General Epidemiology
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 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 | January 11, 2007In yesterday's post regarding the current outbreak of Rift Valley Fever in Kenya, I noted:
...while there's little people in the area can do about periodic flooding, scientists are actively examining the relationship between weather and RVF outbreaks. This hopefully will prove useful to predict--and potentially ward off--future disease outbreaks via animal vaccination.
Little did I know that this outbreak had already been predicted by scientists working in this area--back in September. More after the jump...
The deaths from Rift Valley fever could have been avoided if Kenya had heeded a…
tsmith | January 10, 2007 When it comes to hemorrhagic fevers, Ebola and Marburg tend to get the lions' share of the press. Both are highly fatal, both can cause people to die in excruciating ways, and both have come to represent somewhat our fear of and fascination with emerging exotic diseases. However, as I've pointed out previously, as far as actual fatalities--or even illnesses go--both viruses are small potatoes. Other viruses that can also have hemorrhagic manifestations--including dengue and yellow fever--are much more common. One of these other viruses that frequently causes hemorrhagic fever is Rift…
tsmith | January 8, 2007When people think of Iowa, many of them think of our agriculture (for good reasons). Obviously, it's big business here. We ranked first in the nation in production of corn, soybeans, eggs, and pork in 2005. Indeed, population-wise, hogs here outnumber humans by more than 5 to 1. This is one reason research at our center focuses on zoonotic disease (diseases which can be transferred between animal species), and specifically, diseases of domesticated animals. A story in the news today shows one reason why we study what we do:
Iowa State health officials say someone in eastern Iowa has…
tsmith | January 5, 2007From the Seed mothership: Cancer is due to 'fate', Britons believe
More than a quarter of people believe that fate alone will determine whether they get cancer, not their lifestyle choices, according to a survey conducted by charity Cancer Research UK.
The poll of more than 4,000 adults across the country asked people if they thought they could reduce their risk of getting cancer or whether it was out of their hands.
A total of 27 percent of people said cancer was down to fate, with more women than men believing cancer was a matter of destiny than prevention through measures such as quitting…
tsmith | January 5, 2007 Gina Kolata has an interesting article from Wednesday's New York Times, discussing education and longevity.
James Smith, a health economist at the RAND Corporation, has heard a variety of hypotheses about what it takes to live a long life -- money, lack of stress, a loving family, lots of friends. But he has been a skeptic.
Yes, he says, it is clear that on average some groups in every society live longer than others. The rich live longer than the poor, whites live longer than blacks in the United States. Longevity, in general, is not evenly distributed in the population. But what, he…
tsmith | January 4, 2007I ran across this story study linking breast cancer protection to housework while browsing Scienceblogs briefly over the break (GrrlScientist mentioned it here), but hadn't had a chance until now to read through the actual publication. As usual, I'm late; Orac has a good overview, as well as some comments made by other bloggers railing against "feminism" and how this study proves that feminist philosophy kills women.
First, here's how the BBC story describes it:
Women who exercise by doing the housework can reduce their risk of breast cancer, a study suggests.
The research on more than…
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 | December 19, 2006 Libya to execute HIV medics
(Previous posts on the topic)
A court convicted five Bulgarian nurses and a Palestinian doctor Tuesday of deliberately infecting 400 children with HIV and sentenced them to death, despite scientific evidence the youngsters had the virus before the medical workers came to Libya.
The United States and Europe reacted with outrage to the verdict, which prolongs a case that has hurt Libya's ties to the West. The six co-defendants have already served seven years in jail.
