Sealy D P, Schuman S H
Pediatrics. 1983 Aug;72(2):154-8.
Five surveys of 1,731 children for stool ova and parasites (1971 to 1981) in a rural county provide a unique perspective on naturally occurring, nonepidemic giardiasis. Currently white children in day care centers in Hampton County, South Carolina, experience attack rates of 26%. They enter the first grade with at least six times as much infection as those who do not attend day care. A trend toward more giardiasis linked to working mothers and day care is evident among white preschool children. This has not yet occurred among black preschool-aged children. These and other epidemiologic data indicate that as few as 100 children can maintain endemic levels of infection in a county of 18,000 residents. Person-to-person transmission in the day care setting is sufficient to explain this county's rising rate of stool positivity of infection (8% of all stool specimens submitted to the state laboratory).
1971年至1981年期间，在一个乡村县对1731名儿童进行了五次粪便虫卵和寄生虫调查，为自然发生的非流行性贾第虫病提供了独特视角。目前，南卡罗来纳州汉普顿县日托中心的白人儿童感染率为26%。他们进入一年级时的感染率至少是未参加日托儿童的六倍。在白人学龄前儿童中，与职业母亲和日托相关的贾第虫病增多趋势明显。而在黑人学龄前儿童中尚未出现这种情况。这些以及其他流行病学数据表明，在一个有18000名居民的县中，仅100名儿童就能维持地方性感染水平。日托环境中的人际传播足以解释该县感染粪便阳性率的上升（提交给州实验室的所有粪便标本的8%）。
