General biology
tsmith | January 5, 2006Microbial ecology, and its relation to the development of infectious disease, is an ever-growing field of study. Of course, there are a vast number of bacterial species living amongst us, most of which do not cause us any harm. Others may infect us only when, so to speak, the stars align in a certain manner: when a number of factors collide that result in the development of a diseased state. For instance, we may already be immunocompromised due to the presence of another infection--something minor, such as a rhinovirus, or something more serious, such as HIV--and this chink in our armor…
tsmith | December 24, 2005NHANES is an abbreviation that's quite familiar to epidemiologists of all stripes: the National Health and Nutrition Examination Survey. This survey dates back to 1956 with the passage of the National Health Survey Act, providing legislative authorization for "a continuing survey to provide current statistical data on the amount, distribution, and effects of illness and disability in the United States." Generally, information from these surveys has been used to look at the effect of nutrition, particularly micronutrients, on the health status of the population, or subgroups within the…
tsmith | December 16, 2005 I love these historical analyses of disease--real, or fictional. One historical event that has been the subject of much speculation over the decades has been the Plague of Athens, a mysterious outbreak that is thought to have changed the direction of the Peloponnesian War, and for which the cause still remains uncertain:
[2] As a rule, however, there was no ostensible cause; but people in good health were all of a sudden attacked by violent heats in the head, and redness and inflammation in the eyes, the inward parts, such as the throat or tongue, becoming bloody and emitting an unnatural…
tsmith | December 5, 2005Clostridium difficile has joined MRSA, SARS, avian influenza, and West Nile as a hot new emerging disease. This bacterium, a cousin to Clostridium tetani-the causative agent of tetanus--and Clostridium botulinum--the botulism bacterium--is a spore-forming anaerobe. Carried by about 3 percent of healthy adults, the bacterium is generally present as a metabolically inactive spore. The bacterium typically causes problems in the nosocomial (hospital) environment, where up to 40 percent of hospital patients may be colonized. Clinical disease generally presents as watery diarrhea and cramps, and…
tsmith | December 1, 2005As I've mentioned before, Ebola is a virus near and dear to my heart. (Figuratively, not literally. I'm not quite that enamored of it). In that previous post, I mentioned that we didn't know the reservoir of Ebola in nature. It certainly isn't for lack of trying that it wasn't determined previously. The first field studies took place shortly after the initial 1976 outbreaks in the Democratic Republic of Congo (DRC) and Sudan. In the former, 818 bedbugs, 1500 mosquitoes, 10 domestic pigs, one cow, seven bats, 123 rodents, eight squirrels, six Cercopithecus monkeys, and three small antelopes…
tsmith | November 22, 2005I've mentioned many times on here reservations I have over the current avian flu numbers--how many subclinical or mild infections are being missed? Are they indeed offset by the number of serious disease cases we're also missing? There's a reason for these questions, and it's now out in electronic form in Clinical Infectious Diseases.
A bit of background. I work in Iowa as part of the Center for Emerging Infectious Diseases. One of our pet pathogens happens to be influenza virus, and we have ongoing studies looking at serological evidence of prior infection with swine and avian viruses in…
tsmith | October 31, 2005 As mentioned in the comments to this post, there is a brewing controversy over upcoming guidelines outlining who should receive the "cervical cancer vaccine," a vaccine against the human papilloma virus (HPV). Briefly, the HPV vaccine is a highly effective (100% in a 2-year clinical trial) vaccine which is targeted against two specific serotypes of the human papilloma virus: HPV 16 and HPV 18. Together, these types cause about 70% of cervical cancers in the United States. Previously, Bridget Maher of the Family Research Council, a leading Christian lobby group, has said this about the HPV…
tsmith | October 27, 2005(And not in a supportive way). PZ and Orac discussed a recent New England Journal of Medicine editorial critical of intelligent design. Though the article had several shortcomings, it's always a bonus to see other scientists treating ID as a valid threat (not in the scientific sphere, of course, but in the "hearts and minds" of the populace). Now the Journal of Clinical Investigation, another fairly heavy-hitter as far as medical journals go, recommends to its readers, Don't be stupid about intelligent design. Kudos to them...now come the nitpicks. :)
Neill writes,
For those who have had…
tsmith | October 18, 2005Ah, how rare is it that my interest in stomping creationists and my interest in infectious disease collide. But I guess that when there's a topic as hot as avian influenza, it's inevitable that even the folks at the DI will sit up and take notice, as Casey Luskin has in this post: Avian Flu: An Example of Evolution?
