General Epidemiology

This is the fourth of 6 guest posts on infectious causes of chronic disease. By David Massaquoi Working in public health is an interesting and satisfying job. Adding infectious disease investigation to such task makes the job not only difficult but the challenges of encountering numerous disease conditions; including learning about the Morgellon's disease. In recent years, doctors have been faced with an unexplained skin disease condition, dubbed "Morgellons Disease". I will not go into details with all the debates on merits and demerits of this "New" or "Emerging"? condition. However, as…
This is the third of 6 guest posts on infectious causes of chronic disease. By Whitney Baker While working out at the gym last night, I was perusing the latest SHAPE magazine to help pass the time. In it, I read a small article about researchers finding an association between Adenovirus-36 and human obesity. Since I am in the infectious disease field, I was already aware of this proposed link- an infectious cause (or contributor) for obesity. But for the millions of health-conscious readers hearing of this for the first time, what would they make of it? Would they have visions of…
This is the second of 6 guest posts on infectious causes of chronic disease. By Courtney Cook Scientists have been aware of a relationship between infections and mental illnesses for quite some time. For example, during the 1918 influenza pandemic, some patients were seen to exhibit a delirium unlike that which had typically been associated with a viral infection. In a 1926 report, Karl Menninger called it a "schizophrenic syndrome" and further observed that two-thirds of those diagnosed with schizophrenia after having influenza fully recovered from the mental illness within five years.…
This 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 "…
Four cases of measles have now been confirmed at a San Diego charter school--the first reported outbreak of measles in school-age kids in that city in 17 years. Unsurprising twist: None of the children, including the one most recently reported with the disease, has been vaccinated. New Scienceblogger Drugmonkey already hits the high (or low, such as it may be) points in this case in a much less restrained manner than I'm able to.
The fever hit suddenly in the form of a piercing headache and painful sensitivity to light, like looking into a white sun. At that point, the patient could still hope that it was not yellow fever, maybe just a headache from the heat. But the pain worsened, crippling movement and burning the skin. The fever rose to 104, maybe 105 degrees, and bones felt as though they had been cracked. The kidneys stopped functioning, poisoning the body. Abdominal cramps began in the final days of illness as the patient vomited black blood brought on by internal hemorrhaging. The victim became a palate…
I mentioned previously a clash between religion and public health, where a Liberian immigrant was jailed for importing bushmeat. She argued that infringing upon her religious freedom in this manner was unconstitutional; authorities argued that she couldn't put others at risk because of her religious beliefs. Another clash where religious beliefs are at odds with public health is simmering in the U.K.; more after the jump. Women training in several hospitals in England have raised objections to removing their arm coverings in theatre and to rolling up their sleeves when washing their…
You're probably familiar with the Seinfeld episode where George commits yet another social faux pas, getting caught "double-dipping" a tortilla chip. Just in time for your Superbowl festivities, turns out a soon-to-be-published manuscript (described in the New York Times) examined just how many bacteria are actually transferred by "double-dipping." I have more at Correlations, and the Seinfeld clip is after the jump. [Edited to add: Steve uploaded the poster describing the research here.]
