Pinworms are prevalent around the world, although they are not a serious threat to the overall health of individual, they do cause some discomfort through anal irritation and nervousness mostly in small children.
The most prevalent type of human worm infection in the United States and perhaps around the world is by that of the pinworm.
The term worm in children is a common lay term for pinworm. This frequently used reference to pinworms is almost universal as a descriptive name for this parasite, which is an organism of the genus and species Enterobius vermicularis
E.vermicularis is a nematode. Egg can also be found in specimens collected from perianal skins and occasionally eggs can be found in faeces.
Transmission is by ingesting infective eggs. The eggs are deposited on the anal skins usually during night hours and within a few hours of being laid, they contain an infective larva. Autoinfection by swallowing infected eggs is common in children because the egg causes intense irritation and scratching of the infected area leads to the fingers becoming contaminated with eggs and because many children put their dirty fingers into their mouths, they are most susceptible to Enterobiasis
The life cycle of a pinworm is 4 to 6 weeks. Without treatment, infestation will continue as long as fresh eggs are being swallowed, unless a person develops immunity to pinworms, which is unusual before age 15
The condition is most often confirmed by Microscopic examination of the characteristic eggs where one side of the egg is flattened.
CHARACTERISTIC ENTEROBIUS VERMICULARIS EGG
The egg of the species is oval but flattened on one side. It has a thick and colorless shell and measures 50 to 60 µm in length by 20 to 30µm in width. Larvae may be visible inside the egg due to the colorless shell of the embryonated egg.
SIGNS AND SYMPTOMS OF PINWORM INFECTIONS
Symptoms often range from being Asymptomatic to any or several of the following signs and symptoms. An Itchy anus due to inflammatory response of the adult worm, especially at night, While be the most frequent symptom exhibited.Pain,rash or other skin irritation around the anus
The highest number of eggs can usually be recovered in the morning soon after waking and before bathing. The eggs can be collected from the skin around the anus or from clothing using clear adhesive tape or a saline swab.
Diagnosis is generally made by the presence of eggs using the “SCOTCH TAPE TEST”.Applying a piece of transparent cellophane tape over a tongue blade is into the perianal folds late at night or before daylight affords the best opportunity of recovering evidence of infection.
The slide is then examine microscopically for the typical ova and four to six slide collected at different times should be performed before ruling out the infection. Occasionally the adult worm will also be found on the slide along with the characteristic ova.
Note : Egg ( from perianal skin) may also be found in faeces and occasionally urine from females.
TREATMENT OF PINWORM
Treatment with Mebendazole
The medications used for the treatment of pinworm are either mebendazole, pyrantel pamoate, or albendazole. Any of these drugs are given in one dose initially, and then another single dose of the same drug two weeks later. Pyrantel pamoate is available without prescription
PREVENTION AND CONTROL
- Personal hygiene and sanitary living conditions are necessary to avoid becoming infected or re-infected.
- All family members should be treated when a single-family member is diagnosed with pinworm infection (Enterobiasis)
District Laboratory practice in Tropical Countries (Monica CHEESBROUGH)