Stories tagged infectious disease

Jul
24
2008

Peter Piper picked a peck of pickled salmonella
Peter Piper picked a peck of pickled salmonellaCourtesy lucianvenutian
But did anybody listen?
According to a Star and Tribune article MN’s own “Team Diarrhea” figured out jalapeño peppers were to blame for the MN Salmonella cases and told the FDA and CDC to look at jalapeño peppers as the culprit for cases nationwide instead of tomatoes. The DNA of the strains in MN matched the cases elsewhere. To learn more about this story check out a previous Buzz Blog.

I’m happy to report that these super sleuths were advisors and content experts in the development of Disease Detectives which is currently in the Science Museum of Minnesota’s Human Body Gallery. You can learn more about some of these disease detectives here.

So check out today’s Star and Tribune article and give thanks to Kirk Smith and the rest of his team at the Minnesota Department of Health for doing their best to keep us safe!

Jul
14
2008

Flu vaccine: This is CDC Clinic Chief Nurse Lee Ann Jean-Louis extracting Influenza Virus Vaccine, Fluzone® from a 5 ml. vial.
Flu vaccine: This is CDC Clinic Chief Nurse Lee Ann Jean-Louis extracting Influenza Virus Vaccine, Fluzone® from a 5 ml. vial.Courtesy CDC/Jim Gathany

Did you know back in February scientist and medical professionals selected the influenza virus strains for the upcoming flu season? Now that it is July the pharmaceutical companies are well into manufacturing, purification and testing the vaccine. Meanwhile, it is winter and flu season in the southern hemisphere and the virus is busy mutating. The big question on everyone’s mind is will it mutate so much that the northern hemisphere vaccine will be ineffective?
I agree with Dr. Steven Salzberg remarks in his recent Nature commentary

"The current system, in which most of the world’s vaccine supply is grown in chicken eggs, is an antiquated, inefficient method requiring six months or more to ramp up production, which in turn means that the vaccine strains must be chosen far in advance of each flu season. More crucially it sometimes prevents the use of the optimal strain, as it did in 2007."

Influenza (the flu) is a serious disease
Each year in the United States, on average:

  • 5% to 20% of the population gets the flu;
  • More than 200,000 people are hospitalized from flu complications, and;
  • About 36,000 people die from flu.

Some vaccine problems in the past
In recent years the match between the vaccine viruses and those identified during the flu season has usually been good. In 16 of the last 20 U.S. influenza seasons, including the 2007-08 season, the viruses in the influenza vaccine have been well matched to the predominant circulating viruses. Since 1988, there has only been one season (1997-98) when there was very low cross-reaction between the viruses in the vaccine and the predominate circulating virus and three seasons (1992-93, 2003-04, and 2007-08) when there was low cross-reaction (CDC). So after last year’s miscalculation the committee picked three new strains for the vaccine this year. One is a current southern hemisphere vaccine virus which they expect will still be present next year. In addition, they predict a second new Type A strain, known as H1N1/Brisbane/59, to also hit, along with a newer Type B/Florida strain.

Dr. Salzberg feels last year’s miscalculation was a failure…

"The harm was thus twofold; people fell ill and their trust in the vaccine system was undermined. This failure could have been predicted, if not prevented, through a more open system of vaccine design, a stronger culture of sharing in the influenza research community and a serious commitment to new technologies for production. The habits of the vaccine community must change for the sake of public health."

He goes on to suggest…

"The process of choosing flu-vaccine strains needs to be much more open. Other scientists, such as those in evolutionary biology with expertise in sequence analysis, could meaningfully contribute to the selection. At present, external scientists cannot review the data that went into the decision, nor can they suggest other types of data that might improve it."

Even with all of these miscalculations, I still feel getting the vaccine is worth the risk. But that doesn’t mean the process shouldn’t be improved. So once again I will be vaccinated and I will make sure my family is too—but what can we do as citizens to improve this process? What will you do?

Jul
13
2008

HealthMap screen capture
HealthMap screen captureCourtesy Art Oglesby

Want a warning about disease outbreaks?

With the internet's new capabilities, new information is highly contagious. The web is increasingly being used to exchange information about public health and disease outbreaks. Now, thanks to HealthMap anyone can track where and when infectious disease outbreaks are occurring.

