title: Two outbreaks of occupationally acquired histoplasmosis: more than workers at risk.
abstract: OBJECTIVE
  The objective of this study was to determine the etiology and risk factors for acute histoplasmosis in two outbreaks in Illinois among laborers at a landfill in 2001 and at a bridge reconstruction site in 2003.
  
  
  METHODS
  We performed environmental investigations during both outbreaks and also performed an analytic cohort study among bridge workers.
  
  
  METHODS
  Workers at the landfill during May 2001 and those at the bridge site during August 2003 participated in the study. At the landfill, workers moved topsoil from an area that previously housed a barn; at the bridge, workers observed bat guano on bridge beams.
  
  
  METHODS
  We defined a case by positive immunodiffusion serology, a > or = 4-fold titer rise in complement fixation between acute and convalescent sera, or positive urinary Histoplasma capsulatum (HC) antigen. Relative risks (RR) for disease among bridge workers were calculated using bivariate analysis.
  
  
  RESULTS
  Eight of 11 landfill workers (73%) and 6 of 12 bridge workers (50%) were laboratory-confirmed histoplasmosis cases. Three bridge workers had positive urinary HC antigen. At the bridge, seeing or having contact with bats [RR = 7.0; 95% confidence interval (CI), 1.1-43.0], jack-hammering (RR = 4.0; 95% CI, 1.2-13.3), and waste disposal (RR = 4.0; 95% CI, 1.2-13.3) were the most significant job-related risk factors for acquiring histoplasmosis.
  
  
  CONCLUSIONS
  Workers performing activities that aerosolized topsoil and dust were at increased risk for acquiring histoplasmosis. Relevance to professional and clinical practice: Employees should wear personal protective equipment and use dust-suppression techniques when working in areas potentially contaminated with bird or bat droppings. Urinary HC antigen testing was important in rapidly identifying disease in the 2003 outbreak.
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia, USA. Gregory_Huhn@rush.edu
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Huhn
authors.forename: Connie
authors.initials: C
authors.lastname: Austin
authors.forename: Mark
authors.initials: M
authors.lastname: Carr
authors.forename: Diana
authors.initials: D
authors.lastname: Heyer
authors.forename: Pam
authors.initials: P
authors.lastname: Boudreau
authors.forename: Glynnis
authors.initials: G
authors.lastname: Gilbert
authors.forename: Terry
authors.initials: T
authors.lastname: Eimen
authors.forename: Mark D
authors.initials: MD
authors.lastname: Lindsley
authors.forename: Salvatore
authors.initials: S
authors.lastname: Cali
authors.forename: Craig S
authors.initials: CS
authors.lastname: Conover
authors.forename: Mark S
authors.initials: MS
authors.lastname: Dworkin
mesh_terms: D000328:Adult; D000336:Aerosols; D000946:Antigens, Fungal / Q000032:analysis; D004196:Disease Outbreaks; D004391:Dust; D005160:Facility Design and Construction; D005260:Female; D006660:Histoplasmosis / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D007087:Illinois / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D009790:Occupations; D011482:Protective Devices; D012037:Refuse Disposal; D012307:Risk Factors; D012987:Soil
chemical_list: D000336:Aerosols; D000946:Antigens, Fungal; D004391:Dust; D012987:Soil