Deadly Bites

 

So this is probably what you're thinking, right? Maybe you're thinking something along the line of dogsbite.org's dramatic slogan "Some dogs don't let go". Perhaps you're thinking of lions, tigers, and bears. While all of those can do a lot of damage in a short period of time, and they all call out to a primal terror hidden in all of us, they're not at all the most likely to kill you from a bite.

 

In fact, last year there were only ten fatality shark attacks worldwide, out of seventy-two unprovoked attacks[1]. Unprovoked attacks are those situations where there shark was undisturbed in its natural habitat, and attacked an unsuspecting human. That's actually fewer than the number of people killed by jellyfish in the Philippines alone every year (roughly twenty to forty). [9]Nobody sees jellyfish as the horrible monsters they really are by comparison to sharks, but getting sent into heart failure and drowning feet from shore because you brushed a jellyfish seems almost as terrifying to me as getting tasted by a shark. At least trauma care in the US can do something about shark bites, but it's suspected that many Jelly poisonings are mistaken for heart attacks, and not treated as they should be. [9]

 

When it comes to data on dog bites, other than the CDC for raw injury data, dogsbite.org seems to be the go-to place to get information on the internet. They're the second google hit when you search 'dog bite statistics', coming in ahead of the CDC, and behind a lawyer's 'wanna sue somebody?' page. Their website heralds themselves as a public information site, but I feel that they're about as informative as the National Vaccine Information Center, or other fearmongering sites with a bias to preach. They mention Pit Bulls in specific nineteen times on their front page alone as of the time of this writing. Their site is smattered with distorted statistics (such as using a nine year period of dog bite records to be able to say that pit bulls killed 176 people), and relies heavily on anecdotal, not empirical, accounts to strike fear and sorrow into the reader's mind- a tactic that is frequently used by organizations that have no or weak evidence to support their stance. The studies they cite as being significant are frankly pretty limp (or have nothing to do with bite epidemiology), such as this one which only notes a 0.63 events per 100,000 people a year reduction as a result of breed specific legislation. Their article on pit bull owners, which can be viewed here is nothing short of offensive. The kicker is that they have a directory of dog bite lawyers on their site, for your legal convenience.

 The reality when it comes to dogs is that, on a yearly basis, we have 32 deaths from dog bites in the US (still more than sharks globally, and less than Jellyfish)[2], a total of 4.5 million reported bites, 885,000 of which are deemed to require medical attention. Of those, 27,000 require reconstructive surgery.[3] According to the American Humane Association, breed specific legislation is ineffective at reducing dog bite total incidents. [10]According to an American Veterinary Medical Association  report cited on the CDC's dog bite statistics page, it isn't useful to single out one or two breeds for control. The reason is multifaceted, but essentially boils down to dog bite statistics actually being pretty poor.

"Dog bite statistics are not really statistics, and they do not give an accurate picture of dogs that bite. Invariably the numbers will show that dogs from popular large breeds are a problem. This should be expected because big dogs can physically do more damage if they do bite, and any popular breed has more individuals that could bite." [11, page 2/18]

 So how do we effectively reduce dog bites? The numbers don't lie, unaltered dogs bite more. In fact, 92% of fatal dog attacks involved male dogs, 94% of whom were unaltered. Supervise your kids around unfamiliar dogs, teach them that harassing any animal- especially a dog- is going to get them hurt. Don't approach any unfamiliar, chained up, or stressed out animals. It's that easy; Get your dogs altered, teach your kids, and practice a little common sense.

