ENTEROBIUS ENTEROBIUS VERMICULARVERMICULAR

ISIS

Accounts of pinworm infestation have existed in medical literature since the beginning of recorded time. A worm causing intense pruritus ani (perianal itch)

was described in early Chinese, Indian, Arabic-Persian, and Greco-Roman populations, and even Hippocrates recorded his experience with the sleep

disturbances caused by infestation with E. vermicularis.Direct evidence of enterobiasis in ancient populations emerged with the

discovery of E. vermicularis eggs in dried fecal specimens (known as coprolites) found in archaeological sites. The oldest known eggs were

recovered from the Danger Cave and Hogup Cave in western Utah from a 10,000-year old coprolite. Described by Fry and Moore in a 1969 article

published in Science, the coprolites were positively identified as belonging to the prehistoric humans who inhabited the caves. The eggs reported in that

article still represent the earliest recorded samples of E. vermicularis, although subsequent discoveries have been reported in many ancient

populations around the world, including a recent discovery among ancient Egyptian mummies.Recovery of eggs from various prehistorical human coprolites has allowed

researchers to trace the migratory patterns of the humans carrying the worm. Because the pinworm life cycle occurs entirely within humans and does not rely on specific soil or climatic conditions, it is likely that E. vermicularis was carried over by human migrations across the Bering Strait. Such an early spread of the

worm in human populations helps explain its wide geographic distribution today.

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Pinworms are helminthic pathogens.Pinworms are helminthic pathogens.The worms are white and spindle-shaped with a large, bulbar esophagus. Eggs are ovoid, The worms are white and spindle-shaped with a large, bulbar esophagus. Eggs are ovoid,

thin-shelled, and flat on one side.thin-shelled, and flat on one side.Females are approximately 1 cm long and males are half that size. The curved posterior Females are approximately 1 cm long and males are half that size. The curved posterior end of male worms has a single copulatory spicule. The males are rarely seen because end of male worms has a single copulatory spicule. The males are rarely seen because

they die shortly after copulation and are expelled.they die shortly after copulation and are expelled.

Infections affect about Infections affect about 200 million worldwide.200 million worldwide.

40 million cases in the 40 million cases in the U.S. and Canada.U.S. and Canada.

Most common worm Most common worm infection in the U.S.infection in the U.S.

Eggs will not embryonate at temperatures below Eggs will not embryonate at temperatures below 23°C, but embryonated eggs can remain viable for 23°C, but embryonated eggs can remain viable for

several weeks under moist and cool conditions.several weeks under moist and cool conditions.Little is known about immune responses to Little is known about immune responses to

pinworm infection. Infections are more common in pinworm infection. Infections are more common in children than in adults, suggesting that acquired children than in adults, suggesting that acquired

immunity or some other type of age-related immunity or some other type of age-related resistance develops.resistance develops.

Enterobius ova (Scotch tape Enterobius ova (Scotch tape prep)prep)

Humans become infected by ingestion of Humans become infected by ingestion of infected embryonated eggs which reach the infected embryonated eggs which reach the

mouth by inhalation, hand to mouth mouth by inhalation, hand to mouth transport, or in contaminated food or drink. transport, or in contaminated food or drink. Infections many times involve families living Infections many times involve families living under crowded conditions. Sometimes the under crowded conditions. Sometimes the

entire family may be infected.entire family may be infected.Enterobiasis (pinworm disease) is caused by Enterobiasis (pinworm disease) is caused by

the nematode worm Enterobius the nematode worm Enterobius vermicularis. This organism has a worldwide vermicularis. This organism has a worldwide distribution and can infect horses, mice and distribution and can infect horses, mice and primates (man and monkeys). It does not primates (man and monkeys). It does not

infect cats and dogs.infect cats and dogs.Pinworms reach maturity in the lower GI tract Pinworms reach maturity in the lower GI tract

within 2 to 6 weeks. The female worm within 2 to 6 weeks. The female worm migrates to the perianal region (usually at migrates to the perianal region (usually at

night) to deposit ova. The sticky, gelatinous night) to deposit ova. The sticky, gelatinous substance in which the ova are deposited and substance in which the ova are deposited and

the movements of the female worm cause the movements of the female worm cause perianal pruritus. The ova can survive on perianal pruritus. The ova can survive on

fomites as long as 3 weeks at normal room fomites as long as 3 weeks at normal room temperature. Intestinal lesions are reported, temperature. Intestinal lesions are reported, but the worms usually cause little intestinal but the worms usually cause little intestinal pathology. The parasite has been found in pathology. The parasite has been found in diseased appendices but is not necessarily diseased appendices but is not necessarily the cause of the pathology. Pinworms can the cause of the pathology. Pinworms can make their way to extraintestinal locations make their way to extraintestinal locations and cause complications. For example, the and cause complications. For example, the

parasites may carry bacteria into other parasites may carry bacteria into other organs, resulting in abscess formation.organs, resulting in abscess formation.

Children suffering sleepless nights Children suffering sleepless nights because of perianal itching often have because of perianal itching often have

pinworms. Eggs are rarely found in pinworms. Eggs are rarely found in the feces, and the diagnosis is made the feces, and the diagnosis is made

by finding eggs on perianal swabs by finding eggs on perianal swabs made of Scotch tape. The tape is made of Scotch tape. The tape is

pressed first onto the perianal region pressed first onto the perianal region and then onto a microscope slide, and and then onto a microscope slide, and is examined microscopically. Perianal is examined microscopically. Perianal specimens are best obtained in the specimens are best obtained in the

morning before bathing or defecation. morning before bathing or defecation. Three specimens should be taken on Three specimens should be taken on

consecutive days before pinworm consecutive days before pinworm infection is ruled out.infection is ruled out.