Web crawlers, automated translation, GIS mapmaking, ISP tracking, and cell phone imagery have created a world where, for good or ill, rumors of outbreaks outpace confirmation. The Journal of Life Sciences

Colored pins point to disease outbreaks

Using what is often referred to as Web 2.0 dynamics, Healthmap.org crawls the internet for disease outbreak information, integrating information from various sources like Google News, ProMED, and World Health Organization disease alerts. Through an automated text processing system, the data is sorted by disease and overlayed by location on top of Google Maps.

Want to learn more about HealthMap?

HealthMap was created by Clark Freifeld and John Brownstein through Children's Hospital Informatics Program (CHIP) at Harvard-MIT Division of Health Sciences & Technology. Click this link to view a presentation about HealthMap given at a Georeferencing Workshop at Harvard, March 21, 2008 by John Brownstein.

Jul
11
2008

It was horrible: just horrible.
It was horrible: just horrible.Courtesy Steveie-B
A pipistrelle bat, local to Aberdeen, Scotland, was shocked and disgusted to find the naked leg of a 19-year-old woman thrust into the soft contours of its new cave.

Having just moved from the grim crawlspaces of an Aberdeen flat, in favor of a cozier, denim living space, the two-inch flying mammal assumed that it was set for life.

Shortly after settling in for the day, however, the pipistrelle was bludgeoned into consciousness by the colossal, pale shank of a Scottish receptionist. The invading limb was squeezed through the cloth tube like a kielbasa in the neck of a beer bottle, leaving the bat little choice but to hunker down and wait for the flesh-storm to subside.

Unfortunately, the young receptionist remained maddeningly unaware of the presence of the sorely abused batty for the better part of an hour. It was not until her mother was driving her to work that the nerve signals from her monstrous appendage apparently completed the arduous journey to her brain. The screaming and thrashing that followed was no doubt tortuous for the small creature’s delicate bones and hyper-sensitive ears. One can only imagine how painful the experience must have been to the tiny merkel cells lining the bat’s wings, as the delicate, single-haired structures were meant only to sense subtle changes in air flow, not to endure the scraping of Scotch legs.

The bat was shortly evicted from its new home, and placed into a holding cell, where it was given the humiliating nickname “Rat-bat.”

“My name,” the pipistrelle was quoted, “is Henry Fitzroy-Lennox, and I want to go home.”

Lamentably healthy, the bad wondered how things might have been different, had it been a carrier of rabies. The virus, present in the nerves and saliva, could have been easily passed to the receptionist through one quick bite (or, less likely, but intriguingly possible, via an aerosol through the mucus membranes). The infection would have necessitated an injection of immunoglobulin near the infection site, and another intramuscularly away from the site, followed by several shot of vaccine.

If the receptionist had neglected to seek proper treatment for the Henry’s well-deserved revenge, she could have looked forward to the rapid passage of the virus along her nerves, through her central nervous system, to the ultimate destination of her brain, where it soon would have caused encephalitis—painful and deadly inflammation of the brain.

There’s some small chance that a drug induced coma could have saved her brain from further damage at this point, but very likely the damage would have been done, and irreversible symptoms would soon begin to appear. Initially symptoms would be flu-like, but before long the woman would have suffered from insomnia, confusion, agitation, partial paralysis, paranoia, terror, and severe hallucinations. The receptionist would have become distinctly drippy, as her body would produce excessive amounts of tears and saliva. Her slight paralysis would have prevented her from swallowing, causing the characteristic “foaming at the mouth” of rabies. She may have developed hydrophobia—a fear of water—because the excess fluid in her mouth and inability to swallow could bring her to a panic when presented with liquids to drink (indeed, “hydrophobia” was once synonymous with rabies, so characteristic was the symptom).

Approximately one week after developing symptoms, the receptionist would have died.

So, all in all, it seems that she really dodged a bullet after throwing herself in front of a gun.

Mr. Fitzroy-Lennox was released into the wild (of Aberdeen) at the end of the lucky and inconsiderate woman’s shift. He will never again put himself into a position where a receptionist could abuse him so awfully.

More from Science Buzz on bats and rabies.

More on receptionists.

More on Aberdeen.

Jul
09
2008

So I'm surfing the web and I come across an item about DDT use in Africa. If it's true, then this is the kind of thing that really frosts my shorts. But, as the blogger notes, the item has only appeared in a couple of fringe outlets. Not that I consider the MSM the font of credibility. But I've already been taken to task for the Space Camp Barbie post, so it would be nice to have verification.

Anyway, according to this report, a Dutch textile firm is refusing to buy cotton from parts of Uganda which use the chemical DDT to combat malaria. Malaria kills up to 100,000 Ugandans every year. DDT effectively controls the mosquitoes that spread the disease.

