WEBVTT - What Happens When You Swallow a Leech? 0:00:01.000 --> 0:00:03.920 Welcome to How Stuff Works. Now. I'm your host, Lauren Vogelbaum, 0:00:03.960 --> 0:00:10.680 a researcher and writer. Here's how Stuff Works. Every week 0:00:10.720 --> 0:00:12.880 I'm bringing you three stories from our team about the 0:00:12.920 --> 0:00:16.840 weird and wondrous advances we've seen in science, technology, and culture, 0:00:17.280 --> 0:00:20.200 except when I don't. This week, we've got just one 0:00:20.239 --> 0:00:23.040 story for you, but it's a longer one, so don't worry. 0:00:23.079 --> 0:00:24.960 If you're driving, you've still got about the same amount 0:00:25.000 --> 0:00:26.840 of time before you have to fiddle with your phone again. 0:00:27.400 --> 0:00:30.120 This one is from staff writer and editor Joe McCormick, 0:00:30.200 --> 0:00:33.720 who's also the co host of a compatriot podcast of ours, 0:00:33.720 --> 0:00:37.040 Stuff to Blow Your Mind. Joe wanted to know how 0:00:37.200 --> 0:00:40.920 and what happens when a human swallows a leech, which 0:00:40.960 --> 0:00:43.040 is a thing that happens more often than you'd like 0:00:43.120 --> 0:00:46.640 to thank, which, to be fair, is more often than never. 0:00:47.400 --> 0:00:50.800 So come along as Joe explores the historical and modern 0:00:50.880 --> 0:01:00.800 cases of leech endo parasitism. Here's what happens when you 0:01:00.840 --> 0:01:06.319 swallow a leech. In surgeon Lieutenant T. A. Granger of 0:01:06.360 --> 0:01:09.480 the British Indian Army wrote a letter to the British 0:01:09.480 --> 0:01:13.680 Medical Journal to report a stomach turning case of parasite 0:01:13.680 --> 0:01:29.480 infestation he encountered at his colonial outpost. While working at 0:01:29.480 --> 0:01:32.800 a fort in the Northwest Provinces of India, Granger received 0:01:32.800 --> 0:01:35.440 a letter from an officer asking for his help with 0:01:35.480 --> 0:01:39.880 an unusual medical complaint. According to the note, a local 0:01:39.959 --> 0:01:43.880 man had a leech attached to the inside of his throat. 0:01:44.920 --> 0:01:48.400 At first, Granger assumed it couldn't be true. Nevertheless, he 0:01:48.440 --> 0:01:52.040 agreed to see the patient. The person he encountered was, 0:01:52.200 --> 0:01:56.080 by Granger's account, an elderly pashtooned man with a gray beard. 0:01:56.760 --> 0:02:00.400 When Granger came within sight, the old man immediately spat 0:02:00.440 --> 0:02:04.680 out a heavy mouthful of thick, blackened blood, presumably to 0:02:04.720 --> 0:02:08.880 demonstrate that his complaint was real. With the help of interpreters, 0:02:08.919 --> 0:02:12.519 Granger questioned the man to learn about his condition. According 0:02:12.560 --> 0:02:16.079 to his story, eleven days previous, the old man had 0:02:16.080 --> 0:02:18.880 been drinking out of a rainwater tank when he suddenly 0:02:18.919 --> 0:02:22.200 felt something catch in his throat. When he tried to 0:02:22.240 --> 0:02:25.800 cough it up, he couldn't. Then the thing caught in 0:02:25.880 --> 0:02:29.880 his throat began to move. He had difficulty swallowing and 0:02:29.919 --> 0:02:32.040 felt like he was going to choke on the writhing 0:02:32.080 --> 0:02:35.120 obstruction it caused him to vomit and to spit up 0:02:35.160 --> 0:02:39.919 blood repeatedly. When Granger first looked inside the old man's throat, 0:02:40.000 --> 0:02:42.160 he was able to remove