General Epidemiology
tsmith | July 11, 2008Marburg is a filovirus; a cousin of Ebola. Both cause hemorrhagic fever; both have been recently discovered in fruit bats; both have hit Africa in a small number of human outbreaks. Both also remain largely mysterious; we know very little about their ecology in the wild; how frequently they really infect humans (and other animal species; Ebola especially has taken a toll on great apes); and their mode of transmission from their wild reservoir to primate hosts. These enormous gaps in our knowledge remain despite recently passing the 40-year mark since the discovery of filoviruses in a lab…
tsmith | June 20, 2008Here in the Iowa City-Cedar Rapids corridor, the waters have been going down for several days, and people are being allowed back into their homes and businesses to begin assessing the damage and cleaning up what remains. However, while the dangers from the initial flooding are receding along with the waters, the clean-up and aftermath bring about a new set of misery.
Flooding is a potential nightmare when it comes to infectious diseases. The water can bring people returning to their flooded residences into contact with sewage, animal carcasses, and other sources of pathogens--and warm…
tsmith | May 15, 2008I'm taking a quick hiatus from my hiatus. I mentioned that I had quite a bit of travel upcoming, and I happen to be in the midst of my first trip. However, it just so happens that where I've landed--Ulaanbaatar, Mongolia--is experiencing an outbreak of hand, foot, and mouth disease in kids, caused by Enterovirus-71. More after the jump...
You may have read about this virus in prior weeks, as China has been dealing with a major outbreak there:
The number of hand-foot-mouth disease (HFMD) cases reported in China this year rocketed to 15,799 as of Tuesday, resulting in 26 deaths, according…
tsmith | April 16, 2008This is the sixth of 6 guest posts on infection and chronic disease.
By Courtney Cook
Kidney stone disease affects approximately 5% of Americans. While several risk factors are well-established, including genetic predisposition, metabolic diseases, lifestyle, and diet, there are still questions over the actual mechanism of calcium stone formation. Many cases do not have any kind of underlying disorder and therefore it is difficult to know how to treat these patients to prevent further stone formation.
This seemed to change when, in 1998, Kajandar and Ciftcioglu isolated an unusual…
tsmith | April 16, 2008This is the fifth of 6 guest posts on infection and chronic disease.
By Whitney Baker
My previous blog post examined the idea of an infectious etiology for obesity by a group of possible infectious agents. While these pathogens have been associated with obesity in humans or animals, their causative role in human obesity has not yet been established. So for this round, I thought I'd focus in on the bug showing the most evidence for human obesity: Adenovirus-36.
(More after the jump...)
First, a little background on Adenovirus [1]... it most commonly elicits respiratory illness; however…
tsmith | April 15, 2008This is the fourth of 6 guest posts on infection and chronic disease.
By Ousmane Diallo
Last week in class we tackled an interesting topic, the role of Mycobacterium Avium Paratuberculosis (MAP) in the genesis of Crohn's disease (CD) and ulcerative colitis (UC). The authors Saleh E. Naser (oops the name means in Arabic 'The virtuous helper') and colleagues detected using Polymerase Chain Reaction (PCR) techniques in a lab based case controls study "viable MAP in peripheral blood in higher proportion of individuals with Crohn than controls". Not surprising after all since the pathology of…
tsmith | April 14, 2008This is the second of 6 guest posts on infection and chronic disease.
By Rachel Kirby
In light of April being Autism Awareness Month it is only natural that certain topics be brought about in the media. Until now I was not aware of the controversy behind the "risk factors" of autism. Let's begin with the basics. Autism is a brain development disorder that impairs social interaction and communication, and causes restricted and repetitive behavior, all starting before a child is three years old. Having autism may or may not involve all three characteristics. Some may even have symptoms that…
tsmith | April 14, 2008This is the first of 6 guest posts on infectious causes of chronic disease.
By David Massaquoi
Is this the Beginning of the end of antibiotic resistant problem or just another scientific false hope of eradicating microorganisms that have co-existed with humans for millions of years? In the days before antibiotics, some researchers saw bacteriophages, viruses that can seek out and destroy bacteria, as a promising candidate for fighting infections. Now, as more organisms develop resistance to existing antibiotics, phage research is finding new favor.
(More after the jump...)
At the Society…
tsmith | April 11, 2008 I don't understand how some segments of the population believe that "natural" always equates to "better." I certainly get the appeal of being close to nature; the romanticism of living simply and from the earth. I grew up and live currently in a rural area where people are close to animals and the land. But I also know that some of the most deadly poisons in the world are "natural." I know that, while most microbes out there are harmless, and many are even helpful, there are many that can make you violently ill as well. After all, tetanus, anthrax, and Ebola are all "natural."…
tsmith | April 10, 2008 It's hard to believe that it's been 2 years since Iowa's 2006 mumps outbreak (more background and details on that here, here, here, and here).
By the time the outbreak ended, 8 states had been heavily affected (and 45 reported at least one case), with a total of 6584 cases of mumps and 85 hospitalizations reported by the end of 2006. All told, this was the largest outbreak of the virus in approximately 20 years, after a 1986-1990 outbreak resulted in a change in the recommended vaccine schedule (adding a booster shot of MMR).