An ongoing outbreak of Salmonella associated with turtles has now sickened more than 100 and caused a quarter of that number to be hospitalized: Cases have been reported in 33 states, but mostly in California, Texas, Pennsylvania and Illinois. Most of the patients have been children. No one has died in the latest outbreak, which began in August. But some patients have experienced severe symptoms, including acute kidney failure. The most common symptoms reported to the CDC included bloody diarrhea, abdominal cramping, fever and vomiting. The median age of patients was 7 1/2 . More after the…
A few months back, I blogged about World Rabies Day, noting that this virus is still a huge public health threat in many areas of the world. A few weeks ago, biologist Olivia Judson wrote a post on a potential "coffin for rabies" on her New York Times blog, describing more about the reality of the disease and what we could do to practically wipe out this virus in humans. I have a bit more on it over at Correlations. Image from http://www.powhatananimalhospital.com/disease/rabid%20dog.jpg
Though there still may be some lingering doubt about the cause of the Black Death and subsequent outbreaks of plague, the pathogen behind the outbreaks that have taken place in the last 150 years or so is much less ambiguous. While Koch and Pasteur ushered in the golden age of microbiology, an outbreak of plague began in China and spread from there. In 1894, while plague was raging in Hong Kong, the Pasteur Institute sent Alexandre Yersin, a physician who had trained with both Pasteur and Koch, to investigate. Yersin was able to access material from a corpse, and inoculated material he…
In parts one and two of the "What caused the Black Plague?" series, I discussed objections that had been raised to the conclusion that the bacterium Yersinia pestis was the cause of this pandemic, and the weaknesses with those criticisms. In today's installation, I'll discuss actual molecular evidence that Y. pestis indeed caused this--and does this research shut the door on alternative hypotheses? More after the jump... Much of the evidence for or against hypotheses supporting any pathogen as a cause of an ancient disease are based on symptoms and historical records. While we can…
Yesterday I introduced criticisms that have been raised against Y. pestis causation of the Black Death and subsequent plague outbreaks. Today I'll discuss what I see as weaknesses in these criticisms, after the jump. Selective quoting and interpretation of evidence First and foremost, a big issue I have with the claims by Duncan and Scott are that they are rather selective in what evidence they choose. For example, they selected several quotes from medieval manuscripts and diaries that suggest that people at the time "knew" it was directly contagious from person to person, and…
Methicillin-resistant Staphylococcus aureus (MRSA) has taken up residence in sport teams, prisons, schools, the military, and even swine. A new article in the Annals of Internal Medicine shows that, at least in Boston and San Francisco, it's also causing a lot of infections in men who have sex with men; more after the jump. To examine this, the authors looked at MRSA infections from a variety of health care settings: medical centers, community health clinics, HIV clinics, and emergency rooms. These were examined in separate analyses. For example, for the medical centers they looked at…
As I noted last week, Shelley mentioned a topic that's been brought up here a few times in the comments section: alternative theories for causes of the Black Plague (the devastating plague that ravaged Europe beginning in ~1347 and eventually killed more than a third of the population). Though the bacterium Yersinia pestis is almost universally accepted as the causative organism, like many areas of science, there are a few individuals who disagree with the consensus. To this end, several alternative etiologies for Black Plague have been put forth, and shortcomings with the mainstream Y.…
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.
Some infectious agents, it seems, have been with us since the rise of humanity. Bacteria like E. coli or salmonella don't appear to have one moment enshrined in history where they first appeared on the scene. They've probably long been with us, causing disease sporadically but not spectacularly. Other agents, however, seem to make their presence known. Syphilis is one of these. The first recorded outbreaks of syphilis (caused by the bacterium Treponema pallidum subspecies pallidum) were documented in Europe in 1495. These weren't syphilis as we know it today. Currently, syphilis is…
I'll have new posts up here next week, but meanwhile, over at Retrospectacle, Shelley's made this week plague week. She introduces the topic here, and next dishes about plague fashion. Also in the comments, it's asked: I recently heard that there is some doubt now that the Black Death may not have been bubonic plague. The doubt based on the speed of transmission, but no alternate disease was mentioned. Is there any other disease that matches the symptoms that could be a likely alternative? Long time readers know that I've referred to this previously and promised to post on it, so if even…
As another Ebola outbreak simmers in Uganda (and appears to be increasing), I recently was in touch with Zoe Young, a water and sanitation expert with Médecins Sans Frontières (MSF*, known in the US as Doctors without Borders), who was working in the Democratic Republic of Congo during the DRC Ebola outbreak earlier this fall (and blogging it!) Regular readers know of my interest in this virus, but I'm obviously geographically removed from any of the outbreaks. As such, Zoe and her colleague, physician Armand Sprecher, were generous enough to answer my questions about their work with…
It's been awhile since I wrote anything on influenza. It's certainly not that nothing interesting has happened recently--far from it, there are new stories on influenza out every day. Rather, there are just a lot of people out there covering it, and covering it well. However, it's been an unusually busy few days on the influenza front, so I thought I'd update after the jump. First, though much of the mainstream media has lost interest in avian influenza, scientists are still busy keeping an eye on things--and H5N1 is still spreading. Human cases have now been reported in Pakistan,…