a clot of blood, but 0:02:42.320 --> 0:02:45.600 couldn't see any parasite. If it was there, it had 0:02:45.639 --> 0:02:49.000 to be deeper. So the surgeon Lieutenant produced a pair 0:02:49.040 --> 0:02:54.080 of polypus forceps, essentially very long tweezers with scissor handles, 0:02:54.160 --> 0:02:57.799 and reached into the hidden depths of the man's lower farynx, 0:02:58.000 --> 0:03:01.840 near the esophagus they are. He detected the presence of 0:03:01.840 --> 0:03:05.160 an object, and through the metal of his instrument, Granger 0:03:05.280 --> 0:03:11.359 could feel it moving. With the tips of the four steps, 0:03:11.360 --> 0:03:15.200 he grabbed hold of the squirming object and with considerable force, 0:03:15.320 --> 0:03:19.160 pulled it out. Indeed, it was a leech between two 0:03:19.200 --> 0:03:21.760 point five and three inches or about six and a 0:03:21.840 --> 0:03:24.919 half to seven and a half centimeters long, with a 0:03:25.000 --> 0:03:28.040 body shaped like the three oh three inch ammunition the 0:03:28.080 --> 0:03:33.080 British infantry used in their lee Metford rifles. A slimy, 0:03:33.080 --> 0:03:37.760 writhing rifle cartridge engorged with human blood had been living 0:03:37.760 --> 0:03:42.120 in this man's throat for eleven days. Granger's letter to 0:03:42.120 --> 0:03:44.560 the b MJ doesn't go on to report what happened 0:03:44.560 --> 0:03:47.240 to the old man, But after an experience like this, 0:03:47.320 --> 0:03:49.440 one would at least hope the worst moment in the 0:03:49.480 --> 0:03:56.240 man's life was behind him. When it comes to leeches 0:03:56.240 --> 0:03:59.520 in the throat, Granger's report is not an isolated incident. 0:04:00.080 --> 0:04:03.200 Granger himself heard stories of other cases like this in 0:04:03.280 --> 0:04:06.760 neighboring towns, and this phenomenon is by no means limited 0:04:06.840 --> 0:04:10.320 to nineteenth century India. Getting a leech attached to the 0:04:10.360 --> 0:04:12.960 inside of a body cavity is common enough that there 0:04:12.960 --> 0:04:17.120 are special medicalized terminologies for it, such as leech indo 0:04:17.200 --> 0:04:22.400 parasitism or internal hierodoniasis. These are phrases most of us 0:04:22.400 --> 0:04:26.120 would probably rather not have in our vocabulary, but even today, 0:04:26.240 --> 0:04:29.080 in the twenty first century, people still show up at 0:04:29.120 --> 0:04:32.960 hospitals around the world with leeches stuck inside their throats. 0:04:39.000 --> 0:04:43.919 Strictly speaking, the leeches a worm phylum Analyta subclass heroudonea, 0:04:44.279 --> 0:04:47.479 from which we get the word hierudoniasis, which refers to 0:04:47.520 --> 0:04:51.320 the condition of being parasitized by a leech. Leeches have 0:04:51.480 --> 0:04:56.240 segmented bodies imagine rings like an earthworm, and suckers at 0:04:56.279 --> 0:04:59.159 both ends. One large sucker at the rear of the 0:04:59.200 --> 0:05:02.880 body used crawling and leverage, and a smaller sucker at 0:05:02.920 --> 0:05:06.560 the front containing the jaws and the mouth. Not all 0:05:06.640 --> 0:05:10.440 leeches are blood drinkers. Some scavenge for detritus, some are 0:05:10.440 --> 0:05:13.359 predatory hunters. But the leech we know best is that 0:05:13.480 --> 0:05:17.280 vampiric parasite that clamps onto the larger host and steadily 0:05:17.360 --> 0:05:20.560 drains all the blood it can, often until