Poor personal hygiene and crowded living conditions appear to be the primary risk factors for acquiring infection.
It is most common in elementary school age children (ages 4 to 10), but can affect any age group.
Risk factors identified by Sung et al:
(1) playing on the floor
(2) nail biting
(3) failure to wash hands before meals
(4) living in dwellings other than apartments (single family detached houses, townhouse)
Other factors:
(1) prevalence in the community, including other infected family members
(2) sucking fingers
(3) eating snacks between meals (without handwashing)
(4) poverty (low socioeconomic status)
(5) history of previous infection
(6) crowded living conditions (urban areas, institutions, asylums)
(7) wearing soiled underwear
(8) infrequent bathing
(9) scarcity of water
(10) homosexual men
