Infectious causes of chronic disease
tsmith | February 25, 2008This is the first of 6 guest posts on infectious causes of chronic disease.
by Matthew Fitzgerald
Viruses cause cancer?
Cancer researchers have for decades known that viruses can cause cancer. It is now estimated that 15% of the world's cancers are caused by infectious diseases including viruses. Some of these include: Human Papilloma Virus (HPV) and cervical cancer; Epstein-Barr Virus (EBV) and nasopharyngeal cancer & lymphoma; Hepatitis B and liver cancer. In fact cancer researchers use this knowledge of viruses causing cancer by utilizing EBV and SV40 and other viruses to "…
tsmith | February 24, 2008...my grad students.
My spring semester course is on infectious causes of chronic disease, looking at the role various infections play in cancer, autoimmune disease, mental illness, and other chronic conditions. Since I've often discussed the importance of having scientists communicate with the public, I decided to assign each of them to write 2 blog posts for the course, discussing anything of relevance to the course. Their first round of assignments was due last week, and I'll be posting them beginning on Monday. Constructive comments on their posts are appreciated, but keep in mind…
tsmith | November 19, 2007 It still amazes me sometimes what viruses are capable of doing. I've written a number of times about one virus in particular, the human papilloma virus (HPV). This is the virus implicated in cervical cancer, and it also plays a role in head and neck cancers. There are a number of different strains of HPV--some of them are oncogenic (cancer-causing), while others cause more benign infections, such as warts.
A related virus in rabbits also causes a type of warts, which can replicate out of control and form horny growths (indeed, this is the likely origin of the jackalope myth). Humans…
tsmith | October 9, 2007Following a new PNAS paper regarding the strange facial cancers in Tasmanian devils, I have a post on the topic up over at Correlations. (Be sure to check out the Correlations homepage too!)
tsmith | June 4, 2007 Syphilis is a disease frequently shrouded in many levels of mystery. It appeared suddenly in Europe in the late 1400s as a highly virulent and often fatal disease, a disease that could give Ebola a run for its money when it comes to sheer grotesque-ness. Victims may be covered with pustules from head to toe, diseased flesh peeled from their bodies, and patients may be in agonizing pain for weeks or months prior to death. However, after this inauspicious beginning, syphilis seems to have become less virulent, and instead shifted in presentation to more of the chronic disease that we know…
tsmith | May 21, 2007 I had a strange worry as a kid. I was very scared of getting bit by a tick and developing Rocky Mountain Spotted Fever (RMSF). I know, weird--even for nerdy kids like me, who knows about Rocky Mountain Spotted Fever? How many readers are even familiar with it?
For those who aren't, RMSF is a zoonotic rickettsial disease transmitted by several species of ticks. Though the disease is named after the geographical region where it was first described back in the late 1800s, the bacterium that causes it, Rickettsia rickettsii (an obligate intracellular pathogen), has been found in almost all…
tsmith | April 27, 2007Of all the vaccines in a child's repertoire, perhaps the most controversial is the vaccine against Hepatitis B virus. It's not because of concerns about the vaccine's safety necessarily; parents tend to be more worried about the MMR vaccine, since that has received so much press. But many parents feel that the HBV vaccine is unnecessary. HBV is transmitted primarily via exposure to blood or other body fluids, or by sexual transmission. Because they assume their kids will be smart, stay away from drugs, and not have sex with the "wrong" people, they assert that the vaccine is a waste and…
tsmith | February 2, 2007Introduction to Microbiology and Infectious Disease
You and your normal flora, Part I
You and your normal flora, Part II
tsmith | January 16, 2007Chronic fatigue syndrome (CFS) is one of those nebulous diseases that's really more of a diagnosis of exclusion than anything else. As the name suggests, it's characterized by overwhelming fatigue--often so much so that patients can barely get out of bed--as well as a number of non-specific symptoms, including weakness, muscle pain, and insomnia. Currently, there is no diagnostic test for the disease, and the cause(s) is (are) unknown. Indeed, it should be noted that there's disagreement over even the most basic assumption that such a thing as CFS exists, or whether it's merely…
tsmith | December 21, 2006Ho ho ho, and welcome to the early Christmas edition of Animalcules. Sit back, grab some hot cocoa, and click below to open your Christmas gift of some of the most interesting microbiology-themed blog posts over the past month.
To start us off with, in a new blog to me (the Cornell Mushroom blog), we learn how a fungus assists in the transmission of a nematode from the environment to the host--in this case, cattle. It's a fascinating example of commensalism.
From the same blog comes another post on Batrachochytrium dendrobatidis (or Bd), a fungus which is a cause of skin infections in…
tsmith | October 24, 2006 Regular readers know an interest of mine are infections that cause more than just the typical acute spectrum of disease. For example, I've written on the role microbes might play in obesity, or the role of viruses in chronic disease such as cancer and, of course, AIDS. Still, typically, infections are thought of as acute and self-limited; that is, they infect the individual, cause illness, and are resolved in a matter of days or weeks, even though we know that this doesn't always happen. And increasingly, we're finding that infections are associated with all kinds of long-term diseases…
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 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 15, 2006I've blogged previously about the massive effect vaccines against the human papilloma virus (HPV) could have. HPV is a common sexually-transmitted virus. Though most strains are harmless, a few have the potential to cause cervical cancer. Therefore, the HPV vaccine will be the first one ever specifically intended to prevent a type of cancer.
This vaccine has recently been approved by the FDA, and is set to roll out shortly. This is already expected to be a rather contentious issue as the vaccine is rolled out in the U.S. and elsewhere, as one target group for vaccination is adolescents…
tsmith | July 31, 2006I was busy over the weekend (and disgusted by the hot, nasty weather that will not die), so I don't have a lot on tap for today. Luckily, though, there's some interesting stuff elsewhere that's already written up--thoughtfully saving me some of the trouble.
I discuss the link between infectious and "chronic" disease with some regularity on this site. I think it's a fascinating area; perhaps oversold by some, perhaps over-criticized by others, but certainly a hot topic and an interesting direction for research in microbiology. This weekend's New York Times had a new story that touched on…
tsmith | July 18, 2006I've mentioned previously the "hygiene hypothesis", but don't think I've ever really discussed it. SEED writer Emily Anthes has a new article on the topic at the homepage.
tsmith | June 30, 2006Sure, predator cats may have dined on our ancestors, but it seems we gave them ulcers (or, more correctly, passed along the bacterium that causes them) when they ate us.
Boo-yah! Take that, Simba.
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…