title: Multi-pathogen waterborne disease outbreak associated with a dinner cruise on Lake Michigan.
abstract: We report an outbreak associated with a dinner cruise on Lake Michigan. This took place on the same day as heavy rainfall, which resulted in 42·4 billion liters of rainwater and storm runoff containing highly diluted sewage being released into the lake. Of 72 cruise participants, 41 (57%) reported gastroenteritis. Stool specimens were positive for Shigella sonnei (n=3), Giardia (n=3), and Cryptosporidium (n=2). Ice consumption was associated with illness (risk ratio 2·2, P=0·011). S. sonnei was isolated from a swab obtained from the one of the boat's ice bins. Environmental inspection revealed conditions and equipment that could have contributed to lake water contaminating the hose used to load potable water onto the boat. Knowledge of water holding and distribution systems on boats, and of potential risks associated with flooding and the release of diluted sewage into large bodies of water, is crucial for public health guidance regarding recreational cruises.
authors.affiliation: Communicable Disease Program, Chicago Department of Public Health, Chicago, IL, USA.
authors.forename: F
authors.initials: F
authors.lastname: Serdarevic
authors.forename: R C
authors.initials: RC
authors.lastname: Jones
authors.forename: K N
authors.initials: KN
authors.lastname: Weaver
authors.forename: S R
authors.initials: SR
authors.lastname: Black
authors.forename: K A
authors.initials: KA
authors.lastname: Ritger
authors.forename: F
authors.initials: F
authors.lastname: Guichard
authors.forename: P
authors.initials: P
authors.lastname: Dombroski
authors.forename: B P
authors.initials: BP
authors.lastname: Emanuel
authors.forename: L
authors.initials: L
authors.lastname: Miller
authors.forename: S I
authors.initials: SI
authors.lastname: Gerber
mesh_terms: D000368:Aged; D002641:Chicago / Q000453:epidemiology; D003457:Cryptosporidiosis / Q000453:epidemiology / Q000209:etiology; D003458:Cryptosporidium; D004196:Disease Outbreaks; D004405:Dysentery, Bacillary / Q000453:epidemiology / Q000209:etiology; D005243:Feces / Q000382:microbiology / Q000469:parasitology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology* / Q000209:etiology / Q000382:microbiology / Q000469:parasitology; D005872:Giardia; D005873:Giardiasis / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D060106:Lakes / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D012764:Shigella sonnei; D012767:Ships; D014871:Water Microbiology; D014881:Water Supply