High Seroprevalence of Q Fever Among High-Risk Workers in Italy

Strategic Insights -

Research presented in the journal Comparative Immunology Microbiology and Infectious Diseases has found a significant seroprevalence of Q fever among high-risk workers in Italy. The study, conducted by the University of Bari Aldo Moro, assessed the accuracy of various serodiagnostic tests, including enzyme-linked immunosorbent assay (ELISA) and chemiluminescent immunoassay (CLIA), in detecting anti-Coxiella burnetii antibodies among 269 high-risk workers.

Key Takeaways:

  • The overall seroprevalence of Q fever in the screened population was 55%, with a possible chronic form detected in one case and possible acute forms detected in three cases.
  • ELISA presented high sensitivity (100% and 96%) and negative predictive value (100% and 93.2%) in detecting phase II IgM and IgG, respectively.
  • However, ELISA and CLIA presented low specificity (32.4% and 55.3%, respectively) in detecting phase II IgG.
  • The study suggests that the results of ELISA and CLIA should be confirmed by the reference standard test, indirect fluorescent antibody test (IFAT), to discriminate between acute, chronic, and past disease.
  • The research highlights the need for accurate serodiagnosis of Q fever in high-risk populations, particularly in the presence of suspected risk factors (e.g., employment in high-risk occupations) and/or clinical signs for Q fever.

Statistics:

  • 55% seroprevalence of Q fever in the screened population
  • 36.8% seroprevalence recorded by IFAT
  • 57.2% seroprevalence recorded by CLIA
  • 78.1% seroprevalence recorded by ELISA for phase II IgG
  • 3% detection of phase II IgM by IFAT
  • 22.7% detection of phase II IgG by IFAT
  • 100% sensitivity of ELISA in detecting phase II IgM
  • 96% sensitivity of ELISA in detecting phase II IgG
  • 93.2% negative predictive value of ELISA in detecting phase II IgG
  • 32.4% specificity of ELISA in detecting phase II IgG
  • 55.3% specificity of CLIA in detecting phase II IgG

Sources:

  • Comparative Immunology Microbiology and Infectious Diseases, 2025;124:102405
  • Toward assessing serodiagnosis of Q fever in high occupational-risk workers
  • University of Bari Aldo Moro
  • Paolo Trerotoli, Interdisciplinary Dept. of Medicine, University of Bari Aldo Moro, Bari 70124, Italy
  • Elsevier Sci Ltd, 125 London Wall, London, England