The medications used for the treatment of pinworm are mebendazole, pyrantel pamoate, and albendazole. All three of these drugs are to be given in 1 dose at first and then another single dose 2 weeks later. Pyrantel pamoate is available without prescription. The second dose of medication is to eliminate possible re-

infection since the first dose of medication. Health practitioners and parents should weigh the health risks and benefits of these drugs for patients under 2

years of age. Repeated infections should be treated by the same method as the first infection. In households where more than one member is infected or where repeated, symptomatic infections occur, it is recommended that all household members be treated at the same time. In institutions, mass and simultaneous

treatment, repeated in 2 weeks, can be effective.Wash in the morning. Because pinworms lay their eggs at night, washing the anal area in the morning can help reduce the number of pinworm eggs on your body. Showering may help avoid possible recontamination in bath water.

Change underwear and bed linen daily. This helps remove eggs. Launder in hot water. Wash bed sheets, nightclothes, underwear, washcloths and towels in hot water to help kill pinworm eggs.

Don't scratch. Avoid scratching the anal area. Trim your child's fingernails so there's less space for eggs to collect. Discourage nail biting.

Clean toilet seats daily. This helps remove eggs.

WHEN? HOW?

-Before, during, & after preparing a -Wet hands with clean running water food and also before consumption. (hot or cold) and apply soap.-Before and after caring for someone -Rub your hands together to make a who is sick. lather and scrub them well; be sure -Before and after treating a wound or to scrub the back of your hands, cut. between your finger, & under nails.-After using the toilet. -Continue rubbing your hands for at-After blowing nose, sneezing, or least 20 seconds. (HINT)

coughing. -Rinse hands well under running-After touching an animal, animal water. feed, or waste. -Dry your hands using a clean towel-After touching garbage. or air dry.

*Hint- Need a timer? Try humming Happy Birthday to yourself two times.

What about hand What about hand sanitizer?sanitizer?

Washing hands with soap and water is the best way to reduce the number of germs on them. If soap and water are not

available, use an alcohol-based hand sanitizer that contains at least 60% alcohol. Alcohol-based hand sanitizers can quickly reduce the number of germs on hands in some situations, but sanitizers DO NOT eliminate all types of

germs.How?How?

Apply the product to the palm of one hand (read the label to learn the correct amount). Rub your hands together. Rub the product over all surfaces of your hands and fingers until your hands are dry.

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InfectionSally became unknowingly infected by ingesting infective pinworm eggs. (Possibly from contaminated fingers, clothing, bedding, or by

eating food that was prepared by an infected host who failed to perform proper sanitary practices after defecating.) After about a month and a half, Sally went to her physician complaining about difficulty sleeping due to an itchy rectum, particularly at night.

DiagnosisAfter reporting her symptoms to her physician, he instructed her to

touch her perianal skin with transparent tape first thing in the morning, to collect possible pinworm eggs. She was then to repeat this process for three consecutive days. Upon confirmation of a pinworms diagnosis, Sally’s physician prescribed the following treatment plan.

TreatmentSally was advised to take Combantrin @ 125mg, 6 tablets (750mg)

immediately and then repeat 2 weeks later to eliminate possible reinfection. She was then advised to take nonpharmacological steps to

prevent reinfection.

Even though the current symptoms of pinworms are relatively harmless, future Even though the current symptoms of pinworms are relatively harmless, future evolution of the helminths could possibly result in more harmful symptoms.evolution of the helminths could possibly result in more harmful symptoms.

A second species, Enterobius gregorii has already been found in Europe, Africa, and A second species, Enterobius gregorii has already been found in Europe, Africa, and Asia.Asia.

BRAINS!!

BRAINS!!Will helminths be responsible for the zombie apocalypse?

Dowshen, Steven (2009). Pinworms. Retrieved from http://wesleymc.com/your-health/kidshealth/22282/pinworms?mainCatergory=3.

(pinworm soap image)

Stanford (2006). History. Retrieved from http://www. Stanford.edu/class/humbio103/ParaSites2004/Enterobius/history.htm. (pinworm history)

Cross, John H. (2000). Enteric Nematodes of Humans. Retrieved from http://www.ncbi.nlm.nih.gov/books/NBK8261/. (pathophysiology/description/transmission)

Kiche, Anne O. (2011). Microbiology in the Physicians Laboratory. Retrieved from http://www.healthcare.uiowa.edu/cme/clia/modules.asp?testID=11. (diagnosis/tape procedure image/egg slide)

Evaneko (2007). Avalace the Demon Worm. Retrieved from evaneko.deviantart.com.art.Avalace-the-Demon-Worm-59478396. (Imaginary worm and zombie images)

CDC (2013). Parasites-Enterobiasis. Retrieved from www.cdc.gov/parasites/pinworm/. (wash your hands/treatment/prevention/stats)

Thompson, Jason (2010). Attack of the Pinworms. Retrieved from www.theartofdad.blogspot.com/2010/05/attack-of-pinworms.html. (Pinworms image)