But DDT has a downside -- it gets into the environment and poisons fish, birds and other wildlife. For this reason, it has been banned in the US and other Western countries for more than 30 years.

Countries that use DDT today don't spray food crops. They use small, safe amounts and generally confine its use to indoors, protecting people from malaria-ridden mosquitoes.

But this apparently is not good enough for the Dutch. According to the report, the company is refusing to buy cotton from areas that use DDT, claiming the crop is no longer "organic." As a result, farmers from those areas cannot sell their cotton at full price, and are losing money.

Basically, European eco-purists are giving African farmers a choice: avoid DDT and die of malaria, or use DDT and die of starvation. The Euro-elites, of course, face neither of these fates.

Like I said, this is based on just one report. It would be nice to get independent confirmation.

Jun
12
2008

Be sure to wash pigs carefully: before kissing or eating.
Be sure to wash pigs carefully: before kissing or eating.Courtesy Matt & Helen Hamm
A new study out of Ohio State University has shown that pigs raised outdoors, antibiotic-free, on “animal friendly” farms are more likely to be infected with parasites and bacteria than animals from conventional farms. That’s sort of a surprise—that pigs without antibiotics would have more…biotics

Two of the infections found in the pigs have been seen around Science Buzz recently: toxoplasma gondii, the cat poop parasite, and salmonella, that troublesome bacteria that’s been getting in our tomatoes.

Also found in the antibiotic-free pigs was the parasite Trichinella spiralis, a round worm that can cause very serious illness in humans. Only two of the six hundred or so pigs tested were found to be hosts to trichinella, but this is still a surprising figure for an organism that has been nearly eradicated on conventional farms (veterinarians usually expect perhaps one pig in fourteen thousand to contain trichinella).

So that’s kind of yucky.

But consider this: even pigs treated with antibiotics were not free of salmonella and toxoplasma. 54% of untreated pigs had salmonella in their bodies, but so did 39% of treated pigs, and while about 7% of untreated pigs carried toxoplasma bacteria, over 1% of the treated pigs did too. Also, if you’re into the cruelty-free part of natural farming (not me—I’m all about cruelty to animals) it should be noted that the piggies aren’t actually sick, they’re simply carriers of these organisms.

The scientists behind the study are careful to point out that they aren’t recommending one form of pork production over the other—each has its benefits as well as its downsides. While pigs raised antibiotic-free are more likely to have higher rates of common bacteria of food safety concern, treated pigs can “create a favorable environment for strains of the bacteria that are resistant to antibiotics.” So that’s no good.

The thing is, you shouldn’t really be worried about any of these pathogens, assuming that you handle and cook your pork properly, and don’t go around licking pigs and things.

But far be it from me to judge that sort of thing.

Jun
11
2008

A bowl of diseased plant reproductive organs: Or possibly not. Salmonella is tasteless, odorless, and invisible to the naked eye. So be vigilant, Buzzketters!
A bowl of diseased plant reproductive organs: Or possibly not. Salmonella is tasteless, odorless, and invisible to the naked eye. So be vigilant, Buzzketters!Courtesy Muffet
Did you know that tomatoes are technically ovaries? They are. That goes a long way in explaining why eating a tomato feels so much like eating a raw organ, which in turn could be why they always used to make me puke (the ovary thing, combined with an early “no, really, they’re good” force-feeding session from my dad).

I’m getting over the puking thing, but I’ve spent many long and frustrating summers watching others eat tomatoes, apparently and inexplicably enjoying them. Well, it looks like this is the summer of JGordon, because finally tomatoes are making some other folks hurl too. That these plant ovaries are tainted with human or animal feces is, I think, icing on the cake.

A salmonella outbreak this spring, which has caused at least 167 individuals to become ill (23 of whom have required hospitalization), has been linked to consumption of tomatoes tainted with the salmonella St. Paul.

Salmonella is transferred to humans by consuming food contaminated with human or animal fecal matter. So, as much as you might like it, keep that fecal matter out of your food for a while, okay?

If fecal matter has somehow slipped past your guard, and your lips, there’s a chance that you too will join this latest craze. You’ll know it through flu like symptoms—fever, cramps, headache, nausea, diarrhea, vomiting, etc.—inside of a couple days after contact with the bacteria. Generally people walk away from salmonella feeling a little queasy, but for some people (young children, pregnant mothers, and folks with weakened immune systems) it can be very dangerous.