First, as Luskin admits in the article, the answer to his titular questions is, "well, duh; of course it is." And alas, it doesn't get any better from there.
Allow me a moment to rant a bit here. It's painful for any expert in a field to read articles authored by those who are…
tsmith | October 6, 2005I know I said I was going to discuss a bit more about pandemic preparedness today, but I think I'll hold off on that to discuss this story:
It sounds like a sci-fi thriller. For the first time, scientists have made from scratch the Spanish flu virus that killed millions of people in 1918.
Why? To help them understand how to better fend off a future global epidemic from the bird flu spreading in Southeast Asia.
Researchers believe their work offers proof the 1918 flu originated in birds, and provides insights into how it attacked and multiplied in humans. On top of that, this marks the first…
tsmith | October 5, 2005The scientific community is all too familiar with the dangers an influenza pandemic could bring. The politicians and general public are starting to become aware of the issue as well; indeed, one can hardly open a newspaper or turn on the television without hearing about "bird flu." So, what's actually being done to prevent an influenza catastrophe? What are the issues? What can be done?
These are the questions that keep public health officials awake at night, because the answer is always that we're not doing enough. While we may be resigned to the fact that a future pandemic can't be…
tsmith | October 3, 2005It's hard to avoid hearing about influenza virus these days. In all the noise, it's tough to sort out the facts from the rumors and conspiracy theories. I've already discussed a bit about the basic biology of the virus in this post, so I'm not going to review that here (though a good overview can be found here for those of you who need to bone up on your influenza virus biology). So, this week, as a part of Pandemic influenza awareness week, I'll be writing a 5-part series about various issues regarding influenza. Today, I'll discuss the history of influenza, focusing on past pandemics. The…
tsmith | September 26, 2005Canine flu strikes in Westchester county, NY.
A NEW strain of influenza that began infecting dogs in Florida early last year has recently struck hard in the Westchester area, forcing the temporary closure of two kennels after more than 100 dogs being boarded there became ill, veterinary officials say.
Gracelane Kennels in Ossining underwent decontamination after a viral illness infected dogs. Eddie Loga hoses down a run at the kennel. Although prepared for the less-virulent kennel cough, boarding sites have been blindsided by the new virus.
At least one of the dogs has since died. The two…
tsmith | September 16, 2005The Washington Post today reminds us that there has been little progress in uncovering the source of the 2001 anthrax attacks. [1]
First, a disclaimer. I'm not an "evolutionary biologist," per se. I have what is I swear the longest job title ever--molecular infectious disease epidemiologist. As such, I often get asked, "what's the relevance of evolution to your work?" Or, I'll read editorials such as Dr. Skell's recently in The Scientist [2] questioning the use of evolutionary theory in experimental biology, and be disheartened. Yet the method of investigating the anthrax attacks shows…
tsmith | May 22, 2005Every now and then, I check in over at The Institute for Genomic Research (TIGR) to see what new projects they're up to, as well as to see if they've released a particular genome sequence I'm waiting on. Yesterday I noticed this project:
Innovative Metagenomics Strategy Used To Study Oral Microbes
Rockville, MD - The mouth is awash in microbes, but scientists so far have merely scratched the surface in identifying and studying the hundreds of bacteria that live in biofilm communities that stick to the teeth and gums.
In an innovative new project that could help improve the detection and…