The first reported outbreak of diarrheal illness associated with Cyclospora in the United States.
OBJECTIVE
To investigate and characterize the epidemiology of a diarrheal outbreak associated with a potentially new pathogen, Cyclospora species (previously referred to as Cyanobacteria [blue-green algae]-like bodies).


METHODS
Three retrospective cohort studies supported by laboratory studies, environmental investigation, and community surveillance.


METHODS
A hospital in Chicago.


METHODS
Housestaff physicians and hospital administrative staff.


METHODS
Identification of clinical features associated with illness and potential risks for acquisition of infection.


RESULTS
Illness was characterized by watery diarrhea, abdominal cramping, decreased appetite, and low-grade fever. Symptoms typically occurred in a distinctive cycle of remissions and exacerbations lasting up to several weeks. Stool cultures and examinations for known ova and parasites were negative. Microscopic examination of stool specimens from 11 ill persons showed many spherical bodies, 8 to 10 microns in diameter, that were identified as Cyclospora organisms. The organisms disappeared by 9 weeks after onset of illness in the 7 patients from whom follow-up specimens were obtained. Epidemiologic studies implicated tap water from a physicians' dormitory as the most likely source of the outbreak. Environmental investigation suggested that stagnant water in a storage tank may have contaminated the water supply after a pump failure.


CONCLUSIONS
This is the first reported outbreak of diarrhea associated with Cyclospora in the United States. Cyclospora may be a human enteric pathogen able to produce bouts of acute and relapsing diarrhea, and it should be considered in assessments of patients with unexplained, prolonged diarrheal illness.
Huang
P
P
Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Weber
J T
JT
Sosin
D M
DM
Griffin
P M
PM
Long
E G
EG
Murphy
J J
JJ
Kocka
F
F
Peters
C
C
Kallick
C
C
D000328:Adult; D000818:Animals; D003048:Coccidiosis / Q000453:epidemiology*; D015331:Cohort Studies; D003428:Cross Infection / Q000453:epidemiology* / Q000469:parasitology; D003967:Diarrhea / Q000453:epidemiology* / Q000469:parasitology; D004196:Disease Outbreaks; D016783:Eucoccidiida / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D014881:Water Supply