The immune response in a cat-related outbreak of Q fever as measured by the indirect immunofluorescence test and the enzyme-linked immunosorbent assay.
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 The absence of antibodies to phase I lipopolysaccharide in acute Q fever combined with our unpublished findings of antibodies to phase I lipopolysaccharide in chronic Q fever suggests that this test may be used to distinguish acute from chronic Q fever.
Department of Medicine, Dalhousie University, Halifax, N.S., Canada.
J
J
Embil
J C
JC
Williams
T J
TJ
Marrie
D000328:Adult; D000368:Aged; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D002415:Cats; D003381:Coxiella / Q000276:immunology*; D004196:Disease Outbreaks; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D008070:Lipopolysaccharides / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011778:Q Fever / Q000453:epidemiology / Q000276:immunology* / Q000635:transmission
D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008070:Lipopolysaccharides