The immune response in a cat-related outbreak of Q fever as measured by the indirect immunofluorescence test and the enzyme-linked immunosorbent assay

Can J Microbiol. 1990 Apr;36(4):292-6. doi: 10.1139/m90-050.


The isotypic immune response of 16 individuals who developed Q fever pneumonia following exposure to an infected parturient cat was studied. The enzyme-linked immunosorbent (ELISA) test was used to detect IgM, IgA, and IgG antibodies to phase I and phase II Coxiella burnetii whole-cell antigens and to the phase I lipopolysaccharide. The indirect immunofluorescent antibody (IFA) test was also used to detect antibodies to phase I and phase II whole cells. None of the 16 subjects developed antibodies to the phase I lipopolysaccharide. The ELISA was more sensitive than the IFA test. IgM antibodies to phase II antigen were detectable by ELISA in 80% of the subjects at the time of onset of symptoms and were still present in 7 of the 8 tested at 32 weeks following the onset of symptoms. In all instances (ELISA: IgG, IgM; IFA: IgG, IgM) phase II antibodies developed earlier and reached higher levels than did phase I antibodies. The absence of antibodies to phase I lipopolysaccharide in acute Q fever combined with our unpublished findings of antibodies to phase I lipopolysaccharide in chronic Q fever suggests that this test may be used to distinguish acute from chronic Q fever.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Animals
  • Antibodies, Bacterial / analysis*
  • Cats
  • Coxiella / immunology*
  • Disease Outbreaks
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Fluorescent Antibody Technique
  • Humans
  • Immunoglobulin A / analysis
  • Immunoglobulin G / analysis
  • Immunoglobulin M / analysis
  • Lipopolysaccharides / immunology
  • Male
  • Middle Aged
  • Q Fever / epidemiology
  • Q Fever / immunology*
  • Q Fever / transmission


  • Antibodies, Bacterial
  • Immunoglobulin A
  • Immunoglobulin G
  • Immunoglobulin M
  • Lipopolysaccharides