the leech's 0:05:20.600 --> 0:05:24.400 body is swollen to around ten times its original size. 0:05:25.000 --> 0:05:28.920 In the wild, leeches drink from all manner of hosts, mammals, fish, 0:05:29.000 --> 0:05:32.599 and amphibians. When a leech bites, it makes a y 0:05:32.720 --> 0:05:36.400 shaped incision in the skin with three curved jaws covered 0:05:36.440 --> 0:05:40.800 in serrated teeth like tiny circular saws, and then extracts 0:05:40.800 --> 0:05:44.440 blood with a muscular sucking action. The saliva of the 0:05:44.520 --> 0:05:47.040 leech is known to contain a cocktail of chemicals to 0:05:47.120 --> 0:05:51.520 ease the process, including heroudin, a polypeptide that prevents blood 0:05:51.520 --> 0:05:55.919 from clotting. Leeches are classically known as external parasites, drawing 0:05:55.960 --> 0:05:58.480 their liquid diet through the outer skin of the host, 0:05:58.600 --> 0:06:02.919 but given the ratunity, they will feed from internal surfaces 0:06:02.960 --> 0:06:07.280 as well, such as the nave of pharynx, larynx, vagina, bladder, 0:06:07.400 --> 0:06:11.880 and anus. Humans have an unusual relationship with leeches that's 0:06:11.880 --> 0:06:15.320 perhaps unique among all the world's parasites. The use of 0:06:15.400 --> 0:06:19.160 leeches is pervasive throughout the history of medicine, even giving 0:06:19.200 --> 0:06:23.279 the European medical leech harudo medicine alis its modern name. 0:06:24.120 --> 0:06:27.400 In some historical periods, they were so commonly used as 0:06:27.480 --> 0:06:31.479 instruments of blood letting that collecting wild leeches was a 0:06:31.560 --> 0:06:36.960 solid money making operation. Rural leech gatherers would wage bare 0:06:37.080 --> 0:06:40.280 legged through the scum of stagnant ponds, hoping when they 0:06:40.320 --> 0:06:43.240 emerged on the other side to see patterns of glistening 0:06:43.320 --> 0:06:47.480 green black anelids sucking from their ankles and calves. In 0:06:47.480 --> 0:06:51.280 his eighteen oh seven poem Resolution and Independence, the English 0:06:51.400 --> 0:06:54.680 romantic poet William Wordsworth writes about his encounter with this 0:06:54.800 --> 0:06:58.960 brand of leech harvester quote. He told that to these 0:06:59.000 --> 0:07:02.280 waters he had come to gather leeches, being old and poor, 0:07:02.839 --> 0:07:07.360 employment hazardous and wearisome, and he had many hardships to endure. 0:07:07.800 --> 0:07:11.320 From pond to pond, he roamed from more to more, 0:07:11.320 --> 0:07:15.160 housing with God's good help by choice or chance, And 0:07:15.200 --> 0:07:20.000 in this way he gained an honest maintenance. Assuming you 0:07:20.040 --> 0:07:23.320 find the idea of being sucked by a leech somewhat disgusting, 0:07:23.640 --> 0:07:25.840 and assuming you find the idea of being sucked by 0:07:25.840 --> 0:07:29.080 a leech on the inside of your body even more disgusting, 0:07:29.600 --> 0:07:31.760 you might find it odd that the human taste for 0:07:31.840 --> 0:07:36.440 therapeutic parasitism doesn't stop at the outer skin. During the 0:07:36.520 --> 0:07:40.560 leech craze, leaching enthusiasts open many of their bodily orifices 0:07:40.600 --> 0:07:43.800 and internal cavities to the prized worms with the help 0:07:43.840 --> 0:07:47.680 of some ingenious medical technology. In a two thousand eleven 0:07:47.760 --> 0:07:51.160 article on the technological history of