"But Curt!" You say. "This is the fearblog, and you have made me not afraid!" Well, if the very existence of dogsbite.org wasn't enough for you, I won't disappoint. Here's the bite you should really be afraid of:

The mosquito. In and of themselves, mosquito bites aren't deadly, everybody knows that. Mosquitoes, as ectoparasites, are themselves parasitized by smaller organisms that are deadly and disabling to us. Dengue virus infections cause around 22,000 deaths on an annual basis. [5] West Nile Virus caused 286 US deaths, and 5,674 cases in 2012. [6]Yellow fever was at 200,000 cases, and 30,000 deaths last year. [7]Elephantiasis, while causing few or no deaths, has left 40 million disabled and disfigured. [8] 623,357- that's the number of American lives claimed in both World Wars, the Korean War, the Vietnam War, and the War on Terror combined according to Wikipedia. Every single year, Malaria causes 627,000 deaths, and 207 million clinical episodes. [4]The most efficient method of knocking out these diseases is by knocking out the vector, since the mosquito is a necessary stage in all of these diseases' life cycles, but it's a messy, multi-faceted problem that is unlikely to be solved in the near future. Maybe if we spent as much time and effort and killing mosquitoes as we spend on hunting sharks and attacking pit bulls, there'd be a real glimmer of hope.

So what can you do? Well, you can donate to this cause, which aims to provide better malaria care by tackling the huge problem of counterfeit or watered-down anti-Malarials. Not only is it deadly to people, namely children, who need the medications, it's also contributing to anti-malarial resistance in the parasite population by attacking the parasites with subtherapeutic doses. You can also use an insect repellent of your choosing to protect yourself and your loved ones from mosquito bites. As always, you should support those who support science. Seek to grow your own knowledge, and share what you've learned here (on person, or on facebook, just saying). Please feel free to leave any questions, comments, or concerns here on the blog or on our new facebook page at www.facebook.com/thefearblog

Till next time, kiddies, stay spooky.



[1]http://www.flmnh.ufl.edu/fish/Sharks/ISAF/2013Summary.html
[2]http://www.dogsbite.org/pdf/dog-attack-deaths-maimings-merritt-clifton-2013.pdf (questionable)
[3]http://www.cdc.gov/HomeandRecreationalSafety/Dog-Bites/index.html
[4]http://www.cdc.gov/malaria/malaria_worldwide/impact.html
[5]http://www.cdc.gov/dengue/epidemiology/index.html
[6]http://www.cdc.gov/westnile/statsMaps/finalMapsData/data/2012WNVHumanInfectionsbyState.pdf
[7]http://www.who.int/mediacentre/factsheets/fs100/en/
[8]http://www.who.int/mediacentre/factsheets/fs102/en/
[9]http://www.nsf.gov/news/special_reports/jellyfish/textonly/biology_sting.jsp
[10]http://www.americanhumane.org/animals/stop-animal-abuse/fact-sheets/dog-bites.html
[11]https://www.avma.org/public/Health/Documents/dogbite.pdf

Tapeworms

Right now, you're probably picturing a long, white, segmented, flat worm burrowing into the side of someone's intestines. Some of you probably picture hapless campers eating undercooked fish, or yuppies who don't know any better eating Sushi. Others among you may, perhaps, think that the worms are obtained from eating undercooked beef or pork. Some of you probably even imagine these worms burrowing into someone's brain. None of you are wrong- but then, you're not exactly right, either.

You see, there's not just one tapeworm that can get into people, each with their own special life cycle and possible pathogenic effects. Some of the most common tapeworms found in people are: Bovine tapeworm, Porcine Tapeworm, Fish tapeworm, and Dog tapeworm. The Bovine tapeworm is actually benign in Humans (though quite pathogenic for cattle), except in rare cases where bowel obstruction may occur- the worm, "knowing" that it's in a human, sits in your upper small intestine and simply takes a very small portion of your meals to sustain itself. You won't lose weight, contrary to popular myth, and you will likely never know if you are infested. Occasionally, a worm segment will detach and be shed from your body, ideally shedding the egg-filled segment in a grassy area where the eggs will subsequently be consumed by a cow. Once in the cow, conformational changes in the eggs occur as they pass through each of the cow's four stomachs (which is what prevents them hatching in a human) which cause them to hatch. The juvenile worms then proceed out through the intestinal wall and burrow into the cow's various bodily tissues, including muscle, organ, and brain. Once there, the worms remain dormant until the cow is slaughtered and consumed- in this case, by a human who failed to cook the meat thoroughly enough to kill the juvenile worm- completing the life cycle.[1]