As with the spinachy e. coli outbreak at the end of ’06 (which you can read all about on Science Buzz by going here) medical authorities are recommending that you wash your produce in cold water before eating it (especially if you don’t plan on cooking it—salmonella dies at about 145 degrees), and perhaps avoid eating the specific crop the infection seems to stem from for a couple weeks (in this case red plum, Roma, and round red tomatoes). McDonalds has already made the ironic move of temporarily removing sliced tomatoes from its menu altogether—to make its burgers healthier.

If you’ve got some tomatoes you don’t entirely trust, just return them, or toss them out. Or execute them.

Jun
05
2008

OMG! Cute kitten! LOL!: I r poisnin ur brain!
OMG! Cute kitten! LOL!: I r poisnin ur brain!Courtesy manitoon
I was wrong!

You know, I spend so much time being right, that the occasional (very, very occasional) situation in which I’m slightly…not right, is actually pretty refreshing. It’s like, oh, I don’t know, getting halfway to work and realizing that you forgot to put on pants, and then linking, “Hey, who cares? And it’s a warm day!” It’s liberating.

Some days I can’t help but feel overwhelmed by cat feces. I don’t even live with a cat at the moment, but I’m aware that there are millions of cats out there, and they’re all addicted to pooping (just try forcing a cat to go cold turkey—total junkies for the litter box). There’s just so much cat poop in the world, and none of it smells very good, and I don’t want to touch any of it, and its very existence drives me to distraction.

Nobody else seems to care very much. Here I am, dreaming of cats that emit water vapor and rose-scented hydrogen gas as their only waste products, and the rest of the world seems content to live with a planet suffocating under the weight and odor of cat effluvia. I imagine that Leonardo felt the same way. It’s a lonely existence.

Perhaps no longer.

Toxoplasmosis gondii is an interesting little gooball (gooball is a term of my own, so don’t use it in class, or you’ll get an F and I’ll sue you). It’s a protozoan parasite, capable of living in nearly any warm-blooded mammal (it’s estimated that over 20% of the U.S. population carries the parasite), although its infectious form—responsible for about a third of all deaths from food borne illnesses—is only carried by cats.

The parasite has some interesting tricks up its sleeves too. It seems that when a rodent is infected with T. gondii, it loses its fear of cats. And a little mousey with no fear of cats is a little mousey that gets eaten, successfully passing the parasite back to its favorite host. Weird.

I also have very little fear of cats, which led me initially to believe that I was a carrier of the disease. But a study covered in this article details a whole different set of symptoms in infected humans (of which, again, there are many). Men who are infected “have lower IQs, achieve a lower level of education and have shorter attention spans. They are also more likely to break rules and take risks, be more independent, more anti-social, suspicious, jealous and morose, and are deemed less attractive to women” An unsettling portion of this description applies to me, and so it’s possible that I may still be infected.

Infected women, on the other hand, are generally “more outgoing, friendly, more promiscuous, and are considered more attractive to men compared with non-infected controls.” So, you know, it turns out that kittens are a good gift item after all.

And if that isn’t enough to get people thinking about cat feces, it turns out that some of human’s favorite animals, aquatic mammals, are just swimming in toxoplasmosis. How do you like that? The appearance of the parasite in marine mammal populations (including whales, dolphins, otters, sea lions, and seals) seems to be relatively recent, but it is estimated that up to 17% of sea otter deaths alone could be attributed to toxoplasma.

So how are sea creatures across the world becoming “infected by a parasite that is spread primarily through the consumption of infectious cat feces and infected meat”?

(That quote, by the way, comes from a microbiology researcher from Boston, and, if you remove “and infected meat,” is the winner of the best quote of the day award.)

Anchovies. Probably anchovies. The little fish are filter feeders, and could pick up the parasite before beginning extensive migrations, spreading the disease to the many anchovy eaters of the oceans (people who eat anchovies are safe, because heat kills the protozoa). Just how the organism is getting to the anchovies remains unclear, but it has been proposed that the problem has to do with cat feces-contaminated runoff.

So there. Like sea otters and dolphins? Then start thinking about cat feces. I don’t propose that you do anything about it, but I do want you to obsess over it. You won’t be alone.

Also, especially if you’re a guy, keep that stuff out of your mouth.

It is important to remember that not all microbes make you sick. In fact many are even helpful. Click here for a New York times article that summarizes recent findings or go to the original scientific article in
Genome Research about human skin microbes. Finally you can learn more about gut microbe research at Washington University here.

Why do microbes always get such a bad reputation?