infectious disease
revere | March 10, 2007Human Papilloma Virus (HPV) is in the news lately because its maker Merck is marketing a vaccine against it which they bill as the first anti-cancer vaccine. It may be effective against HPV, one of the main risk factors for cervical cancer, but it isn't the first cancer vaccine. The hepatitis vaccine gets the honors there. The HPV vaccine has become controversial in part because the risk factor it is preventing is infection with a sexually transmitted virus. Anything to do with sex is controversial in the US.
There's another sexually transmitted disease, much better known: gonorrhea ("the…
revere | March 6, 2007While finishing drafting a series of posts on how Tamiflu resistant virus might spread as a result of intense use for influenza control, Melanie at Just a Bump in the Beltway posted this to remind us that drug resistant organisms spread for reasons much less useful than trying to stop people from dying. Like treating cows so they can be killed later and we can eat them and make money for agribusiness:
The government is on track to approve a new antibiotic to treat a pneumonia-like disease in cattle, despite warnings from health groups and a majority of the agency's own expert advisers that…
revere | March 2, 2007My SciBling Mike the Mad Biologist, who is an expert on antibiotic resistance, has an interesting post about an "epidemic" of commensal E. coli. It seems (if I understand his post correctly) that there is not the genetic range of E. coli lineages in humans as in animals. About 20% of our gut E. coli comes from one of three clones. There is no apparent reason for this as the E. coli don't seem to have any features that make one better off than another. I have nothing to add to the basic observation, but I thought I'd use it to review some elementary microbiology, since we talk a lot about…
revere | February 23, 2007If you are attracted to leaving your body to science but still want to be buried au naturel, now you can have it both ways. Just bequeath yourself to the Anthropological Research Facility at the University of Tennessee in Knoxville. There you can quietly decompose on their peaceful three acre facility, where perforated pipes from you buried corpse bring up the gasses produced as microorganisms busily break down your complex molecules to smaller ones. The idea is to discover what dead bodies smell like:
It's not a pleasant smell," Vass said. "You never get used to it."
It takes about 17 days…
tsmith | February 21, 2007...I'm sure they'll be happy to see that Gambia's president is curing AIDS:
From the pockets of his billowing white robe, Gambia's president pulls out a plastic container, closes his eyes in prayer and rubs a green herbal paste onto the rib cage of the patient -- a concoction he claims is a cure for AIDS.
He then orders the thin man to swallow a bitter yellow drink, followed by two bananas.
"Whatever you do, there are bound to be skeptics, but I can tell you my method is foolproof," President Yahya Jammeh told an Associated Press reporter, surrounded by bodyguards in his presidential compound…
tsmith | February 14, 2007...some vintage posters raising awareness about the other VD: venereal disease.
(Click on them to go to the original site). A few more highlights below the fold...
And this one, which is better appreciated at larger size so you can read the print:
There are 20 posters in all, plus this syphilis comic book from 1965:
Happy Valentine's Day!
tsmith | February 9, 2007What's killing honey bees?
Something is wiping out honey bees across North America and a team of researchers is rushing to find out what it is.
What's being called Colony Collapse Disorder (CCD) has now been seen in Pennsylvania, North Carolina, Florida, Georgia and way out in California. Some bee keepers have lost up to 80 percent of their colonies to the mysterious disorder.
Now, I'm admittedly not much of a bee fan. Several of my relatives are highly allergic, and I've only been stung once and hope I'll be fine if it happens again, but they do kind of make me nervous when I see them…
tsmith | February 8, 2007So, I left off on Tuesday noting two things about our normal flora: 1) that in the big picture, we know hardly anything about them; and 2) that one reason we know so little about them is because we've never grown many of them in a laboratory setting--that is, we've never cultured them using our typical tools of the trade.
What's one way to remedy this? Eliminate the need for culture, and take some cues from the microbial ecologists. More on this below.
I've mentioned the term "metagenomics" previously on this blog (see the stories about it here and here). Using this technique,…
tsmith | February 6, 2007 I mentioned in the Introduction to Microbiology and Infectious Disease that many people don't understand the difference between a commensal and a pathogenic organism. I also mentioned that I'd try to write something about microbial ecology. Since I just gave a lecture yesterday on normal human flora in health and disease, now seems as good a time as any to combine these two and discuss just what it means when microbiologists refer to "normal flora" or "commensal organisms," and to talk about the microbial ecology of the human body in a series of posts on this topic.
First, though, a…
tsmith | February 2, 2007Introduction to Microbiology and Infectious Disease
You and your normal flora, Part I
You and your normal flora, Part II
tsmith | February 2, 2007It's been awhile since I've written about HIV/AIDS denial on here. To be honest, the whole area has just burned me out a bit; it gets tiresome to even discuss issues with people who so fundamentally deny the basic tenets of microbiology and infectious disease epidemiology. But in my absence, there's been quite a bit going on, much of it collected here at the AIDStruth website. However, I have to draw your attention to a notable story today.
