, 2006Toddler's death blamed on E. coli, officials say
Heartbreaking.
As federal agents launched a criminal investigation into two produce companies involved in the contaminated spinach outbreak, Idaho health officials confirmed the death of a 2-year-old boy Sept. 20 was caused by tainted spinach.
Kyle Allgood was the second confirmed death in the E. coli outbreak, which also killed a Wisconsin woman.
The boy, who would have turned 3 in December, died in Salt Lake City after developing a type of kidney failure caused by E. coli. Health officials had to wait for the results of genetic testing on the…
tsmith | October 6, 2006Regular readers out there will already be familiar with the groups of people who deny evolutionary theory, who deny that HIV causes AIDS, even those who deny that germs cause disease, period. Wilhelm Godshalk is even on the record for denying gravity. I don't know what it is about this site, and science blogs in general, that bring people out of the woodwork in this manner, but we have another live one. Witness Charles Hoy's assertion that fear, not smoking, causes lung cancer.
What evidence do you want? Lung cancer is as common in smokers as it is in non-smokers. Where it all gets…
tsmith | October 3, 2006Orac has a post up on this new JAMA paper as well. He brings up some better examples than the one I gave:
Does anyone in this day and age still believe that smoking doesn't cause lung cancer? The epidemiological evidence of the association is bulletproof. However, the majority of smokers don't get lung cancer. In fact, there are complex statistical models that allow a pretty accurate calculation of risk in populations based on how long and how much a smoker has been smoking. For example, if you start smoking at age 18 and smoke two packs a day, by age 55, you have about a 5% chance of dying…
tsmith | October 2, 2006Ah, another day, another paper for the anti-HIV establishment to glom onto and misrepresent.
Last week's issue of the Journal of the American Medical Association published this paper examining the relationship between HIV load and CD4 T-cell decline:
Context Plasma human immunodeficiency virus (HIV) RNA level predicts HIV disease progression, but the extent to which it explains the variability in rate of CD4 cell depletion is poorly characterized.
Main Outcome Measures The extent to which presenting plasma HIV RNA level could explain the rate of model-derived yearly CD4 cell loss, as…
tsmith | September 29, 2006Nina Plank, the author of the NY Times article I commented on in this post, stopped by to comment. Rather than just having this lost in the comments to a week-old post, I wanted to take a moment and quickly address two of her points (with potentially a follow-up post next week when I have a bit more free time).
First, to Nina, thanks for stopping by. I'll just say that I very much disagree with your stance on raw milk and dairy. Indeed, contamination can also happen after pasteurization and nothing replaces vigilance, but having seemingly healthy cows is no guarantee of healthy milk.…
tsmith | September 26, 2006I was travelling over the weekend and I'm incredibly busy up through Wednesday, so new material from me will have to wait until later in the week. In the meantime, I'll point you to a stellar post I wanted to highlight last week, from Revere on H5N1 and the evolution ov virulence, and another excellent one from Mike regarding the importance of surveillance when it comes to detecting and containing outbreaks (such as the recent O157 outbreak). He also describes a timeline for how long many of the common procedures take; quite a bit different from what you get watching CSI or similar shows…
tsmith | September 21, 2006 That's certainly the claim in a new New York Times editorial (via The Frontal Cortex). The author, Nina Planck (author of Real Foods: What to Eat and Why), claims that it's as easy as just feeding cattle grass, and poof!--E. coli O157 will vanish.
More on this and why organic farming won't necessarily stop such outbreaks after the jump.
Planck writes:
Where does this particularly virulent strain come from? It's not found in the intestinal tracts of cattle raised on their natural diet of grass, hay and other fibrous forage. No, O157 thrives in a new -- that is, recent in the history of…
tsmith | September 20, 2006 The seventh chapter of Wells' book could be summed up in a single sentence: "biology doesn't need no steeekin' evolution!" Wells argues that, because medicine and agriculture were already doing just fine prior to Darwin's publication of Origin, clearly then, these fields (and others) haven't benefited from an application of evolutionary principles in the time from 1859 to present day, and that Dobzhansky's "nothing in biology makes sense except in the light of evolution" is one big joke.
Wells focuses on medicine and agriculture because these are two fields that we all benefit from, and…
tsmith | September 18, 2006And who said spinach was boring?
If the ongoing E. coli outbreak due to spinach has done one thing, it's highlight the mystery that revolves around Salinas, California:
The sunny Salinas Valley holds a dark mystery: Why, in the past decade, have nine Escherichia coli outbreaks been linked to produce grown here?
It's still unknown why this fertile land has been hit by what an FDA official calls "significant" crop contamination.
Throughout the picturesque terrain here, questions swirl.