A paper out in today's New England Journal analyzes the…
tsmith | April 8, 2008I spent all day yesterday in Madison, Wisconsin, at a conference on Landscape Ecology and infectious disease. I'll discuss a few of the talks and issues below, but I wanted to start out with a bit of an introduction and explain just what landscape ecology (LE) is.
The introductory talk, which covered this ground, was presented by Dr. Michael Wimberly of South Dakota State University. He noted that defining LE wasn't an easy task. At its most basic, of course, it's a field looking at ecology from a landscape perspective--taking a big picture view, if you will. However, what one means by a…
tsmith | April 2, 2008Sent off yet another grant, so I'm still (once again) catching up on everything. Meanwhile, some posts for you to check out:
I thought I was self-sacrificing by submitting myself to Kentucky's creation museum for your amusement. Guess I could have stayed home and wasted 2 1/2 hours of my life as Drek did, live-blogging an anti-vaccine movie he was challenged to watch.
Or, if you've had it with vaccine naysayers (and oh look, CNN gave more space to Jenny McCarthy to gush about how chelation and diet allowed her son to recover from autism), head over to Mike's place for a refreshing post on…
tsmith | March 25, 20081980 marked a milestone in infectious disease epidemiology: the World Health Organization declared the smallpox virus eradicated in the wild. However, while smallpox currently exists only in frozen stocks, poxviruses as a class certainly haven't disappeared. A related virus, monkeypox, regularly causes illness in Africa, and even spread half a world away in the American midwest.
Additionally, Africa isn't the only area with endemic poxvirus infections. Brazil has been dealing with their own poxvirus outbreak, and poxviruses have popped up in Europe as well. More on both of those after…
tsmith | March 24, 2008 As I mentioned Friday, the good folks from Google were part of the crowd at this year's ICEID. This included a talk by Larry Brilliant, described on his wikipedia page as "...medical doctor, epidemiologist, technologist, author and philanthropist, and the director of Google's philanthropic arm Google.org." His talk discussed not only stopping outbreaks in their tracks--as current outbreak investigations seek to do, and Brilliant himself as worked on, as part of his background in vaccination campaigns for polio and smallpox--but to pay attention to "the left of the epidemic curve" as part…
tsmith | March 21, 2008If one over-arching theme came out of this conference, it was the concept noted in the title: "one medicine, one health." In one of the early lectures, a speaker polled the audience to find out how many attending were veterinarians, and how many worked in human health. The room was divided pretty evenly, which attests to the importance of animals in the emergence of new diseases in humans. Regular readers, of course, will know that these diseases that cross species boundaries--zoonoses--make a large proportion of the emerging diseases we see (~75% by several estimates). Early Monday…
tsmith | March 19, 2008
Did Yersinia pestis really cause Black Plague? Part 1: Objections to Y. pestis causation
Did Yersinia pestis really cause Black Plague? Part 2: Examination of the criticisms
Did Yersinia pestis really cause Black Plague? Part 3: Paleomicrobiology and the detection of Y. pestis in corpses
Did Yersinia pestis really cause Black Plague? Part 4: Plague in modern times
Did Yersinia pestis really cause Black Plague? Part 5: Nail in the coffin
tsmith | March 7, 2008It's just not been Vegas' week. First a ricin-laced hotel room, then a clinic-associated outbreak of hepatitis C virus (and potentially hepatitis B and HIV) that could become enormous. Meanwhile, an outbreak of hepatitis E is raging in Uganda. So what are these virues, and how in the world could a medical catastrophe of this magnitude happen in the U.S.? More after the jump...
The group of hepatitis viruses (A, B, C, D, E, and G) are related in name only. They've all been either associated with or found to cause hepatitis--inflammation of the liver. This can be acute inflammation (short…
tsmith | March 3, 2008More grants out the door today, but check out ABC correspondent Jake Tapper's post on John McCain's views on thimerosal and autism:
At a town hall meeting Friday in Texas, Sen. John McCain, R-Ariz., declared that "there's strong evidence" that thimerosal, a mercury-based preservative that was once in many childhood vaccines, is responsible for the increased diagnoses of autism in the U.S. -- a position in stark contrast with the view of the medical establishment.
McCain was responding to a question from the mother of a boy with autism, who asked about a recent story that the U.S. Court of…
tsmith | February 27, 2008This is the sixth of 6 guest posts on infectious causes of chronic disease.
By Ousmane Diallo
I was dumbfounded when I read this news article relating HPV to the increase of lip and oral cancers because of oral sex.
It reminded me my younger years, as a med student, debating with my professor of psychology the fundamentals of Freudian psychoanalysis, the Id, the Ego and the Super-ego. It was a rather philosophical debate more than anything else, a combination of religious and cultural reciprocal statements of beliefs. At that time, we were exposed to the new French "sexual education"…
tsmith | February 27, 2008This is the fifth of 6 guest posts on infectious causes of chronic disease.
By Rachel Kirby
There are about 500,000 (or approx 1 in 544 people) in the United States who suffer from Crohn's disease, and is most prevalent in both men and women between the ages of 20-30. Crohn's Disease is an autoimmune disease which causes a chronic inflammation of the digestive tract. It can affect the entire digestive tract but is most prevalent in the lower small intestine and in the ileum. It will cause swelling, causing pain and diarrhea.
More after the jump...
Though a lot is known about the disease;…