public health
tsmith | June 23, 2011As I've laid out this week (part 1, part 2, part 3), the realization that a fairly simple, toxin-carrying bacterium could cause a "complex" and mysterious disease like hemolytic uremic syndrome came only with 30 years' of scientific investigation and many false starts and misleading results. Like many of these investigations, the true cause was found due to a combination of hard work, novel ways of thinking, and simple serendipity--being able to connect the dots in a framework where the dots didn't necessarily line up as expected, and removing extraneous dots as necessary. It's not an easy…
tsmith | June 22, 2011I left off yesterday with the initial discovery of "Vero toxin," a toxin produced by E. coli (also called "Shiga toxin" or "Shiga-like toxin"). Though this may initially seem unconnected to hemolytic uremic syndrome (HUS), the discovery of this cytotoxin paved the way for a clearer understanding of the etiology of this syndrome, as well as the mechanisms by which disease progressed. By the early 1980s, several lines of research pointed toward E. coli, and particularly O157:H7, as the main cause of HUS.
A 1982 Centers for Disease Control and Prevention MMWR report found a rare E. coli…
tsmith | June 21, 2011As I mentioned yesterday, the epidemiology of hemolytic uremic syndrome (HUS) was murky for several decades after it was first defined in the literature in 1955. In the ensuing decades, HUS was associated with a number of infectious agents, leading to the general belief that it was a "multifactorial disease"--one that had components of genetics and environment, much like we think of multiple sclerosis today, for example.
Several HUS outbreaks made people think twice about that assumption, and look deeper into a potential infectious cause. A 1966 paper documented the first identified outbreak…
mikethemadbiologist | June 13, 2011Note that I said cranky, not mad. Mad is reserved for moral degenerates who cut funding to assist people with cerebral palsy. But cranky? Yes. Recently, I've come across a couple of papers that describe interesting collections of E. coli. For example, one paper isolated a bunch of E. coli from soil and water in Hawaii to determine if there is a dominant point source of fecal contamination and if there are sustainable populations of E. coli in Hawaiian soils (which would mean we can't use simple counts of E. coli to determine if a water source is contaminated by feces). Another paper…
tsmith | June 12, 2011Nick Kristof has an op/ed in today's NY Times noting some sober statistics about the food we eat: that it puts 350,00 people in the hospital and kills 5,000 in the U.S. every year. He also cites three of our papers examining MRSA and swine/swine facilities.
tsmith | June 10, 2011Via H5N1, German officials are calling it for sprouts:
Germany on Friday blamed sprouts for a bacteria outbreak that has left at least 30 dead and some 3,000 ill, and cost farmers across Europe hundreds of millions in lost sales.
"It's the sprouts," Reinhard Burger, the president of the Robert Koch Institute, Germany's national disease centre, told a news conference on the outbreak of enterohaemorrhagic E. coli (EHEC) in northern Germany.
"People who ate sprouts were found to be nine times more likely to have bloody diarrhoea or other signs of EHEC infection than those who did not," he said,…
tsmith | June 9, 2011Maryn McKenna has a great update today on the E. coli situation, looking at where we are as far as unanswered questions about the outbreak and the strain. It's been a messy day; more evidence seems to point to the sprout farm, but CIDRAP also notes that another contaminated cucumber was found in the compost bin of a family sickened by the bacterium (this one had the correct serotype--O104), but it's impossible to tell at this point whether the cucumber was the source of that bacterium or it ended up there from one of the sickened family members. Twists and turns abound in this investigation…
tsmith | June 6, 2011Well, Sunday the said we'd have some results on the sprout tests for E. coli O104:H4. Well, so far the results are negative.
The 1st tests from a north German farm suspected of being the source
of an _E. coli_ [O104:H4] outbreak are negative, officials say. Of 40 samples from the farm being examined, they said 23 tested negative.
Officials had said earlier that bean sprouts produced at the farm in Uelzen, south of Hamburg, were the most likely cause of the outbreak. The outbreak, which began 3 weeks ago and is concentrated in Hamburg, has left 22 people dead. Initially, German officials had…
mikethemadbiologist | June 6, 2011After Friday's post, I've held off on writing much about the German E. coli outbreak, often referred to by its serotype, O104:H4, or as HUSEC041 (HUS stands for hemolytic uremic syndrome). Having had the weekend to digest some of the ongoing analysis and news reports, here are some additional thoughts:
1) The multilocus sequence type (MLST) of this outbreak is definitely ST678. This means this outbreak strain is related to an older strain found in 2001 that caused disease. A new, improved assembly released by BGI yields a perfect match to ST678. In addition, there is independent…
mikethemadbiologist | June 5, 2011...and I can't blame them. The recent and ongoing E. coli outbreak which began in Germany was originally claimed to have been traced to Spanish cucumbers. Erm, not so much:
German agricultural authorities on Sunday identified locally grown bean sprouts as the likely cause of an E. coli outbreak that has killed 22 people and sickened hundreds in Europe.
The Lower Saxony agriculture ministry was sending an alert Sunday warning people to stop eating the sprouts, which are often used in mixed salads, ministry spokesman Gert Hahne told The Associated Press.