The sentence brought cheers in Libya, where there is widespread public anger over the infections.…
tsmith | December 14, 2006Today's New England Journal of Medicine has an article (free access) with more information on the Tripoli Six, who are still awaiting their December 19th verdict.
tsmith | December 13, 2006If the last circumcision post caused a lot of heat, this news is likely to cause even more of an uproar worldwide. From NBC News comes word that the NIH will be announcing shortly that they're stopping two trials looking at circumcision and HIV in Africa, because the intervention group (those who were circumcised) show far less HIV infections than the uncircumcised men:
NBC News has learned that the National Institutes of Health will announce at Noon ET Wednesday that two clinical trials in Africa have been stopped because an independent monitoring board determined the treatment was so…
tsmith | December 12, 2006 I've written previously about how it's a bad idea to import exotic pets, after "exotic" African species of small animals were imported into the United States and housed alongside prairie dogs that were also to be sold as pets. The African animals brought along with them their own diseases, including monkeypox, which then spread to the prairie dogs and onto humans, causing at least 80 cases of monkeypox in the U.S.
Think this is a rare event, unlikely to re-occur? Think again. The Baltimore Sun has a story on how "exotic" pets like these African rodents enter the U.S. by the millions…
tsmith | December 8, 2006As I've been busy this week, other Sciencebloggers (with Revere leading the fray and more posts here) have updated everyone on the newest developments in the case of the Tripoli Six (previous update here), the six medical workers on trial for their lives in Libya, accused of spreading HIV to more than 400 children in a hospital there. Nature's Declan Bulter broke news on a new Nature paper showing, using molecular phylogenetics, that the strains of HIV which infected the children were already circulating in the hospital prior to the medics' arrival--again, showing that these workers are…
tsmith | December 1, 2006Revere over at Effect Measure has an excellent post linking together the current bird flu situation with John Snow's investigations of 19th century cholera outbreaks. It's an interesting take on the situation--check it out.
tsmith | November 16, 2006 I was just lecturing yesterday on streptococci, and discussing how the diseases caused by the group A streptococcus (Streptococcus pyogenes). This is the bacterium that causes diseases as varied as "strep throat," streptococcal toxic shock syndrome, and necrotizing fasciitis (aka the "flesh-eating disease.") It's also caused historical epidemics of scarlet fever, a major scourge in many countries from the mid-1800s or so until around the turn of the century, when it started to wane for no apparent reason. (The worry over this illness was captured in Margery Williams' 1923 book, "The…
tsmith | November 7, 2006Male circumcision is a difficult topic to discuss rationally. At the core, it's a medical procedure, but it's one tinged with centuries of cultural influences, and emotions tend to run high on both the pro- or anti-circumcision side of the discussion. One of the reasons that's been given in favor of circumcision is that it lowers the risk of disease, including diseases transmitted by sexual contact. However, while this data has been fairy unambiguous regarding some diseases (including the reduction in HIV transmission due to circumcision), the effect circumcision has on the spread of…
tsmith | October 25, 2006I previously blogged an editorial by NBC medical correspondent Robert Bazell, where he told scientists to "quit whining" about intelligent design and instead work on teaching "values." While I agreed with him there on the science (he made it clear he gave no respect to "intelligent design" and other types of creationism), his suggestion that teachers and scientists spend more time worrying (and teaching) about more "practical" things such as biotechnology and medical ethics was just, in my opinion, wrong. Luckily, his new editorial on alternative medicine contains no such red herrings.…
tsmith | October 24, 2006Orac has an excellent post discussing the rise in pertussis ("whooping cough") in many areas, and its correlation with easier exemption from mandatory vaccination (using a "personal belief" exemption in addition to a religious exemption, for example). I've written about pertussis previously, and a problem is that the vaccine effectiveness quickly wanes, so that adults frequently lack significant immunity. While we rarely get sick, we can be carriers of the bacterium and infect children around us. As such, new recommendations suggest that adults also should get a pertussis booster. I worry…
tsmith | October 23, 2006Apologies for the radio silence, so to speak. October has been a killer month for me and November won't be that much better, but I'll work on getting back to posting on a regular basis, including a new post for tomorrow. In the meantime, a few things to check out:
Mike on treating strep throat (which he's correct is near and dear to my heart--though not literally, thankfully, since they can cause heart disease!).
A belated Friday the 13th Tangled Bank
Last week's Grand Rounds.