Has cattle waste contaminated irrigation water? Does contaminated soil blow in the wind? Do birds feeding on…
tsmith | September 18, 2006It seems like every other story that comes out about H5N1 contradicts the previous one. I've blogged previously about some reasons to think that the diagnosed cases of H5N1 are only the tip of the iceberg (see here, here, and here, for instance). Though there I present some evidence to suggest that we may be missing asymptomatic or mild influenza cases, other stories have come to the opposite conclusion. For example, a recent news story from Cambodia reports that no mild or asymptomatic cases of H5N1 infection were found:
Researchers who tested 351 Cambodian villagers after they had…
tsmith | September 15, 2006I mentioned Mike also wrote on the E. coli outbreak. Additionally, Carl, who's working on an upcoming book on E. coli (woo hoo!) also has more, including a bit on the evolution of E. coli O157:H7 (while Mike talks about E. coli in general and the bad rap it sometimes gets). Check 'em out.
tsmith | September 15, 2006 E. coli outbreak traced to tainted spinach
An outbreak of E. coli in eight states has left at least one person dead and 50 others sick, federal health officials said Thursday in warning consumers nationwide not to eat bagged fresh spinach.
The death occurred in Wisconsin, where 20 others were also sickened, said Dr. David Acheson of the Food and Drug Administration's Center for Food Safety and Applied Nutrition. The outbreak has sickened others -- eight of them seriously -- in Connecticut, Idaho, Indiana, Michigan, New Mexico, Oregon and Utah.
FDA officials do not know the source of the…
tsmith | September 10, 2006In the comments to this post on creationists'/HIV deniers' (mis)use of statistics, several people have been trying to argue that because overlapping membership in the two groups is limited, my comparison of the two is false. I explained:
It's the *tactics* that are the same in both groups: misleading use of statistics as evidenced in this post, cherry-picking the lit, appeals to authority, grand conspiracies imagined, painting scientists as greedy and hopelessly biased, quote-mining, hell, they even each have their own prizes based on an impossible standard of evidence.
Michael replied:
Oh…
tsmith | September 7, 2006 Drug-Resistant TB in South Africa Draws Attention From U.N.
The World Health Organization will hold an urgent meeting this week to seek ways to deal with deadly strains of tuberculosis that are virtually untreatable with standard drugs.
The meeting, in Johannesburg on Thursday and Friday, comes in response to recent reports from a number of the world's regions about a small but growing number of cases of the deadly strains, known as extreme drug-resistant tuberculosis, or XDR-TB.
"XDR-TB poses a grave public health threat, especially in populations with high rates of H.I.V." and few health…
tsmith | September 4, 2006Regular readers are very familiar with my refrain that many science deniers use the same tactics: bad arguments, quote-mining, appeals to authority, castigation of originators of respective theories, etc. etc. Another common thread is the complete bastardization of statistical analysis. Mark Chu-Carroll elaborates on Peter Duesberg's misuse of statistics here, while mathematician John Allen Paulos destroys creationist/ID analysis here. I'll highlight some of the best parts below:
For those of you who are familiar with creationist/ID arguments, you know that they take an event (say, the…
tsmith | August 30, 2006 Yesterday's New York Times had an excellent story on the discovery of the human papilloma virus as the cause of cervical cancer, and ultimately, the development of a vaccine against it. It's also a good lesson in how, while solid evidence triumphs over anecdotes, even folk stories can be useful in ultimately pointing to a cause if they're rigorously investigated.
If you're curious about what all this has to do with the messed-up looking rabbit in the picture, click on through...
I've written previously about the new cervical cancer vaccine, and its potential to lessen dramatically the…
tsmith | August 25, 2006Most of the stories I blog about here regarding sex (and sexually-transmitted infections) have bad news to offer. People are still poorly educated about STDs, or worse, actively misinform to try to scare people away from sex. Admittedly, good news about sexual issues are few and far between, but there actually have been a few positive stories in the news recently:
In the first article, the good news is that rates of sexual activity in teenagers have decreased a bit since 1991:
Some 46.8 percent of students said they engaged in sexual intercourse in a 2005 survey, down from 54.1 percent in…
tsmith | August 21, 2006I've blogged several times on here about the connection between microbes and obesity (aka "infectobesity;" previous posts here, here, and here.). It's an interesting area of study, with two general directions: investigating which of our gut flora (alone or in combination with others) affect our metabolism; and how other types of infections (such as adenovirus serotype 36) can play a role in this process as well.
A recent story in the New York Times Magazine by Robin Marantz Henig provides a nice introduction to this whole area, weaving in the threads I mentioned above (as far as the…
tsmith | August 19, 2006One catchphrase that permeated the conference this past week was "scaling up." I just want to wrap up my posting here with a brief discussion of what that is, and what that means as far as HIV/AIDS prevention and treatment.
Readers who are scientists or who have some kind of science background will probably be famililar with the concept of a "pilot study." This is a study, generally small in scale, where new ideas are tested, and preliminary data are gathered. For example, a pilot study looking at how the ABCs of prevention work may take 100 individuals and split them into two groups: 50…