As creepy as Bovine tapeworms are, they're the most benign of the various tapeworms. The next worm we'll look at is the fish tapeworm. As with the cow tapeworm, the fish tapeworm infests its host through ingestion of the juvenile stage in undercooked meat. Disease from the fish tapeworm is rare, but it can cause bowel obstruction and, in very rare cases, liver and gall bladder disease. Also, this is the largest among the tapeworms that can infest humans, growing up to thirty feet in length. Sushi lovers need not despair! The fish tapeworm has only ever been found in freshwater fish, and can be readily killed by freezing the meat. Just cook your freshwater fish, and you'll be fine. [2]

The dog tapeworm is a special cycle, where infestation of humans is a complete accident, as far as we can tell. Taenia Hydatigena, which sheds an infectious stage in canine stool, can be ingested by various mammals- typically sheep- and people. Once consumed, the worm leaves the intestine, and forms a large cyst in the abdominal cavity, where it produces more larvae and hides from the intermediate host's immune system while it's waiting for the host- and therefor, the cyst- to be eaten by a dog. If the cyst is ruptured prematurely, such as by abdominal trauma, many thousands of larvae can be released into the abdominal cavity. In Humans, the immune system can recognize the worm from the initial, infectious encounter, which can lead to the sudden onset of anaphylaxis and death subsequent to the worms' release into the abdominal cavity. Failing the rupture of the cyst, you could live a full and healthy life with this worm and be none the wiser. [3]

The Piece de Resistance here is the porcine tapeworm- Taenia Solium. The intent of the porcine tapeworm's life cycle is suspected to be much like that of the bovine worm's, in that the worm exists as a cyst-encased juvenile stage in the various tissues of a pig's body, waiting for consumption by a human. Once consumed, the juvenile develops into a fully fledged worm in the intestines of a human, and sheds eggs to be consumed by pigs. The really scary part about this worm is one of the few things that we'll go over here that's genuinely terrifying- the worm's eggs cannot tell the difference between a human gut tract and a porcine gut tract. If you were to eat bovine tapeworm eggs, no disease would develop. If, however, you were to consume porcine tapeworm eggs because, say, a restaurant chef who is infested didn't wash their hands after they had a stool, the eggs would hatch, and you would develop Cysticercosis (the juvenile stage of the worm in your various tissues). One famous form of this is Neurocysticercosis, where you actually develop juvenile stage worm cysts in your brain, potentially with pathogenic effects, including seizures, headaches, confusion, excess fluid on the brain, difficulty maintaining balance, and death (severity dependent on the number of cysts). What makes it scary is that its epidemiology is subtle and hard to avoid- it's not somebody sneezing, pouring blood out of every pore, or eating undercooked meat; it's as easy as someone else not washing their hands.[4][5][6]

So what can you do? WASH YOUR FILTHY MEAT HOOKS. Washing your hands regularly and after you use the bathroom is how you can help prevent the spread of almost every transmissible disease. There are medications you can take that will treat tapeworm infestation, so see your practitioner if you suspect that you're infected. Make sure that you cook all your meat thoroughly before consumption. As always, you can help by sharing what you've learned here (and sharing the facebook post it rode in on), doing your own research, and supporting those who support science! If you have any questions, comments, or concerns, feel free to leave them on the blog here, or ask me on the facebook post.






[1]http://bioweb.uwlax.edu/bio203/s2009/temanson_caro/Life%20Cycle.htm
[2]http://www.cdc.gov/parasites/diphyllobothrium/
[3]http://www.vetsonline.com/publications/veterinary-times/archives/n-43-46/cysticercosisa-a-controlling-tapeworm-in-dogs-and-sheep.html
[4]http://www.cdc.gov/parasites/taeniasis/biology.html
[5]http://www.cdc.gov/parasites/cysticercosis/disease.html
[6]http://www.cdc.gov/parasites/cysticercosis/