The first is like something out of "Law and Order." An HIV-positive man is appealing his conviction in Australia of endangering the lives of three…
revere | February 1, 2007Most readers probably never gave much thought to tissue culture, the laboratory technique where cells or tissues are grown in flasks or other containers separated from the organism of origin. One of the reasons for doing this is to grow viruses, since a virus needs a host cell to replicate. It can't "live" on its own and doesn't grow in size. It just makes a copy of itself. Dog kidney cancer cells, for example, are used to grow influenza virus in flasks that also contain nutrient medium for the dog cells. Finding the right tissue culture system for a virus is an art in itself. For many…
tsmith | February 1, 2007I've mentioned a few times the work of Ignaz Semmelweis in preventing "childbed fever" in new mothers. To recap:
Semmelweis was a physician in Vienna in the 1840s, with an interested in "childbed fever," a leading cause of mortality in women who'd given birth. During this time, he noticed that the mortality rate from this disease in a hospital division where medical students delivered babies was 16%, while in a division where midwives delivered them was ~2%. It was also known that childbed fever was rare when women gave birth at home. Semmelweis thought there was something the med students…
tsmith | January 30, 2007Readers who are regulars at Effect Measure or Deltoid will be familiar with the opinions of attorney and author Michael Fumento. Fumento considers himself an avian flu "skeptic," and recently issued a "challenge" (the title, "My avian flu challenge to the leftist bird-brained squawkers", might give you some clue as to its scientific value) to bloggers, in response to one blogger's comment that "... there was a "50%/50%" chance of [an influenza] pandemic in the next year":
I took advantage of Mr. Paramedic's oversight to bet him 10-1, with him picking the dollar amount, that there would be…
revere | January 29, 2007Having taken on the American Chemical Society the other day, why stop there. Let's talk about the American Chemistry Council, the ACC (neé the Manufacturing Chemists' Association, then the Chemical Manufacturers Association and now ACC). And bird flu. Yes, bird flu. The ACC is a trade association of the largest chemical companies and has a division called the Chlorine Chemistry Division which has just launched a website "dedicated to educating the public on flu prevention and recovery." If you believe that I've got a 1995 Volvo with low mileage (for a Volvo) just for you. Only driven at the…
revere | January 27, 2007Whenever the topic of sick leave comes up, employers are quick to raise the specter of malingering to get out of work. But a recent report on CNN suggests that showing up when sick may be costing plenty, too. "Presenteeism" is not just a financial problem but a public health one particularly germane to influenza:
Practically every workplace has one - the employee who comes to the job aching, coughing and sneezing.
So-called "presenteeism," or going to work when sick, is a persistent problem at more than half of U.S. workplaces and costs U.S. business a whopping $180 billion a year, research…
tsmith | January 25, 2007Like most fields, microbiology is one filled with jargon. Many laymen don't even realize the differences between a bacterium and a virus, much less the smaller differences between, for example, a pathogenic versus a commensal organism. So, while I haven't decided yet exactly what I might write about in future posts, I thought I'd begin with a very general microbiology primer to get everyone up to speed on the basics of the microbial word.
To begin with, in the "well, duh" category, microbiology is the study of very tiny life. Initially, those studied were mainly disease-causing organisms;…
tsmith | January 25, 2007Measles deaths down 60 percent in six years
Though we tend to think of measles as a mere childhood disease here in the U.S.--a nuisance more than anything--this is a reminder that worldwide, it's still a significant cause of morbidity and mortality. To counter this, a mass vaccine campaign was begun in 2001, and has served to drastically reduce the burden due to the disease:
Deaths from measles have fallen by 60 percent worldwide since 1999 in what experts described on Friday as an historic victory for global health.
Accelerated control measures including an increase in routine measles…
tsmith | January 24, 2007I've previously mentioned a bacterial pathogen called Acinetobacter baumannii (a bit more information here), and Mike has discussed it rather frequently. A. baumannii is ordinarilly a commensal bacterium--one that may live on the skin of healthy people for many years without ever causing disease. It becomes a problem when one is immunocompromised in some manner, and unable to keep growth of the bacterium in check. Once this happens, it's difficult to reverse, as the bacterium brings new meaning to the term "antibiotic resistant." As Mike blogged previously, a genomic analysis revealed…
tsmith | January 23, 2007 As I described previously in this post, war and disease are inextricably intertwined:
War and its concomitant devastation and social upheaval leaves its victims at an increased risk of disease transmission to begin with due to poor sanitation, collapse of public health and medical facilities and support personnel, crowding in refugee camps, breaks in supply chains of food, medicine, and other necessary items, malnutrition and depression, and other factors.
This social upheaval frequently lasts much longer than the actual fighting. Additionally, in some cases where areas have been…