"Bean sprouts have been identified as…
tsmith | June 5, 2011The E. coli story is moving quickly. A news report out today suggests that sprouts might be the culprit (though it should be emphasized that the outbreak strain hasn't been isolated from these vegetables yet):
Mr Lindemann said epidemiological studies all seemed to point to the plant nursery in Uelzen in the state of Lower Saxony, about 100km (62m) south of Hamburg - though official tests had not yet shown the presence of the bacteria there.
"Further evidence has emerged which points to a plant nursery in Uelzen as the source of the EHEC cases, or at least one of the sources," he said.
"The…
tsmith | June 3, 2011Mike has has a great new post up looking at some molecular analyses of the current European outbreak strain. For anyone who hasn't been paying close attention to what's happening across the pond, there's an ongoing outbreak of enterohemorrhagic E. coli (EHEC)--the type of E. coli that includes O157:H7, which has been associated with outbreaks of disease associated with food. The most infamous outbreak was the 1993 Jack-in-the-Box disaster, associated with undercooked hamburgers contaminated with the organism, but there have also been outbreaks associated with contaminated vegetables (such as…
tsmith | June 3, 2011...when it contains a weird gene conferring methicillin resistance that many tests miss.
Methicillin-resistant Staphylococcus aureus (MRSA) has become a big issue in the past 15 years or so, as it turned up outside of its old haunts (typically hospitals and other medical facilities) and started causing infections--sometimes very serious--in people who haven't been in a hospital before. Typically MRSA is diagnosed using basic old-school microbiology techniques: growing the bacteria on an agar plate, and then testing to see what antibiotics it's resistant to. This can be done in a number of…
tsmith | May 30, 2011In the United States, we tend to take our clean drinking water for granted. Even though there are periodic concerns which bubble up about pharmaceuticals or other chemicals in our water supply, we typically believe--with good reason--that we have little to fear when it comes to contamination from microbes. Our drinking water, while far from perfect, is heads and shoulders above what it once was--something many of us forget or have never realized. There have been notable breakdowns, such as the 1993 outbreak of Cryptosporidium in Milwaukee that sickened over 400,000 individuals, but these days…
tsmith | May 24, 2011We've had pertussis and mumps, so it was only a matter of time.
State health officials declared a "public health emergency" Tuesday after a test confirmed a case of measles in an unvaccinated Dallas County baby who apparently picked up the disease in India.
They said people who might have been exposed included passengers on an Americans Airline flight from Chicago to Des Moines May 11 and people who were at Mercy Medical Center or a Mercy pediatric clinic in downtown Des Moines May 14.
Dr. Patricia Quinlisk, medical director for the Iowa Department of Public Health, said many Americans…
lborkowski | May 24, 2011I've written before about "Ten Great Public Health Achievements of the 20th Century," which the Centers for Disease Control and Prevention published in 1999. Now, CDC has put together a list of ten great public health achievements from 2001 to 2010, based on nominations from the agency's public health scientists. Here are the ten achievements from the first decade of the 21st century:
Vaccine-Preventable Diseases -- Cases, hospitalizations, and deaths from vaccine-preventable diseases have dropped over the past decade, and the impact of the pneumococcal conjugate and rotavirus vaccines has…
lborkowski | May 18, 2011By Kim Krisberg
Climate change is one of the greatest challenges of our time. Climate change will affect, in profoundly adverse ways, some of the most fundamental determinants of health: food, air, water. In the face of this challenge, we need champions throughout the world who will work to put protecting human health at the centre of the climate change agenda.
-- Margaret Chan, MD, MPH, director-general, World Health Organization, 2008
Human health may not be the first image that pops to mind when it comes to climate change. People often envision melting icebergs or desperate polar bears…
tsmith | May 16, 2011Via H5N1 and other sources, there's at least one new Ebola case in Uganda:
The rare and deadly Ebola virus has killed a 12-year-old Ugandan girl and health officials said on Saturday they expected more cases.
The girl from Luwero district, 75 km (45 miles) north of the capital Kampala, died on May 6, said Anthony Mbonye, the government's commissioner for community health, in the first outbreak of the virus in Uganda in four years.
"Laboratory investigations have confirmed Ebola to be the primary cause of the illness and death. So there is one case reported but we expect other…
tsmith | May 13, 2011It's been not even a month since the last paper looking at MRSA in meat, and up pops another one. So far here in the US, we've seen studies in Rhode Island (no MRSA found); Louisiana (MRSA found in beef and pork, but "human" types: USA100 and USA300); the recent Waters et al study sampling in California, Florida, Illinois, Washington DC, and Arizona, finding similar strains (ST8 and ST5, associated with USA300 and USA100, respectively). Now a new study has collected MRSA samples in Detroit, collecting 289 samples from 30 retail stores in the city.
For this study, they collected only beef,…
tsmith | May 12, 2011An ahead-of-print paper in Emerging Infectious Diseases is generating some buzz in the mainstream media. While the findings are interesting, I'm honestly not sure how they got published, being so preliminary.
Like many areas, Vancouver, British Columbia has seen a jump in the prevalence of bedbugs. After finding impoverished patients infested with the bugs, researchers decided to collect some and test them for pathogens--specifically, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). So, they tested 5 bugs from 3 patients. That's it--it doesn't…