You are here:
Secondary infections of gastrointestinal illness transmitted to family members by swimmers with swimming- associated G. I. Illness.
Citation:
Wymer, L. AND A. Dufour. Secondary infections of gastrointestinal illness transmitted to family members by swimmers with swimming- associated G. I. Illness. 2023 Great Lakes Beach Association Conference, Sturgeon Bay, WI, October 16 - 18, 2023.
Impact/Purpose:
EPA criteria for bathing beaches are based on health effects among swimmers, but do not account for human-to-human communicability. This study used data collected from the EPA NEEAR studies to characterize secondary cases within families and found that families with swimmers who experience gastrointestinal illness (GI) after swimming have a greater incidence of GI among its non-swimming members 5-12 days later. This is a potentially important consideration in estimating total health cost burden of swimming at beaches with microbial-impaired water quality and of potential use in informing State and local beach management decisions.
Description:
The association between swimming and gastrointestinal illness has been well documented by several epidemiological studies conducted since the 1950s. One aspect of health-related illness associated with swimming activity that has been somewhat neglected is the occurrence of secondary personal-to-person transmission of GI illness within families where one of the family members has contracted a swimming associated GI illness. We have examined data from several EPA epidemiological studies, conducted between 2002 and 2012 in an effort to determine the occurrence and rate of secondary infections within families consisting of a swimmer suffering a GI infection within 4 days after swimming (a primary infection.) Secondary infections within these families were considered to comprise GI illness cases with onset of symptoms on days 5 through 12 after the primary case swimming event. Families with swimmers who did not suffer primary GI illness were effectively controls for early- and late-onset background GI illness rates. The results of the study indicate that of families having a swimmer with GI illness, about 24% experienced secondary GI illnesses. This study presents evidence that illness rates associated with swimming are underestimated and therefore greater economic costs should be taken into consideration when performing a cost/benefit analysis of the economics of recreational swimming-associated illness costs.
