Incident Tick-Borne Infections in a Cohort of North Carolina Outdoor Workers

Details

• Personal Author:
  Apperson CS ; Funkhouser S ; Juliano J ; Kakumanu ML ; Lee, Stephen A. ; Meshnick SR ; Nicholson WL ; Perniciaro JL ; Ponnusamy L ; Vaughn MF ; Wallace JW
• Description:
  Tick-borne diseases cause substantial morbidity throughout the United States, and North Carolina has a high incidence of spotted fever rickettsioses and ehrlichiosis, with sporadic cases of Lyme disease. The occupational risk of tick-borne infections among outdoor workers is high, particularly those working on publicly managed lands. This study identified incident tick-borne infections and examined seroconversion risk factors among a cohort of North Carolina outdoor workers. Workers from the North Carolina State Divisions of Forestry, Parks and Recreation, and Wildlife (n = 159) were followed for 2 years in a randomized controlled trial evaluating the effectiveness of long-lasting permethrin-impregnated clothing. Antibody titers against Rickettsia parkeri, Rickettsia rickettsii, "Rickettsia amblyommii," and Ehrlichia chaffeensis were measured at baseline (n = 130), after 1 year (n = 82), and after 2 years (n = 73). Titers against Borrelia burgdorferi were measured at baseline and after 2 years (n = 90). Baseline seroprevalence, defined as indirect immunofluorescence antibody titers of 1/128 or greater, was R. parkeri (24%), R. rickettsii (19%), "R. amblyommii" (12%), and E. chaffeensis (4%). Incident infection was defined as a fourfold increase in titer over a 1-year period. There were 40 total seroconversions to at least one pathogen, including R. parkeri (n = 19), "R. amblyommii" (n = 14), R. rickettsii (n = 9), and E. chaffeensis (n = 8). There were no subjects whose sera were reactive to B. burgdorferi C6 antigen. Thirty-eight of the 40 incident infections were subclinical. The overall risk of infection by any pathogen during the study period was 0.26, and the risk among the NC Division of Forest Resources workers was 1.73 times that of workers in other divisions (95% confidence interval [CI]: 1.02, 2.92). The risk of infection was lower in subjects wearing permethrin-impregnated clothing, but not significantly (risk ratio = 0.81; 95% CI: 0.47, 1.39). In summary, outdoor workers in North Carolina are at high risk of incident tick-borne infections, most of which appear to be asymptomatic. [Description provided by NIOSH]
• Subjects:
  Cohort Studies Communicable Diseases Epidemiology Insecta Occupational Health Safety
• Keywords:
  Author Keywords: Epidemiology Bacterial Disease Cohort Studies Disease Vectors Infectious Diseases Insects Outdoor Workers Rickettsia Serology Ticks
• ISSN:
  1530-3667
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Georgia ; North Carolina ; OSHA Region 4
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  302-308
• Volume:
  16
• Issue:
  5
• NIOSHTIC Number:
  nn:20069180
• Citation:
  Vector Borne Zoonotic Dis 2016 May; 16(5):302-308
• Contact Point Address:
  John W. Wallace, Department of Epidemiology, University of North Carolina, Gillings School of Global Public Health, 135 Dauer Drive, Campus Box #8165, Chapel Hill, NC 27517
• Email:
  john.wallace@unc.edu
• Federal Fiscal Year:
  2016
• Performing Organization:
  University of North Carolina, Chapel Hill
• Peer Reviewed:
  True
• Start Date:
  20100901
• Source Full Name:
  Vector-Borne and Zoonotic Diseases
• End Date:
  20150831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:174541d5ff0271a4778e89ed239d34517620260aaa48d154a2ef28032ca696142b73847899a2e3707c552c9bf9a833eefc63bedc6d8e55f822e958d5fa8ca6aa
• Download URL:
  https://stacks.cdc.gov/view/cdc/207712/cdc_207712_DS1.pdf
• File Type:
  [PDF - 321.74 KB ]