leeching, Robert G. W. 0:07:51.400 --> 0:07:54.680 Kirk and Neil Pemberton right that quote. The opening of 0:07:54.720 --> 0:07:58.560 the interior of the body often required the physical alteration 0:07:58.760 --> 0:08:01.880 of the leech, for example, the attachment of thread to 0:08:01.920 --> 0:08:05.240 prevent the loss of the leech within, or the supplementation 0:08:05.320 --> 0:08:08.280 of the leech with mechanical tools to enable the passage 0:08:08.280 --> 0:08:11.320 of the creature into locations such as the anus, where 0:08:11.320 --> 0:08:15.360 it was now recommended as a means to treat problematic prostates. 0:08:16.440 --> 0:08:18.600 There are even a few limited ways in which leeches 0:08:18.640 --> 0:08:21.920 have proven useful, though perhaps still controversial, in the science 0:08:21.960 --> 0:08:25.440 based medicine of recent decades, such as to ensure veins 0:08:25.480 --> 0:08:29.640 are working properly and aren't overfilled or distending after microsurgery. 0:08:30.760 --> 0:08:33.720 Here and there, you can still encounter reports in medical 0:08:33.800 --> 0:08:39.960 journals of rare cases of accidental internal hyerdoniasis, including leeches 0:08:40.280 --> 0:08:43.440 in the throat. In two thousand two, a group of 0:08:43.480 --> 0:08:47.240 doctors reported in the journal Pediatric Pulmonology the case of 0:08:47.240 --> 0:08:49.520 a six year old boy in Syria who was brought 0:08:49.520 --> 0:08:52.920 to the emergency room because he couldn't breathe. His mother 0:08:52.960 --> 0:08:55.400 reported that he had been coughing up blood and that 0:08:55.480 --> 0:08:58.240 a month ago a village doctor had diagnosed the boy 0:08:58.280 --> 0:09:02.679 with asthma and prescribed court steroids and broncho dilators. This 0:09:02.800 --> 0:09:07.440 turned out to be a misdiagnosis. The doctors were able 0:09:07.480 --> 0:09:10.800 to remove a seven centimeter or nearly three inch leach 0:09:10.960 --> 0:09:14.560 from the boy's airway through surgery, and subsequently discovered that 0:09:14.600 --> 0:09:17.600 the child had been drinking from a leech infested stream 0:09:17.679 --> 0:09:21.280 in rural northern Syria. After the leech was removed, the 0:09:21.320 --> 0:09:26.120 boy's symptoms disappeared. In two thousand nine, another group reported 0:09:26.120 --> 0:09:28.720 in the European Journal of Pediatrics the case of an 0:09:28.720 --> 0:09:31.880 eleven year old boy in central Iran who presented it 0:09:31.920 --> 0:09:34.800 a rural healthcare center with blood in his mouth and 0:09:34.880 --> 0:09:37.880 a sore throat that had lasted for two weeks. The 0:09:37.920 --> 0:09:40.400 boy had been given antibiotics for his sore throat and 0:09:40.440 --> 0:09:44.360 the problem did not respond. Inspection of his mouth revealed 0:09:44.360 --> 0:09:48.600 a black circular blob about two centimeters by three centimeters 0:09:48.720 --> 0:09:51.840 or about point eight by one point two inches, stuck 0:09:51.880 --> 0:09:54.400 to the back of his throat, with blood oozing all 0:09:54.480 --> 0:09:59.080 around it. Doctors applied litacaine spray, a topical pain killer, 0:09:59.440 --> 0:10:02.880 and then pull the leech out with blunt forceps. Questioning 0:10:02.880 --> 0:10:05.040 revealed the boy had been swimming in a lake near 0:10:05.040 --> 0:10:08.520 his village. After the leech was removed, blood continued to 0:10:08.559 --> 0:10:10.600 ooze out of the wound