Enterobiasis, pinworm infection, is an intestinal nematode infection. The adult female worms (9-12 mm long) may be found in the perianal area. The highest infection rates are found in children living in an institutional setting with poor personal hygiene. Infection is spread by fomites.
CASES/YEAR
10,450,000 (US); 209,000,000 (Global)
OTHER NAMES
Enterobius vermicularis infection; Pinworm infection,
INCUBATION
1-2 months; [CCDM]
INITIAL SYMPTOMS
Asymptomatic or may cause anal itching (pruritis ani) and disturb sleep; Worm is visible as a tiny white thread; [CCDM]
COMMENTS
The adult female worms (9-12 mm long) may be found in the perianal area. The highest infection rates are found in children living in an institutional setting with poor personal hygiene. [Guerrant, p. 788-90] Infection is spread by fomites, e.g., bedding, clothing, and toys, and by inhaling dust containing the eggs. Eggs can survive for 3 weeks on fomites. Autoinfection occurs by transferring the eggs from the anus to the mouth. [Merck Manual, p. 1676] Complications include vaginitis, salpingitis, pelvic and liver granulomas, and, possibly, appendicitis. [CCDM, p. 187] Rarely, pinworms may cause vaginitis and peritoneal lesions. [Merck Manual, p. 1676] Possible findings in heavy infections are abdominal pain and weight loss. Eosinophilia is uncommon. [Harrison ID, p. 1135] Eosinophilic enterocolitis, after a single heavy exposure, has been reported, but peripheral eosinophilia is absent. May be transmitted sexually; [PPID, p. 3439] Pinworms can cause recurrent urinary tract infections in young girls. [Cohen, p. 1777] Not associated with eosinophilia; [Wallach, p. 1201]
DIAGNOSTIC
Microscopic examination of Scotch tape preparation or pinworm paddle best done in the morning before bowel movement; If negative, repeat at least 3 times; [CCDM] Can see adult worms near anus, best 2-3 hours after person falls asleep. [CDC Travel]
SIGNS & SYMPTOMS
-
G abdominal pain
-
H eosinophilia
-
*weight loss
ENTRY
Ingestion, Sexual Contact
SOURCE
Person-to-Person, Human Fecal-Oral
TREATMENT
If more than 1 member of household infected or repeated infections in household, treat all household members at the same time. [CDC Travel]
REFERENCES FOR CASES/YEAR
1. (US) In the US, about 40 million people are infected, mainly children; [Harrison ID, p. 1135] 1/20 X 209 million (global) = 10.45 million;
2. (Global) Global prevalence 209 million; [Harrison ID, p. 1132t]