A large histoplasmosis outbreak among high school students in Indiana, 2001.
BACKGROUND
A histoplasmosis outbreak occurred in an Indiana high school in November-December 2001.


METHODS
To describe the risk factors for this outbreak, we conducted a cohort study of all available students and staff (N = 682) and an environmental investigation.


RESULTS
Of the 523 (77%) persons who displayed serologic evidence of recent Histoplasma capsulatum infection, 355 (68%) developed symptoms consistent with acute pulmonary histoplasmosis. Rototilling of soil in a school courtyard known to be a bird roosting site had been performed during school hours on November 12, 2001, 14 days before both the peak of the onset of illness and a rise in student absenteeism. Being a student (odds ratio, 3.3; 95% confidence interval, 2.2-5.0) and being a student in a classroom near the courtyard during the rototilling (odds ratio, 3.1; 95% confidence interval, 1.8-5.2) were independently associated with infection and symptomatic illness. H. capsulatum was isolated from environmental samples, including soil from the courtyard and dust collected from a filter of a heating, ventilating and air-conditioning system.


CONCLUSIONS
Soil-disrupting activities within a school courtyard caused the largest outbreak to date of histoplasmosis among adolescents. Improved efforts are needed to educate the community in endemic areas about histoplasmosis to prevent the occurrence of such outbreaks in the future. In addition, increased awareness among health care providers of this disease would facilitate appropriate diagnosis and treatment.
Chamany
Shadi
S
Epidemic Intelligence Service, Division of Applied Public Health Training, Epidemiology Program Office, National Center for Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, MS C09, Atlanta, GA 30333, USA.
Mirza
Sara A
SA
Fleming
John W
JW
Howell
James F
JF
Lenhart
Steven W
SW
Mortimer
Vincent D
VD
Phelan
Maureen A
MA
Lindsley
Mark D
MD
Iqbal
Naureen J
NJ
Wheat
L Joseph
LJ
Brandt
Mary E
ME
Warnock
David W
DW
Hajjeh
Rana A
RA
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D015331:Cohort Studies; D004196:Disease Outbreaks; D005260:Female; D006658:Histoplasma / Q000302:isolation & purification; D006660:Histoplasmosis / Q000453:epidemiology*; D006801:Humans; D007196:Indiana / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012574:Schools; D012988:Soil Microbiology