for about an hour, but 0:10:10.679 --> 0:10:14.880 otherwise the boy was all right. In a doctor named 0:10:14.960 --> 0:10:18.880 Demeckey McConnon published an article in the Ethiopian Journal of 0:10:18.920 --> 0:10:21.560 Health Science relaying the case of a seven year old 0:10:21.559 --> 0:10:24.720 boy in Ethiopia who presented with blood stained saliva and 0:10:24.800 --> 0:10:27.880 shortness of breath at his home. Someone had tried to 0:10:27.920 --> 0:10:30.880 treat him with a traditional medicine made of tobacco leaves 0:10:30.880 --> 0:10:34.640 and flax seed to no effect. In the report, McConnon 0:10:34.760 --> 0:10:37.839 indicates that the boy had contact with an unprotected source 0:10:37.880 --> 0:10:41.160 of spring water that was also used for watering animals. 0:10:41.640 --> 0:10:44.680 Luring scopy showed some kind of foreign body at the 0:10:44.679 --> 0:10:47.520 top of the trachea. The child was put under general 0:10:47.559 --> 0:10:52.160 anesthesia and the leech was removed with forceps. After the extraction, 0:10:52.200 --> 0:10:55.680 the boy seemed to have a full recovery. Laryngeal and 0:10:55.720 --> 0:10:59.840 pharyngeal leech infestations are rare these days, especially in developed 0:11:00.000 --> 0:11:03.600 countries with access to clean water, but it can still happen. 0:11:04.040 --> 0:11:07.600 Possible symptoms of a leech in the throat are difficulty swallowing, 0:11:08.000 --> 0:11:12.560 sore throat, vomiting blood, coughing up blood, a sense of 0:11:12.640 --> 0:11:16.480 having a foreign body in the throat melna meaning dark 0:11:16.559 --> 0:11:20.240 sticky feces indicating the swallowing of blood, a feeling of 0:11:20.280 --> 0:11:24.439 suffocation or shortness of breath, and harsh or raspy breathing. 0:11:25.280 --> 0:11:26.920 If you think you've got a leech in your throat 0:11:27.000 --> 0:11:29.600 right now, don't panic. Just see a doctor as soon 0:11:29.640 --> 0:11:31.920 as you can, as you may have gathered from the 0:11:31.920 --> 0:11:35.800 cases we just mentioned, pharyngeal or even laryngeal harrod niasis 0:11:35.920 --> 0:11:38.520 is not necessarily a death sentence, though it can be 0:11:38.600 --> 0:11:41.800 dangerous if the parasite obstructs any part of the airway. 0:11:42.200 --> 0:11:44.199 If the doctor knows what to look for and has 0:11:44.240 --> 0:11:47.080 a pair of blunt forceteps on hand, chances are good 0:11:47.120 --> 0:11:49.360 that you'll be all right. But of course the best 0:11:49.360 --> 0:11:53.080 case scenario is to avoid the problem entirely, So don't 0:11:53.120 --> 0:11:55.720 drink dirty water and don't swim in the water where 0:11:55.720 --> 0:12:01.760 the leeches slim. That's our show for this week. Thank 0:12:01.800 --> 0:12:03.920 you so much for tuning in. Further thanks to our 0:12:03.920 --> 0:12:07.680 audio producer Dylan Fagin and our editorial liaison Alison Laddermilk. 0:12:07.920 --> 0:12:10.520 Subscribe to now Now for more of the lated science 0:12:10.559 --> 0:12:12.440 news and sends links to anything you'd like to hear 0:12:12.520 --> 0:12:15.560 us cover, plus a tattoo artist whose work you dig. 0:12:15.920 --> 0:12:17.800 As always, you can send us an email at now 0:12:17.880 --> 0:12:20.960 podcast at how stuff works dot com, and for lots 0:12:21.000 --> 0:12:23.200 more stories like these, head on over to our home 0:12:23.240 --> 0:12:39.080 planet now dot how stuff works dot com.